Caracterización de la Calidad de Sedimentos Afectados por
Transcription
Caracterización de la Calidad de Sedimentos Afectados por
Caracterización de la Calidad de Sedimentos Afectados por Vertidos de Petróleo Comparación entre Casos de Vertidos Accidentales (Impacto Agudo) frente a Derrames Continuos (Impacto Crónico) TESIS DOCTORAL Carmen Morales Caselles UNIVERSIDADȱDEȱCÁDIZȱ FACULTADȱDEȱCIENCIASȱDELȱMARȱYȱAMBIENTALESȱ CARACTERIZACIÓNȱDEȱLAȱCALIDADȱDEȱSEDIMENTOSȱAFECTADOSȱ PORȱVERTIDOSȱDEȱPETRÓLEO:ȱCOMPARACIÓNȱENTREȱCASOSȱDEȱ VERTIDOSȱACCIDENTALESȱ(IMPACTOȱAGUDO)ȱFRENTEȱAȱDERRAMESȱ CONTINUOSȱ(IMPACTOȱCRÓNICO)ȱ CarmenȱMoralesȱCasellesȱ Cádiz,ȱ2007ȱ ȱ EstaȱTesisȱDoctoralȱhaȱsidoȱrealizadaȱdentroȱdelȱGrupoȱdeȱ Investigaciónȱ delȱ Planȱ Andaluzȱ deȱ Investigaciónȱ OceanografíaȱLitoralȱyȱEcofisiologíaȱ(nºȱRNMȱ0144),ȱdeȱlaȱ Facultadȱ deȱ Cienciasȱ delȱ Marȱ yȱ Ambientalesȱ deȱ laȱ UniversidadȱdeȱCádizȱyȱdelȱInstitutoȱdeȱCienciasȱMarinasȱ deȱ Andalucíaȱ delȱ Consejoȱ Superiorȱ deȱ Investigacionesȱ Científicas,ȱ enȱ elȱ ámbitoȱ deȱ laȱ Unidadȱ Asociadaȱ UCAȬ CSICȱ‘CalidadȱAmbientalȱyȱPatología’ȱenȱelȱmarcoȱdeȱlasȱ actividadesȱ deȱ investigaciónȱ deȱ laȱ cátedraȱ SantanderȬ UNESCOȱ UNITWIN/WiCopȱ enȱ suȱ áreaȱ deȱ calidadȱ ambiental.ȱ Elȱ trabajoȱ queȱ seȱ resumeȱ enȱ estaȱ Memoriaȱ haȱ sidoȱ principalmenteȱ financiadoȱ porȱ losȱ siguientesȱ proyectos:ȱ “Caracterizaciónȱ deȱ laȱ calidadȱ ambientalȱ deȱ ecosistemasȱ costerosȱafectadosȱporȱvertidosȱdeȱpetróleo:ȱcomparaciónȱ entreȱ casosȱ deȱ vertidosȱ accidentalesȱ (impactoȱ agudo)ȱ frenteȱ aȱ derramesȱ continuosȱ (impactoȱ crónico)”ȱ (VEM2003Ȭ20563/INTER),ȱ Ministerioȱ deȱ Cienciaȱ yȱ Tecnología;ȱ“PlanȱNacionalȱdeȱI+D+I.ȱȱDesarrolloȱyȱmejoraȱ delȱanálisisȱintregradoȱparaȱlaȱevaluaciónȱȱ deȱ laȱ calidadȱ deȱ sedimentosȱ litorales,ȱ incluidosȱ losȱ materialesȱ deȱ dragadoȱ portuario.ȱ CTM2005Ȭ07282ȬC03Ȭ01/TECNO.”ȱ Ministerioȱ deȱ Educaciónȱ yȱ Ciencia;ȱ “Asistenciaȱ Técnicaȱ paraȱlaȱEvaluaciónȱyȱseguimientoȱdeȱlosȱdañosȱderivadosȱ delȱvertidoȱdelȱȱPrestigeȱenȱelȱParqueȱNacionalȱdeȱlasȱIslasȱ Atlánticasȱ yȱ enȱ otrosȱ espaciosȱ protegidosȱ deȱ relevanciaȱ comunitaria”ȱMinisterioȱdeȱMedioȱAmbiente.ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ D.ȱ T.ȱ ÁNGELȱ DELVALLSȱ CASILLASȱ Profesorȱ Titularȱ delȱ Departamentoȱ deȱ QuímicaȬFísicaȱdeȱlaȱUniversidadȱdeȱCádiz,ȱDña.ȱINMACULADAȱRIBAȱLÓPEZȱ Investigadoraȱ contratadaȱ delȱ Institutoȱ deȱ Cienciasȱ Marinasȱ deȱ Andalucíaȱ (ICMANȬCSIC)ȱ yȱ Dña.ȱ CARMENȱ SARASQUETEȱ REIRIZȱ Profesoraȱ deȱ Investigaciónȱ delȱ Institutoȱ deȱ Cienciasȱ Marinasȱ deȱ Andalucíaȱ (ICMANȬCSIC)ȱ comoȱsusȱdirectoresȱ HACENȱCONSTAR:ȱ Queȱestaȱmemoria,ȱtituladaȱ“Caracterizaciónȱdeȱlaȱcalidadȱ deȱ sedimentosȱ afectadosȱ porȱ vertidosȱ deȱ petróleo:ȱ comparaciónȱ entreȱ casosȱ deȱ vertidosȱ accidentalesȱ (impactoȱ agudo)ȱ frenteȱ aȱ derramesȱ continuosȱ (impactoȱ crónico)”,ȱ presentadaȱ porȱ Dña.ȱ Carmenȱ Moralesȱ Caselles,ȱ resumeȱ suȱ trabajoȱ deȱ Tesisȱ Doctoralȱ y,ȱ considerandoȱ queȱ reúneȱ todosȱ losȱ requisitosȱ legales,ȱ autorizanȱ suȱ presentaciónȱ yȱ defensaȱ paraȱ optarȱ alȱ gradoȱ deȱ Doctorȱ enȱ CienciasȱdelȱMarȱporȱlaȱUniversidadȱdeȱCádiz.ȱ Cádiz,ȱSeptiembreȱdeȱ2007ȱ Dr.ȱT.ÁngelȱDelVallsȱ ȱDra.ȱCarmenȱSarasqueteȱȱȱȱȱȱȱȱȱȱȱDra.ȱInmaculadaȱRibaȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ Memoriaȱpresentadaȱparaȱoptarȱalȱtítuloȱdeȱ DoctorȱenȱCienciasȱdelȱMarȱ CarmenȱMoralesȱCasellesȱ ȱ Prólogoȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ Fueȱ duranteȱ losȱ últimosȱ añosȱ deȱ laȱ carreraȱ cuandoȱ meȱ diȱ cuentaȱ queȱ loȱ queȱ meȱ gustabaȱ eraȱ laȱ investigación.ȱ Entoncesȱ meȱ incorporéȱ comoȱ alumnaȱ colaboradoraȱalȱdepartamentoȱdeȱQuímicaȱFísicaȱdeȱlaȱfacultadȱdeȱCienciasȱdelȱ Marȱ yȱ Ambientales,ȱ dondeȱ meȱ acogieronȱ conȱ cariño.ȱ Aȱ partirȱ deȱ ahí,ȱ estuveȱ aprendiendoȱ conȱ yȱ graciasȱ aȱ ellos,ȱ losȱ profesoresȱ D.ȱ Ángelȱ delȱ Valls,ȱ D.ȱ Joséȱ AntonioȱRubio,ȱD.ȱAbelardoȱGómezȱParra,ȱD.ȱEduardoȱGonzálezȱMazo,ȱD.ȱJesúsȱ Forja,ȱ ȱ yȱ losȱ compañerosȱ queȱ estabanȱ conȱ laȱ tesisȱ reciénȱ leídaȱ oȱ enȱ proceso,ȱ Inma,ȱDori,ȱRocío,ȱVictor,ȱMónica,ȱQuique,ȱIdoia,ȱMerche,ȱLoli,ȱLaura,ȱNatalia,ȱ Pablo,ȱCarmen,ȱBibianȱyȱDiana.ȱȱ Enȱ losȱ dosȱ últimosȱ veranosȱ deȱ laȱ carreraȱ elȱ Centroȱ Oceanográficoȱ deȱ Murciaȱ delȱ Institutoȱ Españolȱ deȱ Oceanografíaȱ meȱ ofrecióȱ laȱ posibilidadȱ deȱ trabajarȱ conȱ ellos.ȱ Elȱ directorȱ delȱ centroȱ D.ȱ Julioȱ Más,ȱ misȱ tutoresȱ allíȱ Joséȱ BenedictoȱAlbladejoȱ(Nané)ȱyȱConcepciónȱMartínezȱ(Concha)ȱyȱmisȱcompañerosȱ (especialmenteȱInés,ȱAntonio,ȱBeaȱyȱJuan)ȱmeȱrecibieronȱyȱmeȱenseñaronȱenȱmiȱ primerȱpasoȱhaciaȱelȱestudioȱdeȱlaȱcontaminaciónȱmarina.ȱȱ AlȱpocoȱdeȱfinalizarȱlaȱcarreraȱmarchéȱaȱItaliaȱconȱunaȱbecaȱArgoȱqueȱmeȱ permitióȱ continuarȱ miȱ formaciónȱ trabajandoȱ enȱ elȱ Centroȱ Ricercheȱ Ambientaliȱ diȱ Marinaȱ diȱ Ravenna.ȱ Allíȱ deȱ nuevoȱ tuveȱ laȱ posibilidadȱ deȱ aprenderȱ nuevasȱ cosasȱ referentesȱ aȱ laȱ investigación,ȱ graciasȱ aȱ Antonellaȱ Iacondini,ȱ Federicaȱ AbbondanziȱyȱTizianaȱCampisi,ȱiȱcapi,ȱmaravilliose.ȱMisȱcompañerosȱallíȱfueronȱ estupendosȱ especialmenteȱ Agustina,ȱ Amaya,ȱ Ángelesȱ (Angelita),ȱ Alfredo,ȱ Marcoȱ (Racco),ȱ Juan,ȱ Luca…ȱ Tambiénȱ conocíȱ aȱ genteȱ queȱ meȱ hizoȱ laȱ estanciaȱ másȱalegre,ȱlosȱhermanosȱFrezzatiȱ(AnnalisaȱyȱPietro),ȱElena,ȱCristina,ȱGiorgia,ȱ losȱchicosȱdelȱ“AnimalȱHouse”ȱ(Cecco,ȱMatte,ȱCaprix,ȱDanielle,ȱGallo,ȱPaco…)ȱyȱ tantosȱotrosȱamig@sȱdeȱRavenna.ȱȱȱȱȱ AȱlaȱvueltaȱdeȱItaliaȱcompletéȱlosȱcursosȱdeȱdoctoradoȱyȱelȱprofesorȱÁngelȱ delȱVallsȱdepositóȱsuȱconfianzaȱenȱmíȱparaȱcomenzarȱconȱesteȱproyecto,ȱlaȱtesis,ȱ enȱunȱtemaȱqueȱdesdeȱelȱprincipioȱmeȱentusiasmó.ȱSiempreȱagradeceréȱsuȱapoyoȱ queȱfueȱmuyȱimportanteȱenȱlosȱinicios,ȱyȱloȱsiguióȱsiendoȱenȱelȱdesarrolloȱdeȱmiȱ trabajo.ȱ Laȱ doctoraȱ Inmaculadaȱ Riba,ȱ meȱ haȱ prestadoȱ siempreȱ suȱ ayudaȱ asíȱ comoȱ suȱ comprensiónȱ yȱ afecto,ȱ graciasȱ Inma.ȱ Miȱ agradecimientoȱ aȱ laȱ doctoraȱ Carmenȱ Sarasquete,ȱ quienȱ meȱ haȱ ofrecidoȱ suȱ conocimientoȱ yȱ experienciaȱ asíȱ comoȱsuȱayudaȱenȱtodoȱmomento.ȱEllosȱsonȱmisȱdirectoresȱdeȱtesis,ȱlosȱqueȱenȱ definitiva,ȱ hanȱ hechoȱ posibleȱ esteȱ proyecto,ȱ graciasȱ porȱ serȱ misȱ tutores,ȱ porȱ orientarme,ȱenseñarme,ȱyȱporȱtantasȱcosas;ȱtodoȱmiȱcariñoȱparaȱvosotros.ȱ Hayȱmuchasȱpersonasȱȱaȱquienȱagradecerȱsuȱayudaȱduranteȱelȱdesarrolloȱ deȱestaȱtesisȱdoctoral.ȱEspecialmenteȱaȱMiguelȱyȱaȱtodosȱlosȱcompañerosȱdelȱCISȱ (Rosina,ȱ Carlos,ȱ Pablo,ȱ Nazaret…)ȱ porȱ laȱ ayudaȱ prestadaȱ enȱ laȱ tomaȱ yȱ procesamientoȱ deȱ muestrasȱ enȱ Galicia;ȱ graciasȱ tambiénȱ porȱ vuestraȱ hospitalidad.ȱ Graciasȱ alȱ personalȱ delȱ Institutoȱ deȱ Cienciasȱ Marinasȱ deȱ Andalucíaȱ –ȱ CSIC,ȱ enȱ especialȱ aȱ Juliánȱ Blasco;ȱ graciasȱ aȱ laȱ genteȱ deȱ administraciónȱ porȱ suȱ paciencia,ȱ aȱ losȱ técnicos,ȱ compañerosȱ yȱ aȱ aquellaȱ genteȱ queȱ teȱ animaȱ porȱ losȱ pasillosȱ yȱ laboratorios,ȱ haciendoȱ queȱ losȱ problemasȱ noȱ loȱ seanȱ tanto;ȱ graciasȱ aȱ misȱ compañerosȱ deȱ congresoȱ Olivia,ȱ Miriamȱ yȱ Manolo.ȱ Aȱ misȱ compañerosȱ Pabloȱ Vidalȱ yȱ Antonioȱ Moreno,ȱ queȱ meȱ hanȱ hechoȱ disfrutarȱ deȱ losȱ interminablesȱ muestreos,ȱ conȱ losȱ queȱ meȱ heȱ reídoȱ tantoȱ yȱ hanȱ supuestoȱ unaȱ ráfagaȱdeȱaireȱfrescoȱenȱmuchosȱmomentos.ȱ Enȱ laȱ facultadȱ tambiénȱ haȱ habidoȱ muchaȱ gente,ȱ queȱ comoȱ decíaȱ antes,ȱ haceȱ queȱ lasȱ dificultadesȱ seȱ achiquen;ȱ aȱ ellosȱ gracias.ȱ Primordialȱ haȱ sidoȱ laȱ presenciaȱyȱlaȱayudaȱdeȱmisȱcompañerosȱdeȱdepartamento,ȱsobretodoȱaquellosȱ queȱ comoȱ yoȱ estabanȱ “empantanados”ȱ conȱ susȱ tesis.ȱ Natalia,ȱ Carmenȱ yȱ Lauraȱ graciasȱ porȱ vuestraȱ paciencia,ȱ porȱ vuestrasȱ conversaciones,ȱ porȱ escucharmeȱ yȱ porȱserȱasíȱdeȱúnicas;ȱJudit,ȱMariaȱJoséȱyȱDianaȱFdez,ȱgraciasȱporȱestarȱsiempreȱ ahíȱ yȱ habermeȱ ayudadoȱ enȱ tantasȱ ocasiones,ȱ soisȱ geniales;ȱ Sara,ȱ graciasȱ porȱ hacermeȱ reírȱ tantasȱ veces,ȱ porȱ haberȱ sidoȱ miȱ “compi”ȱ deȱ pisoȱ yȱ porȱ olerȱ aȱ fumarolaȱ sinȱ problemas.ȱ Nuria,ȱ muchasȱ graciasȱ porȱ compartirȱ conmigoȱ laȱ primeraȱimpresiónȱdeȱlasȱgusanas,ȱyȱenseñarlasȱaȱhablarȱporȱteléfono…ȱGraciasȱ tambiénȱaȱErku,ȱDianaȱyȱPablo,ȱyȱaȱlaȱgenteȱqueȱhaȱidoȱllegando,ȱJulia,ȱAraceli,ȱ Pilar…GraciasȱaȱQuiqueȱporȱsuȱayuda,ȱaȱManolo,ȱAugustoȱyȱRodrigo.ȱȱ Laȱ beca/contratoȱ FPUȱ meȱ haȱ permitidoȱ realizarȱ tresȱ estanciasȱ enȱ otrosȱ centrosȱduranteȱelȱdesarrolloȱdeȱlaȱtesis.ȱGraciasȱaȱCarlosȱValeȱporȱrecibirmeȱenȱ IPIMARȱ (Lisboa),ȱ dondeȱ Anaȱ Mariaȱ Ferreira,ȱ Cristinaȱ Micaeloȱ eȱ Isabellinaȱ Santosȱ meȱ prestaronȱ suȱ ayuda.ȱ Tambiénȱ agradecerȱ aȱ Tamaraȱ Gallowayȱ elȱ permitirmeȱrealizarȱlaȱestanciaȱenȱlaȱUniversidadȱdeȱPlymouthȱdondeȱrecibíȱelȱ apoyoȱdeȱCeri,ȱTrevor,ȱChris,ȱJo,ȱAlan,ȱWas,ȱMarie...graciasȱtambiénȱaȱCarenȱporȱ suȱ acogida,ȱ yȱ aȱ todaȱ laȱ genteȱ queȱ meȱ hizoȱ conocerȱ laȱ vidaȱ inglesaȱ duranteȱ aquellosȱ meses.ȱ Laȱ últimaȱ estanciaȱ realizadaȱ duranteȱ laȱ tesisȱ fueȱ enȱ elȱ Centroȱ Oceanográficoȱ deȱ Murcia,ȱ deȱ nuevoȱ agradecerȱ aȱ suȱ genteȱ porȱ elȱ tiempoȱ entreȱ ellos.ȱ Aunqueȱ enȱ algunosȱ momentosȱ parecíaȱ imposibleȱ porȱ faltaȱ deȱ tiempo,ȱ conseguíȱ realizarȱ elȱ “Masterȱ Erasmusȱ Mundusȱ inȱ Waterȱ andȱ Coastalȱ Management”.ȱGraciasȱaȱmisȱcompañerosȱporȱhaberȱpasadoȱjuntosȱlosȱbuenosȱyȱ noȱ tanȱ buenosȱ momentos,ȱ Oscar,ȱ Natalia,ȱ Diana,ȱ Carmen,ȱ Maria,ȱ Rodrigoȱ yȱ todosȱlosȱdemásȱaventureros.ȱGraciasȱtambiénȱaȱCarmenȱLópez.ȱ Duranteȱestosȱañosȱheȱdisfrutadoȱdeȱgenteȱmaravillosaȱdentroȱyȱfueraȱdeȱ laȱ ciencia.ȱ Creoȱ queȱ heȱ tenidoȱ muchaȱ suerteȱ enȱ eseȱ sentido,ȱ porȱ esoȱ tambiénȱ quieroȱ agradecerȱ aȱ aquellaȱ genteȱ queȱ haȱ supuestoȱ unaȱ víaȱ deȱ escape,ȱ tanȱ aȱ menudoȱ necesariaȱ duranteȱ laȱ tesis.ȱ Esaȱ peñitaȱ cupuleraȱ yȱ demásȱ compisȱ deȱ laȱ universidad,ȱ queȱ yaȱ seanȱ delȱ Norteȱ oȱ delȱ Sur,ȱ seȱ hicieronȱ gaditanosȱ oȱ puertorrealeñosȱ porȱ unosȱ añosȱ yȱ yaȱ laȱ llevanȱ consigoȱ alláȱ dondeȱ vayan.ȱ Soisȱ tantos,ȱqueȱnoȱvoyȱaȱescribirȱlosȱnombresȱporqueȱtendríaȱqueȱredactarȱunaȱlistaȱ enorme,ȱperoȱosȱguardoȱparaȱmí,ȱesperoȱqueȱloȱsepáisȱcomprenderȱyȱosȱdoyȱlasȱ graciasȱaȱmogollón,ȱconȱunȱabrazoȱenȱelȱqueȱcabéisȱtod@sȱapretujaillos.ȱȱ GraciasȱaȱlaȱgenteȱqueȱmeȱquedóȱdeȱMadrid,ȱmisȱniñas,ȱqueȱaunqueȱnosȱ veamosȱ deȱ muchoȱ enȱ mucho,ȱ pareceȱ queȱ elȱ tiempoȱ noȱ pasa.ȱ Yȱ misȱ isleñosȱ queridos,ȱ misȱ amigosȱ deȱ laȱ infanciaȱ yȱ deȱ siempre,ȱ osȱ echoȱ deȱ menosȱ peroȱ tambiénȱséȱqueȱpuedoȱcontarȱconȱvosotros,ȱgraciasȱdeȱcorazón.ȱȱ Adri,ȱsinȱdarteȱcuentaȱmeȱhasȱdadoȱunȱmontónȱdeȱenergíaȱespecialmenteȱ enȱ algunosȱ momentosȱ deȱ laȱ tesisȱ cuandoȱ flaqueabanȱ lasȱ fuerzas;ȱ graciasȱ porȱ tantasȱcosas,ȱeresȱunȱsol.ȱȱ ȱYȱ porȱ último,ȱ miȱ másȱ tiernoȱ agradecimientoȱ paraȱ miȱ gente,ȱ miȱ familia,ȱ queȱ siempreȱ haȱ estadoȱ ahíȱ paraȱ todo,ȱ fueraȱ buenoȱ oȱ regular.ȱ Graciasȱ aȱ misȱ hermanosȱqueȱsonȱlosȱmejores,ȱyȱqueȱsonȱsinȱdudarloȱloȱmásȱvaliosoȱqueȱtengoȱyȱ queȱconvencieronȱaȱmisȱpadresȱparaȱdejarmeȱirȱaȱestudiarȱaȱCádiz.ȱAȱmisȱpadresȱ graciasȱporȱnoȱhacerȱcasoȱdeȱlosȱqueȱcreenȱqueȱaúnȱsigoȱestudiandoȱlaȱcarrera,ȱ graciasȱporȱcomprenderȱelȱcaminoȱqueȱheȱelegido,ȱgraciasȱporȱvuestroȱapoyoȱyȱ porȱ todoȱ loȱ queȱ meȱ habéisȱ enseñado.ȱ Graciasȱ Abuȱ porȱ serȱ tanȱ estupendaȱ yȱ cuidarmeȱ siempreȱ aunqueȱ estuvieraȱ lejos;ȱ yȱ graciasȱ aȱ losȱ pequeñosȱ porȱ esaȱ alegríaȱqueȱdesprendéis,ȱtanȱpuraȱyȱtanȱcontagiosa.ȱ Aȱtodos,ȱgracias.ȱ ȱ ȱ ȱ ȱ ȱȱȱ Loȱqueȱsabemosȱesȱunaȱgotaȱdeȱagua,ȱloȱ queȱignoramosȱesȱelȱocéanoȱȱ (IsaacȱNewton)ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱȱȱȱ Aȱmiȱfamiliaȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ÍndiceȱdeȱContenidosȱ ȱ Prólogo ȱ Índice de Contenidos ȱ ȱ CAPÍTULOȱ1.ȱINTRODUCCIÓN,ȱZONASȱDEȱESTUDIO,ȱOBJETIVOSȱ YȱORGANIZACIÓNȱDEȱLAȱTESISȱ 1.ȱIntroducción………………………………………………………………ȱȱȱ 1 2.ȱZonasȱdeȱestudio………………………………………………………….ȱ 13 3.ȱObjetivosȱeȱhipótesis……………………………………………………...ȱ 22 4.ȱEstructuraȱdeȱlaȱtesis……………………………………………………..ȱ 24 5.ȱBibliografía………………………………………………………………...ȱ 25 ȱ ȱ CAPÍTULOȱ2.ȱANÁLISISȱDEȱLAȱCONTAMINACIÓNȱYȱ EVALUACIÓNȱȱDEȱLAȱTOXICIDADȱAGUDAȱMEDIANTEȱ ENSAYOSȱENȱLABORATORIOȱ 29 I.ȱAcuteȱtoxicityȱofȱresidualȱfuelȱoilȱfromȱtheȱtankerȱ“Prestige”ȱusingȱ amphipods.......................................................................................................ȱ 35 II.ȱUsingȱtheȱpolychaeteȱArenicolaȱmarinaȱtoȱdetermineȱtoxicityȱandȱ bioaccumulationȱofȱPAHsȱboundȱtoȱsediments.........................................ȱ 53 III.ȱComparingȱsedimentȱqualityȱinȱSpanishȱlittoralȱareasȱaffectedȱbyȱ acuteȱ(Prestige,ȱ2002)ȱandȱchronicȱ(BayȱofȱAlgeciras)ȱoilȱspills................ȱȱ 61 IV.ȱSedimentȱcontamination,ȱbioavailabilityȱandȱtoxicityȱofȱsedimentsȱ affectedȱbyȱanȱacuteȱoilȱspill.ȱFourȱyearsȱafterȱtheȱsinkingȱofȱtheȱtankerȱ Prestigeȱ(2002)………………………………………………………………..ȱ 69 ȱ CAPÍTULOȱ3.ȱESTUDIOȱDEȱEFECTOSȱSUBLETALESȱENȱ ORGANISMOSȱBAJOȱCONDICIONESȱDEȱLABORATORIOȱ 91 V.ȱEcotoxicityȱofȱsedimentsȱcontaminatedȱbyȱtheȱoilȱspillȱassociatedȱ withȱtheȱtankerȱ‘‘Prestige’’ȱUsingȱJuvenilesȱofȱtheȱfishȱSparusȱaurata.....ȱ 97 VI.ȱKineticȱofȱbiomarkerȱresponsesȱinȱjuvenilesȱofȱtheȱfishȱSparusȱ aurataȱexposedȱtoȱcontaminatedȱsediments................................................ȱ 107 VII.ȱRoleȱofȱbiomarkersȱtoȱassessȱoilȬcontaminatedȱsedimentȱqualityȱ usingȱtoxicityȱtestsȱwithȱclamsȱandȱcrabs....................................................ȱȱ 117 VIII.ȱVitellogeninȱvariationȱinȱtheȱcrabȱCarcinusȱmaenasȱexposedȱtoȱ sedimentsȱaffectedȱbyȱoilȱspillsȱ(Spain).......................................................ȱ 141 IX.ȱAȱmultibiomarkerȱapproachȱusingȱtheȱpolychaeteȱArenicolaȱmarinaȱ toȱassessȱoilȱcontaminatedȱsediments..........................................................ȱ 155 ȱ CAPÍTULOȱ4.ȱEVALUACIÓNȱDEȱEFECTOSȱSUBLETALESȱINȱSITUȱ 181 X.ȱSublethalȱresponsesȱinȱcagedȱorganismsȱexposedȱtoȱsedimentsȱ affectedȱbyȱoilȱspills........................................................................................ȱ 187 XI.ȱKineticȱofȱbiomarkersȱinȱtheȱclamȱRuditapesȱphilippinarum.................ȱ 211 XII.ȱAȱkineticȱapproachȱinȱtheȱPAHȱdetoxificationȱsystemȱinȱaȱmarineȱ invertebrateȱspecie:ȱtheȱcrabȱCarcinusȱmaenas.............................................ȱ 229 XIII.ȱAȱcomparativeȱanalysisȱofȱmacrobenthicȱcommunityȱstructureȱinȱ relationȱtoȱdifferentȱoilȱcontaminatedȱsediments:ȱtheȱGalicianȱCoastȱ (acute,ȱPrestigeȱoilȱspill)andȱtheȱBayȱofȱAlgecirasȱ(chronicȱoilȱspills)......ȱ ȱ ȱ 249 CAPÍTULOȱ5.ȱAPLICACIÓNȱDEȱUNȱMÉTODOȱINTEGRADOȱPARAȱ LAȱCARACTERIZACIÓNȱDEȱSEDIMENTOSȱAFECTADOSȱPORȱ 273 VERTIDOSȱDEȱPETRÓLEOȱ XIV.ȱUsingȱaȱclassicalȱweightȬofȬevidenceȱapproachȱforȱ4Ȭyearsȱ monitoringȱofȱtheȱimpactȱofȱanȱaccidentalȱoilȱspillȱonȱsedimentȱqualityȱ 279 XV.ȱAȱweightȱofȱevidenceȱapproachȱforȱqualityȱassessmentȱinȱ sedimentsȱimpactedȱbyȱanȱoilȱspill:ȱtheȱroleȱofȱaȱnewȱlineȱofȱevidenceȱ usingȱaȱsetȱofȱbiomarkers...............................................................................ȱ 307 XVI.ȱTheȱapplicationȱofȱaȱweightȱofȱevidenceȱapproachȱtoȱcompareȱtheȱ qualityȱofȱcoastalȱsedimentsȱaffectedȱbyȱacuteȱ(Prestigeȱ2002)ȱandȱ chronicȱ(BayȱofȱAlgeciras)ȱoilȱspills..............................................................ȱ 331 ȱ CAPÍTULOȱ6.ȱCONCLUSIONESȱȱ 355 ȱ ȱ ȱ ȱ ȱ ȱ Capítuloȱ1.ȱ Introducción,ȱzonasȱdeȱestudio,ȱobjetivosȱyȱ organizaciónȱdeȱlaȱtesisȱ ȱ 1.ȱIntroducciónȱ Enȱ laȱ actualidad,ȱ elȱ petróleoȱ yȱ susȱ derivadosȱ hanȱ llegadoȱ aȱ serȱ imprescindiblesȱ comoȱ fuenteȱ deȱ energíaȱ yȱ paraȱ laȱ fabricaciónȱ deȱ múltiplesȱ productosȱdeȱlaȱindustriaȱquímica,ȱfarmacéutica,ȱalimenticia,ȱetc.ȱSinȱembargo,ȱ alrededorȱdelȱȱ0,2%ȱdeȱlaȱproducciónȱmundialȱdeȱpetróleoȱacabaȱvertidoȱalȱmarȱ (FundaciónȱSantiagoȱReyȱFernándezȬLaTorre.ȱ2003).ȱȱDeȱmaneraȱgeneralȱseȱdiceȱ queȱ elȱ crudoȱ delȱ petróleoȱ estáȱ compuestoȱ principalmenteȱ porȱ hidrocarburos,ȱ aunqueȱ realmenteȱ esȱ unaȱ mezclaȱ muyȱ complejaȱ deȱ hidrocarburosȱ yȱ deȱ derivadosȱ delȱ azufre,ȱ nitrógeno,ȱ oxígenoȱ yȱ complejosȱ organometálicos,ȱ queȱ abarcaȱ desdeȱ compuestosȱ volátilesȱ deȱ bajoȱ pesoȱ molecular,ȱ comoȱ elȱ metano,ȱ hastaȱ compuestosȱ pesadosȱ noȱ volátiles,ȱ comoȱ losȱ asfaltenos.ȱ Estosȱ compuestosȱ seȱdistribuyenȱenȱfamiliasȱdeȱhidrocarburosȱsaturadosȱ(alcanosȱyȱcicloalcanos),ȱ aromáticos,ȱ cicloalcanosȱ parcialmenteȱ aromatizadosȱ (naftenȬaromáticos)ȱ yȱ derivadosȱ heteroaromáticosȱ (Fundaciónȱ Santiagoȱ Reyȱ FernándezȬLaTorre.ȱ 2003).ȱ Elȱ mayorȱ oȱ menorȱ porcentajeȱ deȱ hidrocarburosȱ ligerosȱ oȱ pesados,ȱ asíȱ comoȱ lasȱ variacionesȱ importantesȱ enȱ concentraciónȱ deȱ lasȱ diversasȱ estructurasȱ moleculares,ȱhaceȱqueȱexistanȱgrandesȱdiferenciasȱentreȱlosȱcrudosȱproducidosȱaȱ loȱlargoȱdeȱlaȱgeografíaȱmundialȱ(CSIC,ȱ2003a).ȱLaȱteoríaȱmásȱaceptadaȱsobreȱlaȱ formaciónȱdelȱcrudoȱdeȱpetróleoȱafirmaȱqueȱesȱelȱproductoȱdeȱlaȱdegradación,ȱaȱ -1- Capítuloȱ1 travésȱdeȱgrandesȱpresionesȱyȱtemperaturas,ȱdeȱlaȱmateriaȱorgánicaȱprocedenteȱ deȱrestosȱdeȱanimalesȱyȱplantas.ȱUnaȱvezȱextraídoȱelȱpetróleo,ȱgeneralmenteȱseȱ someteȱ aȱ destilaciónȱ paraȱ separarȱ susȱ componentesȱ yȱ poderȱ utilizarseȱ (FundaciónȱSantiagoȱReyȱFernándezȬLaTorre.ȱ2003).ȱDadoȱqueȱlosȱcomponentesȱ delȱ petróleoȱ cubrenȱ unȱ amplioȱ margenȱ deȱ puntosȱ deȱ ebullición,ȱ seȱ puedenȱ separarȱunaȱserieȱdeȱfraccionesȱdeȱinterésȱeconómicoȱ(gasolina,ȱqueroseno,ȱgasȬ oil,ȱ aceitesȱ lubricantes,ȱ etc),ȱ quedandoȱ unȱ residuoȱ deȱ menorȱ valor,ȱ queȱ seȱ destinaȱ aȱ combustibleȱ industrialȱ (fuelȬoil)ȱ oȱ aȱ asfaltoȱ (Fundaciónȱ Santiagoȱ Reyȱ FernándezȬLaTorre.ȱ2003).ȱȱȱ Característicasȱdeȱlosȱhidrocarburosȱaromáticosȱpolicíclicosȱ Losȱ hidrocarburos,ȱ talȱ yȱ comoȱ suȱ nombreȱ indica,ȱ estánȱ formadosȱ porȱ átomosȱ deȱ carbonoȱ eȱ hidrógeno.ȱ Losȱ hidrocarburosȱ másȱ importantesȱ sonȱ losȱ alcanos,ȱ alquenos,ȱ alquinosȱ yȱ compuestosȱ aromáticos.ȱ Losȱ hidrocarburosȱ aromáticosȱ policíclicosȱ (PAHs)ȱ estánȱ compuestosȱ porȱ átomosȱ deȱ Cȱ eȱ Hȱ ordenadosȱenȱformaȱdeȱdosȱoȱmásȱanillosȱdeȱbenceno.ȱHayȱmilesȱdeȱPAHs,ȱcadaȱ unoȱconȱunȱnúmeroȱyȱunaȱdisposiciónȱparticularȱdeȱlosȱanillosȱaromáticosȱyȱdeȱ losȱ sustituyentesȱ (Simsȱ yȱ Overcash,ȱ 1983).ȱ Lasȱ propiedadesȱ físicoȱ químicasȱ deȱ losȱ PAHsȱ varíanȱ generalmenteȱ conȱ elȱ pesoȱ molecular.ȱ Alȱ aumentarȱ elȱ pesoȱ molecular,ȱlaȱsolubilidadȱenȱaguaȱdisminuye,ȱyȱelȱpuntoȱdeȱfusión,ȱelȱpuntoȱdeȱ ebulliciónȱ yȱ elȱ logȱ Kowȱ (coeficienteȱ deȱ particiónȱ octanolȬagua)ȱ aumentanȱ suponiendoȱunȱaumentoȱdeȱlaȱsolubilidadȱenȱlasȱgrasas,ȱunaȱdisminuciónȱenȱlaȱ resistenciaȱaȱlaȱoxidaciónȬreducción,ȱyȱunaȱdisminuciónȱdeȱlaȱpresiónȱdeȱvaporȱ (tablaȱ2.1).ȱPorȱello,ȱlosȱPAHsȱvaríanȱsuȱcomportamientoȱenȱelȱmedioȱambienteȱ enȱ funciónȱ deȱ suȱ pesoȱ molecularȱ (Eisler,ȱ 2000).ȱ Así,ȱ porȱ ejemplo,ȱ elȱ Benzo[a]pirenoȱdebidoȱaȱsuȱbajaȱsolubilidadȱyȱpresiónȱdeȱvaporȱyȱelevadoȱKowȱ seȱvaȱaȱincorporarȱprincipalmenteȱalȱsueloȱyȱaȱlosȱsedimentos,ȱquedandoȱmenosȱ delȱ1%ȱenȱelȱrestoȱdeȱlosȱcompartimentosȱambientalesȱ(agua,ȱbiota,ȱaireȱyȱsólidosȱ -2- Introducción,ȱzonasȱdeȱestudio,ȱobjetivosȱyȱorganizaciónȱdeȱlaȱtesis enȱsuspensión).ȱOtrosȱPAHs,ȱcomoȱlosȱdeȱ2ȱyȱ3ȱanillosȱ(Naftaleno,ȱAcenafteno,ȱ Antraceno,ȱFluoreno,ȱAcenaftilenoȱyȱFenantreno),ȱsuelenȱenȱcambioȱencontrarseȱ predominantementeȱenȱelȱaireȱ(Baekȱetȱal.,ȱ1991).ȱAsí,ȱseȱhaȱpodidoȱcomprobarȱ comoȱlaȱbajaȱsolubilidadȱdeȱlosȱPAHsȱyȱsuȱaltaȱafinidadȱporȱelȱcarbonoȱorgánicoȱ haceȱqueȱenȱelȱmedioȱacuáticoȱmásȱdeȱ2/3ȱseȱencuentrenȱasociadosȱaȱpartículas,ȱ eliminándoseȱ losȱ deȱ medioȱ yȱ altoȱ pesoȱ molecularȱ porȱ adsorciónȱ alȱ sedimentoȱ principalmenteȱyȱlosȱdeȱbajoȱpesoȱporȱvolatilizaciónȱyȱbiodegradación.ȱȱ Tablaȱ 2.1.ȱ Algunasȱ deȱ lasȱ propiedadesȱ químicasȱ delȱ Naftaleno,ȱ Antraceno,ȱBenzo[a]antraceno,ȱBenzo[a]pireno,ȱBenzo[g,h,i]perileno.ȱ Solubilidadȱ Logȱ enȱaguaȱ Kowȱ (mgȱLȬ1)ȱ Nºȱ anillos Pesoȱ molecularȱ Puntoȱdeȱ fusiónȱ(ºC)ȱ Naftalenoȱ 2ȱ 128ȱ 80ȱ 30.0ȱ 3.37ȱ Antracenoȱ 3ȱ 178ȱ 216ȱ 0.07ȱ 4.45ȱ Benzo[a]antracenoȱ 4ȱ 228ȱ 158ȱ 0.014ȱ 5.61ȱ Benzo[a]pirenoȱ 5ȱ 252ȱ 179ȱ 0.0038ȱ 6.04ȱ Benzo[g,h,i]perilenoȱ 6ȱ 276ȱ 222ȱ 0.00026ȱ 7.23ȱ Compuestoȱ ȱ Elȱ origenȱ deȱ estosȱ hidrocarburosȱ aromáticosȱ policíclicosȱ enȱ elȱ medioȱ ambienteȱ esȱ muyȱ diverso,ȱ aunqueȱ básicamenteȱ seȱ puedenȱ identificarȱ tresȱ fuentesȱdistintasȱ(Eisler,ȱ2000):ȱȱ ȬȱOrigenȱpirolítico,ȱprocedenteȱdeȱlaȱcombustiónȱincompletaȱdeȱlaȱmateriaȱ orgánica,ȱ recienteȱ oȱ fósil,ȱ bienȱ porȱ causasȱ naturalesȱ (incendiosȱ deȱ bosques,ȱ erupcionesȱ volcánicas,ȱ etc.)ȱ oȱ antropogénicasȱ (utilizaciónȱ deȱ combustiblesȱ fósiles,ȱ incineraciónȱdeȱresiduos,ȱ emisionesȱ deȱvehículos,ȱprocesosȱindustrialesȱ deȱgasificaciónȱyȱlicuefacciónȱdelȱcarbón,ȱȱetc.).ȱȱ Ȭ 3ȱȬ Capítuloȱ1 ȬȱOrigenȱpetrogénico,ȱproducidoȱporȱvertidosȱaccidentalesȱoȱintencionadosȱ deȱderivadosȱdelȱpetróleo.ȱSeȱcaracterizanȱporȱserȱmezclasȱcomplejasȱformadasȱ porȱcompuestosȱconȱcadenasȱalquílicasȱdeȱhastaȱ5ȱoȱ6ȱátomosȱdeȱcarbono.ȱ Ȭȱ Origenȱ diagenéticoȱ deȱ laȱ materiaȱ orgánicaȱ sedimentaria,ȱ laȱ cualȱ puedeȱ sufrirȱ unaȱ serieȱ deȱ procesosȱ geoquímicosȱ naturales,ȱ comoȱ sonȱ laȱ descarboxilación,ȱ aromatización,ȱ desfuncionalización,ȱ etc.ȱ paraȱ convertirseȱ enȱ PAHsȱ deȱ origenȱ natural.ȱ Entreȱ éstosȱ encontraríamosȱ ciertosȱ derivadosȱ delȱ crisenoȱyȱdelȱpiceno,ȱasíȱcomoȱelȱretenoȱyȱelȱperileno,ȱaunqueȱestosȱdosȱúltimosȱ tambiénȱpuedenȱtenerȱunȱorigenȱpirolítico.ȱ Aȱ pesarȱ deȱ queȱ losȱ PAHsȱ seȱ encuentranȱ deȱ formaȱ naturalȱ enȱ elȱ medioȱ ambiente,ȱlaȱmayorȱparteȱdeȱestosȱcompuestosȱpresentesȱenȱlaȱnaturalezaȱtienenȱ origenȱantropogénico,ȱllegandoȱaȱdescargarseȱenȱelȱmedioȱacuáticoȱalrededorȱdeȱ 230000ȱtoneladasȱdeȱPAHsȱalȱañoȱ(tablaȱ2.2).ȱ Tablaȱ1.1.ȱPrincipalesȱfuentesȱdeȱPAHsȱenȱelȱmedioȱacuático.ȱ PAHsȱtotalesȱ Toneladas/añoȱ Vertidosȱdeȱpetróleoȱ 170000ȱ Deposiciónȱatmosféricaȱ 50000ȱ Aguasȱresidualesȱ 4400ȱ Escorrentíaȱȱ 2940ȱ Biosíntesisȱ 2700ȱ Comportamientoȱdeȱlosȱhidrocarburosȱenȱelȱmedioȱmarino.ȱ Talȱ yȱ comoȱ seȱ haȱ vistoȱ anteriormente,ȱ elȱ crudoȱ deȱ petróleoȱ estáȱ compuestoȱ principalmenteȱ porȱ hidrocarburosȱ queȱ varíanȱ entreȱ muyȱ volátiles,ȱ -4- Introducción,ȱzonasȱdeȱestudio,ȱobjetivosȱyȱorganizaciónȱdeȱlaȱtesis queȱsonȱsustanciasȱligerasȱcomoȱelȱpropanoȱyȱelȱbenceno,ȱyȱcompuestosȱpesadosȱ comoȱlosȱasfaltenosȱyȱresinas.ȱUnaȱvezȱqueȱlosȱhidrocarburosȱseȱviertenȱalȱmar,ȱ éstosȱ tiendenȱ aȱ volatilizarseȱ oȱ esparcirseȱ enȱ elȱ medio,ȱ enȱ funciónȱ deȱ suȱ composición.ȱ Esteȱ comportamientoȱ deȱ losȱ hidrocarburosȱ enȱ elȱ mar,ȱ vaȱ aȱ determinarȱ queȱ susȱ componentesȱ seȱ distribuyanȱ enȱ losȱ distintosȱ compartimentosȱ ambientales.ȱ ȱ Laȱ formaȱ enȱ queȱ laȱ capaȱ deȱ hidrocarburosȱ seȱ rompeȱyȱseȱdisipaȱenȱelȱmar,ȱvaȱaȱdependerȱenȱgranȱparteȱdeȱlaȱpersistenciaȱdelȱ fuelȱ vertido.ȱLosȱ productosȱligerosȱcomoȱelȱqueroseno,ȱ tiendenȱ aȱevaporarseȱyȱ seȱ disipanȱ rápidamente.ȱ Estosȱ tiposȱ deȱ fuelȱ seȱ denominanȱ “noȱ persistentes”.ȱȱ Porȱotraȱparte,ȱlasȱsustanciasȱ“persistentes”,ȱcomoȱlaȱmayoríaȱdeȱlosȱcrudosȱdeȱ petróleo,ȱseȱdisipanȱmásȱlentamente.ȱLaȱInternationalȱTankerȱOwnersȱPollutionȱ Federation,ȱ ITOPFȱ (http://www.itopf.com/index.html)ȱ haȱ realizadoȱ unaȱ clasificaciónȱ deȱ losȱ procesosȱ queȱ puedenȱ sufrirȱ losȱ hidrocarburosȱ unaȱ vezȱ vertidosȱenȱelȱmedioȱmarino:ȱ A)ȱ Esparcimiento.ȱ Tanȱ prontoȱ comoȱ elȱ fuelȱ esȱ vertidoȱ enȱ elȱ mar,ȱ ésteȱ comienzaȱ aȱ esparcirseȱ porȱ laȱ superficieȱ delȱ agua.ȱ Laȱ velocidadȱ aȱ laȱ queȱ tieneȱ lugarȱ esteȱ proceso,ȱ dependeȱ enȱ granȱ parteȱ deȱ laȱ viscosidadȱ delȱ fuel.ȱ Aquellosȱ queȱseanȱfluidos,ȱconȱbajaȱviscosidadȱseȱvanȱaȱesparcirȱmásȱrápidamenteȱqueȱlosȱ queȱpresentanȱviscosidadȱalta.ȱLaȱcapaȱdeȱfuelȱvaȱaȱromperseȱporȱlaȱacciónȱdelȱ viento,ȱ lasȱ olas,ȱ yȱ lasȱ turbulencias,ȱ deȱ formaȱ queȱ lasȱ llamadasȱ “manchasȱ deȱ petróleo”ȱ seȱ vanȱ aȱ disponerȱ paralelamenteȱ aȱ laȱ direcciónȱ delȱ viento.ȱ Laȱ velocidadȱ aȱ laȱ queȱ seȱ vanȱ aȱ esparcirȱ lasȱ manchasȱ deȱ petróleo,ȱ tambiénȱ vaȱ aȱ dependerȱ deȱ otrosȱ factoresȱ comoȱ laȱ temperatura,ȱ lasȱ corrientes,ȱ laȱ mareaȱ yȱ laȱ velocidadȱdelȱviento.ȱCuantoȱmásȱseverasȱseanȱlasȱcondicionesȱmeteorológicas,ȱ másȱrápidamenteȱseȱvaȱaȱproducirȱelȱesparcimientoȱyȱrupturaȱdeȱlasȱmanchasȱdeȱ petróleo.ȱ Ȭ 5ȱȬ Capítuloȱ1 B)ȱȱEvaporación.ȱAquellosȱcompuestosȱmásȱligerosȱseȱvanȱaȱevaporarȱaȱlaȱ atmósfera.ȱLaȱcantidadȱdeȱhidrocarburoȱqueȱseȱevaporeȱyȱlaȱvelocidadȱconȱqueȱ loȱ haga,ȱ vaȱ aȱ dependerȱ deȱ loȱ volátilesȱ queȱ seanȱ losȱ compuestosȱ queȱ loȱ componen.ȱAsí,ȱporȱejemplo,ȱsiȱseȱtrataȱdeȱunȱfuelȱpesadoȱsóloȱseȱevaporaráȱunaȱ pequeñaȱ parte.ȱ Deȱ maneraȱ general,ȱ seȱ puedeȱ decirȱ queȱ aquellosȱ componentesȱ delȱ fuelȱ cuyoȱ puntoȱ deȱ ebulliciónȱ seaȱ menorȱ queȱ 200ºCȱ vanȱ aȱ tenderȱ aȱ evaporarseȱ enȱ lasȱ primerasȱ 24ȱ horas.ȱ Elȱ fenómenoȱ deȱ evaporaciónȱ seȱ vaȱ aȱ incrementarȱ alȱ aumentarȱ elȱ áreaȱ superficialȱ deȱ laȱ capaȱ deȱ fuel.ȱ Lasȱ altasȱ temperaturas,ȱ laȱ altaȱ velocidadȱ delȱ viento,ȱ etc.,ȱ vanȱ aȱ aumentarȱ laȱ tasaȱ deȱ evaporaciónȱyȱlaȱproporciónȱdeȱfuelȱqueȱsufreȱesteȱproceso.ȱȱȱ C)ȱ Dispersión.ȱ Lasȱ olasȱ yȱ laȱ turbidezȱ enȱ laȱ superficieȱ delȱ marȱ puedenȱ provocarȱqueȱlaȱmanchaȱdeȱfuelȱseȱfragmenteȱenȱtrozosȱdeȱdistintoȱtamaño.ȱEstoȱ haceȱ queȱ muchosȱ deȱ estosȱ trozosȱ deȱ fuelȱ lleguenȱ aȱ losȱ nivelesȱ másȱ altosȱ deȱ laȱ columnaȱ deȱ agua.ȱ Algunosȱ deȱ losȱ trozosȱ másȱ pequeñosȱ seȱ mantendránȱ suspendidosȱenȱlaȱcolumnaȱdeȱagua,ȱmientrasȱqueȱaquellosȱmásȱgrandesȱvanȱaȱ tenderȱaȱȱvolverȱaȱlaȱsuperficie,ȱdondeȱpuedenȱunirseȱconȱotrosȱtrozosȱyȱvolverȱaȱ formarȱunaȱfinaȱcapaȱsuperficial.ȱElȱfuelȱqueȱquedaȱenȱlaȱcolumnaȱdeȱaguaȱtieneȱ unaȱelevadaȱáreaȱsuperficialȱtrasȱelȱprocesoȱdeȱdispersión,ȱloȱqueȱinduceȱaȱqueȱ seȱ denȱ otrosȱ procesosȱ naturalesȱ comoȱ laȱ disolución,ȱ biodegradaciónȱ yȱ sedimentación.ȱȱLaȱvelocidadȱaȱlaȱqueȱunȱfuelȱseȱdispersa,ȱvaȱaȱdependerȱdeȱlaȱ naturalezaȱ delȱ mismoȱ yȱ delȱ estadoȱ deȱ laȱ mar,ȱ incrementándoseȱ siȱ elȱ fuelȱ esȱ ligero,ȱtieneȱbajaȱviscosidad,ȱyȱsiȱlaȱsuperficieȱdelȱmarȱseȱencuentraȱalterada.ȱLaȱ adiciónȱ deȱ dispersantesȱ químicosȱ puedeȱ acelerarȱ elȱ procesoȱ naturalȱ deȱ dispersión.ȱ D)ȱ Emulsificación.ȱ Unaȱ emulsiónȱ seȱ formaȱ cuandoȱ seȱ combinanȱ dosȱ líquidos,ȱdeȱformaȱqueȱunoȱdeȱlosȱdosȱquedaȱsuspendidoȱenȱelȱotro.ȱSeȱhablaȱdeȱ emulsificaciónȱ delȱ fuelȱ cuandoȱ lasȱ gotasȱ deȱ aguaȱ seȱ suspendenȱ conȱ él.ȱ Estoȱ ocurreȱ porȱ mezclaȱ físicaȱ deȱ ambosȱ componentesȱ yȱ vieneȱ determinadaȱ porȱ laȱ -6- Introducción,ȱzonasȱdeȱestudio,ȱobjetivosȱyȱorganizaciónȱdeȱlaȱtesis turbulenciaȱenȱlaȱsuperficieȱdelȱagua.ȱLaȱemulsiónȱformadaȱsueleȱserȱviscosaȱyȱ másȱ persistenteȱ queȱ elȱ fuelȱ original,ȱ yȱ haceȱ queȱ elȱ volumenȱ delȱ contaminanteȱ aumenteȱ entreȱ tresȱ oȱ cuatroȱ veces.ȱ Estoȱ ralentizaȱ yȱ retrasaȱ otrosȱ procesosȱ queȱ permitiríanȱ laȱ disipaciónȱ delȱ fuel.ȱ Aquellosȱ tiposȱ deȱ fuelȱ conȱ unȱ contenidoȱ enȱ asfaltenosȱ mayorȱ delȱ 0.5%ȱ tiendenȱ aȱ formarȱ emulsionesȱ establesȱ queȱ puedenȱ persistirȱvariosȱmesesȱdespuésȱdelȱvertido.ȱSiȱunaȱvezȱenȱlaȱcosta,ȱlasȱemulsionesȱ aumentanȱ suȱ temperaturaȱ debidoȱ aȱ laȱ incidenciaȱ deȱ laȱ luzȱ solar,ȱ éstasȱ vanȱ aȱ poderȱromperseȱseparandoȱdeȱnuevoȱelȱfuelȱyȱelȱagua.ȱ E)ȱDisolución.ȱLosȱcompuestosȱsolublesȱdelȱfuelȱvanȱaȱpoderȱdisolverseȱ enȱelȱagua.ȱEstoȱdependeȱdeȱlaȱcomposiciónȱyȱdelȱestadoȱdelȱfuel,ȱyȱocurreȱmásȱ rápidamenteȱ cuandoȱelȱ fuelȱseȱ encuentraȱdispersoȱenȱlaȱcolumnaȱdeȱagua.ȱLosȱ componentesȱmásȱsolublesȱenȱelȱaguaȱdeȱmarȱsonȱlosȱhidrocarburosȱaromáticosȱ ligerosȱ comoȱ elȱ bencenoȱ yȱ elȱ tolueno.ȱ Sinȱ embargo,ȱ estosȱ compuestosȱ sonȱ aquellosȱqueȱseȱvanȱaȱperderȱenȱprimerȱlugarȱporȱevaporación,ȱunȱprocesoȱqueȱ esȱ10ȱ–ȱ100ȱvecesȱmásȱrápidoȱqueȱlaȱdisolución.ȱȱ F)ȱOxidación.ȱElȱfuelȱvaȱaȱreaccionarȱquímicamenteȱconȱelȱoxígeno,ȱbienȱ rompiéndoseȱ enȱ fraccionesȱ solubles,ȱ oȱ bienȱ formandoȱ compuestosȱ persistentesȱ queȱ recibenȱ elȱ nombreȱ deȱ “alquitrán”.ȱ Esteȱ procesoȱ estáȱ favorecidoȱ porȱ laȱ luzȱ solarȱ (fotooxidación)ȱ yȱ vaȱ aȱ dependerȱ delȱ tipoȱ deȱ fuelȱ yȱ deȱ laȱ formaȱ queȱ seȱ encuentraȱ expuestoȱ aȱ laȱ luz.ȱ Sinȱ embargo,ȱ esȱ unȱ procesoȱ muyȱ lento.ȱ Laȱ formaciónȱ delȱ alquitránȱ seȱ daȱ porȱ laȱ oxidaciónȱ deȱ capasȱ gruesasȱ deȱ fuelȱ muyȱ viscosoȱ oȱ porȱ laȱ oxidaciónȱ deȱ emulsiones.ȱ Esteȱ procesoȱ formaȱ unaȱ protecciónȱ externaȱparaȱlosȱcomponentesȱpesadosȱloȱqueȱhaceȱaumentarȱlaȱpersistenciaȱdelȱ fuel.ȱ Lasȱ conocidasȱ “galletasȱ deȱ alquitrán”ȱ queȱ seȱencuentranȱ normalmenteȱ enȱ laȱcosta,ȱsonȱproductosȱdeȱesteȱprocesoȱdeȱoxidación.ȱ G)ȱ Sedimentación.ȱ ȱ Algunosȱ componentesȱ pesadosȱ tienenȱ densidadesȱ mayoresȱqueȱelȱaguaȱdulceȱporȱloȱqueȱsedimentan.ȱSinȱembargo,ȱelȱaguaȱdeȱmarȱ Ȭ 7ȱȬ Capítuloȱ1 tieneȱ unaȱ densidadȱ mayorȱ queȱ elȱ aguaȱ dulceȱ yȱ muyȱ pocosȱ crudosȱ deȱ petróleoȱ sonȱ loȱ suficientementeȱ densosȱ comoȱ paraȱ hundirseȱ enȱ elȱ medioȱ marino.ȱ Laȱ sedimentaciónȱ ocurreȱ normalmenteȱ porȱ laȱ adhesiónȱ delȱ fuelȱ conȱ partículasȱ deȱ sedimentoȱoȱmateriaȱorgánica.ȱGeneralmente,ȱlasȱaguasȱsomerasȱestánȱcargadasȱ deȱsólidosȱenȱsuspensiónȱfavoreciendoȱelȱprocesoȱdeȱsedimentación.ȱCuandoȱelȱ fuelȱ llegaȱ aȱ costasȱ arenosasȱ sueleȱ mezclarseȱ conȱ arenaȱ yȱ otrosȱ sedimentos.ȱ Siȱ posteriormente,ȱ estaȱ mezclaȱ vuelveȱ alȱ mar,ȱ probablementeȱ seȱ hunda.ȱ Además,ȱ siȱ elȱ fuelȱ seȱ quemaȱ trasȱ serȱ vertido,ȱ losȱ residuosȱ puedenȱ volverseȱ loȱ suficientementeȱdensosȱyȱllegarȱaȱsedimentar.ȱȱȱ H)ȱBiodegradación.ȱElȱaguaȱdeȱmarȱposeeȱunaȱserieȱdeȱmicroorganismosȱ queȱ puedenȱ degradarȱ parcialmenteȱ oȱ completamenteȱ elȱ fuelȱ enȱ compuestosȱ solublesȱenȱagua,ȱhastaȱCO2ȱyȱagua.ȱCadaȱtipoȱdeȱmicroorganismosȱesȱcapazȱdeȱ degradarȱ unȱ grupoȱ deȱ compuestosȱ particulares.ȱ Sinȱ embargo,ȱ algunosȱ compuestosȱdeȱhidrocarburosȱsonȱresistentesȱaȱlaȱdegradación.ȱLaȱeficienciaȱdeȱ laȱ biodegradaciónȱ vaȱ aȱ dependerȱ deȱ variosȱ factores:ȱ losȱ nivelesȱ deȱ nutrientesȱ (nitrógenoȱ yȱ fósforo)ȱ enȱ elȱ agua,ȱ laȱ temperaturaȱ yȱ laȱ presenciaȱ deȱ oxígeno.ȱ Comoȱlaȱbiodegradaciónȱprecisaȱdeȱoxígenoȱparaȱpoderȱrealizarse,ȱesteȱprocesoȱ sóloȱvaȱaȱpoderȱllevarseȱaȱcaboȱenȱlaȱinterfaseȱfuelȬagua,ȱyaȱqueȱelȱfuelȱnoȱposeeȱ oxígeno.ȱ Porȱ tanto,ȱ laȱ biodegradaciónȱ seráȱ mayorȱ alȱ aumentarȱ laȱ relaciónȱ superficie/volumenȱdelȱfuelȱ(porȱejemplo,ȱtrasȱprocesosȱdeȱdispersión).ȱ Losȱprocesosȱdeȱesparcimiento,ȱevaporación,ȱdispersión,ȱemulsificaciónȱyȱ disolución,ȱ sonȱ losȱ másȱ importantesȱ duranteȱ lasȱ primerasȱ fasesȱ delȱ vertido,ȱ mientrasȱ queȱ laȱ oxidación,ȱ laȱ sedimentaciónȱ yȱ laȱ biodegradaciónȱ cobranȱ másȱ importanciaȱ despuésȱ deȱ pasadoȱ unȱ tiempoȱ yȱ determinanȱ elȱ destinoȱ finalȱ delȱ fuel.ȱ -8- Introducción,ȱzonasȱdeȱestudio,ȱobjetivosȱyȱorganizaciónȱdeȱlaȱtesis Efectosȱdeȱlosȱhidrocarburosȱenȱelȱmedioȱmarinoȱ Losȱ efectosȱ deȱ losȱ vertidosȱ deȱ hidrocarburosȱ enȱ elȱ medioȱ ambienteȱ marinoȱ puedenȱ estarȱ causadosȱ porȱ laȱ naturalezaȱ físicaȱ delȱ fuelȱ oȱ bienȱ porȱ laȱ composiciónȱquímicaȱdeȱéste.ȱDesdeȱelȱpuntoȱdeȱvistaȱfísico,ȱlaȱimpregnaciónȱdeȱ losȱorganismosȱqueȱentranȱenȱcontactoȱdirectoȱconȱelȱfuelȱvaȱaȱsuponerȱunaȱdeȱ lasȱ causasȱ letalesȱ másȱ comunes,ȱ asíȱ comoȱ elȱ agotamientoȱ yȱ laȱ ingestaȱ deȱ hidrocarburos.ȱLaȱȱmortalidadȱseȱproduceȱalȱimpedirȱlaȱrespiración,ȱfotosíntesis,ȱ oȱ alȱ modificarȱ laȱ resistenciaȱ térmicaȱ (porȱ ejemploȱ lasȱ aves).ȱ Desdeȱ elȱ puntoȱ deȱ vistaȱquímico,ȱcabeȱdestacarȱlosȱefectosȱtóxicosȱagudosȱyȱcrónicos.ȱAdemás,ȱlasȱ alteracionesȱ aȱ nivelȱ deȱ organismo,ȱ yȱ susȱ consecuenciasȱ demográficas,ȱ puedenȱ desembocarȱ enȱ cambiosȱ enȱ laȱ estructuraȱ deȱ lasȱ comunidadesȱ ecológicasȱ y,ȱ porȱ tanto,ȱ enȱ unaȱ alteraciónȱ deȱ laȱ redȱ deȱ lasȱ interaccionesȱ existentesȱ (Fundaciónȱ SantiagoȱReyȱFernándezȬLaTorre,ȱ2003).ȱȱȱ Losȱcomponentesȱmásȱtóxicosȱdelȱpetróleoȱsonȱaquellosȱhidrocarburosȱdeȱ bajoȱ pesoȱ molecularȱ queȱ seȱ vanȱ aȱ perderȱ rápidamenteȱ porȱ evaporación,ȱ deȱ formaȱ queȱ noȱ suelenȱ llegarȱ aȱ concentrarseȱ loȱ suficienteȱ paraȱ provocarȱ efectosȱ letalesȱenȱlosȱorganismos.ȱPorȱotraȱparte,ȱunaȱexposiciónȱprolongadaȱalȱfuelȱoȱaȱ susȱ componentesȱ puedeȱ producirȱ efectosȱ subletalesȱ queȱ puedenȱ afectarȱ aȱ lasȱ funcionesȱ vitalesȱ deȱ losȱ organismosȱ comoȱ laȱ reproducción,ȱ crecimientoȱ oȱ alimentaciónȱ(ITOPF,ȱhttp://www.itopf.com/index.html).ȱ Laȱ toxicidadȱ deȱ losȱ hidrocarburosȱ deȱ petróleoȱ resideȱ básicamenteȱ enȱ elȱ potencialȱ cancerígenoȱ deȱ losȱ hidrocarburosȱ aromáticosȱ policíclicosȱ (PAHs).ȱ Entreȱ ellosȱ destacanȱ losȱ 16ȱ compuestosȱ incluidosȱ enȱ laȱ listaȱ deȱ contaminantesȱ prioritariosȱ deȱ laȱ Environmentalȱ Protectionȱ Agencyȱ deȱ losȱ Estadosȱ Unidos:ȱ Naftaleno,ȱ Acenaftileno,ȱ Acenafteno,ȱ Fluoreno,ȱ Fenantreno,ȱ Antraceno,ȱ Fluoranteno,ȱ Pireno,ȱ Criseno,ȱ Benzo[a]antraceno,ȱ Ȭ 9ȱȬ Benzo[k]fluoranteno,ȱ Capítuloȱ1 Benzo[a]pireno,ȱ Dibenzo[ah]antraceno,ȱ Indeno[123Ȭcd]pireno,ȱ Benzo[ghi]perilenoȱ(USEPA,ȱ2000).ȱȱ UnaȱdeȱlasȱcaracterísticasȱdeȱlosȱPAHsȱqueȱlosȱhaceȱmásȱpeligrososȱesȱsuȱ acumulaciónȱ enȱ losȱ organismosȱ acuáticosȱ desdeȱ elȱ agua,ȱ elȱ sedimentoȱ oȱ elȱ alimento.ȱ Asíȱ seȱ hanȱ encontradoȱ valoresȱ deȱ factorȱ deȱ bioacumulaciónȱ (BCF)ȱ entreȱ 10ȱ yȱ 10000ȱ paraȱ pecesȱ yȱ crustáceos,ȱ correspondiendoȱ losȱ valoresȱ másȱ elevadosȱ aȱ losȱ PAHsȱ deȱ mayorȱ pesoȱ molecularȱ (Eislerȱ etȱ al.,ȱ 2000).ȱ Estasȱ sustanciasȱ sinȱ embargo,ȱ puedenȱ serȱ rápidamenteȱ metabolizadasȱ porȱ losȱ organismosȱ (deȱ 2ȱ aȱ 9ȱ díasȱ enȱ peces),ȱ loȱ cualȱ evitaȱ laȱ biomagnificaciónȱ peroȱ puedeȱpresentarȱunȱproblemaȱaúnȱmayorȱalȱgenerarseȱmetabolitosȱcarcinógenosȱ yȱmutagénicos.ȱȱ Enȱ teoría,ȱtodosȱlosȱorganismosȱposeenȱencimasȱdeȱbiotransformaciónȱ oȱ detoxificaciónȱ queȱ conviertenȱ lasȱ sustanciasȱ xenobióticasȱ lipofílicosȱ enȱ metabolitosȱsolublesȱenȱaguaȱqueȱpuedenȱserȱexcretadosȱ(Neff,ȱ1979).ȱEnȱlaȱFaseȱ Iȱdeȱlosȱprocesosȱmetabólicos,ȱlosȱPAHsȱsonȱtransformadosȱenȱvariosȱproductosȱ comoȱ epóxidos,ȱ fenoles,ȱ quinónes,ȱ dihidrodioles,ȱ epóxidos,ȱ tetrahidrotriolesȱ yȱ tetrahidrotetroles.ȱ Losȱ metabolitosȱ intermedios,ȱ hanȱ sidoȱ identificadosȱ comoȱ agentesȱmutagénicos,ȱcarcinógenosȱyȱteratógenosȱ(SimsȱandȱOvercash,ȱ1983).ȱLaȱ activaciónȱ deȱ estosȱ mecanismosȱ tóxicosȱ ocurreȱ porȱ hidroxilaciónȱ oȱ porȱ producciónȱ deȱ epóxidosȱ inestablesȱ deȱ PAHsȱ queȱ dañanȱ elȱ ADN,ȱ iniciandoȱ losȱ procesosȱcancerígenosȱ(JackimȱyȱLake,ȱ1978;ȱSchnitzȱyȱO’Connor,ȱ1992).ȱȱȱȱ Importanciaȱdeȱlosȱsedimentosȱenȱestudiosȱdeȱcontaminaciónȱ Cualquierȱ sustanciaȱ queȱ seȱ encuentreȱ enȱ unȱ medioȱ enȱ concentracionesȱ superioresȱ aȱ losȱ nivelesȱ naturales,ȱ puedeȱ alterarȱ elȱ equilibrioȱ delȱ ecosistema,ȱ llegandoȱ inclusoȱ aȱ destruirȱ elȱ biotopo,ȱ aȱ limitarȱ laȱ explotaciónȱ deȱ losȱ recursosȱ biológicosȱyȱaȱponerȱenȱpeligroȱlaȱsaludȱhumana.ȱLaȱpresenciaȱdeȱunaȱsustanciaȱ - 10 - Introducción,ȱzonasȱdeȱestudio,ȱobjetivosȱyȱorganizaciónȱdeȱlaȱtesis enȱ elȱ medioȱ enȱ concentracionesȱ mayoresȱ aȱ lasȱ naturalesȱ seȱ denominaȱ contaminación,ȱ yȱ elȱ fenómenoȱ porȱ elȱ queȱ esteȱ enriquecimientoȱ deȱ contaminantesȱproduceȱefectosȱbiológicos,ȱseȱdefineȱcomoȱpolución.ȱ Muchosȱ deȱ losȱ contaminantesȱ orgánicosȱ eȱ inorgánicosȱ queȱ seȱ originanȱ conȱ laȱ actividadȱ humana,ȱ sonȱ transportados,ȱ tantoȱ enȱ disoluciónȱ comoȱ adsorbidosȱ sobreȱ elȱ materialȱ particuladoȱ enȱ suspensión,ȱ desdeȱ lasȱ zonasȱ continentalesȱhaciaȱlosȱocéanos.ȱLasȱzonasȱcosteras,ȱyȱespecialmenteȱlosȱsistemasȱ másȱ someros,ȱ sonȱ losȱ receptoresȱ principalesȱ deȱ lasȱ sustanciasȱ contaminantesȱ vertidasȱaȱlosȱocéanos.ȱDadoȱelȱcarácterȱactivoȱdeȱestosȱcompuestos,ȱduranteȱelȱ transporteȱ seȱ incorporanȱ alȱ sedimentoȱ aȱ travésȱ deȱ diferentesȱ procesosȱ deȱ adsorciónȱoȱreaccionesȱquímicasȱ(Salomonsȱetȱal.,ȱ1987).ȱȱ Además,ȱ seȱ haȱ demostradoȱ queȱ losȱ contaminantesȱ orgánicosȱ menosȱ polaresȱ yȱ losȱ elementosȱ trazaȱ másȱ tóxicosȱ reaccionanȱ fuertementeȱ conȱ elȱ materialȱ particuladoȱ yȱ seȱ acumulanȱ enȱ elȱ sedimentoȱ enȱ órdenesȱ deȱ magnitudȱ másȱ altosȱ queȱ enȱ soluciónȱ (DelVallsȱ etȱ al.,ȱ 2002).ȱ Losȱ sedimentosȱ actúan,ȱ porȱ tanto,ȱ comoȱ “trampa”ȱ deȱ contaminantes,ȱ deȱ formaȱ queȱ éstosȱ reflejanȱ deȱ unaȱ formaȱ muyȱ eficazȱ elȱ gradoȱ deȱ contaminaciónȱ deȱ unȱ áreaȱ determinada.ȱ Esteȱ hechoȱ haȱ llevadoȱ aȱ numerososȱ autoresȱ aȱ considerar,ȱ desdeȱ unȱ puntoȱ deȱ vistaȱ ecológico,ȱ aȱ losȱ sedimentosȱ comoȱ unȱ elementoȱ deȱ unaȱ importanciaȱ trascendentalȱdelȱhábitatȱacuáticoȱ(Chapman,ȱ1989;ȱLuoma,ȱ1983;ȱ1989;ȱLuomaȱyȱ Ho,ȱ1992).ȱȱȱȱ Losȱestudiosȱdeȱcontaminaciónȱenȱsedimentosȱseȱbasanȱgeneralmenteȱenȱ laȱ comparaciónȱ deȱ losȱ nivelesȱ deȱ contaminantesȱ medidosȱ enȱ unaȱ zonaȱ determinadaȱ conȱ aquellosȱ nivelesȱ deȱ contaminantesȱ medidosȱ enȱ unaȱ zonaȱ deȱ referenciaȱ queȱ seȱ consideraȱ noȱ contaminada.ȱ Enȱ muchosȱ casosȱ losȱ estudiosȱ deȱ esteȱ tipoȱ permitenȱ identificarȱ elȱ origenȱ deȱ laȱ contaminaciónȱ (Luomaȱ yȱ Philips,ȱ 1988;ȱ Philipsȱ etȱ al.,ȱ 1992;ȱ French,ȱ 1993)ȱ eȱ inclusoȱ estimarȱ suȱ biodisponibilidadȱ Ȭ 11ȱȬ Capítuloȱ1 (Harveyȱ yȱ Luoma,ȱ 1985;ȱ Luomaȱ yȱ Bryan,ȱ 1978;ȱ Arjonillaȱ etȱ al.,ȱ 1994).ȱ Estaȱ metodología,ȱ sinȱ embargo,ȱ noȱ permiteȱ obtenerȱ informaciónȱ sobreȱ elȱ fenómenoȱ deȱpolución.ȱ Unaȱgranȱvariedadȱdeȱorganismosȱquedanȱexpuestosȱaȱlosȱcontaminantesȱ presentesȱ enȱ losȱ sedimentos.ȱ Losȱ animalesȱ queȱ ingierenȱ sedimentoȱ oȱ detritusȱ particuladoȱcomoȱalimento,ȱseȱencuentranȱdirectamenteȱafectados,ȱdeȱformaȱqueȱ estosȱcontaminantesȱentranȱaȱformarȱparteȱdeȱlaȱcadenaȱtrófica,ȱporȱloȱqueȱotrosȱ organismosȱ puedenȱ verseȱ tambiénȱ afectadosȱ yȱ seȱ puedenȱ darȱ fenómenosȱ deȱ biomagnificaciónȱdelȱcontaminanteȱenȱlosȱsucesivosȱnivelesȱtróficos.ȱ Laȱcontaminaciónȱdeȱlosȱsedimentosȱnoȱsóloȱafectaȱaȱlosȱorganismosȱdeȱlaȱ zonaȱcontaminadaȱsinoȱqueȱademásȱpuedeȱextenderseȱaȱecosistemasȱalejadosȱdeȱ lasȱfuentesȱmedianteȱlaȱresuspensiónȱyȱtransporteȱdeȱpartículasȱ(Luoma,ȱ1990).ȱ Laȱdefiniciónȱdeȱtoxicidadȱdelȱsedimento,ȱenȱsuȱsentidoȱmásȱamplio,ȱestáȱ referidaȱ aȱ losȱ cambiosȱ ecológicosȱ yȱ biológicosȱ causadosȱ porȱ losȱ contaminantesȱ queȱ seȱ encuentranȱ incorporadosȱ enȱ losȱ sedimentos.ȱ Enȱ términosȱ toxicológicos,ȱ quedaȱ definidaȱ comoȱ laȱ respuestaȱ adversaȱ queȱ seȱ observaȱ enȱ unoȱ oȱ enȱ variosȱ organismosȱ sometidosȱ aȱ unaȱ pruebaȱ dondeȱ seȱ lesȱ exponeȱ aȱ sedimentosȱ contaminados.ȱEstaȱrespuestaȱadversaȱseȱevalúaȱdeȱmaneraȱobjetivaȱcuandoȱlosȱ animalesȱ seȱ exponenȱ aȱ sedimentosȱ limpiosȱ aȱ losȱ queȱ lesȱ hanȱ sidoȱ añadidasȱ concentracionesȱ conocidasȱ deȱ contaminanteȱ (“Spikedȱ Sediment”),ȱ oȱ bienȱ cuandoȱ sonȱ expuestosȱ aȱ sedimentosȱ contaminadosȱ recogidosȱ enȱ elȱ medio.ȱ (ChapmanȱyȱMorgan,ȱ1983;ȱOakdenȱetȱal.,ȱ1984;ȱKempȱyȱSwartz,ȱ1988;ȱSwartzȱetȱ al.,ȱ1989,ȱSwartzȱetȱal.,ȱ1990;ȱMeador,ȱ1990;ȱMcGeeȱetȱal.,ȱ1993;ȱDelValls,ȱ1994).ȱ ȱ Laȱ dificultadȱ delȱ estudioȱ deȱ laȱ toxicidadȱ deȱ losȱ sedimentosȱ marinosȱ seȱ basaȱenȱqueȱlosȱcontaminantesȱpresentesȱenȱellosȱformanȱunaȱmezclaȱcomplejaȱ - 12 - Introducción,ȱzonasȱdeȱestudio,ȱobjetivosȱyȱorganizaciónȱdeȱlaȱtesis deȱ sustanciasȱ queȱ puedenȱ darȱ lugarȱ aȱ efectosȱ biológicosȱ sinérgicosȱ oȱ antagónicos.ȱ Quizásȱ porȱ ello,ȱ enȱ laȱ actualidad,ȱ aúnȱ existeȱ ciertoȱ desconocimientoȱsobreȱlaȱtoxicidadȱdeȱmuchasȱsustanciasȱvertidasȱalȱmedio.ȱDeȱ hecho,ȱ seȱ consideraȱ queȱ sóloȱ delȱ 5ȱ alȱ 10%ȱ deȱ ellas,ȱ hanȱ sidoȱ probadasȱ enȱ laboratorioȱparaȱevaluarȱsuȱtoxicidad.ȱDeȱeseȱnúmero,ȱmenosȱdelȱ1%ȱloȱhanȱsidoȱ utilizandoȱorganismosȱmarinosȱ(Martellȱetȱal.,ȱ1988).ȱȱ Algunosȱ gobiernosȱ hanȱ diseñadoȱ programasȱ paraȱ evaluarȱ laȱ calidadȱ ambientalȱdeȱlosȱsedimentos,ȱyȱhanȱrealizadoȱunasȱguíasȱnuméricasȱdeȱcalidadȱ deȱ losȱ sedimentosȱ (Sedimentȱ Qualityȱ Guidelinesȱ ȬSQGsȬ)ȱ paraȱ cadaȱ contaminanteȱ (Longȱ andȱ Buchman,ȱ 1989;ȱ NOAA,ȱ 1999;ȱ Environmentȱ Canada,ȱ 2003)ȱbasándoseȱenȱestudiosȱpreviosȱdeȱtoxicidad.ȱEstasȱguíasȱseȱdefinenȱcomoȱ lasȱ concentracionesȱ deȱ contaminantesȱ presentesȱ enȱ sedimentosȱ queȱ estánȱ asociadosȱ oȱ noȱ aȱ efectosȱ biológicosȱ enȱ laboratorioȱ oȱ campoȱ (DelVallsȱ yȱ Chapman,ȱ 1998).ȱ Lasȱ guíasȱ permitenȱ compararȱ elȱ gradoȱ deȱ poluciónȱ entreȱ distintasȱ zonas,ȱ deȱ formaȱ queȱ puedeȱ resultarȱ unaȱ herramientaȱ útilȱ enȱ estudiosȱ deȱcalidadȱambiental.ȱ 2.ȱZonasȱdeȱestudioȱ Paraȱllevarȱaȱcaboȱelȱpresenteȱtrabajoȱseȱescogieronȱdosȱzonasȱdelȱlitoralȱ españolȱafectadasȱporȱvertidosȱdeȱpetróleo.ȱAsimismoȱseȱseleccionóȱunȱáreaȱdeȱ referenciaȱparaȱelȱestudio.ȱ LaȱcostaȱdeȱGalicia:ȱelȱvertidoȱdelȱPrestigeȱ Aȱfinalesȱdelȱ2002ȱelȱaccidenteȱdelȱpetroleroȱmonocascoȱPrestigeȱprovocóȱ unȱ vertidoȱ deȱ 63000ȱ toneladasȱ deȱ fuelȱ oilȱ pesadoȱ queȱ seȱ esparcióȱ enȱ manchas,ȱ másȱoȱmenosȱcompactasȱyȱqueȱsupusoȱunaȱdeȱlasȱ‘mareasȱnegras’ȱmásȱdañinasȱ Ȭ 13ȱȬ Capítuloȱ1 deȱ lasȱ ocurridasȱ enȱ Galiciaȱ enȱ losȱ últimosȱ añosȱ juntoȱ aȱ lasȱ causadasȱ porȱ elȱ Urquiolaȱ (1976)ȱ yȱ elȱ Aegeanȱ Seaȱ (1992).ȱ Además,ȱ seȱ trataȱ deȱ laȱ terceraȱ mareaȱ negraȱ deȱ fuelȱ pesadoȱ enȱ aguasȱ europeasȱ enȱ menosȱ deȱ 4ȱ años,ȱ despuésȱ deȱ lasȱ provocadasȱ porȱ losȱ petrolerosȱ Erikaȱ (1999)ȱ yȱ Balticȱ Carrierȱ (2001).ȱ Laȱ costaȱ gallegaȱfueȱlaȱzonaȱmásȱafectadaȱporȱelȱvertidoȱyȱlosȱefectosȱdeȱlaȱcatástrofeȱseȱ dejaronȱsentirȱenȱelȱmedioȱambienteȱyȱenȱlaȱeconomíaȱyȱsupusoȱunȱgranȱimpactoȱ ecológicoȱyȱsocial.ȱ Laȱ costaȱ deȱ Galiciaȱ haȱ vividoȱ muchosȱ naufragiosȱ enȱ susȱ aguasȱ yȱ esȱ consideradaȱunaȱzonaȱdeȱaltoȱriesgoȱparaȱlosȱnavíosȱ(Bulot,ȱ2003).ȱAȱloȱlargoȱdeȱ laȱhistoria,ȱGaliciaȱhaȱsufridoȱenȱvariasȱocasionesȱlaȱllegadaȱdeȱhidrocarburosȱaȱ susȱcostas.ȱUnaȱdeȱlasȱprimerasȱalertasȱdeȱcontaminaciónȱporȱhidrocarburosȱseȱ produjoȱelȱ27ȱdeȱfebreroȱdeȱ1961,ȱcuandoȱelȱpetroleroȱcanadienseȱAndrosȱFortune,ȱ colisionóȱ conȱ unȱ carguero.ȱ Sinȱ embargo,ȱ enȱ estaȱ ocasión,ȱ elȱ vertidoȱ fueȱ muyȱ reducido,ȱ yaȱ queȱ sóloȱ seȱ vertióȱ alȱ marȱ elȱ combustibleȱ previstoȱ paraȱ elȱ funcionamientoȱ deȱ lasȱ máquinasȱ (Bulot,ȱ 2003).ȱ Elȱ 6ȱ deȱ mayoȱ deȱ 1970,ȱ elȱ petroleroȱ noruegoȱ Polycommander,ȱ tocóȱ fondoȱ alȱ salirȱ delȱ puertoȱ deȱ Vigoȱ vertiendoȱ unasȱ 15000ȱ toneladasȱdeȱcrudoȱligeroȱenȱlaȱbahíaȱdeȱVigo.ȱSeisȱañosȱ después,ȱelȱpetroleroȱespañolȱUrquiola,ȱcolisionóȱconȱunaȱagujaȱsumergidaȱenȱelȱ accesoȱ alȱ puertoȱ deȱ Aȱ Coruña.ȱ Seȱ vertieronȱ 110000ȱ toneladasȱ deȱ crudoȱ (Bulot,ȱ 2003).ȱȱElȱ31ȱdeȱdiciembreȱdeȱ1978,ȱelȱpetroleroȱgriegoȱAndrosȱpatria,ȱsufrióȱunaȱ importanteȱbrechaȱliberandoȱunasȱ60000ȱtoneladasȱdeȱpetróleoȱqueȱmancharonȱ unosȱ50ȱkmȱdeȱlaȱcostaȱdeȱLugoȱ(Bulot,ȱ2003).ȱFueȱcasiȱcatorceȱañosȱdespués,ȱelȱ3ȱ deȱdiciembreȱdeȱ1992,ȱcuandoȱelȱAegeanȱSeaȱprovocóȱunaȱnuevaȱmareaȱnegraȱenȱ lasȱcostasȱdeȱGalicia,ȱvertiendoȱ66800ȱtoneladasȱdeȱcrudoȱligeroȱjuntoȱaȱlaȱTorreȱ deȱ Hérculesȱ enȱ Aȱ Coruña.ȱ Esteȱ episodioȱ haȱ servidoȱ deȱ baseȱ paraȱ realizarȱ estudiosȱposterioresȱenȱelȱcasoȱdelȱPrestigeȱ(CSIC,ȱ2003a).ȱȱ Sinȱ embargo,ȱ elȱ comportamientoȱ delȱ fuelȱ enȱ elȱ medioȱ marinoȱ depende,ȱ enȱgranȱparte,ȱdeȱsuȱcomposición.ȱSabiendoȱqueȱlaȱcargaȱdelȱPrestigeȱconsisteȱenȱ - 14 - Introducción,ȱzonasȱdeȱestudio,ȱobjetivosȱyȱorganizaciónȱdeȱlaȱtesis unȱ fuelȱ pesado,ȱ cabeȱ analizarȱ losȱ accidentesȱ deȱ petrolerosȱ queȱ hanȱ originadoȱ esteȱ tipoȱ deȱ vertido,ȱ deȱ formaȱ queȱ nosȱ podamosȱ acercarȱ aȱ losȱ posiblesȱ efectosȱ ocasionadosȱsobreȱelȱmedioȱmarino.ȱAsí,ȱporȱejemplo,ȱlaȱexperienciaȱadquiridaȱ conȱelȱvertidoȱdeȱ20000ȱtoneladasȱdeȱfuelȱpesadoȱdelȱErikaȱ(12ȱdeȱdiciembreȱdeȱ 1999)ȱfrenteȱaȱlasȱcostasȱfrancesas,ȱhaȱpermitidoȱavanzarȱenȱlasȱactuacionesȱyȱlosȱ estudiosȱ delȱ Prestigeȱ (Hoefer,ȱ T.,ȱ 2003;ȱ LeȬCedre,ȱ http://www.leȬcedre.fr/;ȱ Ifremer,ȱhttp://www.ifremer.fr).ȱȱȱȱȱȱȱ Losȱejemplosȱdeȱvertidosȱaccidentalesȱdeȱunȱproductoȱpetrolíferoȱpesadoȱ enȱelȱmar,ȱdeȱunȱpetróleoȱcrudoȱoȱdeȱunȱproductoȱrefinadoȱcuyaȱdensidadȱvaríaȱ entreȱ0.95ȱyȱ1.00ȱgȱmȬ3,ȱsonȱnumerososȱ(LeȬCedre,ȱhttp://www.leȬcedre.fr).ȱEnȱlaȱ tablaȱ 2.3ȱ seȱ resumenȱ algunosȱ deȱ estosȱ accidentes.ȱ Esteȱ tipoȱ deȱ vertidoȱ (fuelȱ pesado)ȱ produceȱ extensasȱ manchas,ȱ galletasȱ yȱ bolasȱ deȱ hidrocarburos,ȱ originadasȱ porȱ laȱ fragmentaciónȱ delȱ productoȱ duranteȱ suȱ derivaȱ marina.ȱ Casiȱ siempre,ȱ elȱ impactoȱ sobreȱ lasȱ avesȱ yȱ losȱ mamíferosȱ marinosȱ impregnadosȱ deȱ petróleoȱ esȱ muyȱ elevado.ȱ Elȱ vertidoȱ deȱ esteȱ fuelȱ pesado,ȱ alȱ presentarȱ unosȱ componentesȱevaporablesȱyȱbiodegradablesȱminoritariosȱ(menosȱdelȱ10ȱ%ȱdeȱsuȱ masa),ȱsueleȱ exigirȱ unosȱ ampliosȱ trabajosȱdeȱlimpieza,ȱqueȱseȱvuelvenȱdifícilesȱ debidoȱaȱlaȱextremadaȱviscosidadȱdelȱproducto.ȱEnȱcompensación,ȱésteȱdifundeȱ enȱelȱaguaȱescasosȱcomponentesȱtóxicosȱy,ȱunaȱvezȱqueȱlaȱlimpiezaȱseȱhaȱllevadoȱ aȱ cabo,ȱ losȱ efectosȱ aȱ largoȱ plazoȱ sonȱ mínimosȱ (LeȬCedre,ȱ http://www.leȬ cedre.fr).ȱȱ Porȱ otraȱ parte,ȱ losȱ fenómenosȱ deȱ sedimentaciónȱ delȱ fuelȱ pesadoȱ vanȱ aȱ suponerȱ unaȱ entradaȱ deȱ contaminantesȱ aȱ losȱ sedimentos,ȱ queȱ másȱ adelanteȱ puedenȱ volverȱ aȱ laȱ columnaȱ deȱ agua.ȱ Esteȱ fenómenoȱ seȱ haȱ comprobadoȱ enȱ estudiosȱ previos,ȱ dondeȱ seȱ detectaronȱ nuevosȱ picosȱ deȱ contaminaciónȱ mesesȱ despuésȱ delȱ vertido,ȱ enȱ elȱ casoȱ delȱ Erikaȱ (Burgeot,ȱ 2001)ȱ debidoȱ aȱ efectosȱ Ȭ 15ȱȬ Capítuloȱ1 mareales,ȱyȱaȱlaȱremociónȱdeȱfondosȱporȱlaȱ extracciónȱdeȱarenas,ȱenȱelȱcasoȱdeȱ AegeanȱSeaȱ(MMA,ȱ1993).ȱȱ Tablaȱ 1.2.ȱ Accidentesȱ deȱ petrolerosȱ queȱ hanȱ vertidoȱ alȱ marȱ fuelȱ pesadoȱ enȱlosȱúltimosȱañosȱ(LeȬCedre,ȱhttp://www.leȬcedre.fr).ȱ Añoȱ Petroleroȱ 2001ȱ BalticȱCarrierȱ Cantidadȱvertidaȱ (toneladas)ȱ Lugarȱ Dinamarcaȱ 2700ȱ Franciaȱ 20000ȱ Japónȱ 6.20ȱ 1997ȱ Katjaȱ Franciaȱ 0.19ȱ 1988ȱ Nestuccaȱ EEUUȱ 11ȱ 1984ȱ Mobiloilȱ EEUUȱ 0.64ȱ 1980ȱ Tanioȱ Franciaȱ 6500ȱ 1976ȱ Bohlenȱ Franciaȱ 6500ȱ 1976ȱ ArgoȱMerchantȱ EEUUȱ 5.70ȱ 1972ȱ Tamanoȱ EEUUȱ 0.40ȱ Canadáȱ 12ȱ GranȱBretañaȱ 0.64ȱ 1999ȱ Erikaȱ 1997ȱ Nakhodkaȱ 1970ȱ Arrowȱ 1969ȱ HamiltonȱTraderȱ ȱ Losȱ análisisȱ químicos,ȱ revelaronȱ unaȱ composiciónȱ delȱ fuelȱ delȱ Prestigeȱ cercanaȱaȱlaȱdelȱErika.ȱLosȱnivelesȱdeȱconcentracionesȱenȱPAHsȱenȱlaȱmuestraȱdeȱ fuelȱ delȱ Prestigeȱ sonȱ próximosȱ aȱ aquellosȱ delȱ fuelȱ delȱ Erikaȱ recogidasȱ enȱ lasȱ playas.ȱSinȱembargo,ȱpareceȱserȱqueȱlaȱmuestraȱdeȱreferenciaȱErikaȱdeȱlaȱrefineriaȱ deȱDunkerqueȱesȱmásȱricaȱenȱPAHs.ȱLaȱequivalenciaȱtóxicaȱenȱBenzo(a)pyreneȱ pareceȱ indicarȱ potencialesȱ tóxicosȱ similaresȱ entreȱ losȱ dosȱ fuelsȱ (Ifremer,ȱ http://www.ifremer.fr/envlit/prestige/indexsp.htm).ȱ - 16 - Introducción,ȱzonasȱdeȱestudio,ȱobjetivosȱyȱorganizaciónȱdeȱlaȱtesis TranscurridosȱtresȱañosȱdelȱnaufragioȱdelȱErika,ȱlosȱanálisisȱquímicosȱenȱ losȱ mariscos,ȱ mostraronȱ queȱ aúnȱ seȱ encuentranȱ huellasȱ delȱ Erikaȱ enȱ ciertosȱ lugares.ȱ Estoȱ muestraȱ laȱ persistenciaȱ deȱ ciertosȱ componentesȱ deȱ eseȱ fuelȱ enȱ elȱ aguaȱ yȱ enȱ losȱ sedimentosȱ (Ifremerȱ http://www.ifremer.fr/)ȱ loȱ queȱ poneȱ deȱ manifiestoȱlaȱimportanciaȱdelȱestudioȱdeȱlaȱpoluciónȱaȱloȱlargoȱdelȱtiempo.ȱ ȱȱ ȱ Bahíaȱdeȱ ȱ CormeȬLaxeȱ Galiciaȱ ȱ ȱ ȱ ȱ ȱ ParqueȱNacionalȱ deȱlasȱislasȱ Atlánticasȱ ȱ ȱ Figuraȱ 1.1.ȱ Áreasȱ deȱ estudioȱ enȱ lasȱ costasȱ gallegasȱ afectadasȱ porȱ elȱ vertidoȱdelȱpetroleroȱPrestigeȱ(imágenesȱtomadasȱdeȱGoogleTMȱEarth).ȱ Trasȱ elȱ accidenteȱ delȱ petroleroȱ Prestige,ȱ losȱ archipiélagosȱ deȱ Cíes,ȱ Onsȱ yȱ Salvora,ȱdeclaradosȱenȱjulioȱdelȱ2002ȱ(Leyȱ15/2002)ȱParqueȱNacionalȱdeȱlasȱIslasȱ Atlánticas,ȱ fueronȱ laȱ barreraȱ naturalȱ queȱ frenóȱ laȱ entradaȱ delȱ fuelȱ enȱ lasȱ Ríasȱ BajasȱGallegas.ȱElȱdirectorȱdeȱParquesȱNaturalesȱreconocióȱqueȱenȱunaȱprimeraȱ Ȭ 17ȱȬ Capítuloȱ1 oleadaȱ deȱ mareaȱ negra,ȱ elȱ 85%ȱ delȱ Parqueȱ Nacionalȱ deȱ lasȱ Islasȱ Atlánticasȱ resultóȱ afectado,ȱ elevándoseȱ esteȱ porcentajeȱ aȱ másȱ delȱ 90%ȱ trasȱ oleadasȱ posterioresȱdeȱfuelȱrecibidasȱporȱelȱParque.ȱȱ ElȱvertidoȱdelȱpetroleroȱPrestigeȱtambiénȱafectóȱdeȱmaneraȱimportanteȱaȱlaȱ Bahíaȱ deȱ CormeȬLaxeȱ laȱ cualȱ eraȱ consideradaȱ unaȱ zonaȱ conȱ bajaȱ influenciaȱ antropogénicaȱ yȱ unaȱ moderadaȱ actividadȱ industrial,ȱ destacandoȱ sobretodoȱ lasȱ tareasȱagropecuariasȱyȱpesquerasȱdeȱlaȱzona.ȱElȱpolígonoȱdeȱviverosȱdeȱCormeȱ tieneȱ bateasȱ experimentalesȱ dedicadasȱ aȱ laȱ producciónȱ deȱ mejillón,ȱ vieira,ȱ zamburiñaȱyȱostraȱplana.ȱCormeȱLaxeȱpresentaȱunaȱinfluenciaȱoceánicaȱgrandeȱ yȱelȱmayorȱriesgoȱestáȱenȱelȱtráficoȱmarítimoȱexteriorȱqueȱtransportaȱmercancíasȱ peligrosasȱ yȱ estáȱ expuestoȱ aȱ sufrirȱ unȱ accidenteȱ marítimoȱ (Diarioȱ oficialȱ deȱ Galicia,ȱ2004).ȱLosȱtiposȱdeȱhidrocarburosȱsusceptiblesȱdeȱserȱvertidosȱenȱlaȱzonaȱ sonȱprincipalmenteȱelȱgasoilȱdeȱconsumoȱdeȱlosȱbarcos,ȱgasolinas,ȱfuelȬoilȱyȱgasȬ oilȱ deȱ losȱ transportesȱ terrestresȱ yȱ estacionesȱ deȱ suministroȱ deȱ combustible,ȱ residuosȱ oleososȱ procedentesȱ deȱ reparacionesȱ enȱ puertoȱ yȱ talleresȱ deȱ automoción.ȱPorȱotraȱparte,ȱelȱríoȱAnllóns,ȱqueȱdesembocaȱenȱlaȱría,ȱhaȱsufridoȱ episodiosȱdeȱcontaminaciónȱporȱvertidosȱdeȱpurinasȱprocedentesȱdeȱgranjas.ȱ ElȱGolfoȱdeȱCádiz:ȱLaȱBahíaȱdeȱAlgecirasȱyȱlaȱBahíaȱdeȱCádizȱ Aȱ partirȱ deȱ losȱ añosȱ 60,ȱ laȱ franjaȱ costeraȱ deȱ laȱ Bahíaȱ deȱ Algecirasȱ seȱ haȱ vistoȱpaulatinamenteȱ sometidaȱaȱdrásticasȱtransformacionesȱprovocadasȱporȱelȱ crecienteȱ desarrolloȱ socioeconómicoȱ deȱ laȱ zona.ȱ Así,ȱ enȱ laȱ actualidad,ȱ enȱ susȱ márgenesȱ seȱ asientaȱ unȱ importanteȱ poloȱ industrialȱ integradoȱ porȱ plantasȱ petroquímicas,ȱ centralesȱ térmicas,ȱ industriasȱ siderometalúrgicas,ȱ papeleras,ȱ astilleros,ȱ ademásȱ deȱ unaȱ intensaȱ actividadȱ portuaria,ȱ unaȱ crecienteȱ presiónȱ demográficaȱ yȱ elȱ elevadoȱ nivelȱ deȱ transformaciónȱ deȱ laȱ costaȱ porȱ distintasȱ construccionesȱ(Conradiȱetȱal.,ȱ1995).ȱȱ - 18 - Introducción,ȱzonasȱdeȱestudio,ȱobjetivosȱyȱorganizaciónȱdeȱlaȱtesis Existenȱpequeñosȱcaucesȱfluvialesȱqueȱdesembocanȱalȱinteriorȱdeȱlaȱbahíaȱ deȱ Algeciras,ȱ siendoȱ losȱ ríosȱ Palmonesȱ yȱ Gaudarranqueȱ losȱ másȱ importantesȱ respectoȱalȱcaudalȱ(Conradiȱetȱal.,ȱ1995).ȱLaȱhidrologíaȱgeneralȱdeȱlaȱbahíaȱseȱveȱ afectadaȱ porȱ laȱ circulaciónȱ generalȱ deȱ lasȱ masasȱ deȱ aguaȱ atlánticasȱ yȱ mediterráneasȱ aȱ travésȱ delȱ Estrechoȱ deȱ Gibraltar,ȱ aunqueȱ lasȱ corrientesȱ queȱ afectanȱlaȱbahíaȱestánȱcausadasȱprincipalmenteȱporȱcambiosȱdeȱdirecciónȱenȱlaȱ corrienteȱ deȱ marea,ȱ vientos,ȱ presiónȱ atmosféricaȱ yȱ laȱ corrienteȱ mediterráneaȱ superficialȱ (Conradiȱ etȱ al.,ȱ 1995).ȱ Estaȱ bahíaȱ presentaȱ unaȱ altaȱ tasaȱ deȱ renovaciónȱ deȱ susȱ aguas,ȱ debidoȱ aȱ suȱ proximidadȱ alȱ Estrecho,ȱ yȱ aȱ lasȱ fuertesȱ corrientesȱ deȱ aguas,ȱ loȱ queȱ daȱ lugarȱ aȱ queȱ losȱ efectosȱ deȱ losȱ vertidosȱ contaminantesȱ seȱ veanȱ notablementeȱ reducidos,ȱ alȱ dispersarseȱ enȱ unaȱ granȱ masaȱdeȱaguaȱ(ConsejeríaȱdeȱMedioȱAmbiente,ȱ2007).ȱȱ ȱ ȱ ȱ ȱ ȱ ȱ Bahíaȱdeȱ Cádizȱ ȱ Golfoȱdeȱ Cádizȱ ȱ ȱ Bahíaȱdeȱ Algeciras Figuraȱ 1.2.ȱ Áreasȱ deȱ estudioȱ seleccionadasȱ enȱ elȱ golfoȱ deȱ Cádizȱ (imágenesȱtomadasȱdeȱGoogleTMȱEarth).ȱȱȱ Ȭ 19ȱȬ Capítuloȱ1 Lasȱ fuentesȱ potencialesȱ deȱ contaminaciónȱ enȱ elȱ entornoȱ deȱ laȱ Bahíaȱ deȱ Algecirasȱsonȱmuyȱdiversas,ȱaunqueȱseȱvinculanȱaȱlasȱindustriasȱasentadasȱenȱlaȱ zona.ȱ Asimismoȱ hayȱ queȱ considerarȱ laȱ contaminaciónȱ difusaȱ yȱ losȱ lixiviadosȱ procedentesȱdeȱlaȱintensaȱactividadȱurbanaȱeȱindustrialȱqueȱseȱdesarrollaȱenȱelȱ área,ȱ asíȱ comoȱ unaȱ intensaȱ actividadȱ portuariaȱ yȱ tráficoȱ marítimo.ȱ Todoȱ elloȱ haceȱ queȱ laȱ Bahíaȱ deȱ Algecirasȱ sufraȱ deȱ formaȱ rutinariaȱ vertidosȱ deȱ petróleo,ȱ aportesȱ deȱ gasesȱ yȱ materialȱ particuladoȱ aȱ laȱ atmósfera,ȱ metalesȱ pesadosȱ yȱ partículasȱ enȱ suspensiónȱ enȱ lasȱ aguas,ȱ queȱ posteriormenteȱ seȱ transfierenȱ aȱ losȱ sedimentos,ȱyȱenȱmuchosȱcasosȱalcanzanȱlosȱsuelosȱdeȱlaȱzonaȱ(CSIC,ȱ2003b).ȱLaȱ mitadȱ deȱ estosȱ vertidosȱ sonȱ urbanosȱ eȱ industriales,ȱ unȱ 19ȱ %ȱ provienenȱ deȱ lasȱ actividadesȱ deȱ mantenimientoȱ deȱ losȱ buquesȱ comoȱ elȱ “bunkering”ȱ realizadosȱ tantoȱporȱparteȱdelȱpuertoȱdeȱAlgecirasȱcomoȱGibraltar,ȱyȱunȱ5ȱ%ȱdeȱlaȱentradaȱ deȱcontaminantesȱȱcorrespondeȱaȱvertidosȱaccidentales.ȱȱ Losȱ aportesȱ urbanos,ȱ correspondenȱ fundamentalmenteȱ aȱ lasȱ aguasȱ residualesȱ deȱ laȱ poblaciónȱ asentadaȱ enȱ elȱ Campoȱ deȱ Gibraltar.ȱ Entreȱ estosȱ núcleosȱdeȱpoblaciónȱcabeȱdestacar:ȱAlgeciras,ȱLaȱLínea,ȱSanȱRoqueȱyȱlosȱBarriosȱ (CSIC,ȱ 2003b).ȱ Porȱ otroȱ lado,ȱ losȱ vertidosȱ industrialesȱ deȱ laȱ zonaȱ estánȱ constituidosȱporȱemisionesȱdeȱgasesȱyȱmaterialȱparticuladoȱyȱefluentesȱlíquidosȱ producidosȱ porȱ lasȱ industriasȱ situadasȱ enȱ elȱ Campoȱ deȱ Gibraltar,ȱ dedicadasȱ fundamentalmenteȱaȱlaȱproducciónȱquímica:ȱrefinoȱdeȱpetróleoȱyȱpetroquímica,ȱ asíȱ comoȱ aquellosȱ asociadosȱ aȱ lasȱ actividadesȱ delȱ tráficoȱ portuarioȱ (CSIC,ȱ 2003b).ȱ Lasȱ principalesȱ empresasȱ seȱ agrupanȱ enȱ tornoȱ aȱ losȱ siguientesȱ núcleosȱ deȱpoblación:ȱ ȬȱAlgeciras:ȱIndustriasȱpapeleras:ȱTorraspapel,ȱC.L.HȱyȱCentralȱTérmica.ȱ Ȭȱ Sanȱ Roque:ȱ Polígonoȱ petroquímico:ȱ Cepsa,ȱ Interquisa,ȱ Eastmanȱ Chemical,ȱPetresa.ȱ ȬȱLosȱBarrios:ȱCentralȱTérmica,ȱAcerinox,ȱEndesaȱPuertos.ȱ - 20 - Introducción,ȱzonasȱdeȱestudio,ȱobjetivosȱyȱorganizaciónȱdeȱlaȱtesis Organizacionesȱ noȱ gubernamentales,ȱ aseguranȱ queȱ alrededorȱ deȱ 4000ȱ yȱ 5000ȱ deȱ losȱ 100000ȱ barcosȱ queȱ cruzanȱ elȱ estrechoȱ cadaȱ año,ȱ sonȱ petroleros,ȱ yȱ muchosȱ entranȱ enȱ laȱ bahíaȱ deȱ Algecirasȱ aȱ realizarȱ operacionesȱ cargaȱ deȱ combustibleȱ ȱ (“bunkering”).ȱ Enȱ elȱ casoȱ deȱ Gibraltar,ȱ elȱ bunkeringȱ seȱ realizaȱ desdeȱunȱbuqueȱ–ȱelȱȇVemabalticȇ,ȱcapacidad:ȱ107544ȱToneladasȱȬȱfondeadoȱenȱlaȱ mismaȱ bahía,ȱ yȱ seȱ trataȱ delȱ únicoȱ lugarȱ deȱ laȱ Uniónȱ Europeaȱ dondeȱ seȱ sigueȱ realizandoȱestaȱoperaciónȱdesdeȱunȱbuqueȱfondeadoȱ(LópezȱdeȱUralde,ȱ2007).ȱ ȱ 7% ȱ 2% 1% 7% 2% ȱ ȱ 57% 21% ȱ ȱ ȱ Aceite de oliva y sus fracciones Alcoholes acíclicos y derivados Fuel-Oil Gas-Oil Hidrocarburos acíclicos Lubricantes Abonos minerales Alcohol etílico sin desnaturalizar Flúor, cloro, bromo y yodo Aceites y Productos Destilación Crudos de petróleos Gas de petróleo Gasolina, Keroseno y Petróleo Refinado Hidrocarburos cíclicos Aceite de oliva y sus fracciones Ácidos policarboxílicos Eteres y derivados halogenados Polímeros de etileno ȱ Figuraȱ 1.3.ȱ Mercancíasȱ peligrosasȱ cargadasȱ yȱ descargadasȱ enȱ elȱ Puertoȱ BahíaȱdeȱAlgecirasȱ(MartínȬDíazȱyȱDelValls,ȱcomunicaciónȱpersonal)ȱȱ Estaȱ evidenteȱ influenciaȱ antropogénicaȱ enȱ laȱ zonaȱ yȱ losȱ posiblesȱ efectosȱ adversosȱ enȱ elȱ ecosistemaȱ deȱ laȱ bahíaȱ noȱ hanȱ transcendidoȱ tantoȱ comoȱ porȱ ejemploȱ elȱ vertidoȱ delȱ petroleroȱ Prestigeȱ enȱ Galicia,ȱ aunqueȱ cadaȱ vezȱ hayȱ másȱ interésȱ yȱ preocupaciónȱ porȱ losȱ posiblesȱ dañosȱ deȱ losȱ vertidosȱ enȱ laȱ Bahíaȱ deȱ Algeciras.ȱ Ȭ 21ȱȬ Capítuloȱ1 OtraȱbahíaȱsituadaȱtambiénȱenȱelȱGolfoȱdeȱCádizȱfueȱescogidaȱdeȱmaneraȱ complementariaȱ paraȱ llevarȱ aȱ caboȱ esteȱ estudio;ȱ unaȱ zonaȱ queȱ noȱ presentaȱ fuentesȱ deȱ contaminaciónȱ importantes:ȱ laȱ bahíaȱ deȱ Cádiz.ȱ Laȱ Consejeríaȱ deȱ MedioȱAmbienteȱ(2007)ȱhaȱdeclaradoȱqueȱestaȱbahíaȱpresentaȱunaȱbuenaȱcalidadȱ ambiental,ȱyȱademás,ȱelȱáreaȱseleccionadaȱhaȱsidoȱampliamenteȱcaracterizadaȱyȱ susȱsedimentosȱhanȱsidoȱanalizadosȱyȱevaluadosȱbajoȱelȱpuntoȱdeȱvistaȱquímicoȱ yȱecotoxicológicoȱresultandoȱserȱaptosȱparaȱsuȱusoȱcomoȱestaciónȱdeȱreferenciaȱ enȱesteȱtrabajo.ȱȱȱ 3.ȱObjetivosȱeȱhipótesisȱ Laȱ hipótesisȱ deȱ partidaȱ consideraȱ queȱ unȱ ecosistemaȱ queȱ recibeȱ deȱ maneraȱ continuaȱ moderadasȱ dosisȱ deȱ vertidosȱ deȱ hidrocarburosȱ duranteȱ unȱ largoȱ periodoȱ deȱ tiempoȱ (impactoȱ crónico)ȱ resultaȱ másȱ dañadoȱ yȱ presentaȱ mayorȱ poluciónȱ (contaminaciónȱ masȱ efectos)ȱ queȱ enȱ elȱ casoȱ deȱ unȱ ecosistemaȱȱ queȱ recibeȱ enȱ unȱ cortoȱ periodoȱ deȱ tiempoȱ unȱ vertidoȱ deȱ grandesȱ dimensionesȱ (impactoȱ agudo).ȱ Elȱ objetivoȱ generalȱ deȱ estaȱ tesisȱ doctoralȱ consisteȱ enȱ determinarȱ yȱ compararȱ laȱ calidadȱ deȱ losȱ sedimentosȱ deȱ dosȱ zonasȱ delȱ litoralȱ españolȱ afectadasȱ porȱ vertidosȱ deȱ petróleo,ȱ laȱ costaȱ gallegaȱ yȱ laȱ Bahíaȱ deȱ Algecirasȱ frenteȱ aȱ unaȱ zonaȱ consideradaȱ noȱ afectadaȱ porȱ esteȱ tipoȱ deȱ contaminación.ȱ Considerandoȱ laȱ metodologíaȱ queȱ seȱ haȱ seguido,ȱ seȱ pretendíaȱ realizarȱ estaȱ aportaciónȱ aȱ travésȱ deȱ laȱ consecuciónȱ deȱ losȱ siguientesȱ objetivosȱ concretos:ȱȱ 1.ȱ Determinarȱ elȱ gradoȱ deȱ contaminaciónȱ porȱ losȱ principalesȱ contaminantesȱ (metalesȱ yȱ PAHs)ȱ queȱ seȱ encontrabanȱ enȱ losȱ vertidosȱ deȱ hidrocarburosȱ enȱ losȱ sedimentosȱ delȱ Parqueȱ Nacionalȱ deȱ lasȱ Islasȱ Atlánticasȱ yȱ Bahíaȱ deȱ CormeȬLaxeȱ (costaȱ deȱ Galicia)ȱ yȱ enȱ laȱ - 22 - Introducción,ȱzonasȱdeȱestudio,ȱobjetivosȱyȱorganizaciónȱdeȱlaȱtesis desembocaduraȱ deȱ losȱ ríosȱ Guadarranqueȱ yȱ Palmonesȱ enȱ laȱ Bahíaȱ deȱ AlgecirasȱasíȱcomoȱestablecerȱsusȱnivelesȱenȱlaȱBahíaȱdeȱCádiz.ȱȱ 2.ȱ Establecerȱ elȱ efectoȱ adversoȱ deȱ estosȱ contaminantesȱ unaȱ vezȱ queȱ seȱ incorporanȱaȱlosȱsedimentosȱmedianteȱdiseñoȱyȱaplicaciónȱdeȱensayosȱdeȱ laboratorioȱ bajoȱ condicionesȱ controladasȱ yȱ enȱ exposicionesȱ deȱ tipoȱ aguda,ȱ letalesȱ yȱ bioacumulaciónȱ utilizandoȱ poblacionesȱ deȱ laȱ bacteriaȱ Vibrioȱfischeri,ȱdeȱlosȱanfípodosȱCorophiumȱvolutatorȱyȱAmpeliscaȱbrevicornis,ȱ yȱdelȱpoliquetoȱArenícolaȱmarinaȱ 3.ȱ Caracterizarȱ losȱ posiblesȱ efectosȱ adversosȱ deȱ losȱ contaminantesȱ bajoȱ condicionesȱ deȱ laboratorioȱ yȱ campoȱ medianteȱ ensayosȱ deȱ laboratorioȱ crónicoȱyȱmedidasȱdelȱefectoȱsubletal,ȱqueȱincorporanȱdeterminacionesȱdeȱ biomarcadoresȱ deȱ exposiciónȱ (actividadȱ EROD,ȱ Metalotioneinas,ȱ actividadȱ GST,ȱ GPX,ȱ GR,ȱ FRAP,ȱ vitelogenina,ȱ TBARS)ȱ yȱ deȱ efectoȱ (Alteraciónȱ deȱ comportamiento,ȱ histopatologíaȱ yȱ dañoȱ deȱ ADN)ȱ utilizandoȱ juvenilesȱ deȱ laȱ especieȱ comercialȱ delȱ pezȱ Sparusȱ aurataȱ (dorada),ȱelȱcangrejoȱCarcinusȱmaenas,ȱlaȱalmejaȱRuditapesȱphilippinarumȱyȱ elȱpoliquetoȱArenicolaȱmarina.ȱ 4.ȱ Determinaciónȱ deȱ lasȱ alteracionesȱ bentónicasȱ “inȱ situ”ȱ queȱ permitenȱ evaluarȱ elȱ posibleȱ impactoȱ deȱ losȱ contaminantesȱ sobreȱ elȱ ecosistemaȱ marino,ȱ aȱ travésȱ delȱ estudioȱ deȱ parámetrosȱ poblacionalesȱ (númeroȱ deȱ especies,ȱ diversidad,ȱ riquezaȱ específica,ȱ dominanciaȱ yȱ presenciaȱ deȱ losȱ taxonesȱprincipales).ȱ 5.ȱ Identificarȱ lasȱ sustanciasȱ contaminantesȱ queȱ producenȱ elȱ efectoȱ adversoȱ medianteȱ laȱ integraciónȱ deȱ losȱ resultadosȱ deȱ contaminaciónȱ (fisicoquímicos)ȱ yȱ deȱ susȱ efectosȱ (toxicidadȱ agudaȱ yȱ crónica)ȱ bajoȱ condicionesȱ deȱ laboratorioȱ yȱ campo,ȱ asíȱ comoȱ laȱ alteraciónȱ bentónica,ȱ Ȭ 23ȱȬ Capítuloȱ1 determinandoȱ laȱ calidadȱ deȱ losȱ sedimentosȱ delȱ Parqueȱ Nacionalȱ deȱ lasȱ IslasȱAtlánticas,ȱlaȱBahíaȱ deȱ CormeȬLaxe,ȱyȱlaȱBahíaȱdeȱ Algeciras,ȱzonasȱ afectadasȱenȱmayorȱoȱmenorȱmedidaȱporȱvertidosȱdelȱpetróleo.ȱ 6.ȱEstablecerȱlosȱnivelesȱdeȱpoluciónȱenȱcadaȱunaȱdeȱlasȱzonasȱestudiadasȱ determinandoȱlaȱseveridadȱdeȱlosȱimpactosȱproducidosȱporȱcadaȱtipoȱdeȱ vertidoȱ estudiadosȱ (agudos,ȱ vertidoȱ Prestigeȱ enȱ zonaȱ Gallega;ȱ crónicos,ȱ vertidosȱ continuosȱ Bahíaȱ deȱ Algeciras),ȱ yȱ siempreȱ porȱ comparaciónȱ frenteȱaȱunaȱestaciónȱdeȱreferencia,ȱlocalizadaȱenȱlaȱBahíaȱdeȱCádiz.ȱ 4.ȱEstructuraȱdeȱlaȱtesisȱ Estaȱtesisȱdoctoralȱseȱhaȱestructuradoȱenȱseisȱcapítulos:ȱelȱprimeroȱconstaȱ deȱ introducción,ȱ descripciónȱ deȱ losȱ objetivosȱ deȱ laȱ tesis,ȱ asíȱ comoȱ laȱ presentaciónȱ deȱ lasȱ áreasȱ deȱ estudio,ȱ mientrasȱ queȱ enȱ losȱ cuatroȱ capítulosȱ siguientesȱseȱpresentaȱlaȱmemoriaȱenȱsí,ȱfinalizandoȱconȱunȱúltimoȱcapítuloȱenȱelȱ queȱ seȱ muestranȱ lasȱ conclusionesȱ obtenidasȱ enȱ elȱ estudio.ȱ Cadaȱ unoȱ deȱ losȱ cuatroȱcapítulosȱcentralesȱconstaȱdeȱunaȱintroducciónȱyȱdescripciónȱresumidaȱenȱ españolȱyȱlosȱtrabajosȱdeȱinvestigaciónȱescritosȱenȱinglésȱpublicados,ȱaceptados,ȱ oȱbienȱenviadosȱaȱdistintasȱrevistasȱinternacionales.ȱDeȱestaȱformaȱenȱelȱcapítuloȱ 2ȱseȱincluyenȱlosȱtrabajosȱI,ȱII,ȱIIIȱyȱIVȱqueȱdescribenȱlosȱresultadosȱdeȱtoxicidadȱ agudaȱ obtenidosȱ deȱ laȱ realizaciónȱ deȱ losȱ bioensayosȱ conȱ dilucionesȱ deȱ fuelȱ extraídoȱ delȱ petroleroȱ Prestigeȱ (trabajosȱ Iȱ yȱ II),ȱ asíȱ comoȱ experimentosȱ conȱ muestrasȱambientalesȱdeȱsedimentoȱ(trabajosȱIIIȱyȱIV).ȱElȱcapítuloȱ3ȱpresentaȱlosȱ resultadosȱ deȱ laȱ evaluaciónȱ deȱ losȱ efectosȱ subletalesȱ bajoȱ condicionesȱ deȱ laboratorio.ȱ Aȱ loȱ largoȱ deȱ 5ȱ trabajosȱ seȱ describenȱ losȱ estudiosȱ deȱ toxicidadȱ realizadosȱ conȱ 4ȱ especiesȱ marinasȱ yȱ enȱ losȱ queȱ seȱ hanȱ obtenidoȱ respuestasȱ subletalesȱdeȱtoxicidadȱtrasȱexponerȱlosȱorganismosȱaȱlosȱsedimentosȱdeȱestudio.ȱ Elȱ capítuloȱ 4ȱ incluyeȱ 4ȱ trabajosȱ enȱ losȱ queȱ seȱ llevaȱ aȱ caboȱ laȱ evaluaciónȱ deȱ losȱ - 24 - Introducción,ȱzonasȱdeȱestudio,ȱobjetivosȱyȱorganizaciónȱdeȱlaȱtesis efectosȱ subletalesȱ deȱ losȱ contaminantesȱ bajoȱ condicionesȱ deȱ campo.ȱ Enȱ esteȱ ámbito,ȱ losȱ trabajosȱ X,ȱ XIȱ yȱ XIIȱ muestranȱ losȱ resultadosȱ deȱ bioensayosȱ realizadosȱ conȱ dosȱ especiesȱ marinasȱ medianteȱ laȱ instalaciónȱ enȱ jaulasȱ enȱ losȱ puntosȱ deȱ muestreo,ȱ mientrasȱ queȱ enȱ elȱ trabajoȱ XIIIȱ seȱ comparanȱ lasȱ alteracionesȱ bentónicasȱ deȱ lasȱ áreasȱ deȱ estudio.ȱ Enȱ elȱ capítuloȱ 5ȱ seȱ realizaȱ laȱ integraciónȱdeȱlosȱresultadosȱmostradosȱaȱloȱlargoȱdeȱestaȱmemoria,ȱyȱconstaȱdeȱ 3ȱ trabajos.ȱ Elȱ trabajoȱ XIVȱ realizaȱ unȱ estudioȱ deȱ laȱ evoluciónȱ deȱ laȱ calidadȱ ambientalȱdeȱlosȱsedimentosȱdeȱGaliciaȱaȱloȱlargoȱdeȱlosȱúltimosȱaños,ȱmedianteȱ elȱempleoȱdeȱunaȱmetodologíaȱTRIADȱclásica.ȱEnȱelȱtrabajoȱXVȱseȱdesarrollaȱunaȱ nuevaȱ metodologíaȱ dentroȱ deȱ unȱ “weightȱ ofȱ evidenceȱ approach”ȱ enȱ laȱ queȱ seȱ incorporaȱunaȱnuevaȱlíneaȱdeȱevidenciaȱdeȱefectosȱsubletalesȱparaȱlaȱevaluaciónȱ deȱ laȱ calidadȱ deȱ losȱ sedimentosȱ enȱ elȱ áreaȱ deȱ Galicia.ȱ Enȱ elȱ últimoȱ trabajo,ȱ elȱ XVI,ȱ seȱ llevaȱ aȱ caboȱ unaȱ integraciónȱ conjuntaȱ deȱ losȱ datosȱ obtenidosȱ enȱ losȱ diferentesȱ estudiosȱ deȱ losȱ sedimentosȱ deȱ laȱ zonaȱ deȱ Galiciaȱ yȱ laȱ Bahíaȱ deȱ Algeciras.ȱ ȱ ȱ Finalmente,ȱ enȱ elȱ capítuloȱ 6ȱ deȱ estaȱ memoria,ȱ seȱ establecenȱ lasȱ conclusionesȱ obtenidasȱ trasȱ laȱ consecuciónȱ deȱ losȱ objetivosȱ propuestosȱ enȱ estaȱ tesisȱdoctoral.ȱ 5.ȱBibliografíaȱ ȱȱȱdelȱ Fuel.ȱ Ensayosȱ sobreȱ elȱ <<Prestige>>.ȱ Fundaciónȱ Santiagoȱ Reyȱ FernándezȬ LaTorre:ȱ10Ȭ41.ȱ Arjonilla,ȱ M.,ȱ Forja,ȱ J.M.,ȱ GómezȬParra,ȱ A.ȱ 1994.ȱSedimentȱanalysisȱdoesȱnotȱprovideȱ aȱ goodȱ measureȱ ofȱ heavyȱ metalȱ bioavalibilityȱ toȱ Cerastodermaȱ glaucumȱ (Mollusca:ȱ Bivalvia)ȱ inȱ confinedȱ coastalȱ sediments.ȱ Bull.ȱ Environ.ȱ Contam.ȱ Toxicol.ȱ52:ȱ810Ȭ817.ȱ Burgeot,ȱT.ȱ2001.ȱAnȱoverviewȱofȱstatusȱandȱ monitoringȱ ofȱ theȱ Erikaȱ Hillȱ spill.ȱ Reportȱ WgbecȬIcesȬcm(Warnemünde,ȱGermany).ȱ Chapman,ȱ P.M,ȱ Morgan,ȱ J.D.ȱ 1983.ȱ Sedimentȱ bioassayȱ withȱ Oysterȱ Larvae.ȱ Bull.ȱ Environ.ȱ Contam.ȱ Toxicol.ȱ 31:ȱ 438Ȭ 444.ȱ Baek,ȱ S.O.,ȱ Goldstone,ȱ M.E.,ȱ Kirk,ȱ P.W.W.,ȱ Lester,ȱ J.N.,ȱ Perry,ȱ R.ȱ 1991.ȱ Phaseȱ distributionȱandȱparticleȱsizeȱdependencyȱ ofȱ polycyclicȱ aromaticȱ hydrocarbonsȱ inȱ theȱ urbanȱ atmosphere.ȱ Chemosphereȱ 22(5Ȭ6):ȱ503Ȭ520. Bulot,ȱJ.ȱ2003.ȱLaȱHuellaȱȱ ȱ Ȭ 25ȱȬ Capítuloȱ1 Chapman,ȱ P.M.ȱ 1989.ȱ Currentȱ approachesȱ toȱ developingȱ sedimentȱ qualityȱ criteria.ȱ Environ.ȱToxicol.ȱChem.ȱ8:ȱ589Ȭ599.ȱ Fundaciónȱ Santiagoȱ Reyȱ FernándezȬ LaTorre.ȱ 2003.ȱ Laȱ Huellaȱ delȱ Fuel.ȱ Ensayosȱsobreȱelȱ<<Prestige>>.ȱ278pp.ȱ Conradi,ȱ M,ȱ etȱ al.ȱ 1995.ȱ Estudioȱ biológicoȱ deȱ lasȱ comunidadesȱ bentónicasȱ deȱ laȱ bahíaȱdeȱAlgeciras.ȱI:ȱSinopsisȱgeneralȱdeȱ resultadosȱ yȱ conclusiones.ȱ Universidadȱ deȱSevilla.ȱ Harvey,ȱ R.W.,ȱ Luoma,ȱ S.N.ȱ 1985.ȱ Effectȱ ofȱ adherentȱ bacteriaȱ andȱ bacterialȱ extracelularȱ polymersȱ uponȱ assimilationȱ byȱ Macomaȱ balthicaȱ ofȱ sedimentȬȱ boundȱ Cd,ȱ Znȱ andȱ Ag.ȱ Mar.ȱ Ecol.ȱ Prog.ȱ Ser.ȱ 22:ȱ 281Ȭ289.ȱȱ Consejeríaȱ deȱ Medioȱ Ambiente.ȱ 2007.ȱ Informeȱ 2006ȱ Medioȱ Ambienteȱ enȱ Andalucía.ȱJuntaȱdeȱAndalucía.ȱ Hoefer,ȱ T.ȱ 2003.ȱ Tankerȱ safetyȱ andȱ coastalȱ environment:ȱ Prestige,ȱ Erika,ȱ andȱ whatȱ else?.ȱ Environmentalȱ Scienceȱ andȱ PollutionȱResearchȱInternationalȱ10ȱ(1):ȱ1Ȭ 5.ȱ CSIC.ȱ 2003a.ȱ Impactoȱ deȱ unȱ vertidoȱ deȱ petróleoȱ sobreȱ losȱ organismosȱ marinos.ȱ Algunasȱ leccionesȱ delȱ vertidoȱ delȱ Aegeanȱ Sea.ȱInformeȱnúmeroȱ15.ȱ3ȱpp.ȱȱ Jackim,ȱ E.,ȱ Lake,ȱ C.ȱ 1978.ȱ Polynuclearȱ aromaticȱ hydrocarbonsȱ inȱ estuarineȱ andȱ nearshoreȱ environments.ȱ Estuarineȱ Interactions.ȱ Academicȱ Press,ȱ Newȱ York.ȱ 415Ȭ428pp.ȱ CSIC.ȱ 2003b.ȱ Informeȱ diciembreȱ 2003:ȱ Diagnósticoȱ sobreȱ laȱ situaciónȱ ambientalȱ delȱ entornoȱ delȱ Campoȱ deȱ Gibraltar.ȱ 194ȱ pp.ȱ Kemp,ȱ P.F.,ȱ Swartz,ȱ R.C.ȱ 1998.ȱ Acuteȱ toxicityȱ ofȱ interstitialȱ andȱ particleȬboundȱ cadmiumȱtoȱaȱmarineȱinfaunalȱamphipod.ȱ Mar.ȱEnviron.ȱRes.ȱ26ȱ:ȱ135Ȭ153.ȱ DelValls,ȱ T.A.ȱ 1994.ȱ Aplicaciónȱ deȱ unȱ métodoȱ integradoȱ paraȱ laȱ medidaȱ deȱ laȱ calidadȱambientalȱenȱecosistemasȱlitoralesȱ delȱ golfoȱ deȱ Cádiz.ȱ Tesisȱ doctoral.ȱ UniversidadȱdeȱCádiz.ȱ389pp.ȱ Long,ȱ E.R.,ȱ Buchman,ȱ M.F.ȱ 1989.ȱ Anȱ evaluationȱ ofȱ candidateȱ measuresȱ ofȱ biologicalȱ effectsȱ forȱ theȱ Nationalȱ Statusȱ andȱ Trendsȱ Program.ȱ NOAAȱ Technicalȱ Memorandumȱ NOSȱ OMAȱ 45.ȱ Nationalȱ Oceanicȱ andȱ Atmosphericȱ Administration.ȱ Seattle,ȱ Washington.ȱ 105pp.ȱ DelValls,ȱT.A.,ȱChapman.ȱ1998.ȱSiteȬspecificȱ sedimentȱ qualityȱ valuesȱ forȱ theȱ gulaȱ ofȱ Cádizȱ (Spain)ȱ andȱ Sanȱ Franciscoȱ Bayȱ (USA),ȱ usingȱ theȱ sedimentȱ qualityȱ triadȱ andȱ multivariateȱ análisis.ȱ Cienciasȱ Marinas,ȱ24(3):ȱ313Ȭ336. ȱ DelValls,ȱ .T.A.,ȱ Forjaȱ J.M.,ȱ GómezȬParraȱ A.ȱ 2002.ȱSeasonalityȱofȱcontamination,ȱȱ Luoma,ȱ S.N.,ȱ Bryan,ȱ G.W.ȱ 1978.ȱ Factorsȱ controllingȱ theȱ availabilityȱ ofȱ sedimentsȬ boundȱ leadȱ toȱ theȱ estuarineȱ bivalveȱ Scrobiculariaȱplana.ȱJ.ȱMar.ȱBiol.ȱAss.ȱU.K.ȱ 58:ȱ793Ȭ802.ȱ ȱȱȱȱtoxicity,ȱ andȱ qualityȱ valuesȱ inȱ sedimentsȱ fromȱ littoralȱ ecosystemsȱ inȱ theȱ Gulfȱ ofȱ Cádizȱ(SWȱSpain).ȱChemosphereȱ46ȱ1033– 1043.ȱ Luoma,ȱ S.N.ȱ 1983.ȱ Bioavailabilityȱ ofȱ traceȱ metalsȱ toȱ aquaticȱ organismsȱ ȬȬȱ Aȱ review.ȱ Sci.ȱTotalȱEnviron.ȱ28:ȱ1Ȭ22.ȱ Eisler,ȱ R.ȱ 2000.ȱ Handbookȱ ofȱ chemicalȱ riskȱ assessment.ȱLewisȱpublishers.ȱChapterȱ25.ȱ Luoma,ȱ S.N.,ȱ Philips,ȱ D.H.J.ȱ 1988.ȱ Distribution,ȱ variability,ȱ andȱ impactsȱ ofȱ traceȱelementsȱinȱSanȱFranciscoȱBay.ȱMar.ȱ Pollut.ȱBull.ȱ19(9):ȱ413Ȭ425.ȱ Environmentalȱ Canada.ȱ 2003.ȱ Canadianȱ EnvironmentalȱQualityȱGuidelines.ȱ - 26 - Introducción,ȱzonasȱdeȱestudio,ȱobjetivosȱyȱorganizaciónȱdeȱlaȱtesis Luoma,ȱ S.N.ȱ 1989.ȱ Canȱ weȱ determineȱ theȱ biologicalȱ availabilityȱ ofȱ sedimentȱ boundȱ traceȱ elements?ȱ Hidrobiologiaȱ 176/177:ȱ 79Ȭ396.ȱ NOAA.ȱ 1999.ȱ Sedimentȱ Qualityȱ Guidelinesȱ developedȱ forȱ theȱ Nationalȱ Statusȱ andȱ TrendȱPrograms.ȱȱȱ Neff,ȱ J.M.ȱ 1979.ȱ Polyciclicȱ Aromaticȱ Hydrocarbonsȱ inȱ theȱ aquaticȱ environment.ȱ Appliedȱ Scienceȱ Publ.Ltd.ȱ London.ȱ262ȱpp.ȱ Luoma,ȱ S.N.ȱ 1990.ȱ Processȱ affectingȱ metalȱ concentrationsȱ inȱ estuarineȱ andȱ coastalȱ marineȱ sediments.ȱ Heavyȱ metalsȱ inȱ theȱ marineȱ environment.ȱ CRCȱ Press,ȱ Inc.ȱ BocaȱRaton,ȱFlorida,ȱ51Ȭ66.ȱ Oakden,ȱ J.M.,ȱ Bejda,ȱ A.J.,ȱ Pearson,ȱ W.H.ȱ 1984.ȱ EDTAȱ chelationȱ andȱ zincȱ antagonismȱ withȱ cadmiumȱ inȱ sediment:ȱ effectsȱonȱtheȱbehaviourȱandȱmortalityȱofȱ twoȱ infaunalȱ amphipods.ȱ Mar.ȱ Biol.ȱ 85:ȱ 125Ȭ130.ȱ Luoma,ȱS.N.,ȱHo,ȱK.T.ȱ1992.ȱTheȱappropiateȱ usesȱ ofȱ marineȱ andȱ estuarineȱ sedimentȱ bioassays.ȱ Theȱ Handbookȱ ofȱ Ecotoxicology.ȱEd.ȱP.ȱCalow.ȱCap.ȱ11:ȱ193Ȭ 226.ȱ Salomons,ȱW.,ȱdeȱRooij,ȱN.M.,ȱKerdjik,ȱBrill,ȱ J.ȱ 1987.ȱ Sedimentsȱ asȱ aȱ sourceȱ forȱ contaminants?ȱHidrobiologiaȱ149:ȱ13Ȭ30.ȱ Martell,ȱ F.L.,ȱ Motekaitis,ȱ R.T.,ȱ Smith,ȱ R.M.ȱ 1988.ȱ StructureȬstabilityȱ relationshipsȱ ofȱ metalȱ complexesȱ andȱ metalȱ speciationȱ inȱ environmentalȱ aqueousȱ solutions.ȱ Environ.ȱToxicol.ȱChem.ȱ7:ȱ417Ȭ434 Schnitz,ȱ A.R.,ȱ O’Connor,ȱ J.M.ȱ 1992.ȱ Inȱ vivoȱ DNA/RNAȱ adductionȱ ofȱ 7,12Ȭ dimethylbenz(a)anthraceneȱ (DMBA)ȱ andȱ benzo(a)pyreneȱ (BaP)ȱ inȱ theȱ liverȱ ofȱ rainbowȱ troutȱ (Oncorhynchusȱ mykiss).ȱ Jour.ȱ Environ.ȱ Pathol.ȱ Toxicol.ȱ Oncol.ȱ 11:229Ȭ233.ȱȱȱ MartínȬDíaz,ȱ L.,ȱ DelValls,ȱ T.A.ȱ Presionesȱ sobreȱ elȱ medioȱ ambienteȱ deȱ laȱ Bahíaȱ deȱ Algecirasȱ debidoȱ aȱ lasȱ actividadesȱ asociadasȱ alȱ tráficoȱ marítimo.ȱ Presentaciónȱoral.ȱ Sims,ȱ R.C,ȱ Overcash,ȱ R.ȱ 1983.ȱ Fateȱ ofȱ Polynuclearȱaromaticȱcompoundsȱ(PNAs)ȱ inȱ soilȬplantȱ systems.ȱ Residueȱ Rev.ȱ 88:ȱ 1Ȭ 68.ȱ McGee,ȱ B.L.,ȱ Schlekat,ȱ Ch.E.,ȱ Reinharz,ȱ E.ȱ 1993.ȱ Assesingȱ sublethalȱ levelsȱ ofȱ sedimentsȱ contaminationȱ usingȱ theȱ estuarineȱ amphipodȱ Leptocheirusȱ plumosus.ȱ Environ.ȱ Toxicol.ȱ Chem.ȱ 12:ȱ 577.587.ȱ Swartz,ȱ R.C.,ȱ Kemp,ȱ P.F.,ȱ Schults,ȱ D.W.,ȱ Ditsworth,ȱG.R.,ȱOzretich,ȱR.J.ȱ1989.ȱAcuteȱ toxicityȱofȱsedimentsȱfromȱEagleȱHarbour,ȱ Washington,ȱ toȱ theȱ infaunalȱ amphipodȱ Rhepoxyniousȱ abronius.ȱ Environ.ȱ Toxicol.ȱ Chem.ȱ8:ȱ212Ȭ222.ȱ Meador,ȱ J.P.,ȱ Ross,ȱ B.D.,ȱ Dinnel,ȱ P.A.,ȱ Picquelle,ȱ S.J.ȱ 1990.ȱ Anȱ analysisȱ ofȱ theȱ relationshipȱ betweenȱ aȱ SandȬDollarȱ embryoȱ elutriateȱ assayȱ andȱ sedimentȱ contaminantsȱ fromȱ stationsȱ inȱ anȱ urbanȱ embaymentȱofȱPugetȱSound,ȱWashington.ȱ Mar.ȱEnviron.ȱRes.ȱ30:ȱ251Ȭ272.ȱ Swartz,ȱ R.C.,ȱ Schults,ȱ D.W.,ȱ DeWitt,ȱ T.H.,ȱ Ditsworth,ȱ G.R.,ȱ Lamberson,ȱ J.O.ȱ 1990.ȱ Toxicityȱ ofȱ fluorantheneȱ inȱ sedimentȱ toȱ marineȱ amphipods:ȱ aȱ testȱ ofȱ theȱ equilibriumȱ partitioningȱ approachȱ toȱ sedimentȱ qualityȱ criteria.ȱ Environ.ȱ Toxicol.ȱChem.ȱȱ9:ȱ1071Ȭ1080.ȱ MMA.ȱ 1993.ȱ Seguimientoȱ deȱ lasȱ contaminacionesȱ producidasȱ porȱ elȱ accidenteȱ delȱ buqueȱ Aegeanȱ Sea.ȱ Ed.ȱ Centroȱ Publ.ȱ Sec.ȱ G.ȱ Técnica.ȱ Ministerioȱ deȱMedioȱAmbiente.ȱMadrid.ȱ USEPA,ȱ 2000.ȱ Toxicȱ Releaseȱ Inventoryȱ PublicDataRelease,hppt://www.epa.gov/t riinter/tridata/index.htm,ȱ Officeȱ ofȱ EnvironmentalȱInformation,ȱUnitedȱStatesȱ Ȭ 27ȱȬ ȱ - 28 - ȱ Capítuloȱ2.ȱ Análisisȱdeȱlaȱcontaminaciónȱyȱevaluaciónȱȱdeȱlaȱ toxicidadȱagudaȱmedianteȱensayosȱenȱlaboratorioȱ Laȱpropiedadȱqueȱtieneȱunaȱsustanciaȱdeȱproducirȱefectosȱadversosȱaȱunȱ sistemaȱ biológicoȱ seȱ denominaȱ toxicidad.ȱ Sinȱ embargo,ȱ elȱ hechoȱ deȱ queȱ unaȱ sustanciaȱtóxicaȱestéȱpresenteȱenȱelȱmedioȱnoȱimplicaȱnecesariamenteȱqueȱvayaȱaȱ causarȱ efectosȱ tóxicos.ȱ Unaȱ sustanciaȱ presenteȱ enȱ elȱ medioȱ ambienteȱ aȱ concentracionesȱ superioresȱ deȱ lasȱ naturalesȱ conllevaȱ unȱ episodioȱ deȱ contaminación,ȱ yȱ enȱ elȱ casoȱ deȱ queȱ tambiénȱ presenteȱ efectosȱ tóxicosȱ sobreȱ laȱ biotaȱestaremosȱhablandoȱdelȱfenómenoȱdeȱpolución.ȱEnȱesteȱúltimoȱcaso,ȱdosisȱ bajasȱdeȱcontaminanteȱpuedenȱproducirȱalteracionesȱenȱlasȱfuncionesȱvitalesȱdeȱ losȱ organismos,ȱ mientrasȱ queȱ dosisȱ altasȱ deȱ laȱ mismaȱ sustanciaȱ puedenȱ serȱ letales.ȱȱȱ Tradicionalmenteȱ seȱ haȱ evaluadoȱ laȱ calidadȱ ambientalȱ deȱ unȱ sedimentoȱ medianteȱelȱanálisisȱdeȱlasȱconcentracionesȱdeȱcontaminantesȱyȱlaȱcomparaciónȱ conȱ guíasȱ numéricasȱ (SQGs).ȱ Deȱ esteȱ modoȱ seȱ pretendíaȱ evaluarȱ elȱ riesgoȱ potencialȱdeȱlosȱcontaminantesȱasociadosȱalȱsedimentoȱ(CasadoȬMartínez,ȱ2006).ȱ Enȱ laȱ actualidadȱ seȱ hanȱ propuestoȱ determinacionesȱ basadasȱ enȱ análisisȱ químicosȱ juntoȱ conȱ ensayosȱ deȱ toxicidadȱ enȱ laboratorioȱ conȱ elȱ finȱ deȱ llevarȱ aȱ caboȱ unȱ estudioȱ deȱ losȱ procesosȱ deȱ poluciónȱ enȱ ecosistemasȱ costeros.ȱ Losȱ bioensayosȱ deȱ toxicidadȱ sonȱ instrumentosȱ queȱ seȱ empleanȱ paraȱ determinarȱ laȱ ȱ Ȭȱ29ȱȬȱ Capítuloȱ2 ecotoxicidadȱ yȱ biodisponibilidadȱ queȱ producenȱ losȱ compuestosȱ químicosȱ delȱ sedimentoȱ enȱ losȱ organismosȱ bentónicos.ȱ ȱ Enȱ esteȱ tipoȱ deȱ experimentos,ȱ losȱ organismosȱ seȱ exponenȱ aȱ muestrasȱ deȱ sedimentoȱ yȱ trasȱ unȱ periodoȱ deȱ exposiciónȱ seȱ mideȱ unaȱ respuestaȱ biológica.ȱ Estaȱ respuestaȱ haȱ deȱ serȱ sensible,ȱ relevanteȱyȱfácilȱdeȱestandarizarȱ(Stebbingȱetȱal.,ȱ1980).ȱȱ Laȱ toxicidadȱ agudaȱ haceȱ referenciaȱ alȱ efectoȱ nocivoȱ resultanteȱ deȱ unaȱ exposiciónȱ relativamenteȱ cortaȱ aȱ unaȱ sustanciaȱ tóxica.ȱ Estosȱ efectosȱ sobreȱ elȱ organismoȱ suelenȱ desarrollarseȱ rápidamenteȱ yȱ suelenȱ dejarȱ deȱ aparecerȱ enȱ elȱ momentoȱ queȱ cesaȱ laȱ dosis.ȱ Losȱ ensayosȱ deȱ toxicidadȱ agudaȱ seȱrealizanȱ enȱ unȱ periodoȱ deȱ tiempoȱ queȱ puedeȱ variarȱ deȱ minutosȱ aȱ variosȱ días,ȱ yȱ vanȱ aȱ proporcionarȱ respuestasȱ puntualesȱ (mortalidad,ȱ inhibiciónȱ delȱ crecimiento,ȱ inhibiciónȱdeȱlaȱbioluminiscencia,ȱetc.)ȱ Enȱesteȱcapítuloȱseȱpresentanȱcuatroȱtrabajosȱenȱlosȱqueȱseȱllevanȱaȱcaboȱ distintosȱ ensayosȱ deȱ toxicidadȱ agudaȱ conȱ cuatroȱ especiesȱ deȱ invertebradosȱ marinos.ȱ Enȱ losȱ primerosȱ dosȱ trabajosȱ (Iȱ yȱ II)ȱ seȱ llevaȱ aȱ caboȱ unȱ estudioȱ preliminarȱparaȱdeterminarȱlaȱtoxicidadȱdelȱfuelȱdelȱpetroleroȱPrestige.ȱParaȱelloȱ seȱ realizaronȱ unaȱ serieȱ deȱ dilucionesȱ deȱ fuelȱ extraídoȱ delȱ barcoȱ hundidoȱ conȱ sedimentoȱlimpioȱprocedenteȱdeȱlaȱBahíaȱdeȱCádiz,ȱdeȱformaȱqueȱseȱobtuvieronȱ distintasȱ concentracionesȱ deȱ fuelȱ enȱ sedimento.ȱ Enȱ elȱ trabajoȱ Iȱ seȱ efectuaronȱȱ exposicionesȱconȱelȱanfípodoȱAmpeliscaȱbrevicornisȱyȱtrasȱunȱperiodoȱdeȱdiezȱdíasȱ seȱ contabilizóȱ laȱ mortalidadȱ enȱ cadaȱ unaȱ deȱ lasȱ diluciones.ȱ Losȱ resultadosȱ obtenidosȱpermitieronȱllevarȱaȱcaboȱelȱcálculoȱdelȱLC50,ȱparámetroȱtoxicológicoȱ queȱindicaȱlaȱconcentraciónȱdeȱsustanciaȱcapazȱdeȱproducirȱunaȱmortalidadȱdelȱ 50ȱ%.ȱLosȱanfípodosȱsonȱutilizadosȱdeȱmaneraȱhabitualȱenȱtestsȱdeȱtoxicidadȱyȱseȱ correlacionanȱpositivamenteȱconȱcambiosȱenȱlasȱcomunidadesȱbentónicas.ȱȱ Enȱelȱsegundoȱtrabajoȱ(II)ȱseȱllevóȱaȱcaboȱunaȱexposiciónȱsimilarȱaunqueȱ estaȱ vezȱ conȱ elȱ poliquetoȱ Arenicolaȱ marinaȱ yȱ seȱ calculóȱ elȱ LC50ȱ trasȱ 10ȱ díasȱ deȱ - 30 - Contaminaciónȱyȱtoxicidadȱagudaȱȱ exposiciónȱyȱunȱsegundoȱLC50ȱpasadosȱ21ȱdías;ȱademásȱseȱdeterminóȱelȱfactorȱ deȱ bioacumulaciónȱ (BCF)ȱ paraȱ PAHsȱ aȱ partirȱ deȱ laȱ relaciónȱ entreȱ laȱ concentraciónȱ deȱ contaminanteȱ enȱ elȱ organismoȱ frenteȱ aȱ laȱ concentraciónȱ delȱ mismoȱenȱelȱsedimento.ȱElȱpoliquetoȱArenicolaȱmarinaȱmostróȱserȱmenosȱsensibleȱ frenteȱaȱlaȱcontaminaciónȱorgánicaȱqueȱelȱanfípodoȱAmpeliscaȱbrevicornisȱaunqueȱ aȱsuȱvezȱpresentaȱlaȱcapacidadȱdeȱhabitarȱenȱzonasȱpolucionadasȱofreciendoȱlaȱ posibilidadȱdeȱllevarȱaȱcaboȱestudiosȱdeȱbioacumulación.ȱ Tablaȱ 2.1.ȱ Relaciónȱ deȱ bioensayosȱ agudosȱ realizadosȱ paraȱ laȱ evaluaciónȱ deȱlaȱcalidadȱdeȱlosȱsedimentosȱ(adaptadoȱdeȱCasadoȬMartínezȱetȱal.,ȱ2006).ȱ Bioensayoȱ Especieȱ Medidaȱfinalȱ Rutaȱdeȱ exposiciónȱ Tiempoȱdeȱ exposiciónȱ Lixiviadoȱ 5ȱȬȱ30ȱ minutosȱ Inhibiciónȱdeȱlaȱ Microtox®ȱȱȱȱ Vibrioȱfischeriȱ bioluminescenciaȱ (IC50)ȱ Anfípodosȱ Ampeliscaȱbrevicornisȱ supervivenciaȱ Faseȱsólidaȱ 10ȱdíasȱ Anfípodosȱ Corophiumȱvolutatorȱ supervivenciaȱ Faseȱsólidaȱ 10ȱdíasȱ Poliquetosȱ Arenicolaȱmarinaȱ Supervivenciaȱyȱ bioacumulaciónȱ Faseȱsólidaȱ 10ȱ–ȱ15ȱdíasȱ Elȱ tercerȱtrabajoȱ (III)ȱ muestraȱlaȱprimeraȱaproximaciónȱalȱestudioȱdeȱlosȱ sedimentosȱdeȱlaȱBahíaȱdeȱAlgecirasȱyȱelȱParqueȱNacionalȱdeȱlasȱIslasȱAtlánticasȱ enȱ Galicia.ȱ 14ȱ puntosȱ deȱ muestreosȱ fueronȱ evaluadosȱ juntoȱ aȱ dosȱ controlesȱ (negativoȱ yȱ positivo)ȱ medianteȱ elȱ usoȱ deȱ unaȱ caracterizaciónȱ físicoȱ químicaȱ deȱ losȱ sedimentosȱ yȱ suȱ relaciónȱ conȱ resultadosȱ deȱ dosȱ ensayosȱ deȱ toxicidad:ȱ Microtox®ȱ ȱ ȱ yȱ elȱ testȱ deȱ 10ȱ díasȱ conȱ elȱ anfípodoȱ Corophiumȱ volutator.ȱ Elȱ testȱ Microtox®ȱseȱbasaȱenȱlaȱmediciónȱdeȱlaȱemisiónȱdeȱluzȱdeȱunaȱbacteriaȱmarinaȱ Vibrioȱ fischeri,ȱ laȱ cualȱ seȱ exponeȱ aȱ unaȱ serieȱ deȱ dilucionesȱ deȱ unaȱ muestraȱ deȱ sedimento.ȱ Laȱ bioluminiscenciaȱ esȱ directamenteȱ proporcionalȱ alȱ estadoȱ metabólicoȱdeȱlaȱcélula;ȱcuandoȱlaȱbacteriaȱseȱexponeȱaȱunaȱsustanciaȱtóxica,ȱelȱ Ȭ 31ȱȬ Capítuloȱ2 cuerpoȱcelularȱsufreȱalgunosȱcambiosȱdeȱformaȱqueȱlaȱbioluminiscenciaȱemitidaȱ disminuye.ȱElȱ testȱ evalúaȱlaȱ disminuciónȱdeȱlaȱbioluminiscenciaȱdespuésȱdeȱlaȱ exposiciónȱ deȱ losȱ organismosȱ alȱ sedimento,ȱ deȱ formaȱ queȱ losȱ resultadosȱ obtenidosȱ seȱ expresanȱ enȱ términosȱ deȱ laȱ concentraciónȱ efectivaȱ deȱ unaȱ determinadaȱ sustanciaȱ presenteȱ enȱ elȱ medioȱ queȱ produceȱ unaȱ reducciónȱ deȱ laȱ emisiónȱdelȱluzȱdelȱmicroorganismoȱdelȱ50%ȱ(IC50).ȱLaȱNormativaȱCanadienseȱ estableceȱqueȱunaȱmuestraȱesȱtóxicaȱcuandoȱelȱvalorȱdeȱIC50ȱesȱmenorȱdeȱ1000ȱ mgȱ LȬ1ȱ pesoȱ secoȱ yȱ noȱ tóxicaȱ cuandoȱ elȱ medidoȱ esȱ mayorȱ deȱ 1000ȱ mgȱ LȬ1ȱ pesoȱ seco.ȱPorȱsuȱparte,ȱelȱCentroȱdeȱEstudiosȱyȱExperimentaciónȱdeȱObrasȱPúblicasȱ (CEDEX)ȱdefineȱunaȱmuestraȱcomoȱtóxicaȱcuandoȱIC50ȱesȱmenorȱdeȱ750mgȱLȬ1ȱ pesoȱ secoȱ yȱ noȱ tóxicaȱ cuandoȱ ésteȱ esȱ mayorȱ deȱ 750ȱ mgȱ LȬ1.ȱ Tambiénȱ existenȱ distintosȱ criteriosȱ paraȱ considerarȱ aȱ unaȱ muestraȱ comoȱ tóxicaȱ enȱ funciónȱ delȱ resultadoȱ obtenidoȱ enȱ elȱ testȱ agudoȱ realizadoȱ conȱ anfípodos.ȱ Todosȱ estosȱ criteriosȱ utilizanȱ elȱ valorȱ delȱ porcentajeȱ deȱ mortalidadȱ deȱ anfípodosȱ queȱ seȱ obtieneȱ restandoȱ aȱ 100ȱ elȱ valorȱ delȱ porcentajeȱ deȱ supervivenciaȱ observado.ȱ Enȱ esteȱsentidoȱsonȱdiversosȱlosȱpaísesȱqueȱincluyenȱesteȱtestȱdentroȱdeȱlasȱbateríasȱ paraȱ establecerȱ laȱ nocividadȱ deȱ muestrasȱ deȱ sedimentosȱ y/oȱ materialȱ deȱ dragado.ȱ Entreȱ ellosȱ cabeȱ destacarȱ laȱ Normativaȱ Holandesa,ȱ establecidaȱ porȱ elȱ MinisterioȱdeȱfomentoȱHolandésȱqueȱconsideraȱqueȱunaȱmuestraȱdeȱsedimentoȱ esȱtóxicaȱsiȱlaȱmortalidadȱdeȱlaȱespecieȱCorophiumȱvolutatorȱesȱigualȱoȱmayorȱdelȱ 25%.ȱPorȱsuȱparte,ȱlaȱNormativaȱInglesaȱconsideraȱque,ȱparaȱestaȱmismaȱespecieȱ deȱanfípodo,ȱlaȱmortalidadȱdeȱlaȱpoblaciónȱexpuestaȱhaȱdeȱserȱigualȱoȱmayorȱalȱ 40%ȱ paraȱ queȱ laȱmuestraȱ deȱ sedimentoȱ seaȱconsideradaȱ tóxica.ȱ ȱ Laȱ Normativaȱ paraȱelȱáreaȱdeȱHongȱKongȱutilizaȱunaȱespecieȱdeȱanfípodosȱnoȱdetalladaȱenȱlosȱ testȱdeȱtoxicidad,ȱyȱproponeȱqueȱlaȱmortalidadȱdeȱlosȱindividuosȱhaȱdeȱserȱigualȱ oȱ mayorȱ alȱ 30%ȱ paraȱ considerarȱ queȱ existeȱ toxicidad.ȱ Porȱ otraȱ parte,ȱ existenȱ normativasȱdondeȱnoȱseȱproponenȱunȱúnicoȱvalorȱindicativoȱsinoȱqueȱseȱutilizaȱ unȱ dobleȱ criterio,ȱ incluyendoȱ unȱ valorȱ observadoȱ yȱ unȱ criterioȱ estadístico.ȱ Enȱ esteȱ sentido,ȱ laȱ Normativaȱ Estadounidense,ȱ elaboradaȱ porȱ laȱ Environmentalȱ - 32 - Contaminaciónȱyȱtoxicidadȱagudaȱȱ Protectionȱ Agencyȱ (USEPA)ȱ yȱ elȱ cuerpoȱ deȱ ingenierosȱ delȱ Ejércitoȱ Americano,ȱ utilizaȱ laȱ especieȱ Ampeliscaȱ abditaȱ yȱ estableceȱ comoȱ criterioȱ deȱ toxicidadȱ unaȱ mortalidadȱ superiorȱ alȱ 20%ȱ conȱ respectoȱ alȱ sedimentoȱ deȱ referenciaȱ yȱ ademásȱ significativamenteȱ diferenteȱ (p<0.05)ȱ delȱ control.ȱ Elȱ Centroȱ deȱ Estudiosȱ yȱ ExperimentaciónȱdeȱObrasȱPúblicasȱ(CEDEX)ȱproponeȱesteȱmismoȱcriterioȱdobleȱ paraȱ clasificarȱ lasȱ muestrasȱ deȱ sedimentoȱ comoȱ tóxicasȱ oȱ noȱ tóxicasȱ paraȱ elȱ litoralȱ español.ȱ Losȱ resultadosȱ deȱ esteȱ trabajoȱ muestranȱ lasȱ diferenciasȱ entreȱ ambasȱ zonasȱ deȱ estudioȱ yȱ determinaȱ queȱ laȱ Bahíaȱ deȱ Algecirasȱ presentaȱ unaȱ degradaciónȱambientalȱmayorȱqueȱaquellaȱobservadaȱenȱlasȱcostasȱgallegas.ȱ Enȱelȱúltimoȱtrabajoȱ(IV)ȱdeȱesteȱsegundoȱcapítulo,ȱseȱaplicanȱlosȱtestȱdeȱ toxicidadȱanteriormenteȱdescritos:ȱanfípodos,ȱMicrotox®ȱyȱArenicolaȱmarinaȱparaȱ evaluarȱ laȱ toxicidadȱ deȱ sedimentosȱ muestreadosȱ enȱ lasȱ costasȱ gallegasȱ cuatroȱ añosȱ despuésȱ delȱ vertidoȱ delȱ petroleroȱ Prestige.ȱ Parteȱ deȱ esteȱ estudio,ȱ enȱ concretoȱlosȱanálisisȱdeȱbioacumulaciónȱdeȱPAHsȱenȱelȱpoliquetoȱA.ȱmarina,ȱseȱ realizaronȱduranteȱunaȱestanciaȱenȱelȱcentroȱIPIMARȱenȱLisboa.ȱLosȱresultadosȱ indicanȱ unaȱ disminuciónȱ deȱ laȱ contaminaciónȱconȱrespectoȱaȱestudiosȱprevios,ȱ asíȱ comoȱ unaȱ desapariciónȱ deȱ laȱ toxicidadȱ agudaȱ aunqueȱ unaȱ importanteȱ bioacumulaciónȱ deȱ PAHsȱ fueȱ detectadaȱ principalmenteȱ enȱ elȱ áreaȱ deȱ CormeȬ Laxe,ȱloȱqueȱsugiereȱqueȱaȱpesarȱdeȱqueȱlaȱcalidadȱambientalȱseȱhaȱrecuperadoȱ deȱformaȱnotable,ȱexisteȱlaȱposibilidadȱdeȱefectosȱsubletalesȱenȱlaȱbiota.ȱȱȱȱ Bibliografíaȱ AZURȱ(1998a).ȱBasicȱSolidȬPhaseȱTestȱ(Basicȱ SPT).ȱ 16ȱ p.,ȱ AZURȱ Environmental,ȱ Carlsbad,ȱCA.ȱ Burton,ȱG.A.,ȱDenton,ȱD.L.,ȱHo,ȱK.,ȱIreland,ȱ D.S.ȱ 2003.ȱ Sedimentȱ Toxicityȱ Testing:ȱ IssuesȱandȱMethods.ȱIn:ȱTheȱHandbookȱofȱ Ecotoxicology.ȱEd.ȱLewisȱpublishers.ȱ AZURȱ (1998b).ȱ SolidȬPhaseȱ Testȱ (SPT).ȱ 19ȱ p.,ȱAZURȱEnvironmental,ȱCarlsbad,ȱCA.ȱ CasadoȬMartínez,ȱ C.ȱ 2006.ȱ Caracterizaciónȱ deȱ materialȱ deȱ dragadoȱ optimizandoȱ unȱ Ȭ 33ȱȬ Capítuloȱ2 MoralesȬCaselles,ȱC.ȱ2005.ȱEvaluaciónȱdeȱlaȱ contaminaciónȱ yȱ susȱ efectosȱ enȱ sedimentosȱ delȱ Parqueȱ Nacionalȱ deȱ lasȱ Islasȱ Atlánticasȱ (Galicia)ȱ asociadosȱ conȱ elȱ vertidoȱ delȱ petroleroȱ Prestige.ȱ Tesisȱ deȱ Licenciatura.ȱ121ȱpp.ȱ métodoȱ integradoȱ deȱ evaluaciónȱ deȱ laȱ calidadȱambiental.ȱTesisȱDoctoral.ȱȱ CEDEX.ȱ 1994.ȱ Recomendacionesȱ paraȱ laȱ gestiónȱ deȱ losȱ materialesȱ deȱ dragadoȱ enȱ losȱ puertosȱ españolesȱ (RMDM),ȱ MinisterioȱdeȱObrasȱPúblicas,ȱTransportesȱ yȱMedioȱAmbiente,ȱMadrid,ȱSpain,ȱ45pp.ȱ Stebbing,ȱ A.R.D.,ȱ Akesson,ȱ B.,ȱ Calabresse,ȱ A.,ȱ Gentile,ȱ J.H.,ȱ Jensen,ȱ A.,ȱ Lloyd,ȱ R.ȱ 1980.ȱ Theȱ roleȱ ofȱ bioassaysȱ inȱ marineȱ pollutionȱmonitoringȱbioassay.ȱPanelȱRepȱ Rappȱ PȬVȱ Reunȱ Consȱ Intȱ Explorȱ Merȱ 179:322–332.ȱ CEDEX.ȱ 2003.ȱ Investigaciónȱ conjuntaȱ sobreȱ laȱ selecciónȱ yȱ puestaȱ aȱ puntoȱ deȱ ensayosȱ biológicosȱ paraȱ laȱ caracterizaciónȱ deȱ materialȱ deȱ dragado.ȱ Informeȱ finalȱ deȱ laȱ UniversidadȱdeȱCádiz.128pp.ȱ USEPA,ȱ 2000.ȱ Toxicȱ Releaseȱ Inventoryȱ Publicȱ Dataȱ Release,ȱ hppt://www.epa.gov/triinter/tridata/index.htm,ȱ Officeȱ ofȱ Environmentalȱ Information,ȱ Unitedȱ Statesȱ Environmentalȱ Protectionȱ Agency,ȱWashington,ȱD.C.ȱ Environmentalȱ Canada.ȱ 2003.ȱ Canadianȱ EnvironmentalȱQualityȱGuidelines.ȱ Long,ȱ E.R.,ȱ Buchman,ȱ M.F.ȱ 1989.ȱ Anȱ evaluationȱ ofȱ candidateȱ measuresȱ ofȱ biologicalȱ effectsȱ forȱ theȱ Nationalȱ Statusȱ andȱ Trendsȱ Program.ȱ NOAAȱ Technicalȱ Memorandumȱ NOSȱ OMAȱ 45.ȱ Nationalȱ Oceanicȱ andȱ Atmosphericȱ Administration.ȱ Seattle,ȱ Washington.ȱ 105pp.ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ - 34 - Acuteȱtoxicityȱofȱresidualȱfuelȱoilȱfromȱtheȱtankerȱ“Prestige”ȱusingȱ amphipodsȱ MoralesȬCaselles,ȱC.ȱ1,2,*,ȱRiba,ȱI.ȱ1,2;ȱSarasquete,ȱC.1,ȱDelValls,ȱT.A.1,2ȱ 1 ȱUnidadȱAsociadaȱdeȱCalidadȱAmbientalȱyȱPatologíaȱ(CSICȱ&ȱUCA)ȱinstitutoȱdeȱ CienciasȱMarinasȱdeȱAndalucíaȱ(ICMANȬCSIC),ȱAvda.ȱRepúblicaȱSaharauiȱs/n,ȱPuertoȱ Realȱ11510,ȱCádiz,ȱSpainȱ UNESCOȱUNITWIN/WiCop,ȱFacultadȱdeȱCienciasȱdelȱMarȱyȱAmbientales,ȱ 2ȱ UniversidadȱdeȱCádiz,ȱPolígonoȱRíoȱSanȱPedroȱs/n,ȱPuertoȱRealȱ11510,ȱCádiz,ȱSpain.ȱ Abstractȱ Inȱ Novemberȱ 2002,ȱ theȱ simpleȱ hullȱ tankerȱ “Prestige”ȱ sinkedȱ inȱ theȱ GalicianȱCoastȱ(NWȱSpain)ȱandȱspiltȱ63,000ȱTonsȱofȱfuelȱoil.ȱTwoȱyearsȱafterȱtheȱ spill,ȱ theȱ remaindingȱ oilȱ hasȱ beenȱ extractedȱ fromȱ theȱ hullȱ andȱ hasȱ beenȱ physicochemicallyȱ andȱ ecotoxicologicallyȱ characterized.ȱ Anȱ acuteȱ bioassayȱ usingȱ theȱ amphipodȱ Ampeliscaȱ brevicornisȱ hasȱ beenȱ carriedȱ outȱ inȱ orderȱ toȱ determineȱ toxicityȱ associatedȱ withȱ theȱ contaminantsȱ presentsȱ inȱ theȱ fuel.ȱ Theȱ bioassayȱ wasȱ conductedȱ byȱ exposingȱ duringȱ 10ȱ daysȱ theȱ individualsȱ ofȱ Ampeliscaȱtoȱcleanȱsedimentȱmixedȱwithȱdifferentȱproportionsȱofȱfuelȱoilȱ(0.1%,ȱ 0.5%,ȱ 2%,ȱ 8%,ȱ 16%ȱ andȱ 32%).ȱ Resultsȱ wereȱ linkedȱ withȱ theȱ chemicalȱ dataȱ inȱ orderȱ toȱ determineȱ theȱ sensitivityȱ ofȱtheȱamphipodȱtoȱtheȱfuelȱoilȱcompounds.ȱ TheȱLC50ȱvalueȱobtainedȱforȱAmpeliscaȱbrevicornisȱ(1.37%ȱ±ȱ0.33)ȱandȱtheȱPAHsȱ concentrationsȱ measuredȱ inȱ theȱ fuelȱ oilȱ haveȱ permittedȱ toȱ calculateȱ theȱ Sedimentȱ Qualityȱ Valuesȱ (SQVs)ȱ thatȱ areȱ similarȱ fromȱ thoseȱ obtainedȱ fromȱ previousȱ studiesȱ corroboratingȱ thatȱ theȱ acuteȱ toxicityȱ ofȱ theȱ fuelȱ oilȱ itȱ wasȱ mainlyȱassociatedȱwithȱtheȱconcentrationȱofȱPAHs.ȱ Keywords:ȱ PAHs,ȱ Ampeliscaȱ brevicornis,ȱ qualityȱ values,ȱ bioassay,ȱ sedimentȱ toxicity,ȱ sedimentȱdilution.ȱ EnvironmentalȱToxicologyȱ(enviado)ȱ - 35 - 1.ȱIntroductionȱ Onȱ 13thȱ Novemberȱ 2002ȱ theȱ tankerȱ Prestigeȱ brokedownȱ inȱ theȱ Galicianȱ Coastȱ(NWȱSpain)ȱandȱsankȱsixȱdaysȱlaterȱinȱwaterȱ3,500ȱmetresȱdeep.ȱInȱall,ȱitȱisȱ estimatedȱthatȱtheȱPrestigeȱspiltȱ63,000ȱtonnesȱofȱheavyȱfuelȱoilȱleadingȱtoȱoneȱofȱ theȱ greatestȱ ecologicalȱ catastropheȱ inȱ Spain.ȱ Onȱ Septemberȱ 2004ȱ theȱ 58,000ȱ tonnesȱofȱremainingȱfuelȱthatȱwereȱstillȱinȱtheȱtankerȱwereȱfinallyȱcollected.ȱȱ Theȱ compositionȱ ofȱ thisȱ fuelȱ wasȱ aȱ mixtureȱ ofȱ saturatedȱ hydrocarbons,ȱ aromaticȱ hydrocarbons,ȱ resinsȱ andȱ asphaltenes,ȱ beingȱ mostȱ ofȱ theȱ polycyclicȱ aromaticȱ hydrocarbonsȱ ȬPAHsȬȱ ofȱ anȱ intermediumȬhighȱ molecularȱ weightȱ (Blancoȱetȱal.,ȱinȱpress).ȱTheȱphysicochemicalȱcharacteristicsȱofȱtheȱoilȱspilledȱbyȱ theȱ tankerȱ Prestigeȱ showȱ thatȱ theȱ solubleȱ fractionȱ isȱ lowȱ andȱ theȱ kineticȱ ofȱ degradationȱ isȱ slowȱ underȱ naturalȱ conditionsȱ soȱ itȱ isȱ expectedȱ toȱ beȱ accumulatedȱ inȱ sedimentsȱ (CSICȱ 2003).ȱ Theȱ biologicalȱ effectsȱ associatedȱ withȱ theȱ chemicalsȱ fromȱ theȱ oilȱ spillȱ willȱ beȱ dependentȱ onȱ theȱ natureȱ ofȱ theȱ ecosystemȱthatȱacceptsȱthemȱandȱtheȱorganismsȱlivingȱinȱitȱ(DelVallsȱ2003).ȱTheȱ firstȱresearchȱnotesȱaboutȱtheȱearlyȱimpactȱsupportȱthatȱtheȱacuteȱtoxicityȱofȱtheȱ weatheredȱ fuelȱ (MariñoȬBalsaȱ 2003),ȱ veryȱ richȱ inȱ highȱ molecularȱ weightȱ compounds,ȱwasȱrelativelyȱlowȱforȱtheȱorganismsȱtestedȱ(clamsȱandȱmicroalga).ȱ Theȱ Polycyclicȱ aromaticȱ hydrocarbonsȱ (PAHs)ȱ withȱ intermediateȱ toȱ highȱ molecularȱ weightȱ doȱ notȱ usuallyȱ showȱ severeȱ toxicityȱ withinȱ theirȱ solubilityȱ limitsȱ inȱ water.ȱ However,ȱ itȱ isȱ necessaryȱ toȱ noteȱ thatȱ someȱ PAHsȱ canȱ becomeȱ moreȱdangerousȱdueȱtoȱtheirȱphotomodification.ȱThisȱisȱparticularlyȱdangerousȱ forȱorganismsȱlivingȱinȱtheȱintertidalȱzoneȱorȱnearȱtheȱwaterȱsurfaceȱ(Carballeiraȱ 2003).ȱReportedȱresponsesȱofȱinfaunaȱafterȱanȱoilȱspillȱincludeȱveryȱhighȱinitialȱ mortalitiesȱ inȱ speciesȱ sensitiveȱ toȱ hydrocarbons,ȱ suchȱ asȱ crustaceansȱ andȱ especiallyȱamphipods,ȱandȱtheirȱsubsequentȱdisappearanceȱ(Pearsonȱetȱal.ȱ1978;ȱ Sandersȱetȱal.ȱ1980;ȱGlémarecȱandȱHussenotȱ1982;ȱGrayȱandȱPearsonȱ1982).ȱ - 36 - Sedimentȱ toxicityȱ testsȱ provideȱ informationȱ onȱ theȱ toxicityȱ ofȱ contaminatedȱsedimentsȱthatȱcanȱbeȱneitherȱderivedȱfromȱchemicalȱanalysisȱnorȱ fromȱecologicalȱsurveysȱperformedȱaloneȱ(ChapmanȱandȱLongȱ1983;ȱLongȱandȱ Chapmanȱ 1985).ȱ Theȱ speciesȱ ofȱ organismsȱ usedȱ inȱ theȱ sedimentȱ toxicityȱ testsȱ shouldȱprovideȱanȱappropriateȱindicationȱofȱtheȱhazardsȱofȱchemicalȱstressorsȱinȱ theȱsedimentȱ(Chapmanȱetȱal.ȱ2002).ȱAmphipodsȱareȱgenerallyȱacknowledgedȱasȱ theȱ organism’sȱ choiceȱ forȱ manyȱ sedimentȱ toxicityȱ assessments,ȱ andȱ amphipodȱ toxicityȱ testȱ resultsȱ canȱ correlateȱ positivelyȱ withȱ changesȱ inȱ benthicȱ communitiesȱ(Longȱetȱal.ȱ2001;ȱMarínȬGuiraoȱetȱal.ȱ2005).ȱ TheȱaimȱofȱthisȱworkȱisȱtoȱassesȱtheȱsensibilityȱofȱtheȱamphipodȱAmpeliscaȱ brevicornisȱtoȱtheȱcontaminationȱassociatedȱwithȱtheȱremainentȱfuelȱoilȱcollectedȱ fromȱtheȱtankerȱPrestigeȱonȱseptemberȱ2004ȱandȱtoȱstablishȱtheȱusefulnessȱofȱtheȱ toxicȱresponseȱmeasuredȱforȱfurtherȱmanagementȱofȱsedimentsȱcontaminatedȱbyȱ theȱ oilȱ spillȱ andȱ inȱ generalȱ byȱ organicȱ pollutants.ȱ Inȱ orderȱ toȱ reachȱ theseȱ objetives,ȱ aȱ bioassayȱ wasȱ conductedȱ exposingȱ aȱ populationȱ ofȱ theȱ amphipodȱ Ampeliscaȱbrevicornisȱtoȱdifferentȱdilutionsȱofȱfuelȱoilȱwithȱcleanȱsediment.ȱ 2.ȱMaterialȱandȱmethodsȱ 2.1.ȱApproachȱ Theȱ presentȱ studyȱ wasȱcarriedȱoutȱusingȱsixȱdifferentȱ sedimentȱdilutionȱ ofȱ fuelȱ oil.ȱ Theȱ oilȱ usedȱ wasȱ extractedȱ fromȱ theȱ remainingȱ fuelȱ ofȱ theȱ tankerȱ Prestigeȱ(Septemberȱ2004)ȱandȱwasȱmixedȱwithȱcleanȱsedimentȱfromȱtheȱBayȱofȱ Cádizȱ(0.1%,ȱ0.5%,ȱ2%,ȱ8%,ȱ16%ȱandȱ32ȱ%ȱȬȱdryȱweightȱofȱfuelȱoilȬ)ȱthatȱwasȱalsoȱ usedȱasȱnegativeȱcontrolȱ(BC).ȱCleanȱsedimentȱwasȱcollectedȱinȱaȱpristineȱareaȱofȱ theȱBayȱofȱCádizȱ(Ribaȱetȱal.ȱ2003)ȱandȱwasȱfilteredȱ(0.6ȱmm)ȱpriorȱtoȱtheȱtoxicityȱ testȱ inȱ orderȱ toȱ removeȱ meansȱ interferencesȱ asȱ shells,ȱ predatorsȱ andȱ otherȱ - 37 - residues.ȱ Theseȱ sedimentsȱ wereȱ driedȱ andȱ homogenizedȱ atȱ roomȱ temperatureȱ priorȱtoȱchemicalȱanalysis.ȱ IndividualsȱofȱtheȱspecieȱAmpeliscaȱbrevicornisȱusedȱinȱtheȱbioassayȱwereȱ collectedȱfromȱtheȱcleanȱsedimentȱ(negativeȱcontrol)ȱlocatedȱinȱtheȱintermarealȱ zoneȱofȱ theȱBayȱ ofȱ Cádiz,ȱbyȱsievingȱtheȱsedimentȱthroughȱaȱ0.6ȱmmȱ mesh,ȱasȱ reportedȱ byȱ Ribaȱ etȱ al.ȱ (2003).ȱ Theyȱ wereȱ inmediatelyȱ transportedȱ toȱ theȱ laboratoryȱ whereȱ theyȱ wereȱ placedȱ inȱ 11ȱ litersȱ aquariumsȱ withȱ cleanȱ seawaterȱ andȱsievedȱsedimentȱfromȱtheȱsameȱlocation.ȱAirationȱwasȱprovidedȱandȱnaturalȱ photoperiodȱwasȱselected.ȱDuringȱacclimatationȱtheȱorganismsȱwereȱfedȱtwiceȱaȱ weekȱ withȱ aȱ specialȱ foodȱ forȱ invertebratesȱ (mixtureȱ madeȱ ofȱ aminoacidsȱ andȱ organicȱparticles)ȱandȱwaterȱwasȱreplaced.ȱ 2.2.ȱChemicalȱanalysisȱofȱsedimentsȱ Forȱ traceȱ metalȱ analysisȱ (Ni,ȱ V,ȱ Cd,ȱ Pb,ȱ Cr,ȱ Co)ȱ theȱ sedimentȱ wasȱ digestedȱ asȱ describedȱ byȱ Loringȱ andȱ Rantalaȱ (1992).ȱ Traceȱ metalsȱ wereȱ measuredȱ byȱ graphiteȱ furnaceȱ atomicȱ absorptionȱ spectrophotometryȱ (Perkin– Elmerȱ4100ȱZL)ȱ(CobeloȬGarcíaȱetȱal.ȱ2005)ȱResultsȱareȱexpressedȱasȱmgkgȬ1ȱdryȱ sediment.ȱ Theȱ analyticalȱ proceduresȱ wereȱ checkedȱ usingȱ referenceȱ materialȱ (MESSȬ1ȱ NRCȱ andȱ CRMȱ 277ȱ BCR)ȱ andȱ showedȱ agreementȱ withȱ theȱ certifiedȱ valuesȱhigherȱthanȱ90%.ȱ Polycyclic aromatic hydrocarbons (Fluorene, Acenaphthene, Naphthalene, Phenanthrene, Anthracene, Fluoranthene, Pyrene, Benzo[a]anthracene, Chrysene, Benzofluoranthene, Benzo[e]pyrene, Benzo[a]pyrene, Perilene, Dibenzo[ah]anthracene, Indene[123-cd]pyrene, Benzo[ghi]perilene) were analyzed by using a gas chromatography equipped with an electron capture detector (GC/MS) (U.S. Environmental Protection Agency SW-846 Method 8270) (USEPA 1984). Briefly, dried samples were soxhlet extracted with n-hexane for 18 h, and the extracts were isolated by column chromatography on Florisil-alumino-silica. PAHs were eluted and their - 38 - fractions were dried in a rotatory evaporator and re-dissolved in isooctane. Aromatic fractions were analyzed on a Hewlett–Pakard (HP) 5890 Series II gas chromatograph coupled with HP 5970 mass spectrometer. Chromatographic resolution was achieved with a 30 m × 0.250 mm DB-5 capillary column, which has a 0.25 µm film thickness, with helium as carrier gas. Quality control was carried out using NRC-CNRC HS-6 sediment reference material. The analytical procedure allow agreement with the certified values higher than 90%.ȱ 2.3.ȱToxicityȱtestȱ Theȱtoxicityȱtestȱwasȱperformedȱexposingȱindividualsȱofȱtheȱamphipodsȱ Ampeliscaȱbrevicornisȱtoȱbulkȱsedimentȱusingȱtheȱpercentageȱofȱsurvivalȱafterȱtenȱ daysȱ ofȱ exposureȱ asȱ theȱ endȱ pointȱ (ASTMȱ 1993).ȱ Theȱ dilutionsȱ withȱ cleanȱ sedimentȱandȱfuelȱoilȱ(0.1%,ȱ0.5%,ȱ2%,ȱ8%,ȱ16%ȱandȱ32%ȱȬdryȱweightȱofȱfuelȱoilȬ)ȱ andȱtheȱnegativeȱcontrolȱ(200ȱg)ȱwereȱplacedȱinȱ2ȱLȱglassȱbeakersȱandȱaboutȱ800ȱ mLȱ ofȱ cleanȱ seawaterȱ wereȱ added.ȱ Whenȱ theȱ sedimentȱ settledȱ downȱ inȱ theȱ beakers,ȱaerationȱwasȱprovided,ȱandȱ12ȱhoursȱafterȱtheȱindividualsȱwereȱsievedȱ fromȱtheȱacclimatizationȱaquariumsȱandȱ20ȱadultsȱ(3Ȭ5ȱmm)ȱofȱAmpeliscaȱwhereȱ placedȱ inȱ eachȱ replicate.ȱ Noȱ foodȱ wasȱ providedȱ duringȱ theȱ experiment.ȱ Theȱ containersȱwhereȱkeptȱinȱanȱincubatorȱwithȱphotoperiodȱ12hȬlight/12hȬdarkȱandȱ mantainedȱ atȱ 19ȱ ±ȱ 1ȱ ºCȱ duringȱ theȱ 10ȱ daysȱ ofȱ exposure.ȱ Afterȱ thatȱ time,ȱ theȱ beakersȱwhereȱsievedȱandȱtheȱsurvivalȱwasȱcountedȱinȱeachȱreplicate.ȱ ȱ 2.4.ȱDataȱcalculationȱ TheȱmortalityȱofȱAmpeliscaȱbrevicornisȱmeasuredȱafterȱ10ȱdaysȱofȱexposureȱ timeȱ wasȱ usedȱ toȱ deriveȱ aȱ toxicȱ parameterȱ (LC50)ȱ associatedȱ withȱ theȱ fuelȱ oil.ȱ Fromȱ theȱ toxicȱ responsesȱ (mortality)ȱ obtainedȱ duringȱ theȱ exposureȱ toȱ theȱ differentȱ dilutionsȱ (0.1%,ȱ 0.5%,ȱ 2%,ȱ 8%,ȱ 16%ȱ andȱ 32%)ȱ wasȱ definedȱ theȱ concentrationȱ(percentageȱofȱdryȱweightȱofȱfuelȱoil)ȱthatȱprovokesȱtheȱmortalityȱ - 39 - ofȱ theȱ 50%ȱ ofȱ theȱ Ampeliscaȱ brevicornisȱ populationȱ exposed.ȱ Theȱ LC50ȱ wasȱ calculatedȱbyȱlinearȱregressionsȱofȱlogȱtoxicantȱdilutionȱofȱfuelȱoilȱonȱdecliningȱ probitȱvaluesȱ(probitȬanalysisȬprogram,ȱversionȱ1.5).ȱȱ Sedimentȱqualityȱvaluesȱ(SQVs)ȱhaveȱbeenȱcalculatedȱinȱorderȱtoȱidentifyȱ theȱ concentrationȱ ofȱ PAHsȱ (Fluorene,ȱ Acenaphthene,ȱ Naphthalene,ȱ Phenanthrene,ȱ Anthracene,ȱ Fluoranthene,ȱ Pyrene,ȱ Benzo[a]anthracene,ȱ Chrysene,ȱ Benzofluoranthene,ȱ Benzo[e]pyrene,ȱ Benzo[a]pyrene,ȱ Perilene,ȱ Dibenzo[ah]anthracene,ȱ Indene[123Ȭcd]pyrene,ȱ Benzo[ghi]perilene)ȱ responsibleȱ ofȱtheȱtoxicityȱassociatedȱwithȱtheȱfuelȱoilȱfromȱtheȱPrestigeȱspill.ȱTheȱSQVsȱhaveȱ beenȱ calculatedȱ usingȱ theȱ LC50ȱ valuesȱ obtainedȱ andȱ theȱ concentrationȱ ofȱ individualsȱ PAHsȱ measuredȱ inȱ theȱ fuelȱ oil.ȱ Thus,ȱ theȱ SQVsȱ areȱ definedȱ asȱ theȱ concentrationȱofȱindividualȱandȱtotalȱPAHsȱassociatedȱwithȱtheȱmortalityȱofȱ50%ȱ ofȱtheȱtotalȱpopulationȱofȱamphipodsȱafterȱ10ȱdaysȱofȱexposureȱtoȱfuelȱoil.ȱȱȱȱ 3.ȱResultsȱ Tableȱ1ȱshowsȱsummarizedȱresultsȱofȱcontaminantsȱȬtotalȱandȱindividualȱ PAHsȱ andȱ traceȱ metalsȱ (Ni,ȱ V,ȱ Cd,ȱ Pb,ȱ Cr,ȱ Co)ȱ expressedȱ asȱ mgȱ KgȬ1ȱ dryȱ sedimentȬȱthatȱwereȱmeasuredȱinȱtheȱdilutionsȱofȱfuelȱoilȱȱ(0.1%,ȱ0.5%,ȱ2%,ȱ8%,ȱ 16%ȱandȱ32%ȱȬdryȱweightȱofȱfuelȱoilȬ)ȱandȱinȱtheȱnegativeȱcontrolȱ(BC).ȱ Theȱ pureȱ fuelȱ oilȱ extractedȱ fromȱ theȱ tankerȱ Prestigeȱ (Septemberȱ 2004)ȱ presentsȱaȱconcentrationȱofȱtotalȱPAHsȱofȱ1443ȱmgȱKgȬ1ȱȬdryȱweightȬ,ȱwhereasȱinȱ theȱnegativeȱcontrolȱ(BC)ȱPAHsȱwereȱnotȱdetected;ȱtherefore,ȱtheȱconcentrationȱ ofȱPAHsȱinȱtheȱdilutionsȱdependsȱonlyȱinȱtheȱpresenceȱofȱPAHsȱinȱtheȱfuelȱoil.ȱ Regardingȱtoȱtheȱcontentȱofȱtraceȱmetalsȱinȱtheȱfuelȱoilȱresultsȱshowȱthatȱlevelsȱofȱ theseȱcontaminantsȱareȱnotȱhighȱexceptȱforȱNiȱ(55ȱmgȱkgȬ1)ȱandȱVȱ(170mgȱkgȬ1).ȱȱ - 40 - ItȱasȱbeenȱobservedȱthatȱtheȱindividualsȱPAHsȱpredominantsȱinȱtheȱfuelȱ oilȱareȱNaphtaleneȱ(395ȱmgȱkgȬ1),ȱPhenantreneȱ(385ȱmgȱkgȬ1),ȱPyreneȱ(111ȱmgȱkgȬ 1 ),ȱChryseneȱ(mgȱkgȬ1),ȱFluoreneȱ(99.3ȱmgȱkgȬ1)ȱandȱAcenaphtheneȱ(75.3ȱmgȱkgȬ1).ȱȱ Tableȱ1.ȱTotalȱPAHsȱandȱmetalȱconcentrationȱinȱmgȱKgȬ1ȱȬdryȱsedimentȬȱ measuredȱinȱtheȱnegativeȱcontrolȱandȱinȱtheȱfuelȱoilȱdilutions.ȱ ȱ ȱȱ Oilȱ BCȱ 0.10%ȱ 0.50%ȱ 2%ȱ 8%ȱ 16%ȱ 32% PAHsȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ TotalȱPAHsȱ Fluoreneȱ Acenaphtheneȱ Naphthaleneȱ Phenanthreneȱ Anthraceneȱ Fluorantheneȱ Pyreneȱ Benzo[a]anthraceneȱ Chryseneȱ Benzofluorantheneȱ Benzo[e]pyreneȱ Benzo[a]pyreneȱ Perileneȱ Dibenzo[ah]anthraceneȱ Indene[123Ȭcd]pyreneȱ Benzo[ghi]perileneȱ 1443ȱ 99.3ȱ 75.3ȱ 395ȱ 385ȱ 51.4ȱ 28.5ȱ 111ȱ 55.9ȱ 102ȱ 16.0ȱ 45.7ȱ 29.7ȱ 11.4ȱ 5.70ȱ 5.23ȱ 17.1ȱ n.dȱ n.dȱ n.dȱ n.dȱ n.dȱ n.dȱ n.dȱ n.dȱ n.dȱ n.dȱ n.dȱ n.dȱ n.dȱ n.dȱ n.dȱ n.dȱ n.dȱ 0.72ȱ 0.05ȱ 0.04ȱ 0.20ȱ 0.19ȱ 0.03ȱ 0.01ȱ 0.06ȱ 0.03ȱ 0.05ȱ 0.01ȱ 0.02ȱ 0.01ȱ 0.01ȱ 0.00ȱ 0.00ȱ 0.01ȱ 3.61ȱ 0.25ȱ 0.19ȱ 0.99ȱ 0.96ȱ 0.13ȱ 0.07ȱ 0.28ȱ 0.14ȱ 0.22ȱ 0.04ȱ 0.11ȱ 0.07ȱ 0.03ȱ 0.01ȱ 0.01ȱ 0.04ȱ 14.4ȱ 0.99ȱ 0.75ȱ 3.95ȱ 3.85ȱ 0.51ȱ 0.29ȱ 1.11ȱ 0.56ȱ 9.98ȱ 0.16ȱ 0.46ȱ 0.30ȱ 0.11ȱ 0.06ȱ 0.04ȱ 0.17ȱ 57.7ȱ 3.97ȱ 3.01ȱ 15.8ȱ 15.4ȱ 2.05ȱ 1.14ȱ 4.43ȱ 2.24ȱ 3.63ȱ 0.64ȱ 1.83ȱ 1.19ȱ 0.46ȱ 0.23ȱ 0.16ȱ 0.68ȱ 115ȱ 7.95ȱ 6.03ȱ 31.6ȱ 30.8ȱ 4.11ȱ 2.28ȱ 8.86ȱ 4.48ȱ 7.12ȱ 1.28ȱ 3.65ȱ 2.37ȱ 0.91ȱ 0.46ȱ 0.32ȱ 1.37ȱ 231ȱ 15.9 12.1 63.2 61.6 8.22 4.57 17.7 8.95 14.3 2.56 7.31 4.75 1.83 0.91 0.65 2.74 Metalsȱ ȱ ȱ ȱ ȱ ȱ Niȱ Vȱ Cdȱ Pbȱ Crȱ Coȱ 55ȱ 170ȱ n.dȱ n.dȱ 0.31ȱ n.dȱ 14.1 80.0 n.dȱ 23.0 31.0 3.40 7.07ȱ 40.1ȱ n.dȱ 11.5ȱ 15.5ȱ 1.70ȱ 7.15ȱ 40.2ȱ n.dȱ 11.4ȱ 15.4ȱ 1.69ȱ 7.46ȱ 40.9ȱ n.dȱ 11.3ȱ 15.2ȱ 1.67ȱ 8.69ȱ 43.6ȱ n.dȱ 10.6ȱ 14.3ȱ 1.56ȱ 10.3ȱ 47.2ȱ n.dȱ 9.7ȱ 13.0ȱ 1.43ȱ 13.6 54.4 n.dȱ 7.80 10.6 1.16 Figureȱ1ȱshowsȱsummarizedȱresultsȱofȱtheȱamphipodsȱmortalityȱ(%)ȱafterȱ 10ȱdaysȱofȱexposureȱtoȱtheȱdifferentȱdilutionsȱofȱfuelȱoil.ȱMeanȱsurvivalȱinȱallȱtheȱ replicatesȱ ofȱ cleanȱ sedimentȱ fromȱ theȱ Bayȱ ofȱ Cádizȱ (control)ȱ wasȱ higherȱ thanȱ 95%.ȱ Theȱ mortalityȱ ofȱ Ampeliscaȱ increasesȱ withȱ theȱ %ȱ ofȱ theȱ fuelȱ oilȱ inȱ theȱ dilutions.ȱ Resultsȱ obtainedȱ atȱ theȱ lowestȱ dilutionȱ ofȱ fuelȱ oilȱ (0.1%)ȱ showȱ aȱ survivalȱ rangedȱ betweenȱ 80Ȭ100%ȱ duringȱ theȱ tenȱ daysȱ ofȱ exposure.ȱ Allȱ - 41 - replicatesȱ inȱ theȱ concentrationȱ ofȱ 0.5%ȱ ofȱ fuelȱ oilȱ indicateȱ aȱ survivalȱ ofȱ 80%ȱ inȱ thisȱdilution.ȱ Theȱ mortalityȱregisteredȱforȱtheȱdilutionȱ ofȱ2%ȱofȱfuelȱoilȱrangedȱ betweenȱ70Ȭ100%ȱwhereasȱnoȱsurvivalȱwasȱdetectedȱinȱtheȱhighestȱdilutionsȱofȱ %ȱMortality fuelȱoilȱ(8%,ȱ16ȱ%ȱandȱ32%)ȱafterȱtheȱexposureȱperiod.ȱȱ 150 100 50 0 BC 0.1% 0.5% 2% 8% 16% 32% Dilutions ȱ Figureȱ1.ȱAverageȱandȱstandardȱdeviationsȱofȱtheȱpercentageȱofȱmortalityȱ ofȱ theȱ amphipodȱ Ampeliscaȱ brevicornisȱ afterȱ 10ȱ daysȱ ofȱ exposureȱ toȱ eachȱ dilutionȱofȱfuelȱoil.ȱȱ Fromȱ theȱ mortalityȱ obtainedȱ duringȱ theȱ exposureȱ ofȱ theȱ amphipodsȱ toȱ theȱ differentȱ dilutionsȱ itȱ hasȱ beenȱ calculatedȱ theȱ percentageȱ ofȱ dryȱ weightȱ ofȱ fuelȱ oilȱ thatȱ provokesȱ theȱ mortalityȱ ofȱ theȱ 50%ȱ ofȱ theȱ Ampeliscaȱ brevicornisȱ populationȱ exposed.ȱ Theȱ lethalȱ concentrationȱ (LC50)ȱ ofȱ dryȱ weightȱ ofȱ fuelȱ oilȱ associatedȱ withȱ theȱ toxicȱ responsesȱ calculatedȱ inȱ Ampeliscaȱ brevicornisȱ isȱ 1.37±0.33ȱ(percentageȱofȱdryȱweightȱofȱfuelȱoil).ȱ Theseȱ LC50ȱ valueȱ obtainedȱ forȱ Ampeliscaȱ brevicornisȱ andȱ theȱ PAHsȱ concentrationsȱ measuredȱ inȱ theȱ fuelȱ oilȱ andȱ inȱ theȱ negativeȱ controlȱ (BC)ȱ haveȱ permittedȱ toȱ calculateȱ theȱ ȱ Sedimentȱ Qualityȱ Valuesȱ (SQVs)ȱ shownȱ inȱ tableȱ 2.ȱ TheȱSQVsȱobtainedȱforȱtheȱdifferentȱcontaminantsȱareȱcomparedȱtoȱotherȱvaluesȱ - 42 - ȱȱ PAHsȱ(ΐgȱkgȬ1)ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ Metals(mgȱkgȬ1)ȱ ȱ ȱ ȱ ȱ ȱȱ ȱȱ TotalȱPAHsȱ Fluoreneȱ Acenafphtheneȱ Naphthaleneȱ Phenanthreneȱ Anthraceneȱ Fluorantheneȱ Pyreneȱ Benzo[a]anthraceneȱ Chryseneȱ Benzofluorantheneȱ Benzo[e]pyreneȱ Benzo[a]pyreneȱ Perileneȱ Dibenzo[ah]anthracene Indene[123Ȭcd]pyreneȱ Benzo[ghi]perileneȱ Niȱ Vȱ Cdȱ Pbȱ Crȱ Coȱ Ampeliscaȱbrevicornisȱ 19790.7ȱ 1362ȱ 1033ȱ 5417ȱ 5276ȱ 705ȱ 391ȱ 1519ȱ 767ȱ 1398ȱ 219ȱ 626ȱ 407ȱ 157ȱ 78ȱ 71.7ȱ 235ȱ 7.3ȱ 40.6ȱ 0.0ȱ 11.3ȱ 15.3ȱ 1.7ȱ ERM PugetȱSoundȱAET CommencementȱBay 44792 11752±14548ȱ 16771ȱ 540ȱ 1000ȱ 707±1341ȱ 500ȱ 2000ȱ 654±1049ȱ 2100ȱ 2400ȱ 1564±1735ȱ 1500ȱ 5400ȱ 2838±4603ȱ 1100ȱ 1900ȱ 476.2±549.2ȱ 5100ȱ n.a.ȱ n.a.ȱ 2600ȱ 4300ȱ 1820±2252ȱ 1600ȱ 1600ȱ 931±1322.8ȱ 2800ȱ 2800ȱ 1363±1970ȱ n.a.ȱ n.a.ȱ n.a.ȱ n.a.ȱ n.a.ȱ n.a.ȱ 1600ȱ 2400ȱ 890±1322ȱ n.a.ȱ n.a.ȱ n.a.ȱ 260ȱ 260ȱ 183±344ȱ n.a.ȱ n.a.ȱ n.a.ȱ n.a.ȱ n.a.ȱ n.a.ȱ 51.6ȱ n.a.ȱ 41±32ȱ n.a.ȱ n.a.ȱ n.a.ȱ 9.6ȱ 93ȱ 63.2±148ȱ 218ȱ 660ȱ 170.8±192ȱ 370ȱ n.a.ȱ n.a.ȱ n.a.ȱ n.a.ȱ n.a.ȱ - 43 - ERL 4022 19ȱ 16ȱ 160ȱ 240ȱ 85ȱ 600ȱ 665ȱ 261ȱ 384ȱ n.a.ȱ n.a.ȱ 430ȱ n.a.ȱ 63ȱ n.a.ȱ n.a.ȱ 20.9 n.a.ȱ 1.2ȱ 46.7 81ȱ n.a.ȱ CommencementȱBay,ȱTetraȱTechȱ(1985);ȱSanȱFranciscoȱBay,ȱLongȱetȱal.ȱ(1989)). SanȱFranciscoȱBayȱȱ n.a.ȱ n.a.ȱ n.a.ȱ n.a.ȱ 510ȱ 1100ȱ n.a.ȱ 2600ȱ 1100ȱ 2100ȱ n.a.ȱ n.a.ȱ 432±344ȱ n.a.ȱ 80±88ȱ n.a.ȱ n.a.ȱ 99±35ȱ n.a.ȱ 70ȱ 95.7±93ȱ 141.8±86.5ȱ n.a.ȱ dataȱ(ERL=ȱEffectsȱRangeȬLowȱandȱERM=ȱEffectsȱRangeȬMedian,ȱNOAAȱ(1999);ȱPugetȱSoundȱAET,ȱSwartzȱetȱal.ȱ(1985,ȱ1986);ȱ Ampeliscaȱ brevicornisȱ usedȱ inȱ theȱ sedimentȱ toxicityȱ test.ȱ Sedimentȱ Qualityȱ Guidelinesȱ wereȱ derivedȱ usingȱ previousȱ studiesȱ ȱTableȱ 2.ȱ Sedimentȱ qualityȱ valuesȱ forȱ PAHsȱ (ΐgȱ kgȬ1ȱ –dryȱ weightȬ)ȱ areȱ obtainedȱ fromȱ theȱ LC50ȱ andȱ calculatedȱ forȱ theȱ proposedȱ byȱ previousȱ studiesȱ (NOAAȱ 1999)ȱ whichȱ showȱ aȱ compilationȱ ofȱ SedimentȱQualityȱGuidelinesȱthatȱhaveȱbeenȱcalculatedȱbasedȱonȱaȱwideȱrangedȱ dataȱbaseȱ(LongȱandȱMorganȱ1991;ȱLongȱetȱal.ȱ1995).ȱNOAAȱ(1999)ȱexplainsȱtheȱ 10thȱ percentileȱ valuesȱ namedȱ theȱ ERLȱ (Effectsȱ RangeȬLow)ȱ asȱ theȱ concentrationsȱ belowȱ whichȱ adverseȱ effectsȱ rarelyȱ occur,ȱ whereasȱ theȱ 50thȱ percentilesȱ namedȱ ERMȱ (Effectsȱ RangeȬMedian)ȱ values,ȱ areȱ representativeȱ ofȱ concentrationsȱ aboveȱ whichȱ effectsȱ frequentlyȱ occurȱ (NOAAȱ 1999).ȱ ȱ Someȱ examplesȱfromȱSQVsȱobtainedȱfromȱpreviousȱstudiesȱ(tableȱ2)ȱwithȱamphipodsȱȬ Pugetȱ Soundȱ AET,ȱ Commencementȱ Bayȱ andȱ Sanȱ Franciscoȱ BayȬȱ (Longȱ andȱ Morganȱ 1991)ȱ areȱ similarȱ toȱ thoseȱ recordedȱ withȱ theȱ presentȱ studyȱ forȱ A.ȱ brevicornis.ȱȱ 4.ȱDiscussionȱ Resultsȱ obtainedȱ fromȱ theȱ chemicalȱ analysisȱ showȱ aȱ contentȱ ofȱ totalȱ PAHsȱ ofȱ 1443ȱ mgȱ KgȬ1ȱ Ȭdryȱ weightȬȱ fromȱ whichȱ moreȱ thanȱ 27%ȱ isȱ Naphtaleneȱ (395ȱmgȱKgȬ1ȱ ȬdryȱweightȬ).ȱPreviousȱstudiesȱ(AlbaigésȱandȱBayonaȱ2003)ȱshowȱ thatȱ Naphtaleneȱ mayȱ significantlyȱ accumulateȱ inȱ theȱ biotaȱ andȱ thatȱ concentrationsȱ ofȱ Naphtaleneȱ inȱ sedimentsȱ higherȱ thanȱ 34.6ȱ mgȱ KgȬ1ȱ Ȭdryȱ weightȬ)ȱ mayȱ produceȱ negativeȱ effectsȱ onȱ theȱ benthicȱ organisms.ȱ Specifically,ȱ oilsȱ spillsȱ suchȱ asȱ theȱ Seaȱ Empressȱ haveȱ involvedȱ aȱ declineȱ inȱ theȱ amphipodȱ faunaȱ withȱ theȱ generaȱ Ampeliscaȱ particularlyȱ affectedȱ (Nikitikȱ andȱ Robinsonȱ 2003).Theȱ LC50ȱ obtainedȱ fromȱ theȱ acuteȱ bioassayȱ usingȱ Ampeliscaȱ brevicornisȱ showsȱthatȱtheȱfuelȱoilȱisȱtoxicȱatȱconcentrationsȱequalȱorȱlowerȱthanȱ1.37%.ȱThisȱ valueȱ andȱ theȱ concentrationȱ ofȱ chemicalsȱ onȱ theȱ fuelȱ oilȱ andȱ cleanȱ sediment,ȱ allowsȱcalculatingȱtheȱSedimentȱQualityȱValuesȱ(SQVs)ȱforȱeachȱcontaminant.ȱ Resultsȱ ofȱ SQVsȱ forȱ metalsȱ areȱ lowerȱ thanȱ theȱ NOAAȱ guidelinesȱ whatȱ explainsȱthatȱtheȱtoxicityȱitȱisȱnotȱprobablyȱassociatedȱwithȱtheȱconcentrationȱofȱ - 44 - metalsȱinȱtheȱfuelȱoilȱdilutions.ȱOnȱtheȱotherȱhandȱPAHsȱseemȱtoȱbeȱresponsibleȱ forȱtheȱacuteȱtoxicityȱmeasuredȱatȱtheȱendȱofȱtheȱtestȱandȱtheȱSQVsȱobtainedȱforȱ totalȱ PAHsȱ (19790.7ȱ ΐgȱ kgȬ1)ȱ areȱ inȱ theȱ sameȱ rangeȱ thanȱ thoseȱ previouslyȱ reportedȱ forȱ theseȱ contaminantsȱ byȱ differentȱ authorsȱ (4022ȱ ΐgȱ kgȬ1ȱ (ERL)ȱ –ȱȱ 44792ȱ ΐgȱ kgȬ1ȱ (ERM)ȱ (NOAAȱ 1999);ȱ 11752±14548ȱ ΐgȱ kgȬ1ȱ ȱ (Pugetȱ Soundȱ AET)ȱ (Swartzȱ etȱ al.ȱ 1985;ȱ Swartzȱ etȱ al.ȱ 1986);ȱ 16771ȱ ΐgȱ kgȬ1ȱ ȱ (Commencementȱ Bay)ȱ (Tetraȱ Techȱ 1985)).ȱ Mostȱ ofȱ theȱ SQVsȱ ofȱ individualsȱ PAHsȱ calculatedȱ inȱ theȱ presentȱ studyȱ surpassȱ theȱ rangesȱ orȱ theyȱ areȱ inȱ theȱ sameȱ rangeȱ asȱ theȱ SQGsȱ recordedȱinȱpreviousȱstudiesȱ(NOAAȱ1999;ȱSwartzȱetȱal.ȱ1985;ȱSwartzȱetȱal.ȱ1986;ȱ TetraȱTechȱ1985;ȱLongȱandȱBuchmanȱ1989).ȱNaphtaleneȱshowsȱtheȱhighestȱvalueȱ ofȱSQVȱofȱtheȱtotalȱPAHsȱ(5417ȱΐgȱkgȬ1)ȱwhichȱisȱhigherȱthanȱtheȱdataȱrecordedȱ inȱ previousȱ studiesȱ (2400ȱ ΐgȱ kgȬ1ȱ (Pugetȱ Soundȱ AET);ȱ 1564±1735ȱ ΐgȱ kgȬ1ȱ (CommencentȱBay);ȱ160ȱΐgȱkgȬ1ȱ(ERL)ȱȬȱ2100ȱΐgȱkgȬ1ȱ(ERM)(NOAAȱ1999)).ȱTheȱ SQVȱcalculatedȱfromȱtheȱA.ȱbrevicornisȱtoxicityȱtestȱforȱFluoreneȱ(1362ȱΐgȱkgȬ1),ȱisȱ alsoȱhigherȱthanȱthoseȱSQGsȱfromȱotherȱstudiesȱasȱitȱisȱshownȱinȱtableȱ2,ȱbutȱitȱisȱ closedȱtoȱtheȱvalueȱcalculatedȱforȱCommencentȱBayȱ(707±1341ΐgȱkgȬ1)ȱandȱPugetȱ Soundȱ AETȱ (1000ΐgȱ kgȬ1)ȱ forȱ thisȱ individualȱ PAH.ȱ Acenaphtheneȱ presentsȱ aȱ SQVȱ(1033ȱΐgȱkgȬ1)ȱclosedȱtoȱtheȱSQGȱforȱCommencementȱBayȱ(654±1049ȱΐgȱkgȬ 1 ).ȱ Theȱ SQVȱ calculatedȱ forȱ theȱ individualȱ PAHȱ Phenanthreneȱ (5276ȱ ΐgȱ kgȬ1)ȱ isȱ closedȱ toȱ thoseȱ SQGsȱ fromȱ Commencentȱ Bayȱ (2838±46031ΐgȱ kgȬ1)ȱ andȱ Pugetȱ SoundȱAETȱ(5400ΐgȱkgȬ1)ȱwhereasȱtheȱSQVȱforȱAnthraceneȱderivedȱfromȱtheȱA.ȱ brevicornisȱtoxicityȱtestȱ(705ȱΐgȱkgȬ1)ȱisȱinȱtheȱrangeȱofȱtheȱsameȱvaluesȱproposedȱ byȱ NOAAȱ (1999)ȱ (85ȱ ΐgȱ kgȬ1ȱ (ERL)ȱ Ȭȱ 1100ȱ ΐgȱ kgȬ1)ȱ andȱ itȱ isȱ closedȱ toȱ theȱ SQGȱ derivedȱforȱSanȱFranciscoȱBayȱ(1100ΐgȱkgȬ1).ȱSimilarȱcomparisonsȱȱareȱforȱSQVsȱ ofȱ Pyreneȱ (1519ΐgkgȬ1),ȱ Benzo[a]anthraceneȱ (767ȱ ΐgȱ kgȬ1)ȱ andȱ Dibenzo[ah]anthracene(78ȱΐgȱkgȬ1)ȱwhichȱareȱinȱtheȱrangeȱofȱNOAAȱ(1999)ȱ(665ȱ ΐgȱkgȬ1ȱ(ERL)ȱȬȱ2600ȱΐgȱkgȬ1;ȱȱ261ȱΐgȱkgȬ1ȱ(ERL)ȱȬȱ1600ȱΐgȱkgȬ1;ȱ63ȱΐgȱkgȬ1ȱ(ERL)ȱȬȱ - 45 - 260ȱΐgȱkgȬ1,ȱrespectively),ȱwhereasȱBenzo[a]anthraceneȱisȱalsoȱclosedȱtoȱtheȱSQGȱ inȱSanȱFranciscoȱBayȱ(1100ΐgȱkgȬ1).ȱTheȱSQVȱobtainedȱforȱChryseneȱ(1519ȱΐgȱkgȬ 1 )ȱisȱquiteȱclosedȱtoȱtheȱSQGȱdeterminedȱȱforȱCommencementȱBayȱ(1363±1970ȱΐgȱ kgȬ1)ȱandȱisȱinȱtheȱrangeȱdeterminedȱbyȱNOAAȱ(1999)ȱ(ȱ384ȱΐgȱkgȬ1ȱ(ERL)ȱȬȱ2800ȱ ΐgȱ kgȬ1).ȱ Theȱ dataȱ obtainedȱ forȱ Fluorantheneȱ (391ΐgȱ kgȬ1)ȱ andȱ Benzo[a]pyreneȱ (407ΐgȱ kgȬ1)ȱ areȱ lowerȱ thanȱ thoseȱ obtainedȱ inȱ previousȱ studiesȱ (tableȱ 2),ȱ althoughȱtheȱSQVȱofȱBenzo[a]pyreneȱisȱclosedȱtoȱtheȱERLȱofȱNOAAȱ(1999)ȱ(430ȱ ΐgȱkgȬ1).ȱȱ Fromȱ theȱ comparisonsȱ carriedȱ out,ȱ weȱ canȱ sayȱ thatȱ theȱ SQVsȱ obtainedȱ fromȱ theȱ A.ȱ brevicornisȱ acuteȱ toxicityȱ test,ȱ areȱ similarȱ toȱ thoseȱ reportedȱ inȱ previousȱstudiesȱforȱtheȱsameȱcontaminants.ȱThisȱcorroboratesȱtheȱfactȱthatȱtheȱ toxicityȱ measuredȱ inȱ theȱ testȱ isȱ dueȱ toȱ theȱ presenceȱ ofȱ PAHsȱ inȱ theȱ fuelȱ oil.ȱ Benzofluoranthenes,ȱ Perilene,ȱ Dibenzo[ah]anthracene,ȱ Indene[123Ȭcd]pyreneȱ andȱ Benzo[ghi]perileneȱ showȱ theȱ lowestȱ SQVsȱ obtainedȱ fromȱ theȱ experimentȱ whatȱmeansȱthatȱtheseȱPAHsȱareȱpotentiallyȱtheȱmostȱtoxicȱagreeingȱwithȱotherȱ studiesȱ (NOAAȱ 1999;ȱ Swartzȱ etȱ al.ȱ 1985;ȱ Swartzȱ etȱ al.ȱ 1986;ȱ Tetraȱ Techȱ 1985;ȱ Longȱ andȱ Buchmanȱ 1989;ȱ Batelleȱ 2000;ȱ Leeȱ etȱ al.ȱ 2001).ȱ Howeverȱ theseȱ higherȱ molecularȱweightȱPAHsȱprobablyȱareȱtightlyȱboundȱtoȱparticlesȱwhatȱdecreasesȱ theirȱbioavailability.ȱ Furtherȱ studiesȱ wouldȱ beȱ needȱ toȱ establishȱ theȱ toxicityȱ effectȱ ofȱ eachȱ ofȱ theȱ individualȱ PAHsȱ presentedȱ inȱ theȱ fuelȱ oilȱ ofȱ theȱ tankerȱ Prestige,ȱ speciallyȱ whenȱ theyȱ reachȱ theȱ environmentȱ whereȱ theyȱ canȱ sufferȱ changesȱ inȱ theȱ proportionȱ ofȱ individualsȱ PAHsȱ andȱ becomeȱ moreȱ dangerousȱ dueȱ toȱ photomodificationȱ(DelVallsȱ2003;ȱCarballeiraȱ2003).ȱPreviousȱstudiesȱ(Pelletierȱ etȱal.ȱ1997;ȱPelletierȱetȱal.ȱ2000)ȱhaveȱshownȱthatȱAnthracene,ȱFlourantheneȱandȱ Pyreneȱincreaseȱtheirȱtoxicityȱonȱlarvaeȱandȱembryosȱofȱmarineȱinvertebrates.ȱInȱ thisȱsense,ȱstudiesȱcarriedȱoutȱwithȱenvironmentalȱsedimentȱsamplesȱaffectedȱbyȱ - 46 - theȱ oilȱ spillȱ willȱ beȱ ableȱ toȱ establishȱ theȱ toxicologicalȱ effectȱ ofȱ theȱ individualsȱ PAHsȱonceȱtheyȱhaveȱbeenȱmodifiedȱbyȱtheȱenvironmentalȱconditionsȱbeingȱtheȱ workȱhereȱ presentedȱ aȱfirstȱstepȱtoȱaddressȱtheȱpotentialȱadverseȱeffectsȱofȱtheȱ contaminantsȱ presentedȱ inȱ theȱ originalȱ fuelȱ whenȱ dilutedȱ withȱ naturalȱ andȱ cleanȱlittoralȱsediments.ȱȱȱ 5.ȱConclusionsȱȱ Previousȱstudiesȱ(Ribaȱetȱal.ȱ2003)ȱhaveȱshownȱthatȱtheȱamphipodȱspecieȱ Ampeliscaȱbrevicornisȱisȱaȱsensitiveȱorganismȱvalidȱtoȱassessȱtoxicityȱofȱsedimentsȱ contaminatedȱ byȱ traceȱ metals.ȱ Resultsȱ obtainedȱ inȱ thisȱ studyȱ showȱ thatȱ thisȱ specieȱ canȱ beȱ alsoȱ usedȱ toȱ assessȱ sedimentȱ toxicityȱ associatedȱ withȱ samplesȱ contaminatedȱ byȱ PAHs,ȱ andȱ sedimentȱ bioassaysȱ withȱ Ampeliscaȱ brevicornisȱ couldȱ beȱ includedȱ inȱ theȱ assessmentȱ ofȱ oilȱ spillsȱ toȱ determineȱ acuteȱ toxicityȱ responsesȱandȱtoȱderiveȱSedimentȱQualityȱGuidelines.ȱȱ Inȱthisȱsense,ȱtheȱamphipodȱAmpeliscaȱbrevicornisȱhasȱbeenȱvalidatedȱasȱanȱ appropriateȱ organismȱ toȱ conductȱ sedimentȱ toxicityȱ testsȱ withȱ metalsȱ andȱ hydrocarbonsȱ contaminatedȱ sedimentsȱ andȱ makesȱ thisȱ specieȱ suitableȱ forȱ theȱ assessmentȱ ofȱ hazardousȱ materialsȱ thatȱ mayȱ accumulateȱ inȱ sedimentsȱ andȱ produceȱeffectsȱonȱtheȱbiota.ȱ 6.ȱAknowledgmentsȱ Theȱ workȱ describedȱ wasȱ partlyȱ supportedȱ byȱ theȱ projectsȱ VEM2003Ȭ 20563/INTER,ȱ andȱ CTM2005Ȭ07282ȬC03Ȭ01/TECNOȱ financedȱ byȱ theȱ Spanishȱ Educationȱ andȱ Scienceȱ Ministryȱ andȱ byȱ CISȱ fundedȱ byȱ theȱ Ministryȱ ofȱ Environment.ȱ Carmenȱ MoralesȬCasellesȱ thanksȱ theȱ Ministryȱ ofȱ Educationȱ andȱ Scienceȱ forȱ fundingȱ herȱ researchȱ fellowshipȱ (FPU).ȱ Dr.ȱ Ribaȱ thanksȱ theȱ I3pȱ - 47 - programȱ forȱ supportingȱ herȱ participationȱ inȱ thisȱ research.ȱ ȱ Inmaculadaȱ Ribaȱ thanksȱ theȱ CSICȱ forȱ herȱ I3Pȱ contract.ȱ Weȱ thankȱ theȱ supportȱ andȱ helpȱ ofȱ theȱ membersȱofȱtheȱCIS.ȱ 7.ȱReferencesȱȱȱȱ Albaigésȱ J,ȱ Bayonaȱ JM.ȱ 2003.ȱ Laȱ Huellaȱ delȱ Fuel,ȱ in:ȱ Ensayosȱ sobreȱ elȱ <<Prestige>>.ȱ (Eds)ȱFundaciónȱSantiagoȱReyȱFernándezȬLaTorre,ȱAȱCoruñaȱ(Spain)ȱ AmericanȱSocietyȱforȱTestingȱandȱMaterials.ȱ1993.ȱStandardȱguideȱforȱconductingȱ10Ȭ dayȱ staticȱ sedimentȱ toxicityȱ testsȱ withȱ theȱ marineȱ andȱ estuarineȱ amphipods.ȱ Publ.ȱE.ȱPhiladelphia,ȱ1367Ȭ1392ȱȱ Battelle.ȱ 2000.ȱ Ecologicalȱ RiskȬBasedȱ Approachȱ toȱ Developingȱ Cleanupȱ Goalsȱ Protectiveȱ ofȱ Aquaticȱ Receptorsȱ forȱ Petroleumȱ Contaminatedȱ Sitesȱ atȱ Navalȱ Facilities.ȱ Reportȱ toȱ Navalȱ facilitiesȱ Engineeringȱ Serviceȱ Center,ȱ Portȱ Huneme,ȱ CA.ȱ Blancoȱ CG,ȱ Pregoȱ R,ȱ Azpírozȱ MDG,ȱ FernándezȬDomínguezȱ I.ȱ inȱ press.ȱ Hydrocarbonȱ characterizationȱ ofȱ surfaceȱ sedimentsȱ inȱ theȱ Riaȱ Laxeȱ andȱ itsȱ relationȱ withȱ theȱ PretigeȱfuelȬoilȱspillȱ(NWȱIberianȱPenninsula).ȱCiencȱMarȱȱ Carballeiraȱ A.ȱ 2003.ȱ Considerationsȱ inȱ theȱ designȱ ofȱ aȱ monitoringȱ programȱ ofȱ theȱ biologicalȱeffectsȱofȱtheȱPrestigeȱoilȱspill.ȱCiencȱMarȱ29(1)ȱ123Ȭ139ȱ ChapmanȱPM,ȱHoȱKT,ȱMunnsȱWR,ȱSolomonȱK,ȱWeisteinȱMP.ȱ2002.ȱIssuesȱinȱsedimentȱ toxicityȱandȱecologicalȱriskȱassessment.ȱMarȱPollutȱBullȱ44:ȱ271–278ȱ Chapmanȱ PM,ȱ Longȱ ER.ȱ 1983.ȱ Theȱ useȱ ofȱ bioassaysȱ asȱ aȱ partȱ ofȱ aȱ comprehensiveȱ approachȱtoȱmarineȱpollutionȱassessment.ȱMarȱPollutȱBullȱ14:ȱ81Ȭ84ȱȱ - 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51 - USȱ EPA.ȱ 1984.ȱ Testȱ methodsȱ forȱ evaluatingȱ solidȱ waste,ȱ physical/chemicalȱ methods.ȱ Officeȱ ofȱ Solidȱ Wasteȱ andȱ Emergencyȱ Response,ȱ Washington,ȱ DC.ȱ Thirdȱ Edition.ȱUSȱEnvironmentalȱProtectionȱAgency.ȱEPAȱ530/SWȬ846ȱ ȱ - 52 - Environ Monit Assess DOI 10.1007/s10661-007-9926-5 Using the polychaete Arenicola marina to determine toxicity and bioaccumulation of PAHS bound to sediments Carmen Morales-Caselles & Julia Ramos & Inmaculada Riba & T. Ángel DelValls Received: 27 February 2007 / Accepted: 27 August 2007 # Springer Science + Business Media B.V. 2007 Abstract The present study was conducted to evaluate a sediment toxicity and bioavailability test with the polychaete Arenicola marina as a potential tool to assess sediments contaminated by oil spills. A bioassay using the lugworm Arenicola marina was carried out in order to determine toxicity and bioaccumulation associated with the contaminants present in the fuel oil extracted from a sank tanker. After 10 and 21 days of exposure to sediments with different proportions of fuel oil (0.5, 1, 2, 4 and 8%) polychaetes were sampled to determine the mortality and the levels of individual PAHs in the organisms. During the experiment, mortality was recorded and the concentration (percentage of fuel oil) that provokes the mortality of the 50% of the Arenicola marina population exposed was calculated for both sampling dates (LC50(10)=6.4%; LC50(21)=2.4%). Bioaccumulation was mainly produced for fluoranthene, pyrene, benzo(b)fluoranthene and benzo(k)fluoranthene, whereas phenantrene and anthracene where initially accumulated and then metabolized. The results obtained in the present study suggest Arenicola marina can be a suitable species for assessing PAHs toxicity and bioaccumulation as part of oil spill management. Keywords LC50 . Quality values . Sediment toxicity . Oil spill Introduction C. Morales-Caselles : I. Riba Instituto de Ciencias Marinas de Andalucía (CSIC), Polígono Río San Pedro s/n., 11510 Puerto Real (Cádiz), Spain The biological effects associated with the chemicals from the oil spill depend on the nature of the affected ecosystem (DelValls 2003). Petroleum can adversely affect organisms by physical action (smothering, reduced light), habitat modification (altered pH, decreased dissolved oxygen, decreased food availability) and toxic action (Albers 2003). The remaining fuel from an important oil spill in the North of Spain (Prestige, 2002) that was still in the tanker was eventually extracted in 2004; the composition of this heavy fuel-oil (type M-100) was a mixture of saturated hydrocarbons, aromatic hydrocarbons, resins and asphaltenes, being most of the polycyclic aromatic hydrocarbons – PAHs – of an intermedium- J. Ramos : I. Riba : T. Á. DelValls UNESCO/UNITWIN/Wicop, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Polígono Río San Pedro s/n, 11510 Puerto Real (Cádiz), Spain C. Morales-Caselles (*) : T. Á. DelValls Unidad Asociada Universidad de Cádiz-Calidad Ambiental y Patología (UCA-CSIC), Avenida Saharaui s/n, 11510 Puerto Real (Cádiz), Spain e-mail: [email protected] -53- Environ Monit Assess high molecular weight (Alzaga et al. 2004; Blanco et al. 2006). PAHs are a ubiquitous group of contaminants and can accumulate and persist in marine sediments (Neff 1979), and affect organisms through toxic action (Albers 2003). Sediment bioassays (toxicity and bioaccumulation) are instruments used to test the toxicity and bioavailability of chemical compounds in sediments to benthic organisms. In the present study we selected Arenicola marina, in order to test the toxicity and bioaccumulation of the fuel oil extracted from the tanker. A. marina is a bulk sediment feeding polychaete worm that lives in a U-shaped burrow. This species was chosen for the bioassay because it: (a) is continuously exposed to contaminants in the sediment, which it ingest while feeding; (b) is available all the year round, often in reasonably high densities; (c) tolerates a wide range of particle sizes and salinities, (d) has a broad geographic range; and (e) supposes an important species in coastal food chain (Bat and Raffaeli 1997). In addition this species has been recommended by Oslo-Paris Commission (1995) as monitoring organism. Accumulation of hydrophobic organic contaminants by benthic organisms can occur either from aqueous phase or dietary exposure (Lamoureux and Brownawell 1998). Uptake of hydrophobic compounds from ingested material has been reported as a major contributor to an animal’s total body burden of toxicants (Kaag et al. 1996; Kaag et al. 1998; Penry and Weston 1998; Selck et al. 2003). Also bioaccumulation studies have shown that lugworms accumulate organic contaminants to higher concentrations than filter feeding animals (Kaag et al. 1997). The ability of organisms to metabolize and excrete PAHs also has been shown to be related to bioaccumulation (Rust et al. 2004a, 2004b), where species with limited metabolic ability tend to accumulate higher PAHs concentrations in their tissue (Varanari et al. 1985; Driscoll and McElroy 1996; Rust et al. 2004b). Even though the presence of a PAH metabolising system in A. marina (Christensen et al. 2002) has been strongly suggested, invertebrates tend to excrete metabolites more slowly than vertebrate species (Rust et al. 2004b). Metabolites have been found to be eliminated at rates either greater or lower than those of the parent compound (Spacie and Hamelink 1995). Therefore, toxicity will depend on a combination of relative retention time and relative toxicity of parent versus metabolites (Selck et al. 2003). Previous studies agree that A. marina appears to be an appropriate choice as indicator species for PAH bioaccumulation (Rust et al. 2004b), and a suitable organism to monitor PAH pollution. The aim of this study is to asses the sensitivity of the polychaete A. marina to the contamination associated with PAHs from oil spills by using the remaining fuel oil extracted from a tanker and to determine the bioavailability of PAHs present in the fuel oil by measuring the bioaccumulation in the exposed organisms. The results obtained will permit the calculation of the Sediment Quality Guidelines (SQGs) for this group of PAHs and will help to predict toxicity and bioaccumulation of the fuel oil in invertebrates. In order to reach these objectives, a bioassay was conducted exposing a population of the polychaete Arenicola marina to different dilutions of fuel oil with clean sediment. Material and methods Toxicity test Intertidal clean sediment from the Bay of Cádiz (South of Spain) was mixed with fuel oil extracted from the tanker (0.5, 1, 2, 4 and 8% dry weight). The sediment was filtered (0.6 mm) prior to the toxicity to remove inorganic and organic debris and benthic organisms capable of preying A. marina (Riba et al. 2003). These sediments were dried and homogenized at room temperature prior to chemical analysis. The A. marina lugworms were sampled in field by hand-digging and immediately transported to laboratory in containers with sea water. Once there, lugworms were placed in aquariums with sieved sediment from the Bay of Cádiz (5 cm thick) and acclimated for 10 days; air was provided and water was replaced three times per day. Water temperature was kept at 18°C and natural photoperiod was selected. The dilutions of fuel oil (0.5, 1, 2, 4 and 8% dry weight) in sediment and the clean sediment without fuel oil (2 kg) were placed in replicates (three) in 11 L tanks and clean sea water was added. Lugworms were put into the tanks (six per tank) which were covered to avoid evaporation. The experiment lasted 21 days. Mortality was daily recorded and after 10 and 21 days of exposure sampling was performed by transferring individuals -54- Environ Monit Assess to aerated clean sea water without sediment, where they were held for approximately 4 h to empty the sediment of the body. Organisms were then frozen at −20°C. (Fraction I: aliphatic hydrocarbons) and finally 40 ml of hexane/methane 4:1 (Fraction II: PAHs). Flasks with Fraction II were dried in a rotatory evaporator and re-dissolved in hexane (final volume 10 ml). These extracts were evaporated until a final volume of 0.5 ml. Aromatic fractions were analyzed with a gas chromatograph coupled with a mass spectrometer (Finnigan Mat, GCQ tm). Chromatographic resolution was achieved with a 30 m×0.250 mm DB-5 capillary column, which has a 0.25 μm film thickness, with helium as carrier gas. Chemical analysis Sediment was digested as described by Loring and Rantala (1992) for trace metal analysis (Ni, V, Cd, Pb, Cr, Co). Measurement was performed by graphite furnace atomic absorption spectrophotometry (PerkinElmer 4100 ZL) (USEPA 1984), et al. Results are expressed as milligrams per kilogram of dry sediment. The analytical procedures were checked using reference material (MESS-1 NRC and CRM 277 BCR) and showed a recovery greater than 90% of the certified concentration. Polycyclic aromatic hydrocarbons (fluorene, acenaphthene, naphthalene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzofluoranthene, benzo[e]pyrene, benzo[a]pyrene, perylene, dibenzo[ah]anthracene, indene[123-cd]pyrene, benzo[ghi]perilene) were analyzed by using a gas chromatograph equipped with an electron capture detector (GC/MS) (US Environmental Protection Agency 1984). Briefly, dried samples were soxhlet extracted with n-hexane for 18 h, and the extracts were isolated by column chromatography on Florisil– alumino–silica. PAHs were eluted and their fractions were dried in a rotatory evaporator and re-dissolved in isooctane. Aromatic fractions were analyzed on a Hewlett-Packard (HP) 5890 Series II gas chromatograph coupled with HP 5970 mass spectrometer. Chromatographic resolution was achieved with a 30 m×0.250 mm DB-5 capillary column, which has a 0.25 μm film thickness, with helium as carrier gas. Quality control was carried out using NRC-CNRC HS-6 sediment reference material. The analytical procedure showed a recovery greater than 90% of the certified concentration. The individuals of each treatment were put together and liophilized for the PAHs analysis. Briefly, the samples were soxhlet extracted with hexane/acetone 1:1 during 24 h; then, the extracts were transferred into tubes and dissolved with hexane until a final volume of 20 ml. Samples of each tube were evaporated to 2 ml. These extracts were isolated by column chromatography on alumino–silica using 20 ml hexane, then 30 ml hexane/methane 9:1 Data calculations The toxic parameter associated with the fuel oil (LC50) was obtained from the mortality data of Arenicola marina measured after 10 and 21 days of exposure to the fuel dilutions (0.5, 1, 2, 4 and 8%). LC50 was defined as the concentration (percentage of fuel oil) that provokes the mortality of 50% of the Arenicola marina population exposed. The LC50 was calculated by linear regressions of log toxicant dilution of fuel oil on declining probit values (ProbitAnalysis-Program, version 1.5). Sediment Quality Values were calculated basing in the LC50 results. Results and discussion Acute toxicity The mortality of the lugworm Arenicola marina in each treatment was recorded after 10 and 21 days of exposure. Figure 1 shows how mortality in control (clean sediment from the Bay of Cádiz) was 0 after 10 days of exposure, while after 21 days 5.6% of the organisms exposed died. However, mean survival in all the replicates of clean sediment from the control (Ca1) was higher than 94% after 10 and 21 of exposure. Death of test organisms was positively related to dose at time of exposure. No survival was detected in the highest dilutions of fuel oil (8%) after 21 days of exposure. For all treatments, the day 21 of exposure shows higher mortality of Arenicola than the day 10. Survival results for Arenicola show substantial variability among replicates which has been already observed in previous studies (Matthiessen et al. 1998). Other authors obtained differences in tolerance to toxicants, including PAHs, depending on -55- Environ Monit Assess Fig. 1 Average and standard deviations of the percentage of mortality of the polychaete Arenicola marina after 10 (dotted bars) and 21 (striped bars) days of exposure to each dilution the polychaete specie (Bach et al. 2005) whereas low percentages of oil contaminated sediment inhibited Arenicola feeding almost completely (Grant and Briggs 2002). The mortality of individuals of A. marina exposed to dredged material demonstrated a slight correlation with the organic contaminants (PAHs and PCBs) even though these correlations were not significant (Casado-Martínez 2007). Results obtained in this study show a toxicity related to time of exposure, what was previously confirmed by previous studies (Rossi and Neff 1978). Despite the variability of mortality results in the Arenicola bioassays the estimation of LC50 values can be performed. The mortality data were used to calculate two LC50s: LC50(10) to describe toxicity after 10 days of exposure and LC50(21) to describe toxicity after 21 days of exposure. The LC50 value and the concentration of PAHs or metals in the sediment permits calculation of the Sediment Quality Values (SQVs) for each contaminant (Table 1). The LC50(10) value of fuel oil associated with the toxic responses for Arenicola marina is 6.4% of fuel oil, which corresponds with a concentration of 92.42 mg kg−1 of total PAHs ([PAH]oil*6.4/100) (SQV1). On the other hand the LC50(21) of fuel oil associated with toxicity for this polychaete is 2.4%, which accounts for a concentration of 34.52 mg kg−1 of total PAHs ([PAH] oil*2.4/100) (SQV2). Previously, a 10-day exposure study with the amphipod Corophium volutator and fuel oil from the tanker produced an LC50 of 1.37% (Morales-Caselles, ICMAN-CSIC, personal observa- tions) which suggests that Arenicola presents lower sensitivity to the fuel than Corophium. Previous studies have demonstrated that Arenicola marina shows markedly lower acute toxicity to hydrocarbon and other contaminants bound to sediments than Corophium (Matthiessen et al. 1998; Grant and Briggs 2002). The values of total PAHs concentration obtained from the LC50s calculations (SQV1 and SQV2) may be compared with international Sediment Quality Guidelines (SQGs). National Oceanic and Atmospheric Administration (1999) explains the 10th percentile values named the ERL (Effects Range-Low) as the concentrations below which adverse effects rarely occur, whereas the 50th percentiles named ERM (Effects Range-Median) values are representative of concentrations above which effects frequently occur. SQV1 for total PAHs (92.42 mg kg−1) is higher than the guidelines ERL and ERM calculated (4,022 μg kg−1 and 44,792 μg kg−1 respectively) while SQV2 (34.52 mgkg−1) keeps higher than ERL and lower than ERM. The justification about why the SQVs obtained for Arenicola marina are higher than the ERM could be because of the fact that this polychaete species presents lower sensitivity to the PAHs toxicity than other marine organisms, which allows Arenicola to survive in an environment highly contaminated by these compounds. On the other hand results of SQVs for metals are lower than the National Oceanic and Atmospheric Administration guidelines, hence metals are probably not a toxicity factor. -56- Environ Monit Assess Table 1 Total PAHs and metal concentration measured in the negative control (Ca1) and in the fuel oil −1 PAHs (μg kg ) Metals (mg kg−1) Total PAHs Fluorene Acenaphthene Naphthalene Phenanthrene Anthracene Fluoranthene Pyrene Benzo[a]anthracene Chrysene Benzofluoranthene Benzo[e]pyrene Benzo[a]pyrene Perilene Dibenzo[ah]anthracene Indene[123-cd]pyrene Benzo[ghi]perilene Ni V Cd Pb Cr Co Fuel Ca1 ERL ERM SQV1 SQV2 1443 99.3 75.3 395 385 51.4 28.5 111 55.9 102 16.0 45.7 29.7 11.4 5.70 5.23 17.1 55 170 n.d n.d 0.31 n.d n.d n.d n.d n.d n.d n.d n.d n.d n.d n.d n.d n.d n.d n.d n.d n.d n.d 14.1 80.0 n.d 23.0 31.0 3.40 4022 19 16 160 240 85 600 665 261 384 n.a. n.a. 430 n.a. 63 n.a. n.a. 20.9 n.a. 1.2 46.7 81 n.a. 44792 540 500 2100 1500 1100 5100 2600 1600 2800 n.a. n.a. 1600 n.a. 260 n.a. n.a. 51.6 n.a. 9.6 218 370 n.a. 92424 − − − − − − − − − − − − − − − − 8.3 42.7 n.d 10.8 14.6 1.6 34517 − − − − − − − − − − − − − − − − 7.5 41.1 n.d 11.2 15.1 1.7 Sediment quality values for PAHs are obtained from the LC50 and calculated for the Arenicola marina used in the sediment toxicity test. Sediment Quality Guidelines were derived using previous studies data (ERL= Effects Range-Low and ERM= Effects RangeMedian, National Oceanic and Atmospheric Administration (1999) (n.d, not detected; n.a., not analyzed). the highest amount of fuel oil. This trend has been shown in previous studies on other invertebrates (Landrum et al. 2003) where, in general, the uptake coefficient declined with increasing PAHs concentration, especially with pyrene. Also, lower accumulation factors were found to correspond to treatments for which significant mortality was observed (Rust et al. 2004a). The BCF calculated for the day 10 of exposure is higher for phenanthrene, anthracene, fluoranthene, pyrene and benzofluoranthenes (Fig. 2); after 21 days of exposure the highest levels of bioaccumulation were for fluoranthene, pyrene and benzofluoranthenes but not for the lower molecular weight compounds phenantrene and anthracene. The decreased of the BCF for phenantrene and anthracene could be due to the fact that after 21 days the organisms have been able to metabolize the PAHs with lower molecular weight. On the other hand, during long-term contact between PAHs and sediment particles, PAHs become tightly bound to organic phases in the sediment, reducing their bioavailability (Neff 2002). Bioaccumulation The polychaetes ingest sediment and thus are exposed to PAHs in solution in the interstitial water and those adsorbed to sediment particles (Neff 2002). Organisms were sampled the day 10 and 21 of the fuel oil exposure experiment in order to analyze the content of PAHs in their bodies. A biota/sediment bioaccumulation factor (BCF) was defined to interpret the results obtained. This factor accounts for the concentration of PAHs in the organisms (Co) related to the concentration of that contaminant in the sediment (Cs) (BCF = Co/Cs). BCF results are shown in Fig. 2. In general, bioaccumulation decreases when the percentage of fuel in the sediment sample increases. This behaviour could be due to the fact that toxicity increases with the content of fuel. Casts were not found in those tanks with higher concentrations of hydrocarbons, so probably feeding was inhibited by the presence of contaminants in the sediment; this fact could lead to lower levels of bioaccumulation in those treatments with -57- Environ Monit Assess Fig. 2 Bioaccumulation factors (BCF) calculated for Arenicola marina after 10 and 21 days of exposure to the dilutions of fuel oil (0.5, 1, 2, 4 and 8%). ANA Acenaphtene, F fluorene, P phenantrene, A anthracene, FL fluoranthene, PY pyrene, BA benzoanthrazene, C chrysene, BBF + BKF benzo(b)fluoran- thene and Benzo(k)fluoranthene, BEP benzo[e]pyrene, BAP benzo[a]pyrene, IN indene[123-cd]pyrene, DBA dibenzo[ah] anthracene, BPE benzo[ghi]perilene, TOTAL sum of individual PAHs Levels of BCF confirm that those PAHs that present logKow values of 5–6 show the highest accumulation potential as reported in previous studies (Kaag et al. 1997; kaag et al. 1998; Rust et al. 2004a). Fluoranthene presents high bioaccumulation potential relative to smaller or larger PAHs and it is known to be highly toxic to benthic invertebrates (Selck et al. 2003; Landrum 1989; Swartz et al. 1990). This compound may also possess genotoxic (mutagenic and carcinogenic) properties, though these effects are not associated directly with the parent compound, but arise largely as a result of biotransformation processes that lead to the formation of reactive intermediates (Rastetter et al. 1982; Babson et al. 1986; Bach et al. 2005). Pyrene presents a high bioaccumulation factor and associates strongly to sediment particles (Landrum 1989). Results of BCF for pyrene increase from day 10 to day 21, in contrast with other authors that found that the fraction of unmetabolized pyrene in tissues of A. marina was unaffected by the duration of exposure (Christensen et al. 2002). Benzo(b)fluoranthene and benzo(k)fluoranthene present similar values of BCF for the day 10 and 21 of exposure, which suggests that these PAHs with high molecular weight were initially bound to the organism tissues and were not metabolized probably due to their low solubility. On the other hand this could be as a result of the fact that threshold effect has been achieved and the availability of the high molecular weight compounds decreases as a consequence of tight organic bonding in the sediment. Conclusions In the present study the sensitivity of the polychaete Arenicola marina to the fuel oil from a tanker (Prestige 2002) has been tested, and in spite of the variability in mortality results, it showed a clear doserelated mortality but more endurance than other organisms. Bioaccumulation was mainly produced for fluoranthene, pyrene, benzo(b)fluoranthene and benzo(k)fluoranthene whereas phenantrene and anthracene where initially accumulated and then probably metabolized. -58- Environ Monit Assess Although PAHs do not biomagnify through trophic levels (Neff 2002), A. marina, which is often used as a bite, is able to live in PAH-contaminated environments and accumulate PAHs. Although A. marina is less sensitive than other species, it is likely to be available even in at polluted sites, for studies of PAH bioaccumulation. Attending to this, we propose that Arenicola marina should be used in the assessment of oil impacts associated with spills included in a set of bioassays, in order to determine acute and sublethal toxicity responses; in addition further research towards including biomarkers in this species it is recommended. Christensen, M., Andersen, O., & Banta, G. T. (2002). Metabolism of pyrene by the polychaetes Nereis diversicolor and Arenicola marina. Aquatic Toxicology, 58, 15–25. DelValls, T. A. (2003). The oil spill produced by the tanker Prestige (13/11/2002): Impact assessment of the northwest coast of the Iberian Peninsula. Ciencias Marinas, 29(1), i–iii. Driscoll, S. K., & McElroy, A. E. (1996). Bioaccumulation and metabolism of benzo[a]pyrene in three species of polychaete worms. Environmental Toxicology and Chemistry, 15, 1401–1410. Grant, A., & Briggs, A. D. (2002). Toxicity of sediments from around a North Sea oil platform: are metals or hydrocarbons responsible for ecological impacts? Marine Environmental Research, 53, 95–116. Kaag, N. H. B. M., Foekema, E. M., Scholten, M. C. Th., & Van Straalen, N. M. (1996). Comparison of contaminant accumulation in three species of marine invertebrates with different feeding habits. Environmental Toxicology and Chemistry, 16(5), 837–842. Kaag, N. H. B. M., Foekema, E. M., Scholten, M. C. Th., & Van Straalen, N. M. (1997). Comparison of contaminant accumulation in three species of marine invertebrates with different feeding habits. Environmental Toxicology and Chemistry, 16, 837–842. Kaag, N. H. B. M., Scholten, M. C. Th., & Van Straalen, N. M. (1998). Factors affecting PAH residues in the lugworm Arenicola marina a sediment feeding polychaete. Journal of Sea Research, 40, 251–261. Lamoureux, E. M., & Brownawell, B. J. (1998). Chemical and biological availability of sediment-sorbed hydrophobic organic contaminants. Environmental Toxicology and Chemistry, 18(8), 1733–1741. Landrum, P. F. (1989). Bioavailability of polycyclic aromatic hydrocarbons sorbed to sediments for the amphipod Pontoporeia hoyi. Environmental Science & Technology, 23, 588–595. Landrum, P. F., Lotufo, G. R., Gossiaux, D. C., Gedeon, M. L., & Lee, J. H. (2003). Bioaccumulation and critical body residue of PAHs in the amphipod, Diporeia spp.: Additional evidence to support toxicity additivity for PAHs mixtures. Chemosphere, 51, 481–489. Loring, D. H., & Rantala, R. T. T. (1992). Methods for the geochemical analyses of marine sediments and suspended particulate matter. Earth-Science Reviews, 32, 235–283. Matthiessen, P., Bifield, S., Jarrett, F., Kirby, F., Law, R. J., McMinn, W. R., et al. (1998). An assessment of sediment toxicity in the River Tyne Estuary, UK by means of bioassays. Marine Environmental Research, 45, 1–15. National Oceanic and Atmospheric Administration (1999). Sediment quality guidelines developed for the national status and trend programs. Neff, J. M. (1979). Polycyclic aromatic hydrocarbons in the aquatic environment: Source, fates, and biological effects. London, UK: Applied Science. Neff, J. M. (2002). Polyciclic aromatic hydrocarbons in the ocean, in Bioaccumulation in Marine Organisms. New York: Elsevier, p. 452. Oslo-Paris Commission (1995). Report of the workshop on biological effects monitoring techniques. Aberdeen, Scotland, 2–6 October. Acknowledgments The work described was supported by a Grant funded by the Ministry of Education and Science VEM2003-20563. Carmen Morales-Caselles thanks the Ministry of Education and Science for funding her research fellowship (FPU). We are grateful for the support and help of the members of the CIS (Spain) and IPIMAR (Portugal). Special thanks are given to Carlos Vale, Ana Ferreira, Isabellina Santos, Ana Cristina Micaelo and Judit Kalman. 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M., & DelValls, T. A. (2003). Deriving sediment quality guidelines in the Guadalquivir estuary associated with the Aznalcóllar mining spill: A comparison of different approaches. Ciencias Marinas, 29(3). Rossi, S. S., & Neff, J. M. (1978). Toxicity of polynuclear aromatic hydrocarbons to the polychaete Neanthes arenaceodentata. Marine Pollution Bulletin, 9, 220–223. Rust, J. A., Burgess, R. M., Brownawell, B. J., & McElroy, A. E. (2004a). Relationship between metabolism and bioaccumulation of benzo[a]pyrene in benthic invertebrates. Environmental Toxicology and Chemistry, 23(11), 2587– 2593. Rust, J. A., Burgess, R. M., McElroy, A. E., Cantwell, M. G., & Brownawell, B. J. (2004b). Influence of soot carbon on the bioaccumulation of sediment-bound polycyclic aromatic hydrocarbons by marine benthic invertebrates: An interspecies comparison. Environmental Toxicology and Chemistry, 23(11), 2594–2603. Selck, H., Palmqvist, A., & Forbes, V. E. (2003). Uptake, depuration and toxicity of dissolved and sediment-bound flouranthene in the polychaete Capitella sp. I. Environmental Toxicology and Chemistry, 22(10), 2354–2363. Spacie, A., & Hamelink, J. L. (1995). Appendix D, bioaccumulation. In G. M. Rand (Ed), Fundamentals of Aquatic Toxicology (pp. 1052–1082). Washington DC: Taylor & Francis. Swartz, R. C., Schults, D. W., DeWitt, T. H., Ditsworth, G. R., & Lamberson, J. O. (1990). Toxicity of fluoranthene in sediment to marine amphipods: A test of the equilibrium partitioning approach to sediment quality criteria. Environmental Toxicology and Chemistry, 9, 1074–1080. US Environmental Protection Agency (1984). Test methods for evaluating solid waste, physical/chemical methods. Office of Solid Waste and Emergency Response, Washington, DC. Third Edition. US Environmental Protection Agency. EPA 530/SW–846. Varanasi, U., Reichert, W. L., Stein, J. E., Brown, D. W., & Sanborn, H. R. (1985). Bioavailability and biotransformation of aromatic hydrocarbons in benthic organisms exposed to sediment from an urban estuary. Environmental Science & Technology, 19, 836–841. -60- Environmental Pollution 146 (2007) 233e240 www.elsevier.com/locate/envpol Comparing sediment quality in Spanish littoral areas affected by acute (Prestige, 2002) and chronic (Bay of Algeciras) oil spills C. Morales-Caselles a,c, J. Kalman a,c, I. Riba a,c, T.A. DelValls b,c,* a Instituto de Ciencias Marinas de Andalucı́a (ICMAN-CSIC), Avda. República Saharaui s/n, Puerto Real 11510, Cádiz, Spain UNESCO UNITWIN/UNICOP, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Polı́gono Rı́o San Pedro s/n, Puerto Real 11510, Cádiz, Spain c Unidad Asociada de Calidad Ambiental y Patologı́a (CSIC & UCA), Avda. República Saharaui s/n, Puerto Real 11510, Cádiz, Spain b Received 7 December 2005; received in revised form 6 April 2006; accepted 12 April 2006 Littoral sediments affected by low or moderated but continuous oil spills are more polluted than those affected by accidental oil spills such as the Prestige. Abstract The quality of sediments collected from two areas of the Spanish coast affected by different sources of contaminants has been compared in this study. The areas studied are the coast of Galicia affected by the oil spill from the tanker Prestige (November 2002) and the Gulf of Cádiz which suffers continuous inputs of contaminants from industries located in the area and from oil spills. Contamination by several chemicals (metals, PCBs and PAHs) that bind to sediments was analyzed, and two toxicity tests (Microtox and amphipod 10-day bioassay) were conducted. PAHs were identified as the compounds responsible for the toxic effects. Results show differences between an acute impact related to the sinking of the tanker Prestige and the chronic impact associated with continuous oil spills associated with the maritime and industrial activities in the Bay of Algeciras, this being the most polluted part of the two coastal areas studied in this work. 2006 Elsevier Ltd. All rights reserved. Keywords: Amphipods; Microtox; PAHs; Toxicity; Contamination 1. Introduction Sediments are an important part of the ecosystem and play a key role in the distribution of contaminants in the aquatic environment; the study of the quality of sediments provides information about the ecosystem health. Human activities in coastal areas usually involve an input of contaminants to the natural environment that becomes evident in the decreased quality of coastal sediments. Many authors agree that sediment quality is best determined by integrating the information * Corresponding author. UNESCO UNITWIN/UNICOP, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Polı́gono Rı́o San Pedro s/n, Puerto Real 11510, Cádiz, Spain. Tel.: þ34 956 016794; fax: þ34 956 016040. E-mail address: [email protected] (T.A. DelValls). 0269-7491/$ - see front matter 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.envpol.2006.04.042 -61- obtained from measures of chemicals concentration and from specific tests to determine sediment toxicity (DelValls and Conradi, 2000; Chapman et al., 2002). The biological effects can be established based on laboratory tests that determine toxic responses. Sediment bioassays are usually relatively simple tests that evaluate the responses of the tested organism to contaminated sediments under controlled conditions (Riba et al., 2004a). In the present study, we have selected two different tests in order to determine sediment toxicity: the Microtox test and an amphipod acute bioassay. Use of the commercial bioassay Microtox has increased in recent years since it detects the ‘‘hot spots’’ of field contamination in the screening procedure (Mowat and Bundy, 2001; Stronkhorst et al., 2003; Van Beelen, 2003); Microtox has also been used before to assess the impact of oil spills and oil contaminated 234 C. Morales-Caselles et al. / Environmental Pollution 146 (2007) 233e240 sediments (Brohon et al., 2001; Kenneth et al., 2003; Pelletier et al., 2004). The other acute bioassay was carried out with the amphipod Corophium volutator which is an important test organism for the ecotoxicological quality assessment of marine and estuarine sediment samples (Peters and Ahlf, 2005). The bioassay with C. volutator is integrated in test batteries for dredged material management (Peters et al., 2002; Stronkhorst et al., 2003) and it is required for compliance with certain International Standardization Organisation quality standards (ISO, 2003). This kind of bioassay has been used in previous studies for the assessment of spills (Grant and Briggs, 2002; Briggs et al., 2003). In this study a comparison is made between the quality of sediments sampled on two lengths of Spanish coast affected by different sources of contaminants. In the coast of Galicia, the study addresses the acute impact provoked by the oil spill resulting from the break-up and sinking of the tanker Prestige (November 2002), whereas in the Gulf of Cádiz the sediments studied have suffered a chronic impact lasting several decades, caused by the input of oil and other contaminants from the various industries located in the area and from accidental spills and deliberate discharges from commercial shipping activities. The main objectives of this study are: (1) to characterise the contamination by PAHs in the selected areas of study on the Galician Coast and in the Gulf of Cádiz; (2) to establish the sediment toxicity caused by the presence of contaminants in the sediment samples; (3) to compare the sediment quality of the various areas studied by linking contamination and ecotoxicological data. 2. Materials and methods 2.2. Chemical analysis Sediment aliquots for chemical analysis were dried at room temperature and then gently homogenized. Total organic carbon (TOC) concentration and sediment grain size (fines: % of dry sediment < 63 mm) were studied in order to determine the geochemical matrix characteristics. Organic carbon content was determined using the method of Gaudette et al. (1974) with the El Rayis (1985) modification. For sediment grain size, an aliquot of wet sediment was analyzed using a Fristch laser particle sizer (model Analysette 22) following the method reported by DelValls and Chapman (1998). For trace metal analysis, the sediments were digested as described by Loring and Rantala (1992). Zn and Cu concentrations in the extracts were determined using a PerkineElmer 2100 flame atomic absorption spectrophotometer. The other trace metals were measured by graphite furnace atomic absorption spectrophotometry (PerkineElmer 4100 ZL). Concentrations of Hg were determined using a PerkineElmer MHS-FIAS coupled with a PerkineElmer 4100 ZL spectrophotometer. Results are expressed as mg kg1 dry sediment. The analytical procedures were checked using reference material (MESS-1 NRC and CRM 277 BCR) and showed agreement with the certified values of more than 90%. The analyses of PAHs and PCBs were carried out according to USEPA SW-846 Method 827C78082. Briefly, following recommendations by Riba et al. (2002), dried samples were Soxhlet extracted with n-hexane for 18 h, and the extracts were isolated by column chromatography on Florisile alumino-silica. PCBs and PAHs were eluted and their fractions were dried in a rotating evaporator and re-dissolved in isooctane. Aromatic fractions were analyzed on a HewlettePackard (HP) 5890 Series II gas chromatographer coupled with an HP 5970 mass spectrometer. Chromatographic resolution was achieved with a 30 m 0.250 mm DB-5 capillary column, which has a 0.25 mm film thickness, with helium as carrier gas. The 16 priority PAHs considered by the US Environmental Protection Agency were analyzed by GCeMS using selected ion monitoring (SIM). Quality control was carried out using NRC-CNRC HS-6 sediment reference material. Analysis of PCBs as AROCLOR 1242 and AROCLOR 1260 was performed using the same instrument with an electron capture detector (GC/ECD) and a 30 m 0.25 mm MDN-5S capillary column. Quantification was performed by the external standard technique by comparison of peak areas in the sample with those obtained by injecting a standard mixture of AROCLOR 1242 and 1260. Quality control was carried out with NRC-CNRC HS-1 sediment reference material. For both set of organic chemicals, PAHs and AROCLOR, the analytical procedure showed agreement with the certified values of more than 90%. 2.1. Approach Fig. 1 shows the seven sediment sampling stations located in the National park of the Atlantic Islands that were selected in the area of Galicia, three stations in the island of Ons (D07, D09 and D18) and four stations in the Cı́es archipelago (D60, D66, D79 and FIG). In the Gulf of Cádiz seven stations were selected in the area of the Bay of Algeciras: three stations in the mouth of the river Guadarranque (GR1, which is near an oil-fired electricity generating plant, GR30 and GR4, both near chemical processing plants), one station in the mouth of the river Palmones (P4) and three stations in the Bay (AL1 and AL2, both located in the port and near the city of Algeciras, and AL5, near a chemical plant). All these sediments have suffered repeated impacts by moderate or small oil spills caused by maritime traffic and bunkering activities in the area during recent decades. Clean sediment from the Bay of Cádiz was used as the negative control (Ca1). An artificial sample (TM) was made by mixing a toxic mud from an accidental mining spill in Spain (Aznalcóllar, April 1998) with the same clean sediment and used as positive toxicity control (Riba et al., 2003). Sediments were collected with a 0.025 m2 Van Veen grab and transferred to the cooler. When sufficient sediment had been collected from a particular station, the cooler was transported to the laboratory. The contents of the cooler were homogenized with a Teflon spoon until no colour or textural differences could be detected. The samples were subsampled for physical characterization and chemical quantification. After that, sediment samples were maintained in the cooler at 4 C in the dark until they were used for sediment toxicity testing, but no longer than 2 weeks. 2.3. Microtox bioassay The commercial Microtox test is a bioassay that uses the bioluminescence of the bacteria Vibrio fischeri as an indicator of the quality of the sample (liquid or solid phase) exposed; the bioluminescence of the bacteria is related to its metabolism therefore, a diminution of the sediment quality will be reflected in the decrease of the quantity of light emitted. In the Microtox toxicity test, the measures of the IC50 (which is the concentration of dry sediment that provokes a 50% inhibition of the light emitted by the bacteria) provide the information about the sediment toxicity. The bioassay of bioluminescence inhibition with the bacteria V. fischeri was conducted on solid phase with the commercial Microtox apparatus (model 500) by following the protocols for the solid phase test (SPT) according to the standard operating procedure (AZUR Environmental, 1998). Briefly, 7 g (0.01 g) of sediment were tested as suspensions prepared with 35 mL of commercial Microtox Solid Phase Test Diluent and diluted to a series of nine concentrations in the cuvettes. The reconstituted bacteria were added to the dilutions which were incubated for a period of 20 min at 15 C in a waterbath. Next the dilutions were filtered through the filter columns and 500 mL of content of each cuvette of the bath were transferred to its corresponding cuvette in the apparatus and bioluminescence was measured in the ‘‘read well’’. The modification of the basic solid phase test (BSPT) reported by Campisi et al. (2005) was carried out and an average value of the IC50 from using both protocols was obtained for each sample. -62- C. Morales-Caselles et al. / Environmental Pollution 146 (2007) 233e240 •D18 235 Galician Coast •D07 Spain •D09 N Gulf of Cádiz Ons Bay of Algeciras GR1• •GR3’ •GR4 •P4 •AL5 •FIG Bay of Cádiz •D79 •AL2 •AL1 •D66 •D60 •Ca1 Cíes Fig. 1. Map of the coastal area of Galicia, the Bay of Algeciras and the Bay of Cádiz showing the general areas sampled and locations of the sampling stations. D(#) refers to the stations located in Galicia and AL(#), P(#), and GR(#) to those in the Bay of Algeciras. Ca1 was the station selected as negative control in the Bay of Cádiz. 2.4. Amphipod bioassay Individuals of C. volutator were obtained from the field in a clean area located in the coast of Galicia (Morales-Caselles, 2005) by sieving mud through a 1 mm mesh; when the organisms were isolated they were placed in 11 L capacity aquariums with clean seawater and sieved sediment (collected in the same area as the organisms) and were maintained in the laboratory under controlled conditions for acclimation until the start of the test. Aeration was provided and natural photoperiod was selected. During acclimation (1 month) the organisms were fed twice a week with food for invertebrates (‘‘Marine Invertebrate Diet’’ which is a mixture of amino acids and organic particles) and water was replaced. The toxicity test was conducted in replicate (5) by exposing individuals of the amphipods C. volutator to bulk sediment using the percentage of survival after 10 days of exposure as the end point (ASTM, 1993). Mortality is measured after the time of exposure and the results obtained have been correlated positively with changes in benthic communities (Long et al., 2001). Approximately, 250 g of sieved (1 mm) sediment was placed in 2 L glass containers and then about 750 mL of clean seawater were added. Aeration was provided after the sediment had settled down. The individuals of Corophium were sieved and separated from sediment of the acclimatising tanks and were placed in each replicate container (20 individuals per container). The containers were covered in order to avoid water evaporation (a hole was made in the lid to provide aeration), and maintained at 19 C during the 10 days of exposure. After that time, the contents from the different stations with the various replicates were sieved and the organisms’ survival rate was recorded. 2.5. Statistical analysis ANOVA was performed in order to determine significant differences ( p < 0.05) in amphipod survival among the toxicity results obtained for the control site and the other sampling sites. Also, contamination and toxicity data were linked by factor analysis, using principal components analysis (PCA) as the extraction procedure; this is a multivariate statistical technique for exploring variable distributions (Riba et al., 2003). The original data set -63- used in the analysis included two acute toxicity responses (amphipod survival and the IC50 measured in the Microtox bioassay), the sediment concentration of different contaminants (PAHs, PCBs, Cd, Cu, Ni, Co, V, Pb, Zn, Hg), and the geochemical matrix characteristics (including total organic carbon and grain size distributions). The objective of PCA is to derive a reduced number of new variables as linear combinations of the original variables. This provides a description of the structure of the data with the minimum loss of information. 3. Results 3.1. Chemical analysis Summarized results of chemical analyses in the sediments used for both bioassays are shown in Table 1. In general, results do not show a prevailing tendency in the concentration of metals among sediments from the different areas, although the toxic mud presents the highest concentration of metals. On the other hand, organic contaminants (PAHs and PCBs) seem to be at higher levels in sediments collected in the Bay of Algeciras than in the area of Galicia. The negative control (Ca1) shows the lowest levels of metals, and no organic contamination was found. 3.2. Microtox bioassay The highest inhibition of bioluminescence, which corresponds to an IC50 < 600 mg L1 dry weight, is shown in the samples collected at the Bay of Algeciras stations AL2 (69 mg L1), AL1 (208 mg L1), GR30 (235 mg L1), GR4 (249 mg L1) and GR1 (522 mg L1), and in the sediments from the coast of Galicia D60 (358 mg L1), D79 (364 mg L1), D18 (390 mg L1) and D66 (486 mg L1). C. Morales-Caselles et al. / Environmental Pollution 146 (2007) 233e240 236 Table 1 Average values of total organic carbon (%dry weight), fines (% of dry sediment < 63 mm) and the concentration of contaminants (metals (mg kg1 dry weight); PAHs and PCBs (mg kg1 dry weight)) in sediment samples (negative control: Ca1; positive control: TM; Algeciras Bay: GR1, GR30 , GR4, P4, AL1, AL2, AL5; Galicia: D07, D09, D18, D60, D66, D79 and FIG.) Not detected is expressed by n.d. Ca1 GR1 GR30 GR4 P4 AL1 AL2 AL5 D07 D09 D18 D60 D66 D79 FIG TM TOC Fines Zn Cd Pb Cu Ni Co V Hg PAH PCBs 1.07 3.12 2.15 3.19 2.09 2.35 3.22 1.22 3.79 4.61 2.42 3.56 0.37 3.58 2.10 1.00 1.04 75.1 89.2 39.5 34 92.3 90.8 3.2 45.6 59.9 12.9 60.9 11.3 70.2 2.12 10.1 21.3 44.8 138 35.3 50.4 137 54.0 23.0 85.3 107 55.5 101 14.0 114 76.2 2181 0.92 0.61 0.17 0.10 0.62 0.16 0.11 0.14 n.d. n.d. n.d. n.d. n.d. n.d. n.d. 5.40 2.31 9.10 22.0 6.21 5.64 32.0 9.81 7.12 23.1 28.3 14.2 31.0 4.10 29.1 26 789 6.98 12.6 5.01 3.67 11.3 30.5 7.59 10.8 251 160 20.8 70.9 16.2 150 18.5 210 0.06 6.01 74.7 13.1 24.7 50.9 15.1 52.6 1.04 11.7 3.44 16.2 4.60 4.44 11.8 8.5 3.40 n.d. 12.8 5.59 1.11 n.d. 1.69 5.09 n.d. n.d. 2.00 n.d. 0.30 n.d. 0.50 n.d. 80.0 6.69 26.1 n.d. 85.0 60.8 4.82 2.19 81.2 116 54.0 125 n.d. 13.7 n.d. n.d. n.d. n.d. 1.04 0.25 0.11 1.11 0.81 0.26 0.08 0.07 0.04 0.12 0.06 0.09 0.04 5.61 n.d. 546 2961 802 21.4 1383 1376 1218 465 240 480 702 384 273 390 n.d. n.d. 0.86 22.0 1.75 4.64 0.46 0.65 0.33 n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. The positive control of toxicity TM shows a 50% inhibition of bioluminescence at very low concentration (142 mg L1). The sediment obtained from the Bay of Cádiz and used as the clean reference (station Ca1), showed the highest value of IC50 (6013 mg L1) and confirms its validity as the negative toxicity control. Microtox results are shown in Fig. 2. measured in the sediments from GR30 (100%), TM (100%), GR4 (75%), D18 (45%), D66 (60%), P4 (33.3%) and AL5 (35%) was significantly different *p < 0.05 from the negative control Ca1. The other stations did not present significant differences in the mortality results compared to the control station (Ca1). 3.3. Amphipod bioassay 3.4. Statistical analysis Mean mortality results after the 10 days amphipod toxicity test are shown in Fig. 3. The highest mortality measurements (100%) were associated with sediments found in the Bay of Algeciras at station GR30 and with the positive control of toxicity TM, while lowest mortality (3.3%) was associated with sediments from the reference station Ca1. The mortality To link the set of data obtained, the original variables from chemical concentration and toxicity responses were analyzed by factor analysis, using principal components analysis (PCA) as the extraction procedure; this is a multivariate statistical technique (MAA) for exploring distributions of the variables (chemical concentration, n ¼ 14; toxicity data, n ¼ 2). 2000 1800 8000 IC50 (mgL-1 dry weight) Not Toxic Toxic 1600 1400 1200 [1] 1000 [2] 800 6000 600 400 200 0 4000 D09 P4 D07 FIG GR1 D66 D18 D79 D69 GR4 GR3’ AL1 TM AL2 2000 0 Ca1 AL 5 D09 P4 D07 FIG GR1 D66 D18 D79 D60 GR4 GR3' AL1 TM AL2 Fig. 2. IC50 results obtained from the application of the Microtox test to sediment samples from the various stations. A zoom is provided for IC50 < 1800 mg L1 (dry weight). Lines displayed show the limits below which the sediment sample is considered toxic by the Canadian Standards (1000 mg L1 dry weight) and by the proposed Spanish Standards (Casado-Martı́nez et al., in press), 750 mg L1 (dry weight). -64- C. Morales-Caselles et al. / Environmental Pollution 146 (2007) 233e240 237 120.0 * * * 80.0 * 60.0 * * Toxic Mortality ( ) 100.0 * 40.0 Not Toxic 20.0 0.0 Ca1 Gr1 Gr3' Gr4 P4 AL1 AL2 AL5 D07 D09 D18 D60 D66 D79 FIG TM stations Fig. 3. Mortality results after 10 days of exposing C. volutator to the sediment samples. Asterisks indicate significant differences between the amphipod mortality rate in the treatments and the negative control (*p < 005). The line displayed shows the limits below which the sediment samples are considered toxic by the proposed Spanish Standards (DelValls et al., 2004; Casado-Martı́nez et al., in press). Those samples where the mortality rate of the amphipods is 20% higher than the mortality recorded in the negative control (Ca1) and show significantly different (*p < 005) results compared to those obtained in Ca1, are considered as toxic. The factor analysis was performed on the correlation matrix; the variables were autoscaled (standardized) so as to be treated with equal importance (Riba et al., 2004a). The application of MAA to the original 14 variables indicates that they can be grouped in three new factors. These factors explain 78.3% of the total variance in the original data set. In the present study, we decided to interpret a group of variables as those associated with a particular component where the loading was 0.30 or higher (Table 2). This approximates to Comreys’ cut-off of 0.55 (Comreys, 1973) for a good association between an original variable and a factor, and also takes into account discontinuities in the magnitudes of loadings approximating the original variables. The first principal factor, #1 is predominant and accounts for 35.0% of the variance; it shows the toxicity to the bacteria and the amphipods associated with the presence of trace metals in sediments (Zn, Cd, Pb, Cu and Hg). The second Table 2 Sorted rotated factor loadings (pattern) of 14 variables for the three principal factors resulting from the multivariate analysis of results obtained from the chemical analysis and the acute toxicity tests (Microtox and C. volutator bioassay) %Variance TOC Fines Zn Cd Pb Cu Ni Co V Hg PAH PCBs Microtox Corophium Factor 1 Factor 2 Factor 3 35.01 28.76 14.54 e e 0.98 0.93 0.98 0.51 e e e 0.98 e e 0.43 0.59 e 0.40 e e e e 0.86 0.88 e e 0.94 0.88 0.30 0.52 0.86 0.84 e e e 0.42 e e 0.41 e e e e e factor, #2 accounts for 28.8% of the variance; it explains the amphipods and bacteria toxicity associated with the chemical concentrations of the metals Co and Ni, the organic contaminants PAHs and PCBs. The third factor, #3 accounts for 14.5% of the variance; it shows the relationship between the grain size and the total organic carbon in the sediments with the presence of Cu and V, but toxicity does not contribute to this factor. The influence of the three factors at the 16 stations is reflected by the Factor score at these stations and is shown in Fig. 4. The definition of Factor 1, with positive loading, is the acute toxicity of the organisms to metals bound to sediment, it is mainly prevalent in the positive control TM (3.65) followed by GR30 (0.02) and AL2 (0.01) with low prevalence. Factor 2 is defined as the lethal toxicity of the amphipods related to the concentration of metals Co and Ni and to the organic compounds, mainly PAHs, bound to sediments; this factor shows significant prevalence in the stations from the Bay of Algeciras: GR4 (0.49), AL1 (0.49), AL2 (0.47), AL5 (0.61) and mainly in GR30 (3.28). The definition of Factor 3, with negative loading, does not include information about the toxicity of the contaminants, but indicates the association of geochemical features of the sediment, described by the relationship between total organic carbon and grain size. 4. Discussion The chemical data obtained in the analyses show how the levels of PAHs are, in general, higher at the stations in the Bay of Algeciras than in the stations selected on the coast of Galicia. These chemical data can be compared to international sediment quality guidelines (SQGs) that specify the levels of chemical contaminants associated with biological effects (DelValls et al., 2004). In this regard, the samples collected at GR30 , AL1, AL2 and AL5 exceed the SQGs for PAHs defined by Dutch agencies (Tweede Kamer, vergaderjaar, 1994e1995); this implies that the sediments from these locations could be considered slightly or moderately polluted -65- C. Morales-Caselles et al. / Environmental Pollution 146 (2007) 233e240 238 Factor 1 4 TM GR3' AL2 0 AL1 D07 GR4 GR1 D79 D09 D18 P4 D60 D66 FIG AL5 Ca1 -1 4 GR3' 3 1 Factor 2 GR4 AL1 AL2 AL5 0 P4 GR1 -1 D18 D60 D66 Ca1 D07 D09 D79 FIG TM -2 2 AL2 1 Factor 3 D09 D07 AL1 D60 D79 GR1 GR3' 0 GR4 P4 D18 TM -1 FIG Ca1 AL5 D66 -2 Fig. 4. Estimated factor scores for the three factors in each of the 16 cases. The factor scores quantify the prevalence of each factor for every station and is used to establish the definition of each factor. according to the Dutch SQGs for PAHs. Following the recommendations described by MacDonald et al. (1996), the sediments from GR4 and D60 would also be considered as slightly polluted by this contaminant and adverse effects could be frequent. There are some stations in the Galician islands (D07, D09, D18, D60, D79 and FIG) where sediment exceeds the SQGs defined for Cu by international agencies and previous studies (CEDEX, 1994; Tweede Kamer, vergaderjaar, 1994e1995; MacDonald et al., 1996; NOAA, 1999). Although contamination by copper was observed in the uppermost layer in the Prestige shipwreck area of the Northeast Atlantic Ocean (Prego and Cobelo-Garcı́a, 2004; Cobelo-Garcı́a et al., 2004), this Cu contamination should not be related to the shipwreck, because levels of Cu in the fuel oil carried by the Prestige were relatively low (3.39 mg kg1) and previous studies have shown that there are other sources of this metal in the area (Carballeira et al., 1997). Also, there are some stations in the Bay of Algeciras (GR30 , AL1 and AL5) where sediment exceeds some international SQGs (CEDEX, 1994; Tweede Kamer, vergaderjaar, 1994e1995; MacDonald et al., 1996; NOAA, 1999) defined for Ni and for Hg (GR30 , GR4, AL1, AL2 and AL5). The positive control TM exceeds almost all the SQGs defined by international agencies and other authors (CEDEX, 1994; Tweede Kamer, vergaderjaar, 1994e1995; MacDonald et al., 1996; NOAA, 1999) for the metals Zn, Cd, Pb, Hg and Cu. In Fig. 2 the Microtox results are shown. The lines represent the values below which sediment toxicity is assumed by different international agencies (Casado-Martı́nez et al., in press). The Canadian Standards (Environment Canada, 2002) considers the limit to be 1000 mg L1 (dry weight) while in the Spanish Standards (DelValls et al., 2004; Casado-Martı́nez et al., in press) this limit is associated with a concentration of 750 mg L1 (dry weight). In this case both guidelines agree and the sediments from GR1, D66, D18, D79, D69, GR4, GR30 , AL1, TM and AL2 would all be considered as toxic. The line displayed in the graph for the Corophium mortality (Fig. 3) shows the limit above which sediments are considered toxic by the US Environmental Protection Agency (USEPA, 1994) and the Spanish Standards (DelValls et al., 2004; Casado-Martı́nez et al., in press). These agencies establish that a sediment sample can be considered toxic when the mortality rate recorded from the treatment is 20% higher than the mortality measured in the negative control sediment; it also shows significantly different (*p < 0.05) mortality results compared with those obtained in the negative control. In this case all the samples that are significantly different (*p < 0.05) from Ca1 would be considered toxic by these agencies because they also have a mortality rate higher than 20% compared to the control sediment (10%). From the MMA performed to link together the chemical and ecotoxicological data, we have obtained three factors that account for all the variables and have a different influence for each sampling site. Factor 1 accounts for the toxicity responses of the two bioassays due to the metals that bind to sediments. This factor is seen with most prevalence in the positive control TM which presents the highest levels of metals in the study, a low IC50 and a 100% mortality of Corophium after 10 days of exposure. Regarding the toxicity due to the presence of organic contaminants in the sediments, Factor 2 is mainly prevalent at the stations in the Bay of Algeciras: GR30 , GR4, AL1, AL2 and AL5. This factor also includes toxicity due to the metals Ni and Co and the toxicity is determined by the mortality of the amphipods and the low IC50 measured with the bacteria bioassay. The content of PCBs in the sediments studied does not exceed the SQGs and the highest concentration of PCBs is found in sediments from GR30 whereas in the Galician sediments, it was not found at all. Thus, the PAHs can be considered as the main organic contaminant producing the toxicity measured in the study. The metals Ni and Co have been previously reported associated with PAHs in the oil spills occurring in the area of Algeciras (CSIC, 2005) caused both by the industrial plants located in the area and by maritime activities, and in other areas affected by oil spills (Massoud et al., 1998). However, both of these metals (Co and Ni) could originate from any of the various local activities, not only accidental oil spills. The toxicity results from Microtox have a low loading in this factor, maybe because this is not the best test for -66- C. Morales-Caselles et al. / Environmental Pollution 146 (2007) 233e240 organic compounds, due to the insoluble nature of most of the oil compounds (Simon et al., 2004). However, it is important to highlight that the Microtox is a screening bioassay and it is suggested that the biotests alone may not be representative in certain cases of the full impact of a given pollutant on an ecosystem (Brohon et al., 2001). On the other hand, previous studies have shown that the toxicity of sediments to Corophium is closely correlated with their hydrocarbon content (Grant and Briggs, 2002). In general, results obtained in the MAA suggest that the sediments from the Bay of Algeciras and the Galician islands are contaminated with PAHs and that toxic responses due to these compounds occur in both places. However, toxicity is mainly seen in sediments from the Bay of Algeciras, and toxic sediments show a higher frequency in the stations located in this area (GR1, GR30 , GR4, P4, AL1, AL2 and AL5) than in those sampled on the coast of Galicia (D07, D09, D18, D60, D66, D79 and FIG). This could be associated either with the higher quantity of PAHs or with the presence of a more complex mixture of contaminants that has not been analyzed in this study, in sediments from the Bay of Algeciras rather than in those from Galicia. Also, based on the results obtained in this study, the concentration of PAHs bound to sediments in the Bay of Algeciras could be more bioavailable for the organisms studied and would produce more toxicity than that found in Galicia. However, this greater bioavailability of PAHs bound to sediments in the Bay of Algeciras is only a hypothesis that needs to be taken into account in later work. Sediment quality guidelines (benchmarks) for PAHs can be determined with the information obtained in this study by means of MAA using the Factor scores. The highest concentrations of PAHs measured at those stations where the value of the Factor 2 score is 0 or below 0, define the concentration of PAHs ‘‘not associated with the toxic effect’’ measured in the study. It is determined at station D60 with a value of 702 mg kg1 (dry weight) (V1). The lowest concentration of PAHs measured at the station where the value of Factor 2 score is positive defines the concentration of PAHs ‘‘associated with the toxic effect measured in this study’’. It is determined at station GR4 with a value of 802 mg kg1 (dry weight) (V2). In general, our results have shown that the highest pollution measured in the Gulf of Cádiz was determined in sediments sampled from the Bay of Algeciras and especially at station GR30 , related to chronic contamination, while moderate contamination and low toxicity was determined on the coast of Galicia in the Cı́es archipelago. Previous studies (Riba et al., 2004b) agree that moderate but chronic inputs of contaminants can produce more pollution in coastal sediments than higher but acute environmental impacts. 5. Conclusions From the results obtained in the various analyses performed in this study, we can conclude that PAHs are the main contaminant at the sites studied on the coast of Galicia and in the Bay of Algeciras, while there is no such contamination in the sediments from the station located in the Bay of Cádiz; the -67- 239 concentrations of PAHs in sediments from the Bay of Algeciras are, in general, higher than in sediments from the coast of Galicia. Toxicity is also higher in the Bay of Algeciras than in the Galician islands, but no toxicity was detected in the sediment from the Bay of Cádiz station. Finally, it has been shown that sediments from the Bay of Algeciras are chronically polluted by PAHs (V1: 702 mg kg1; V2: 802 mg kg1) while those of the coast of Galicia can only be considered as moderately or not polluted. In the Bay of Cádiz no environmental degradation was measured. To sum up, with the present study we have shown that sediments found in the Bay of Algeciras, affected by chronic oil spills, are more environmentally degradated (polluted) than those found in the coast of Galicia, which was mainly affected by the Prestige accidental oil spill. Acknowledgements The work described was partly supported by a Grant funded by the Ministry of Education and Science VEM2003-20563 and by CIS funded by the Ministry of Environment. Carmen Morales-Caselles thanks the Ministry of Education and Science for funding her research fellowship (FPU). We are grateful for the support and help of the members of the CIS. Special thanks are given to Mercedes Conradi, Augusto César and Carmen Casado-Martı́nez. References American Society for Testing and Materials, 1993. Standard Guide for Conducting 10-day Static Sediment Toxicity Tests with the Marine and Estuarine Amphipods. ASTM, Philadelphia, pp. 1367e1392. AZUR Environmental, 1998. Microtox M500 Manual. AZUR Environmental, Carlsbad, CA, USA. Briggs, A.D., Greenwood, N., Grant, A., 2003. Can turbidity caused by Corophium volutator (Pallas) activity be used to assess sediment toxicity rapidly? Mar. Environ. Res. 55, 181e192. Brohon, B., Delolme, C., Gourdon, R., 2001. Complementarity of bioassays and microbial activity measurements for the evaluation of hydrocarboncontaminated soils quality. Soil Biol. Biochem. 33, 883e891. 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Using marine bioassays to classify the toxicity of Dutch Harbor sediments. Environ. Toxicol. Chem. 22, 1535e1547. Tweede Kamer, vergaderjaar, 1994e1995, Evaluatienota Water, Dutch standards for contaminated sediments, 21 250, 2728. USEPA, 1994. Methods for Assessing the Toxicity of Sediment-associated Contaminants with Estuarine and Marine Amphipods. United States Environmental Protection Agency (USEPA). EPA/600/R-94/025. Van Beelen, P., 2003. A review on the application of microbial toxicity tests for deriving sediment quality guidelines. Chemosphere 53, 795e808. -68- Sedimentȱcontamination,ȱbioavailabilityȱandȱtoxicityȱofȱsedimentsȱ affectedȱbyȱanȱacuteȱoilȱspill.ȱFourȱyearsȱafterȱtheȱsinkingȱofȱtheȱ tankerȱprestigeȱ(2002).ȱ C.ȱMoralesȬCaselles1,2,*,ȱJ.ȱKalman1,2,ȱA.C.ȱMicaelo3,ȱA.M.ȱFerreira3,ȱC.ȱVale3,ȱI.ȱ Riba1,2,ȱT.A.ȱDelValls1,2ȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱ 1 ȱUniversidadȱdeȱCádizȬCalidadȱAmbientalȱyȱPatologíaȱ(UCAȬCSIC).ȱConsejoȱSuperiorȱ deȱInvestigacionesȱCientíficasȱ(CSIC).ȱInstitutoȱdeȱCienciasȱMarinasȱdeȱAndalucíaȱ (ICMAN).ȱPolígonoȱRíoȱSanȱPedroȱs/n.ȱ11510ȱPuertoȱReal.ȱCádiz.ȱ ȱ2ȱUNITWIN/UNESCO/WiCoP.ȱDepartamentoȱdeȱQuímicaȱFísica.ȱFacultadȱdeȱ CienciasȱdelȱMarȱyȱAmbientales.ȱPolígonoȱRíoȱSanȱPedroȱs/n.ȱ11510ȱPuertoȱReal.ȱCádizȱ 3 ȱDepartamentoȱdoȱAmbienteȱAquatico.ȱInstitutoȱdeȱInvestigaçaoȱdasȱPescasȱeȱdoȱMar,ȱ (INIAPȬIPIMAR).ȱAV.ȱBrasilia,ȱ1400ȱLisboa,ȱPortugal.ȱ Abstractȱ Sedimentȱ contaminationȱ andȱ threeȱ bioassaysȱ wereȱ usedȱ toȱ determineȱ theȱ sedimentȱqualityȱfourȱyearsȱafterȱanȱoilȱspillȱ(Prestige,ȱ2002):ȱtheȱMicrotox®ȱtest,ȱ aȱ10ȬdayȱbioassayȱusingȱtheȱamphipodȱAmpeliscaȱbrevicornis,ȱandȱaȱpolychaeteȱ 10Ȭdayȱ toxicityȱ testȱ withȱ theȱ lugwormȱ Arenicolaȱ marina.ȱ Inȱ addition,ȱ bioaccumulationȱ ofȱ PAHsȱ wasȱ examinedȱ inȱ theȱ polychaeteȱ afterȱ 10ȱ daysȱ ofȱ exposure.ȱ Theȱ resultsȱ obtainedȱ fromȱ theȱ toxicityȱ testsȱ andȱ bioaccumulationȱ analysesȱwereȱstatisticallyȱcomparedȱtoȱtheȱsedimentȱchemicalȱdata,ȱinȱorderȱtoȱ assessȱ theȱ bioavailabilityȱ ofȱ theȱ contaminants,ȱ theirȱ effects,ȱ andȱ theirȱ relationshipȱwithȱtheȱoilȱspill.ȱTheȱsedimentsȱstudiedȱwereȱfromȱtwoȱareasȱofȱtheȱ GalicianȱCoastȱ(NWȱSpain):ȱtheȱBayȱofȱCormeȬLaxeȱandȱtheȱCíesȱIsland,ȱlocatedȱ inȱ theȱ Atlanticȱ Islandȱ Nationalȱ Park.ȱ Theȱ resultsȱ pointȱ toȱ aȱ decreaseȱ inȱ contaminationȱwithȱrespectȱtoȱpreviousȱstudiesȱandȱtoȱtheȱdisappearanceȱofȱtheȱ acuteȱ toxicityȱ fourȱ yearsȱ afterȱ theȱ oilȱ spill.ȱ Howeverȱ anȱ importantȱ bioaccumulationȱofȱPAHsȱwasȱdetectedȱinȱtheȱorganismsȱexposedȱtoȱsedimentsȱ ȱChemosphereȱ(aceptadoȱconȱrevisiones) - 69 - fromȱ CormeȬLaxe,ȱ suggestingȱ thatȱ despiteȱ theȱ recoveryȱ ofȱ theȱ environmentalȱ qualityȱofȱtheȱarea,ȱeffectsȱinȱtheȱbiotaȱmightȱbeȱoccuring. Keywords:ȱPAHs,ȱtoxicity,ȱbioaccumulation,ȱMicrotox,ȱamphipod,ȱpolychaeteȱȱ 1.ȱIntroductionȱ Theȱ informationȱ obtainingȱ byȱ integratingȱ theȱ chemicalȱ concentrationȱ inȱ sedimentsȱandȱfromȱspecificȱsedimentȱbioassaysȱ(toxicityȱandȱbioaccumulation)ȱ isȱ consideredȱ atȱ theȱ presentȱ timeȱ theȱ bestȱ approachȱ toȱ assessȱ theȱ sedimentȱ qualityȱ andȱ toȱ testȱ theȱ toxicityȱ andȱ bioavailabilityȱ ofȱ chemicalȱ compoundsȱ inȱ sedimentsȱtoȱbenthicȱorganismsȱ(CasadoȬMartínezȱetȱal.,ȱinȱpress;ȱDelVallsȱandȱ Conradi,ȱ 2000;ȱ Chapmanȱ etȱ al.,ȱ 2002).ȱ Chemicalȱ analysesȱ performedȱ aloneȱ inȱ bulkȱ sedimentȱ doȱ notȱ alwaysȱ reflectȱ theȱ toxicȱ fractionȱ sinceȱ theyȱ varyȱ dependingȱonȱtheȱbioavailabilityȱandȱbioreactivityȱofȱtheȱtoxicȱcompounds.ȱAnȱ approachȱtoȱthisȱinformationȱcanȱbeȱreachedȱbyȱrunningȱbioassays.ȱȱ Theȱ useȱ ofȱ theȱ commercialȱ bioassayȱ Microtox®ȱ hasȱ increasedȱ inȱ recentȱ years,ȱ dueȱ toȱ theȱ straightforwardȱ wayȱ toȱ detectȱ theȱ ‘‘hotȱ spots’’ȱ ofȱ fieldȱ contaminationȱ inȱ theȱ screeningȱ procedureȱ (Mowatȱ andȱ Bundy,ȱ 2001;ȱ Stronkhorstȱ etȱ al.,ȱ 2003;ȱ Vanȱ Beelen,ȱ 2003,ȱ CasadoȬMartinezȱ etȱ al,ȱ 2006a).ȱ Microtox®ȱhasȱalsoȱbeenȱusedȱsuccessfullyȱinȱtheȱpast,ȱtoȱassessȱtheȱimpactȱofȱoilȱ spillsȱandȱoilȱcontaminatedȱsedimentsȱ(Brohonȱetȱal.,ȱ2001;ȱKennethȱetȱal.,ȱ2003;ȱ Pelletierȱetȱal.,ȱ2004;ȱMoralesȬCasellesȱetȱal.,ȱ2007).ȱPreviousȱstudiesȱhaveȱshownȱ thatȱ theȱ amphipodȱ specieȱ Ampeliscaȱ brevicornisȱ isȱ aȱ sensitiveȱ organismȱ validȱ toȱ assessȱtoxicityȱofȱcontaminatedȱsedimentsȱ(Ribaȱetȱal.ȱ2003;ȱCasadoȱMartinezȱetȱ al.,ȱ 2006b;ȱ MoralesȬCaselles,ȱ etȱ al.ȱ submitted).ȱ Theȱ toxicityȱ testȱ accordingȱ toȱ standardȱmethodologiesȱ(ASTMȱ1993)ȱhasȱbeenȱusedȱinȱpreviousȱstudiesȱforȱtheȱ assessmentȱ ofȱ spillsȱ (Grantȱ andȱ Briggs,ȱ 2002;ȱ Briggsȱ etȱ al.,ȱ 2003).ȱ Theȱ 10Ȭdȱ Arenicolaȱ bioassayȱ (ASTMȱ 1993)ȱ isȱ relevantȱ inȱ PAHȱ accumulationȱ studiesȱ - 70 - becauseȱA.ȱmarinaȱisȱaȱbulkȱsedimentȱfeedingȱpolychaeteȱwormȱthatȱlivesȱinȱaȱUȬ shapedȱ burrowȱ andȱ isȱ consideredȱ anȱ indicatorȱ ofȱ PAHȱ pollutionȱ (Rustȱ etȱ al.,ȱ 2004b,ȱCasadoȬMartínezȱetȱal.,ȱinȱpress).ȱȱ Inȱ Novemberȱ 13thȱ 2002ȱ theȱ oilȱ tankerȱ Prestigeȱ sufferedȱ anȱ accidentȱ 30ȱ milesȱ offȱ theȱ Galicianȱ Coastȱ (NWȱ Spain).ȱ Fewȱ daysȱ later,ȱ theȱ tankerȱ sankȱ 150ȱ milesȱoffshoreȱreleasingȱapproximatelyȱ60ȱ000ȱtonnesȱofȱheavyȱfuelȱoilȱintoȱtheȱ surroundingȱwaters,ȱwhichȱcontaminatedȱmoreȱthanȱ1000ȱkmȱofȱcoastline.ȱTheȱ physicochemicalȱ characteristicsȱ ofȱ theȱ fuelȱ oilȱ fromȱ theȱ tankerȱ wereȱ similarȱ toȱ thoseȱfromȱtheȱErikaȱ(France,ȱ1999)ȱ(CSIC,ȱ2003)ȱ)ȱandȱshowedȱaȱlowȱsolubleȱandȱ slowȱkineticsȱofȱdegradationȱunderȱnaturalȱconditions,ȱsoȱthatȱitȱwasȱexpectedȱtoȱ beȱ accumulatedȱ inȱ sedimentsȱ (DelVallsȱ 2003).ȱ Thisȱ paperȱ presentsȱ theȱ firstȱ attemptȱ toȱ assessȱ theȱ sedimentȱ contamination,ȱ toxicityȱ andȱ bioavailabilityȱ ofȱ PAHsȱ inȱ theȱ coastȱ ofȱ Galiciaȱ fourȱ yearsȱ afterȱ theȱ sinkingȱ ofȱ theȱ tankerȱ Prestigeȱ (2002).ȱȱ 2.ȱMaterialȱandȱmethodsȱ 2.1.ȱSamplingȱ Afterȱ theȱ accidentȱ ofȱ theȱ tankerȱ Prestige,ȱ theȱ Cíiesȱ Islandȱ inȱ theȱ Atlanticȱ IslandsȱNationalȱParkȱȱinȱGaliciaȱactedȱasȱaȱnaturalȱbarrierȱprotectingȱtheȱcoast.ȱ Theȱ Bayȱ ofȱ CormeȬLaxe,ȱ consideredȱ anȱ areaȱ whichȱ developsȱ farming,ȱ fishing,ȱ andȱshellȱfishingȱactivitiesȱ(Blancoȱetȱal.,ȱ2006)ȱwasȱalsoȱimportantlyȱaffectedȱbyȱ theȱ spill.ȱ Surfaceȱ sedimentsȱ wereȱ collectedȱ inȱ ȱ 2005Ȭ2006ȱ withȱ aȱ 0.025ȱ m2ȱ Vanȱ Veenȱ grabȱ nearȱ theȱ islandȱ ofȱ Cíesȱ Islandȱ inȱ theȱ Atlanticȱ Islandsȱ Nationalȱ Parkȱ (stationsȱ A,ȱ Bȱ andȱ C)ȱ inȱ theȱ ´Bayȱ ofȱ CormeȬLaxe’ȱ (stationsȱ D,ȱ E,ȱ F),ȱ andȱ inȱ theȱ Bayȱ ofȱ Cádizȱ (CA),ȱ theȱ latterȱ usedȱ asȱ referenceȱ stationȱ (Figureȱ 1).ȱ Sedimentȱ samplesȱwereȱkeptȱinȱaȱcoolerȱ(4ºC)ȱandȱthenȱtransferredȱtoȱtheȱlaboratory.ȱEachȱ - 71 - sedimentȱ sampleȱ wasȱ homogenizedȱ withȱ aȱ Teflonȱ spoonȱ untilȱ noȱ colourȱ orȱ texturalȱdifferencesȱcouldȱbeȱdetected,ȱandȱafterwardsȱsubsampledȱforȱphysicalȱ characterization,ȱ chemicalȱ analysisȱ andȱ toxicityȱ tests.ȱ Sedimentȱ toxicityȱ testsȱ wereȱrunȱnoȱlongerȱthanȱ2ȱweeksȱafterȱsampling.ȱ ȱ ȱ ȱ ƒE ƒF ƒD ȱ Ría de CormeLaxe ȱ Galician Coast ȱ ȱ Spain ȱ ȱ ȱ •CA Cíes •C •A •B Ría de Vigo N ȱ ȱ Figureȱ1.ȱMapȱofȱtheȱcoastalȱareaȱofȱGaliciaȱshowingȱtheȱlocationsȱofȱtheȱ samplingȱstations.ȱA,ȱBȱandȱCȱrefersȱtoȱtheȱstationsȱlocatedȱinȱtheȱCiesȱIslandȱinȱ theȱAtlanticȱIslandȱNationalȱParkȱandȱD,ȱEȱandȱFȱtoȱthoseȱinȱtheȱBayȱofȱCormeȬ Laxe.ȱ Theȱstationȱ CAȱ locatedȱ inȱtheȱBayȱofȱCadizȱcorrespondsȱtoȱtheȱsedimentȱ usedȱasȱnegativeȱcontrol.ȱ - 72 - 2.2ȱMicrotox®ȱtestȱ InȱtheȱcommercialȱMicrotox®ȱtestȱtheȱdecreaseȱofȱtheȱbioluminescenceȱofȱ theȱbacteriaȱVibrioȱfischeriȱisȱusedȱasȱaȱqualityȱindicatorȱofȱtheȱsampleȱexposed.ȱ Measuresȱ ofȱ theȱ IC50ȱ (whichȱ isȱ theȱ dryȱ sedimentȱ concentrationȱ thatȱ provokesȱ 50%ȱ inhibitionȱ ofȱ theȱ lightȱ emittedȱ byȱ theȱ bacteria)ȱ provideȱ theȱ informationȱ aboutȱ theȱ sedimentȱ toxicity.ȱ Theȱ bioassayȱ ofȱ bioluminescenceȱ inhibitionȱ withȱ theȱ bacteriaȱ V.ȱ fischeriȱ wasȱ conductedȱ onȱ solidȱ phaseȱ withȱ theȱ commercialȱ Microtox®ȱapparatusȱ(modelȱ500),ȱbyȱfollowingȱtheȱprotocolsȱforȱtheȱbasicȱsolidȱ phaseȱ testȱ (BSPT),ȱ accordingȱ toȱ theȱ standardȱ operatingȱ procedureȱ (AZURȱ Environmental,ȱ 1998)ȱ withȱ theȱ modificationsȱ reportedȱ byȱ Campisiȱ etȱ al.ȱ (2005)ȱ andȱCasadoȬMartínezȱetȱal.ȱ(2006a).ȱȱȱ 2.3.ȱAmphipodȱtoxicityȱtestȱ IndividualsȱofȱtheȱspecieȱAmpeliscaȱbrevicornisȱusedȱinȱtheȱbioassayȱwereȱ collectedȱ byȱ sievingȱ theȱ sedimentȱ inȱ theȱ fieldȱ throughȱ aȱ 0.6ȱ mmȱ mesh,ȱ asȱ reportedȱbyȱRibaȱetȱal.ȱ(2003)ȱandȱCasadoȬMartínezȱetȱal.ȱ(2006b).ȱTheȱcollectedȱ biotaȱ wereȱ immediatelyȱ transportedȱ toȱ theȱ laboratoryȱ whereȱ theyȱ wereȱ placedȱ inȱ 11ȬLȱ aquariumsȱ withȱ cleanȱ seawaterȱ andȱ sievedȱ sedimentȱ fromȱ theȱ sameȱ location.ȱAerationȱwasȱprovidedȱandȱnaturalȱphotoperiodȱwasȱselected.ȱDuringȱ acclimationȱ waterȱ wasȱ replacedȱ twiceȱ aȱ week,ȱ andȱ organismsȱ wereȱ fedȱ withȱ specialȱ foodȱ forȱ invertebratesȱ (mixtureȱ madeȱ ofȱ aminoacidsȱ andȱ organicȱ particles).ȱ Theȱsedimentsȱwereȱfilteredȱ(1ȱmm)ȱpriorȱtoȱtheȱtoxicityȱtest,ȱinȱorderȱtoȱ removeȱinorganicȱandȱorganicȱdebrisȱandȱbenthicȱorganismsȱcapableȱofȱpreyingȱ Ampeliscaȱ brevicornis.ȱ Theȱ toxicityȱ testȱ wasȱ performedȱ byȱ exposingȱ individualȱ amphipodsȱ toȱ theirȱ respectiveȱ sedimentȱ fromȱ theȱ differentȱ studyȱ sites.ȱ Theȱ percentageȱ ofȱ survivalȱ afterȱ 10ȱ daysȱ ofȱ exposureȱ wasȱtheȱ measuredȱ endȱ point.ȱ - 73 - 200ȱgȱofȱsedimentsȱwereȱplacedȱinȱ2ȱLȱglassȱbeakersȱandȱaboutȱ800ȱmLȱofȱcleanȱ seawaterȱwasȱadded.ȱWhenȱtheȱsedimentȱsettledȱdownȱinȱtheȱbeakers,ȱaerationȱ wasȱ provided,ȱ andȱ 12ȱ hoursȱ afterwardsȱ theȱ individualsȱ wereȱ sievedȱ fromȱ theȱ acclimatizationȱaquariumsȱandȱ20ȱadultsȱ(3Ȭ5ȱmm)ȱofȱAmpeliscaȱwhereȱplacedȱinȱ eachȱ replicate.ȱ Noȱ foodȱ wasȱ providedȱ duringȱ theȱ experiment.ȱ Theȱ containersȱ whereȱ keptȱ inȱ anȱ incubatorȱ withȱ photoperiodȱ 12hȬlight/12hȬdarkȱ andȱ maintainedȱ atȱ 19ȱ ±ȱ 1ȱ ºCȱ duringȱ theȱ 10ȱ daysȱ ofȱ exposure.ȱ Afterȱ thisȱ time,ȱ theȱ beakersȱwhereȱsievedȱandȱtheȱsurvivalȱwasȱcountedȱinȱeachȱreplicate.ȱ 2.4.ȱPolychaeteȱbioassayȱ TheȱA.ȱmarinaȱlugwormsȱwereȱsampledȱinȱtheȱfieldȱbyȱhandȬdiggingȱandȱ immediatelyȱtransportedȱtoȱtheȱlaboratoryȱinȱcontainersȱwithȱseaȱwater.ȱOnceȱinȱ theȱlaboratory,ȱlugwormsȱwereȱplacedȱinȱaquariumsȱwithȱsievedȱsedimentȱfromȱ theȱsurveyȱareaȱ(5ȱcmȱthick)ȱandȱacclimatedȱforȱ7ȱd;ȱairȱwasȱprovidedȱandȱwaterȱ wasȱ replacedȱ threeȱ timesȱ perȱ day.ȱ Waterȱ temperatureȱ wasȱ keptȱ atȱ 18ȱ ºCȱ andȱ naturalȱphotoperiodȱwasȱselected.ȱFilteredȱsedimentsȱfromȱtheȱstudyȱsitesȱwereȱ placedȱinȱreplicatesȱinȱ11ȱLȱtanksȱreachingȱaȱ5ȱcmȱthickȱlayerȱandȱcleanȱseaȱwaterȱ wasȱadded.ȱLugwormsȱwereȱputȱintoȱtheȱtanksȱ(6ȱperȱtank)ȱwhichȱwereȱcoveredȱ toȱ avoidȱ evaporation.ȱ Mortalityȱ wasȱ recordedȱ dailyȱ andȱ afterȱ 10ȱ daysȱ ofȱ exposureȱ survivingȱ organismsȱ wereȱ transferredȱ toȱ aeratedȱ cleanȱ seaȱ waterȱ withoutȱ sediment,ȱ whereȱ theyȱ wereȱ heldȱ forȱ approximatelyȱ 8ȱ hoursȱ toȱ induceȱ gutȱemptying.ȱOrganismsȱwereȱthenȱfrozenȱatȱȬ20ȱºCȱforȱPAHsȱbioaccumulationȱ analysis.ȱȱȱ 2.5.ȱChemicalȱanalysisȱ Geochemicalȱ matrixȱ characteristicsȱ wereȱ examinedȱ byȱ analyzingȱ totalȱ organicȱ carbonȱ concentrationȱ andȱ sedimentȱgrainȱsize.ȱ Organicȱcarbonȱ contentȱ wasȱdeterminedȱusingȱtheȱmethodȱofȱGaudetteȱetȱal.ȱ(1974)ȱwithȱElȱRayis’ȱ(1985)ȱ - 74 - modification.ȱForȱsedimentȱgrainȱsize,ȱanȱaliquotȱofȱwetȱsedimentȱwasȱanalyzedȱ usingȱaȱlaserȱparticleȱsizeȱFristchȱ(modelȱAnalysetteȱ22),ȱfollowingȱtheȱmethodȱ reportedȱbyȱDelVallsȱetȱal.ȱ(1998).ȱ TraceȱmetalȱanalysisȱwereȱanalyzedȱasȱdescribedȱbyȱCasadoȬMartínezȱetȱ al.ȱ (2006c);ȱ briefly,ȱ 2.5ȱ gȱ ofȱ sedimentsȱ (<0.065ȱ mm)ȱ wereȱ placedȱ inȱ Teflonȱ containersȱ andȱ wereȱdigestedȱ inȱ microwaveȱ(400W,ȱ15ȱmin,ȱtwice)ȱwithȱHNO3ȱ 2Nȱ inȱ orderȱ toȱ extractȱ theȱ fractionȱ ofȱ metalȱ withȱ theȱ greatestȱ potentialȱ toȱ beȱ bioavailable.ȱTheȱextractsȱwereȱpurifiedȱbyȱpassingȱthroughȱaȱCȬ18ȱcolumnȱandȱ metalsȱ analysesȱ wereȱ performedȱ byȱ anodicȱ voltamperimetryȱ (ȬZn,ȱ Cd,ȱ Pb,ȱ Ni,ȱ Coȱ andȱ CuȬȱ Metrohmȱ Applicationȱ Bulletinȱ Nºȱ 147;ȱ Ȭȱ VȬȱ Metrohmȱ Applicationȱ NoteȱNºȱVȬ81).ȱForȱHgȱtheȱcoldȱvapourȱtechniqueȱwasȱusedȱandȱwasȱquantifiedȱ usingȱatomicȱabsorptionȱspectrometry.ȱTheȱanalyticalȱproceduresȱwereȱcheckedȱ usingȱ referenceȱ materialȱ (MESSȬ1ȱ NRCȱ andȱ CRMȱ 277ȱ BCR)ȱ andȱ showedȱ aȱ recoveryȱgreaterȱthanȱ90%ȱofȱtheȱcertifiedȱconcentration.ȱTheȱreasonȱwhyȱmetalsȱ wereȱanalyzedȱinȱsedimentsȱisȱbecauseȱweȱareȱstudyingȱenvironmentalȱsamplesȱ whichȱmayȱpresentȱaȱmixtureȱofȱcontaminantsȱandȱthisȱinformationȱmayȱhelpȱtoȱ elucidateȱ ifȱ theȱ biologicalȱ effectsȱ areȱ dueȱ toȱ otherȱ contaminantsȱ apartȱ fromȱ PAHs.ȱ ȱ Toȱ analyseȱ polycyclicȱ aromaticȱ hydrocarbonsȱ inȱ driedȱ sedimentsȱ andȱ lugworms,ȱ samplesȱ wereȱ soxhletȱ extractedȱ withȱ nȬhexaneȱ forȱ 18ȱ h,ȱ andȱ withȱ acetoneȱ /hexaneȱ (1:1)ȱ duringȱ 24h,ȱ respectively.ȱ Beforeȱ extractionȱ ofȱ organisms,ȱ surrogateȱ PAHsȱ standardsȱ wereȱ addedȱ toȱ eachȱ sampleȱ (acenaphetheneȬd10,ȱ phenanthreneȬd10,ȱchryseneȬd12ȱandȱperyleneȬd12)ȱwereȱdone.ȱCompoundsȱwereȱ isolatedȱfromȱextractsȱbyȱcolumnȱchromatographyȱonȱFlorisilȬaluminoȬsilicaȱforȱ sedimentsȱ orȱ silicaȬaluminaȱ forȱ lugworms.ȱ PAHsȱ wereȱ elutedȱ withȱ - 75 - dichlorometane/hexaneȱ (9:1ȱ andȱ 4:1).ȱ Aromaticȱ fractionsȱ inȱ sedimentsȱ wereȱ analyzedȱonȱaȱHewlett–Packardȱ(HP)ȱ5890ȱSeriesȱIIȱgasȱchromatographȱcoupledȱ withȱ HPȱ 5970ȱ massȱ spectrometer.ȱ PAHȱ concentrationsȱ inȱ organismsȱ wereȱ determinedȱ inȱ aȱ GCȬMSȱ Finniganȱ Matȱ GCQȱ TMȱ inȱ theȱ selectedȱ ionȱ mode.ȱ Chromatographicȱanalysisȱwasȱachievedȱwithȱaȱ30ȱmȱ×ȱ0.250ȱmmȱDBȬ5ȱcapillaryȱ columnȱ (0.25ȱ ΐmȱ filmȱ thickness)ȱ withȱ heliumȱ asȱ carrierȱ gas.ȱ Injectionȱ wasȱ performedȱinȱtheȱsplitlessȱmodeȱatȱ280ºC.ȱHeliumȱwasȱusedȱasȱcarrierȱgasȱwithȱaȱ flowȱofȱ1ȱmlȱminȱ Ȭ1.ȱTheȱovenȱtemperatureȱwasȱprogrammedȱasȱfollows:ȱinitialȱ temperatureȱwasȱ75°ȱCȱandȱthenȱrampedȱtoȱ130°Cȱatȱ20°/minȱandȱthenȱrampedȱ toȱ 320°Cȱ atȱ theȱ rateȱ ofȱ 4°C/minȱ andȱ heldȱ forȱ 15ȱ minutes.ȱ Theȱ electronȱ impactȱ ionizationȱmodeȱconditionsȱwereȱtheȱfollowing:ȱionȱenergyȱ70ȱeVȱandȱionȱsourceȱ andȱ transferȱ lineȱ temperaturesȱ 220ºC.ȱ PAHȱ wereȱ identifiedȱ byȱ retentionȱ timeȱ andȱ oneȱ characteristicȱ massȱ fragmentȱ ion.ȱ Quantificationȱ ofȱ 16ȱ PAHȱ (acenaphethylene,ȱ fluorene,ȱ phenanthrene,ȱ anthracene,ȱ fluoranthene,ȱ pyrene,ȱ chrysene,ȱ benz[a]anthracene,ȱ benzo[b]fluoranthene,ȱ benzo[k]fluoranthene,ȱ benzo[a]pyrene,ȱ benzo[e]pyrene,ȱ perylene,ȱ indeno[1,2,3Ȭcd]pyrene,ȱ dibenz[a,h]anthraceneȱ andȱ benzo[g,h,i]ȱ perylene)ȱ wereȱ doneȱ usingȱ aȱ 9Ȭpointȱ calibrationȱcurveȱforȱeachȱcompound.ȱQualityȱcontrolȱsamplesȱwereȱanalyzedȱinȱ eachȱ batchȱ ofȱ 12ȱ samples,ȱ referenceȱ materialȱ NIST,ȱ SRMȱ 2977ȱ (mussels),ȱ NRCȬ CNRCȱ HSȬ6ȱ (sediments)ȱ andȱ blanks.ȱ Theȱ analyticalȱ procedureȱ showedȱ aȱ recoveryȱ greaterȱ thanȱ 90%ȱ forȱ sedimentȱ materialsȱ andȱ betweenȱ 75Ȭ125%ȱ forȱ NISTȱ material.ȱ Detectionȱ limitsȱ rangedȱ fromȱ 1.0ȱ toȱ 5.0ȱ ngȱ gȬ1,ȱ dryȱ weight,ȱ forȱ organismsȱandȱforȱsediments.ȱ 2.6.ȱStatisticalȱanalysisȱ Resultsȱ obtainedȱ fromȱ theȱ bioassaysȱ andȱ theȱ chemicalȱ measurementsȱ wereȱ linkedȱ byȱ factorȱ analysis,ȱ usingȱ principalȱ componentsȱ analysisȱ (PCA)ȱ asȱ theȱ extractionȱ procedure,ȱ whichȱ isȱ aȱ multivariateȱ statisticalȱ techniqueȱ forȱ - 76 - exploringȱ variableȱ distributionsȱ (Ribaȱ etȱ al.,ȱ 2003).ȱ Theȱ objectiveȱ ofȱ PCAȱ isȱ toȱ deriveȱaȱreducedȱnumberȱofȱnewȱvariablesȱasȱlinearȱcombinationsȱofȱtheȱoriginalȱ variables.ȱThisȱ providesȱ aȱdescriptionȱofȱtheȱdataȱstructureȱwithȱtheȱminimumȱ lossȱ ofȱ information.ȱ ANOVAȱ wasȱ performedȱ inȱ orderȱ toȱ determineȱ significantȱ differencesȱ(p<0.05)ȱinȱsurvivalȱorganismsȱbetweenȱtheȱtoxicityȱresultsȱobtainedȱ forȱtheȱreferenceȱsiteȱandȱtheȱotherȱsamplingȱsites.ȱ 3.ȱResultsȱandȱdiscussionȱ 3.1.ȱChemicalȱanalysisȱ Tableȱ 1ȱ presentsȱ theȱ generalȱ characteristicsȱ (fineȱ particlesȱ andȱ organicȱ carbon)ȱ andȱ theȱ levelsȱ ofȱ PAHȱ andȱ traceȱ elementsȱ inȱ sedimentsȱ fromȱ threeȱ groupsȱofȱstations:ȱReferenceȱsiteȱ(CA),ȱAtlanticȱIslandsȱNationalȱParkȱ(A,ȱBȱandȱ C)ȱandȱCormeȬLaxeȱ(D,ȱEȱandȱF).ȱȱȱȱSedimentsȱconsistedȱofȱlargeȱproportionȱofȱ sandȱ withȱ lowȱ organicȱ carbonȱ contentȱ andȱ diminishedȱ metalȱ concentrations.ȱ Onlyȱ Znȱ presentedȱ moderateȱ concentrationsȱ inȱ stationsȱ Aȱ andȱ F.ȱ Theȱ levelsȱ ofȱ PAHsȱ variedȱ broadlyȱ amongȱ theȱ stations:ȱ belowȱ detectionȱ limitȱ inȱ CAȱ andȱ Cȱ andȱ higherȱ valuesȱ inȱ Aȱ (108ȱ mgȱ kgȬ1)ȱ andȱ Fȱ (323ȱ mgȱ kgȬ1).ȱ Theȱ comparisonȱ ofȱ PAHȱlevelsȱinȱ2005Ȭ06ȱwithȱsedimentsȱcollectedȱinȱ2003Ȭ04ȱ(MoralesȬCasellesȱetȱ al.,ȱ2007)ȱandȱ2004Ȭ05ȱ(MoralesȬCasellesȱetȱal,ȱ2006)ȱshowedȱaȱgeneralȱdecreaseȱ inȱ concentrationsȱ inȱ theȱ stationsȱ surveyedȱ atȱ AINPȱ andȱ CormeȬLaxeȱ (Tableȱ 2).ȱ ThisȱcomparisonȱsuggestsȱaȱdecreaseȱofȱPAHsȱinȱtheȱsedimentsȱofȱtheȱtwoȱareasȱ affectedȱbyȱtheȱPrestigeȱoilȱspill.ȱȱ 3.2.ȱMicrotox®ȱtestȱ Figureȱ 2ȱ showsȱ theȱ IC50ȱ resultsȱ obtainedȱ throughȱ theȱ Microtox®ȱ testȱ withȱtheȱsedimentsȱcollectedȱinȱtheȱthreeȱareasȱinȱ2005Ȭ06.ȱAllȱIC50ȱresultsȱwereȱȱ - 77 - Tableȱ 1.ȱ Concentrationȱ ofȱ PAHsȱ (ΐgȱ kgȬ1ȱ dryȱ weight),ȱ metalsȱ (mgȱ kgȬ1ȱ dryȱweight),ȱorganicȱcarbonȱ(%dryȱweight)ȱandȱpercentageȱofȱfineȱparticlesȱ(<ȱ63ȱ ΐmȱ ofȱ dryȱ sediment)ȱ inȱ sedimentȱ samples.ȱ Reference:ȱ CA;ȱ Atlanticȱ islandsȱ Nationalȱ Park:ȱ A,ȱ Bȱ andȱ C;ȱ CormeȬLaxe:ȱD,ȱ Eȱ andȱ F.ȱ n.d.ȱ =ȱ notȱ detectedȱ valueȱ (<0.005ȱΐgȱKgȬ1). ȱȱ ȱȱ PAHȱ Znȱȱ Cd Pbȱ Cu Niȱȱ Coȱ Vȱ Hgȱ OCȱ fines REFERENCEȱ CA n.d.ȱ 21.3ȱ 0.9 2.3ȱ 7.0ȱ 0.1ȱ 0.05ȱ 1.1ȱ 1.0ȱ ȱȱ AINPȱ ȱȱ Aȱ Bȱ Cȱ 108ȱ 377ȱ 0.3 1.5ȱ 5.2ȱ 13.3ȱ 0.3ȱ 0.7ȱ 0.04ȱ 0.4ȱ 67ȱ 91ȱ 0.2 0.9ȱ 1.4ȱ 2.4ȱ 0.2ȱ 0.8ȱ 0.28ȱ 0.4ȱ n.d.ȱ 164ȱ n.d 0.9ȱ 1.4ȱ 4.5ȱ 0.1ȱ 0.6ȱ 0.09ȱ 0.3ȱ 4.3ȱ 2.8ȱ 2.8ȱ CormeȬ Laxeȱ Dȱ Eȱ Fȱ 38ȱ 25ȱ 0.2 3.7 0.7 52ȱ 19.9ȱ 0.1 7.3 0.4 323ȱ 271ȱ 0.2 5.9 4.2 3.8ȱ 5.5ȱ 6.0ȱ 1.7ȱ 1.5ȱ 5.7ȱ 3.4ȱ 80ȱ 0.3 2.0 0.4 2.1 0.4 3.4 0.16ȱ 0.3ȱ 0.08ȱ 0.4ȱ 0.08ȱ 0.7ȱ ȱ Tableȱ 2.ȱ Tableȱ 2.ȱ ȱ Concentrationȱ ofȱ PAHsȱ (ΐgȱ kgȬ1ȱ dryȱ weight)ȱ inȱ theȱ followingȱ yearsȱ afterȱ theȱ Prestigeȱ oilȱ spillȱ (November,ȱ 2002).ȱ n.a:ȱ notȱ availableȱ data;ȱn.d.=ȱnotȱdetectedȱvaluesȱ(<0.005ȱmgȱkgȬ1)ȱ station 2003-2004 2004-2005 2005-2006 A 390 119 108 B 2120 366 67 C 420 239 n.d. D n.a 537 38 E n.a 558 52 F n.a 820 323 ȱ ȱ - 78 - clearlyȱaboveȱtheȱlimitsȱassumedȱforȱsedimentȱtoxicityȱ(expressedȱonȱdryȱweightȱ units):ȱ1000ȱmgȱLȬ1ȱ(CanadianȱStandardsȱinȱEnvironmentȱCanada,ȱ2002)ȱandȱ750ȱ mgȱLȬ1ȱ(SpanishȱStandardsȱinȱDelVallsȱetȱal.,ȱ2004;ȱCasadoȬMartínezȱetȱal.,ȱ2006).ȱ Theseȱresultsȱindicateȱthatȱtheȱtestedȱsedimentsȱhadȱnoȱacuteȱtoxicity.ȱ ȱ 25000 ȱ IC50 (mg L-1 dry weight) ȱ 20000 ȱ ȱ 10000 ȱ ȱ5000 ȱ ȱ 0 CA A B ȱ C D E F treatments Figureȱ2.ȱIC50ȱresultsȱobtainedȱfromȱtheȱapplicationȱofȱtheȱMicrotox®ȱtestȱ toȱ sedimentȱ samplesȱ fromȱ theȱ variousȱ stations.ȱ Theȱ lineȱ indicatesȱ theȱ limitsȱ belowȱ whichȱ theȱ sedimentȱ sampleȱ isȱ consideredȱ toxicȱ byȱ theȱ Canadianȱ Standardsȱ(1000ȱmgȱLȬ1ȱdryȱweight).ȱ 3.3.ȱAmphipodȱandȱpolychaeteȱtoxicityȱtestsȱ Theȱ resultsȱ ofȱ theȱ 10Ȭdȱ bioassaysȱ withȱ amphipodsȱ andȱ polychaeteȱ areȱ givenȱ inȱ Figureȱ 3.ȱ Meanȱ valuesȱ ofȱ mortalityȱ wasȱ lessȱ thanȱ 25ȱ ȱ andȱ 27%ȱ forȱ Ampeliscaȱ andȱ Arenicolaȱ bioassays,ȱ respectively.ȱ Noneȱ ofȱ theȱ testedȱ sedimentsȱ wereȱ significantlyȱ (p<0,05)ȱ differentȱ fromȱ theȱ referenceȱ sedimentȱ (CA),ȱ suggestingȱ thatȱ sedimentsȱ areȱ notȱ toxicȱ inȱ accordanceȱ withȱ theȱ USȱ - 79 - Environmentalȱ Protectionȱ Agencyȱ (USEPA,ȱ 1994)ȱ andȱ guidelinesȱ reportedȱ byȱ CasadoȬMartínezȱ etȱ al.ȱ (2006b).ȱ Aȱ highȱ variabilityȱ inȱ theȱ mortalityȱ resultsȱ wasȱ observedȱinȱtheȱpolychaeteȱassayȱandȱnoȱcorrelationȱwasȱobservedȱbetweenȱtheȱ amphipodȱ andȱ polychaeteȱ mortalityȱ results,ȱ whichȱ canȱ beȱ dueȱ toȱ theȱ differentȱ susceptibilities.ȱThisȱfactȱhighlightsȱtheȱimportanceȱofȱusingȱdifferentȱorganismsȱ inȱ thisȱ kindȱ ofȱ studies,ȱ especiallyȱ whereȱ diverseȱ knownȱ andȱ unknownȱ contaminantsȱareȱpresentȱandȱsinergic/antagonicȱeffectsȱmayȱoccur.ȱ ȱ 50 ȱ Ampelisca brevicornis Arenicola marina Mortality (%) 40 ȱ ȱ 30 ȱ 20 ȱ ȱ 10 ȱ ȱ 0 ȱ ȱ CA A B C D E F treatments Figureȱ 3.ȱ Averagedȱ mortalityȱ resultsȱ andȱ standardȱ deviationsȱ afterȱ 10ȱ daysȱ ofȱ exposingȱ Ampeliscaȱ brevicornisȱ andȱ Arenicolaȱ marinaȱ toȱ theȱ sedimentȱ samples.ȱ ȱ ȱ - 80 - 3.4.ȱBioaccumulationȱassayȱ Despiteȱ theȱ absenceȱ ofȱ acuteȱ toxicity,ȱ lugwormsȱ exposedȱ 10ȱ daysȱ toȱ sedimentsȱfromȱtheȱGalicianȱCoastȱshowedȱaȱhigherȱaccumulationȱofȱPAHsȱthanȱ thoseȱ exposedȱ toȱ sedimentsȱ fromȱ theȱ referenceȱ station.ȱ Theȱ concentrationsȱ ofȱ PAHsȱ inȱ thoseȱ wormsȱ exposedȱ toȱ sedimentsȱ variedȱ fromȱ 3.2Ȭ3.9ȱ mgȱ kgȬ1ȱ (CormeȬLaxe)ȱ toȱ 2.6Ȭ2.7ȱ mgȱ kgȬ1ȱ (Atlanticȱ Islandȱ Nationalȱ Park).ȱ Aȱ PAHsȱ bioaccumulationȱ indexȱ BI=Cx/CRȱ wasȱ definedȱ byȱ theȱ ratioȱ betweenȱ theȱ PAHȱ concentrationȱinȱtheȱlugwormȱexposedȱtoȱsedimentȱXȱ(Cx)ȱandȱtoȱtheȱreferenceȱ (CR).ȱ Theȱ BIȱ rangedȱ withinȱ theȱ narrowȱ intervalȱ ofȱ 1.0Ȭ1.6,ȱ meaningȱ thatȱ lugwormsȱpresentedȱaȱnarrowȱintervalȱofȱaccumulationȱthanȱsediments.ȱȱ ȱ 1.0 Zn ȱ ȱ Ampelisca 0.6 ȱ Factor 2 Cu Ni 0.8 0.4 Microtox 0.2 ȱ PAH fines ȱ 0.0 -1.0 -0.8 ȱ Cd Hg ȱ -0.6 -0.4 -0.2 0.0 0.2 -0.2 Arenicola 0.4 0.6 Co 0.8 1.0 1.2 Bioaccumulation O.C. -0.4 V Pb -0.6 ȱ Factor 1 ȱ Figureȱ 4.ȱ Factorȱ loadingsȱ ofȱ 15ȱ variablesȱ forȱ theȱ twoȱ principalȱ factorsȱ resultingȱ fromȱ theȱ multivariateȱ analysisȱ ofȱ resultsȱ obtainedȱ fromȱ theȱ chemicalȱ analysis,ȱtheȱacuteȱtoxicityȱtestsȱandȱtheȱbioaccumulationȱassay.ȱ - 81 - 3.5.ȱPrincipalȱcomponentȱanalysisȱ Aȱ principalȱ componentȱ analysisȱ (PCA)ȱ wasȱ performedȱ includingȱ sedimentȱchemicalȱparameters,ȱtoxicityȱtestsȱandȱPAHsȱbioaccumulationȱindex.ȱ Theȱ15ȱvariablesȱcanȱbeȱgroupedȱinȱ2ȱnewȱfactorsȱwhichȱexplainȱaȱ61.6ȱ%ȱofȱtheȱ totalȱ variance.ȱ Figureȱ 4ȱ representsȱ theȱ loadingsȱ ofȱ theȱ variablesȱ inȱ eachȱ factor.ȱ Forȱaȱgoodȱassociationȱbetweenȱvariableȱandȱaȱfactorȱweȱdecidedȱtoȱinterpretȱaȱ groupȱ ofȱ variablesȱ asȱ thoseȱ associatedȱ toȱ aȱ particularȱ componentȱ whereȱ theȱ loadingȱ wasȱ 0.50ȱ orȱ higherȱ whichȱ approximatesȱ toȱ Comreys’ȱ cutȬoffȱ ofȱ 0.55ȱ (Comreys,ȱ 1973).ȱ ȱ Theȱ firstȱ factor,ȱ Factorȱ #1,ȱ accountsȱ forȱ 39.0ȱ %ȱ ofȱ theȱ totalȱ varianceȱ andȱ linksȱ theȱ bioaccumulationȱ ofȱ PAHsȱ inȱ theȱ polychaeteȱ withȱ theȱ presenceȱ ofȱ PAHs,ȱ Pb,ȱ Co,ȱ andȱ finesȱ inȱ theȱ sediments.ȱ Factorȱ #2ȱ accountsȱ forȱ 22.6ȱ%ȱofȱtheȱvarianceȱandȱshowsȱtheȱrelationshipȱbetweenȱmetalsȱZn,ȱCuȱandȱ Niȱ withȱ theȱ lowȱ toxicityȱ (<25%ȱ ofȱ mortality)ȱ toȱ theȱ amphipodȱ Ampeliscaȱ brevicornis.ȱ Figureȱ5ȱshowsȱtheȱinfluenceȱofȱeachȱfactorȱinȱtheȱ7ȱstudyȱsites.ȱFactorȱ#1,ȱ definedȱ asȱ theȱ PAHsȱ bioaccumulationȱ dueȱ toȱ theirȱ presenceȱ inȱ sedimentsȱ andȱ theȱassociationȱwithȱPbȱandȱCo;ȱitȱhasȱmainlyȱprevalenceȱinȱtheȱsitesȱDȱ(0.35),ȱEȱ (1.07)ȱ andȱ Fȱ (0.86)ȱ fromȱ CormeȬLaxe.ȱ Thisȱ meansȱ thatȱ theseȱ stationsȱ presentȱ aȱ contaminationȱ byȱ PAHsȱ whichȱ areȱ ableȱ toȱ bioaccumulateȱ inȱ theȱ biotaȱ andȱ areȱ accompaniedȱ byȱ theȱ metalsȱ Pbȱ andȱ Co.ȱ Howeverȱ itȱ doesȱ notȱ reflectȱ anȱ acuteȱ toxicityȱ ofȱ theȱ benthicȱ organismsȱ exposedȱ toȱ theȱ sediments.ȱ Despiteȱ theȱ lowȱ mortalityȱ withȱ theȱ 10Ȭdȱ bioassaysȱ (Figureȱ 3)ȱ theȱ PCAȱ suggestsȱ aȱ relationshipȱ betweenȱsedimentȱquality,ȱbioaccumulationȱandȱtheȱslightȱmortality.ȱFactorȱ#2,ȱ whichȱ relatesȱ aȱ slightȱ toxicityȱ withȱ theȱ metalsȱ Zn,ȱ Cuȱ andȱ Niȱ boundȱ toȱ sediments,ȱpresentsȱaȱpositiveȱloadingȱinȱtheȱsitesȱAȱ(1.75),ȱCȱ(0.49)ȱandȱFȱ(0.34).ȱȱ - 82 - 2.0 A 1.5 1.0 Factor 2 C 0.5 F 0.0 -2.5 -2.0 -1.5 -1.0 -0.5 B 0.0 0.5 1.0 1.5 -0.5 CA -1.0 D E -1.5 Factor 1 Figureȱ 5.ȱ Estimatedȱ factorȱ scoresȱ forȱ theȱ twoȱ factorsȱ inȱ eachȱ ofȱ theȱ 7ȱ studiedȱcases.ȱTheȱfactorȱscoresȱquantifyȱtheȱprevalenceȱofȱeachȱfactorȱforȱeveryȱ stationȱandȱareȱusedȱtoȱestablishȱtheȱdefinitionȱofȱeachȱfactor.ȱ 3.6.ȱGeneralȱdiscussionȱ Chemicalȱ analysesȱ ofȱ surfaceȱ sedimentsȱ fromȱ theȱ Galicianȱ coastȱ (Ríaȱ deȱ CormeȬLaxeȱ andȱ Cíes)ȱ indicateȱ aȱ substantialȱ decreaseȱ inȱ theȱ contentȱ ofȱ PAHsȱ fourȱ yearsȱ afterȱ theȱ oilȱ spill.ȱ Theȱ effectȱ ofȱ theȱ oilȱ spillȱ fromȱ Prestigeȱ probablyȱ diminishedȱ dueȱ toȱ biotransformationȱ andȱ volatilizationȱ ofȱ compoundsȱ inȱ theȱ sedimentsȱ (Albers,ȱ 2003).ȱ Itȱ shouldȱ notȱ beȱ ignoredȱ thatȱ hydrodynamicȱ processes,ȱ namelyȱ sedimentȱ resuspension,ȱ mayȱ haveȱ influenceȱ inȱ thoseȱ processesȱ(Neff,ȱ2002).ȱInȱaddition,ȱenhancedȱlevelsȱofȱVȱandȱNi,ȱwhichȱareȱoftenȱ associatedȱ withȱ hydrocarbonȱ spills,ȱ suggestsȱ thatȱ theirȱ presenceȱ couldȱ beȱ relatedȱ toȱ theȱ Prestigeȱ oilȱ spill.ȱ Additionalȱ sourcesȱ couldȱ contributeȱ toȱ theȱ amountȱofȱZnȱandȱCuȱfoundȱinȱtheseȱareasȱ(CobeloȬGarcíaȱetȱal.,ȱ2004).ȱȱ - 83 - Apparently,ȱ theȱ linkȱ betweenȱ theȱ resultsȱ ofȱ theȱ 10Ȭdȱ bioassaysȱ andȱ theȱ presenceȱofȱPAHsȱinȱtheȱsedimentsȱfromȱCormeȬLaxeȱisȱindicativeȱofȱsedimentȱ toxicity.ȱ Thisȱ linkȱ isȱ howeverȱ insufficientȱ toȱ describeȱ thoseȱ sedimentsȱ asȱ toxic,ȱ sinceȱvaluesȱwereȱlowerȱthanȱtheȱinternationalȱguidelinesȱemployedȱforȱthisȱtest.ȱ Moreover,ȱtheȱresultsȱofȱtheȱMicrotoxȱtestȱwereȱunrelated.ȱDespiteȱtheȱdecreaseȱ withȱ theȱ timeȱ (Tableȱ 2)ȱ ofȱ PAHȱ concentrationsȱ inȱ sedimentsȱ fromȱ theȱ Galicianȱ areaȱ affectedȱ byȱ theȱ oilȱ spillȱ (Fernándezȱ etȱ al.,ȱ 2006;ȱ SorianoȬSanz,ȱ 2006;ȱ MoralesȬCasellesȱ etȱ al.,ȱ 2007;ȱ MoralesȬCasellesȱ etȱ al.,ȱ accepted),ȱ PAHsȱ accumulationȱ wasȱ identifiedȱ inȱ theȱ organismsȱ exposedȱ toȱ 10Ȭdȱ tests.ȱ Residuesȱ stillȱremainȱinȱtissuesȱofȱbenthicȱorganisms,ȱprobablyȱindicatingȱthatȱPAHsȱareȱ availableȱ toȱ theȱ foodȱ chain,ȱ andȱ thusȱ representingȱ aȱ potentialȱ riskȱ toȱ theȱ wellbeingȱofȱtheȱecosystem.ȱTheȱfactȱthatȱnoȱacuteȱtoxicityȱwasȱdetectedȱinȱtheȱ sedimentsȱandȱtheȱbioaccumulationȱproducedȱbyȱtheȱPAHsȱinȱCormeȬLaxeȱ(siteȱ Eȱ andȱ F)ȱ suggestsȱ thatȱ thereȱ hasȱ beenȱ aȱ recoveryȱ ofȱ theȱ areaȱ affectedȱ byȱ theȱ accidentalȱoilȱspill.ȱSimilarȱresultsȱwhereȱobtainȱyearsȱafterȱmajorȱtankerȱspills,ȱ suchȱasȱtheȱExxonȱValdezȱ(USA,ȱ1989)ȱ(LeeȱandȱPageȱ1997),ȱtookȱplace.ȱHowever,ȱ previousȱstudiesȱhaveȱshownȱtheȱrelationshipȱbetweenȱtheȱPrestigeȱoilȱspillȱandȱ sublethalȱeffectsȱinȱtheȱorganismsȱexposedȱtoȱcontaminatedȱsedimentsȱfromȱtheȱ Galicianȱ areaȱ (MartínezȬGómezȱ etȱ al.,ȱ 2006;ȱ Marigómezȱ etȱ al.,ȱ 2006;ȱ MoralesȬ Casellesȱetȱal.,ȱ2006;ȱFernándezȱetȱal.,ȱ2006;ȱSorianoȬSanz,ȱ2006).ȱȱ 4.ȱConclusionsȱȱ Theȱ resultsȱ obtainedȱ inȱ theȱ presentȱ studyȱ suggestȱ thatȱ thereȱ hasȱ beenȱ aȱ recoveryȱofȱtheȱqualityȱofȱtheȱsedimentsȱaffectedȱbyȱtheȱPrestigeȱoilȱspillȱinȱtheȱ GalicianȱCoast.ȱSedimentsȱfromȱCormeȬLaxeȱandȱtheȱAINPȱdoȱnotȱpresentȱacuteȱ toxicityȱ althoughȱ theȱ presenceȱ ofȱ someȱ metalsȱ andȱ PAHsȱ inȱ theȱ sedimentsȱ isȱ consideredȱ aȱ potentialȱ riskȱ inȱ thoseȱ areas;ȱ evenȱ thoughȱ PAHsȱ doȱ notȱ tendȱ toȱ - 84 - bioaccumulateȱalongȱtheȱtrophicȱchainȱ(Neff,ȱ2002),ȱtheȱaccumulationȱofȱPAHsȱ inȱ theȱ polychaeteȱ Arenicolaȱ marinaȱ wasȱ relatedȱ toȱ theȱ presenceȱ ofȱ thisȱ contaminantȱ inȱ theȱ Bayȱ ofȱ CormeȬLaxeȱ andȱ suggestsȱ theȱ possibilityȱ ofȱ producingȱ sublethalȱ toxicȱ effectsȱ toȱ theȱ organismsȱ exposedȱ despiteȱ thereȱ wasȱ notȱ acuteȱtoxicityȱ detected.ȱFurtherȱstudiesȱareȱrequired,ȱinȱorderȱtoȱfollowȱupȱ theȱsublethalȱeffectsȱyearsȱafterȱtheȱoilȱspill.ȱ 5.ȱAcknowledgmentsȱ Theȱ workȱ describedȱ wasȱ partlyȱ supportedȱ byȱ theȱ projectsȱ VEM2003Ȭ 20563/INTER,ȱ andȱ CTM2005Ȭ07282ȬC03Ȭ01/TECNOȱ financedȱ byȱ theȱ Spanishȱ Educationȱ andȱ Scienceȱ Ministryȱ andȱ byȱ CISȱ fundedȱ byȱ theȱ Ministryȱ ofȱ Environment.ȱ Carmenȱ MoralesȬCasellesȱ thanksȱ theȱ Ministryȱ ofȱ Educationȱ andȱ Scienceȱ forȱ fundingȱ herȱ researchȱ fellowshipȱ (FPU).ȱ Dr.ȱ Ribaȱ thanksȱ theȱ I3pȱ programȱ forȱ supportingȱ herȱ participationȱ inȱ thisȱ research.ȱ ȱ Inmaculadaȱ Ribaȱ thanksȱtheȱCSICȱforȱherȱI3Pȱcontract.ȱWeȱareȱgratefulȱforȱtheȱsupportȱandȱhelpȱofȱ theȱ membersȱ ofȱ theȱ CISȱ andȱ IPIMAR.ȱ Specialȱ thanksȱ areȱ givenȱ toȱ Isabelinaȱ Santos.ȱ 6.ȱReferencesȱȱȱȱ Albersȱ P.H.ȱ 2003.ȱ Petroleumȱ andȱ individualȱ polycyclicȱ aromaticȱ hydrocarbons.ȱ In:ȱ HoffmanȱDJ,ȱRattnerȱBA,ȱBurtonȱGA,ȱCairnsȱJȱ(eds)ȱHandbookȱofȱecotoxicology.ȱ LewisȱPublishers,ȱBocaȱRaton,ȱFLȱChaptȱ14ȱ AmericanȱSocietyȱforȱTestingȱandȱMaterials,ȱ1993.ȱStandardȱGuideȱforȱConductingȱ10Ȭ dayȱStaticȱSedimentȱToxicityȱTestsȱwithȱtheȱMarineȱandȱEstuarineȱAmphipods.ȱ ASTM,ȱPhiladelphia,ȱpp.ȱ1367Ȭ1392.ȱ - 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89 - Corophiumȱ volutatorȱ andȱ Ampeliscaȱ brevicornis.ȱ Bȱ Environȱ Contamȱ Toxȱ 71,ȱ 1061Ȭ1068.ȱ SorianoȬSanz,ȱJ.A.,ȱFrancoȬHernández,ȱA.,ȱViñasȬDiéguez,ȱL.,ȱCambeiroȬCambeiro,ȱB.,ȱ GonzálezȬFernández,ȱ J.J.ȱ 2006.ȱ Preliminaryȱ dataȱ onȱ polycyclicȱ aromaticȱ hydrocarbonsȱ (PAHs)ȱ inȱ wildȱ musselsȱ fromȱ theȱ Cantabrianȱ coastȱ (Nȱ Spain)ȱ followingȱtheȱPrestigeȱoilȱspill.ȱCienc.ȱMar.ȱ32,ȱ457Ȭ463.ȱ Stronkhorst,ȱJ.,ȱSchipper,ȱC.,ȱBrils,ȱJ.,ȱDubbeldam,ȱM.,ȱPostman,ȱJ.,ȱVanȱDeȱHoeven,ȱN.,ȱ 2003.ȱUsingȱmarineȱbioassaysȱtoȱclassifyȱtheȱtoxicityȱofȱDutchȱHarborȱsediments.ȱ Environ.ȱToxicol.ȱChem.ȱ22,ȱ1535Ȭ1547.ȱ USEPA,ȱ 1994.ȱ Methodsȱ forȱ Assessingȱ theȱ Toxicityȱ ofȱ SedimentȬassociatedȱ Contaminantsȱ withȱ Estuarineȱ andȱ Marineȱ Amphipods.ȱ Unitedȱ Statesȱ EnvironmentalȱProtectionȱAgencyȱ(USEPA).ȱEPA/600/RȬ94/025.ȱ Vanȱ Beelen,ȱ P.,ȱ 2003.ȱ Aȱ reviewȱ onȱ theȱ applicationȱ ofȱ microbialȱ toxicityȱ testsȱ forȱ derivingȱsedimentȱqualityȱguidelines.ȱChemosphereȱ53,ȱ795Ȭ808.ȱ - 90 - ȱ Capítuloȱ3.ȱ Estudioȱdeȱefectosȱsubletalesȱenȱorganismosȱbajoȱ condicionesȱdeȱlaboratorioȱ Laȱimportanciaȱdeȱlosȱtestȱdeȱtoxicidadȱaȱnivelȱsubletalȱradicaȱenȱqueȱesteȱ tipoȱdeȱestudioȱpermiteȱevaluarȱconȱunaȱmayorȱsensibilidadȱlaȱrespuestaȱdeȱunȱ organismoȱ anteȱ unȱ tipoȱ deȱ contaminaciónȱ ademásȱ deȱ discriminarȱ puntosȱ conȱ unaȱcontaminaciónȱmoderadaȱidentificandoȱlosȱefectosȱsubletales.ȱȱAntesȱdeȱqueȱ seȱ produzcaȱ laȱ muerteȱ oȱ laȱ enfermedad,ȱ tantoȱ organismosȱ comoȱ poblacionesȱ respondenȱ alȱ estrésȱ alterandoȱ diferentesȱ parámetrosȱ aȱ nivelȱ molecular,ȱ histológico,ȱ inmunológicoȱ yȱ fisiológico,ȱ aȱ nivelȱ deȱ organismo,ȱ poblaciónȱ oȱ ecosistemaȱ (Livingstone,ȱ 1993;ȱ LópezȬBarea,ȱ 1994).ȱ Losȱ biomarcadores,ȱ permitenȱevaluarȱlosȱefectosȱdelȱestrésȱsubletalȱsobreȱlosȱorganismosȱexpuestosȱ aȱ sustanciasȱ contaminantes,ȱ reflejandoȱ elȱ estadoȱ deȱ losȱ individuosȱ aȱ nivelȱ molecularȱ oȱ celularȱ comoȱ respuestaȱ aȱ dichoȱ estrés.ȱ Además,ȱ estasȱ medidasȱ puedenȱ identificarȱ rápidamenteȱ laȱ presenciaȱ deȱ sustanciasȱ tóxicas,ȱ ofreciendoȱ unaȱ alertaȱ tempranaȱ antesȱ deȱ queȱ lasȱ alteracionesȱ lleguenȱ aȱ nivelesȱ deȱ organizaciónȱ mayores.ȱ ȱ Losȱ biomarcadoresȱ hanȱ mostradoȱ serȱ lasȱ herramientasȱ adecuadasȱ paraȱ caracterizarȱ elȱ estadoȱ deȱ losȱ organismosȱ presentesȱ enȱ zonasȱ impactadasȱ dondeȱ seȱ daȱ laȱ presenciaȱ deȱ mezclasȱ complejasȱ deȱ contaminantesȱ (Lafontaineȱetȱal.,ȱ2000;ȱMunnsȱetȱal.,ȱ2002;ȱGallowayȱetȱal.,ȱ2004;ȱMartínȬDíazȱetȱ al.,ȱ2005,ȱMontserratȱetȱal.,ȱ2006). ȱ Ȭȱ91ȱȬȱ Capítuloȱ3 Existenȱtresȱtiposȱgeneralesȱdeȱbiomarcadores:ȱ Ȭ Losȱ biomarcadoresȱ deȱ exposición,ȱ determinan,ȱ dentroȱ deȱ losȱ organismosȱ expuestosȱ aȱ contaminantes,ȱ metabolitosȱ derivadosȱ deȱ laȱ biotransformaciónȱ oȱ productosȱdeȱsuȱreacciónȱconȱmoléculasȱbiológicas.ȱȱ Ȭ Losȱ biomarcadoresȱ deȱ efecto,ȱ muestranȱ laȱ respuestaȱ delȱ organismoȱ expuestoȱalȱagenteȱxenobióticoȱenȱparticularȱoȱalȱcomplejoȱdeȱmezcla.ȱȱ Ȭ Losȱ biomarcadoresȱ aȱ nivelesȱ deȱ población,ȱ comunidadȱ yȱ ecosistema,ȱ proporcionandoȱ informaciónȱ deȱ lasȱ alteracionesȱ aȱ mayoresȱ nivelesȱ deȱ organización.ȱȱȱ Unaȱ vezȱ realizadosȱ losȱ ensayosȱ agudosȱ bajoȱ condicionesȱ deȱ laboratorioȱ talȱyȱcomoȱseȱdescribeȱenȱelȱcapítuloȱanterior,ȱenȱelȱpresenteȱcapítuloȱseȱrecogenȱ cincoȱtrabajosȱenȱlosȱqueȱseȱdiscutenȱlosȱresultadosȱobtenidosȱenȱbioensayosȱdeȱ tipoȱ subletalȱ realizadosȱ bajoȱ condicionesȱ deȱ laboratorioȱ conȱ cuatroȱ especiesȱ marinas:ȱ elȱ pezȱ Sparusȱ aurata,ȱ elȱ cangrejoȱ Carcinusȱ maenas,ȱ laȱ almejaȱ Ruditapesȱ philippinarumȱ yȱ elȱ poliquetoȱ Arenicolaȱ marina.ȱ Losȱ ensayosȱ subletales,ȱ complementanȱyȱmejoranȱlaȱinformaciónȱobtenidaȱporȱlosȱexperimentosȱagudosȱ yȱfueronȱrealizadosȱenȱperiodosȱdeȱtiempoȱqueȱvaríanȱentreȱlosȱ15ȱyȱ60ȱdías.ȱEnȱ elȱprimerȱartículoȱ(V)ȱseȱpresentaȱunȱestudioȱdeȱdosȱmesesȱdeȱduraciónȱenȱelȱqueȱ seȱ llevaronȱ aȱ caboȱ exposicionesȱ deȱ S.ȱ aurataȱ aȱ sedimentosȱ deȱ laȱ costaȱ gallegaȱ afectadosȱporȱelȱvertidoȱdelȱpetroleroȱPrestige,ȱyȱseȱmidieronȱbiomarcadoresȱdeȱ exposiciónȱ (actividadȱ ERODȱ yȱ metalotioneinas)ȱ yȱ efectoȱ (histopatología),ȱ poniendoȱ deȱ manifiestoȱ laȱ importanciaȱ inicialȱ delȱ vertido.ȱ Enȱ elȱ trabajoȱ VIȱ seȱ realizaȱ unaȱ valoraciónȱ deȱ laȱ cinéticaȱ deȱ lasȱ enzimasȱ implicadasȱ enȱ laȱ detoxificaciónȱ deȱ PAHsȱ (actividadȱ EROD)ȱ enȱ S.ȱ aurataȱ yȱ seȱ relacionanȱ conȱ losȱ dañosȱsobreȱlosȱtejidosȱcausadosȱporȱlosȱcontaminantesȱorgánicos.ȱEnȱelȱtrabajoȱ VIIȱ seȱ muestranȱ losȱ resultadosȱ deȱ unȱ estudioȱ realizadoȱ conȱ C.ȱ maenasȱ yȱ R.ȱ philippinarumȱ dondeȱ seȱ expusieronȱ losȱ organismosȱ aȱ sedimentosȱ deȱ Galiciaȱ yȱ - 92 - Estudioȱdeȱefectosȱsubletalesȱenȱorganismosȱbajoȱcondicionesȱdeȱlaboratorioȱ Algeciras.ȱ Enȱ esteȱ estudioȱ seȱ seleccionóȱ unaȱ bateríaȱ deȱ biomarcadoresȱ deȱ exposiciónȱrelacionadosȱconȱprocesosȱdeȱdetoxificaciónȱ(actividadȱERODȱcomoȱ biomarcadorȱdeȱlaȱfaseȱIȱyȱGSTȱdeȱlaȱfaseȱII)ȱyȱactividadȱantioxidanteȱ(GPX,ȱGRȱ yȱFRAP).ȱEstosȱbiomarcadoresȱseȱrelacionaronȱconȱlosȱcontaminantesȱanalizadosȱ enȱ losȱ sedimentosȱ conȱ elȱ finȱ deȱ identificarȱ lasȱ sustanciasȱ causantesȱ delȱ estrés,ȱ entreȱ lasȱ queȱ destacaronȱ losȱ PAHsȱ yȱ algunosȱ metales,ȱ principalmenteȱ enȱ laȱ BahíaȱdeȱAlgecirasȱyȱCormeȬLaxeȱenȱGalicia.ȱ Tablaȱ 3.1.ȱ Relaciónȱ deȱ bioensayosȱ subletalesȱ realizadosȱ paraȱ laȱ evaluaciónȱdeȱlaȱcalidadȱdeȱlosȱsedimentos.ȱ Especieȱ Tiempoȱdeȱ exposiciónȱ Medidaȱfinalȱ Sparusȱaurataȱ 60ȱdíasȱ ActividadȱEROD,ȱMetalotioneinas,ȱ Histopatología,ȱȱ Carcinusȱmaenasȱ 28ȱdíasȱ ActividadȱEROD,ȱGST,ȱGPX,ȱGR,ȱFRAP,ȱ Vitelogenina,ȱHistopatologíaȱ Ruditapesȱphilippinarumȱ 28ȱdíasȱ ActividadȱEROD,ȱGST,ȱGPX,ȱGR,ȱFRAP,ȱ Histopatologíaȱ Arenicolaȱmarinaȱ 15ȱdíasȱ alteraciónȱdelȱcomportamientoȱyȱ alimentación,ȱGR,ȱGPX,ȱGST,ȱFRAP,ȱ TBARS,ȱfagocitosis,ȱdañoȱdeȱADNȱ Elȱ trabajoȱ VIIIȱ incluyeȱ unȱ estudioȱ deȱ laȱ variaciónȱ deȱ vitelogeninaȱ enȱ elȱ cangrejoȱC.ȱmaenasȱtrasȱ28ȱdíasȱdeȱexposiciónȱaȱsedimentosȱrecogidosȱenȱGaliciaȱ yȱ Algeciras.ȱ Losȱ resultadosȱ confirmanȱ laȱ relaciónȱ deȱ laȱ variaciónȱ deȱ esteȱ biomarcadorȱ conȱ contaminantesȱ presentesȱ enȱ elȱ sedimento,ȱ principalmenteȱ PAHsȱyȱalgunosȱmetalesȱqueȱvaríanȱenȱfunciónȱdeȱlaȱzonaȱdeȱestudio,ȱsiendoȱlaȱ másȱafectadaȱlaȱBahíaȱdeȱAlgeciras.ȱEsteȱtrabajoȱfueȱpresentadoȱenȱelȱcongresoȱ CEMEPE/SECOTOXȱ 2007ȱ yȱ obtuvoȱ elȱ premioȱ deȱ mejorȱ presentaciónȱ oralȱ deȱ jóvenesȱ científicos.ȱ Paraȱ finalizarȱ esteȱ capítulo,ȱ elȱ trabajoȱ IX,ȱ realizadoȱ enȱ granȱ parteȱ duranteȱ unaȱ estanciaȱ enȱ laȱ Universidadȱ deȱ Plymouthȱ (UK),ȱ presentaȱ losȱ Ȭ 93ȱȬ Capítuloȱ3 resultadosȱobtenidosȱtrasȱrealizarȱexposicionesȱdeȱquinceȱdíasȱdeȱduraciónȱconȱ elȱpoliquetoȱArenicolaȱmarinaȱyȱanalizarȱunȱsetȱdeȱbiomarcadoresȱqueȱincluyen:ȱ alteraciónȱdelȱcomportamientoȱyȱalimentación,ȱenzimasȱimplicadasȱenȱprocesosȱ deȱ defensaȱ (GR,ȱ GPX,ȱ GST,ȱ FRAP,ȱ TBARSȱ yȱ fagocitosis),ȱ efectosȱ genotóxicosȱ (dañoȱ deȱ ADN).ȱ Cabeȱ destacarȱ queȱ enȱ esteȱ estudioȱ seȱ determinóȱ porȱ primeraȱ vezȱ laȱ capacidadȱ deȱ esteȱ invertebradoȱ marinoȱ deȱ activarȱ procesosȱ fagocíticosȱ comoȱ respuestaȱ aȱ losȱ contaminantesȱ delȱ sedimento.ȱ Lasȱ exposicionesȱ seȱ realizaronȱprincipalmenteȱconȱsedimentosȱprocedentesȱdeȱlaȱBahíaȱdeȱAlgecirasȱ yȱ elȱ Parqueȱ Nacionalȱ deȱ lasȱ Islasȱ Atlánticasȱ yȱ losȱ resultadosȱ deȱ losȱ biomarcadoresȱ seȱ relacionaronȱ conȱ losȱ contaminantesȱ ligadosȱ alȱ sedimento,ȱ mostrando,ȱ deȱ nuevo,ȱ laȱ degradaciónȱ ambientalȱ enȱ laȱ Bahíaȱ deȱ Algecirasȱ yȱ laȱ recuperaciónȱdeȱlasȱIslasȱCíesȱcuatroȱañosȱdespuésȱdelȱvertido.ȱ Bibliografíaȱ transition,ȱ 1994ȱ EUROTOXȱ proceedings,ȱ Springer,ȱBerlinȱ57Ȭȱ79ȱ Galloway,ȱ T.S.,ȱ Brown,ȱ R.J.,ȱ Browne,ȱ M.A.,ȱ Dissanayake,ȱ A.,ȱ Lowe,ȱ D.,ȱ Jones,ȱ M.B.,ȱ Depledge,ȱ M.H.ȱ Aȱ multibiomarkerȱ approachȱ toȱ environmentalȱ assessment.ȱ Environ.ȱSci.ȱTechnol.ȱ2004,ȱ38,ȱ1723Ȭ1731.ȱ MartínȬDíaz,ȱ L.ȱ 2004.ȱ Determinaciónȱ deȱ laȱ calidadȱ ambientalȱ deȱ sistemasȱ litoralesȱ yȱ deȱ estuarioȱ deȱ laȱ penínsulaȱ ibéricaȱ utilizandoȱ ensayosȱ deȱ campoȱ yȱ laboratorio.ȱTesisȱDoctoral.ȱȱ LafontaineȱY.,ȱGagné,ȱF.,ȱBlaise,ȱC.,ȱCostan,ȱ G.,ȱ Gagnon,ȱ P.ȱ andȱ Chan,ȱ H.M.ȱ Biomarkersȱ inȱ zebraȱ musselsȱ (Dreissenaȱ polymorpha)ȱ forȱ theȱ assessmentȱ andȱ monitoringȱ ofȱ waterȱ qualityȱ ofȱ theȱ St.ȱ LawrenceȱRiverȱ(Canada).ȱAquat.ȱToxicol.ȱ 2000,ȱ50,ȱ51Ȭ70ȱȱ MartínȬDíaz,ȱ M.L.,ȱ VillenaȬLincoln,ȱ A.,ȱ Bamber,ȱ S.,ȱ Blasco,ȱ J.,ȱ DelValls,ȱ T.A.ȱ Anȱ integratedȱ approachȱ usingȱ bioaccumulationȱ andȱ biomarkerȱ measurementsȱ inȱ femaleȱ shoreȱ crab,ȱ Carcinusȱmaenas.ȱChemosphere.ȱ2005,ȱ58,ȱ 615Ȭ626.ȱ Livingstone,ȱ D.R.ȱ 1993.ȱ Biotechnologyȱ andȱ pollutionȱ monitoring:ȱ useȱ ofȱ molecularȱ biomarkersȱ inȱ theȱ aquaticȱ environment.ȱ Journalȱ ofȱ Chemistry,ȱ Technologyȱ andȱ Biotechnologyȱ57:ȱ195Ȭ211ȱ Montserrat,ȱ J.M.,ȱ Martínez,ȱ P.E.,ȱ Geracitano,ȱ L.A.,ȱ Amado,ȱ L.L.,ȱ Martinezȱ Gasparȱ Martins,ȱ C.,ȱ Lopesȱ Leaesȱ Pinho,ȱ G.,ȱ Soaresȱ Chaves,ȱ I.,ȱ FerreiraȬCravo,ȱ M.,ȱ VenturaȬLima,ȱ J.,ȱ Bianchini,ȱ A.ȱ Pollutionȱ biomarkersȱ inȱ estuarineȱ animals:ȱ Criticalȱ LópezȬBarea,ȱ J.ȱ 1995.ȱ Biomarkersȱ inȱ ecotoxicology:ȱ anȱ overview.ȱ Enȱ G.H.ȱ Degenȱ etȱ al.,ȱ (Eds.),ȱ Toxicologyȱ inȱ - 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Environ. Contam. Toxicol. 51, 652–660 (2006) DOI: 10.1007/s00244-005-0251-0 Ecotoxicity of Sediments Contaminated by the Oil Spill Associated with the Tanker ‘‘Prestige’’ Using Juveniles of the Fish Sparus aurata Carmen Morales-Caselles,1,3 Natalia Jimnez-Tenorio,2 M. Luisa Gonzlez de Canales,2,3 Carmen Sarasquete,1,3 T. ngel DelValls2,3 1 2 3 Instituto de Ciencias Marinas de Andaluca CSIC, Avda. Repfflblica Saharaui s/n. Puerto Real 11510, Cdiz, Spain Facultad de Ciencias del Mar y Ambientales, University of Cdiz, Avda. Repfflblica Saharaui s/n Apdo, 40 Puerto Real 11510, Cdiz, Spain Unidad Asociada de Calidad Ambiental y Patologa (CSIC & UCA), Spain Received: 27 October 2005 /Accepted: 4 February 2006 Abstract. In November 2002, the oil spill from the tanker Prestige in the Galician Coast caused an ecological catastrophe in Spain. The adverse effects associated with the contaminants bound to sediments were tested using juveniles of the fish Sparus aurata (seabream). The approach evaluates sediment quality by using an integrated assessment including chemical and ecotoxicological data. Sediment samples were physicochemically characterized, and the concentration of contaminants (polycyclic aromatic hydrocarbons—(PAHs) and metals) was measured. Different biomarkers of exposure (metallothioneins and ethoxyresorufin O-deethylase activity (EROD)) and biomarkers of effect (histopathology) were analyzed along the time. A multivariate analysis approach was used to correlate concentration of contaminants and sublethal effects measured in individuals of fish. Results show that increasing concentrations of PAHs in sediments were related to increased EROD activities and histopathological lesions. This is the first evidence showing adverse effects associated with petroleum contamination of PAHs in sediments after this spill, and it demonstrates the utility of the sublethal toxicity tests for monitoring the impact of petroleum spills. It has long been demonstrated that sediments can adsorb persistent and toxic chemicals to levels many times higher than water column concentrations (DelValls et al. 2002), whereas the sediment may become sufficiently polluted to disrupt natural biological communities (Adams et al. 1992; Tolun et al. 2001). For a better assessment of the pollution process in the marine coastal environment, several authors have proposed determinations based on chemical measurements together with laboratory toxicity tests (Chapman 1988; Luoma and Ho 1992). Sediment toxicity bioassays are instruments used to test the ecotoxicity and bioavailability of chemical compounds in sediments to benthic organisms. In this kind of bioassay, the organisms are exposed to sediment samples collected in situ Correspondence to: T. . DelValls; email: [email protected] -97- and after the incubation period, a biological response is measured; this response must be sensitive, ecologically relevant, and easy to standardize (Stebbing et al. 1980). Bioassays provide information on the toxicity of contaminated sediments that can be neither derived from chemical analysis nor from ecological surveys performed alone (Chapman and Long 1983; Long and Chapman 1985). Interest in the effects of environmental stressors on health and disease in fish and other marine organisms has increased in recent years, and in particular, histological and cellular alterations have been observed in marine fish from polluted coastal waters and estuaries (Malins et al. 1984; Stein et al. 1992). These sublethal responses have been found to be a powerful tool to evaluate sediment toxicity effects (DelValls et al. 1998a). Biomarkers in fishes have been previously studied in the assessments of oil spills such as Exxon Valdez (Varanasi et al. 1995; Jewett et al. 2002), Braer (Ritchie and OÕSullivan 1994), and Sea Empress (Kirby et al. 1998). In the present study, histopathology was conducted as a biomarker of effect in order to measure the damage caused in the target tissues by the presence of chemicals in the sediments. Two biomarkers of exposure were selected to address the biological adverse effects associated with contaminants present in the studied sediments. The toxicity of metals was assessed by metallothionein (MT) induction, whereas ethoxyresorufin O-deethylase activity (EROD) represents a good marker in MFO (mixed-function oxygenase), which is the first mode of detoxification of many organic pollutants (polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls). The EROD measurement in fish is considered a monitor of pollution exposure and an indicator of potential future problems in the health of fish populations (Carballeira 2003). Furthermore, EROD induction can be documented in fish exposed to spilled petroleum despite low tissues of PAHs (George et al. 1995; Whyte et al. 2000); The reason for using metallothionein induction is because we are studying a mixture of contaminants in the environment, and metallothioneins are one of the main biomarkers. In addition, it has been proved that the induction of this biomarker is not always just related to metals (Stegeman et al. 1992; Muto et al. 1999; Van der Oost et al. 2003). 653 Tanker Oil Spill Toxicity Testing Using Sparus aurata matrix characteristics were studied analyzing total organic carbon concentration and sediment grain size. Organic carbon content was determined using the method of Gaudette et al. (1974) with El Rayis (1985) modification. For sediment grain size, an aliquot of wet sediment was analyzed using a laser particle size Fristch (model Analysette 22) following the method reported by DelValls and Chapman (1998b). For trace metal analysis, the sediments were digested as described by Loring and Rantala (1992). Fe, Mn, Zn, and Cu concentrations in the extracts were determined with a Perkin–Elmer 2100 flame atomic absorption spectrophotometer. Concentrations of Hg and As were determined by means of Perkin–Elmer MHS-FIAS coupled with a Perkin–Elmer 4100 ZL spectrophotometer. The other trace metals were measured by graphite furnace atomic absorption spectrophotometry (Perkin–Elmer 4100 ZL). Results are expressed as mg kg)1 dry sediment. The analytical procedures were checked using reference material (MESS-1 NRC and CRM 277 BCR) and showed a 90–110 range. PAHs were analyzed by using gas chromatography/mass spectrometry (U.S. Environmental Protection Agency SW-846 Method 8270); briefly, dried samples were Soxhlet extracted with n-hexane for 18 h, and the extracts were isolated by column chromatography on Florisil-alumino-silica. PAHs were eluted and their fractions were dried in a rotatory evaporator and redissolved in isooctane. Aromatic fractions were analyzed on a Hewlett–Packard (HP) 5890 Series II gas chromatograph coupled with HP 5970 mass spectrometer. Chromatographic resolution was achieved with a 30 m · 0.250 mm DB-5 capillary column, which has a 0.25-lm film thickness, with helium as carrier gas. Quality control was carried out using NRC-CNRC HS-6 sediment reference material. The analytical procedure allows agreement with the certified values in a 90–112 range. The composition of the oil spilled by the tanker Prestige was a mixture of saturated hydrocarbons, aromatic hydrocarbons, resins, and asphaltenes, with most of the PAHs being of medium to high molecular weight (Albaigs and Bayona 2003). Furthermore, it presents some trace metals such as Ni, V, Cu, Pb, and Zn (CSIC 2003; Albaigs and Bayona 2003; Prego and Cobelo-Garca 2003; Prego and Cobelo-Garca 2004). The physicochemical characteristics of this fuel show that the soluble fraction is low and the kinetics of degradation are slow under natural conditions so it is expected to be accumulated in sediments. The biological effects associated with the chemicals from the oil spill will be dependent on the nature of the ecosystem that accepts them and the organisms living in it (DelValls 2003). The first research notes about the early impact support the prediction that the acute toxicity of the weathered fuel (MariÇo-Balsa 2003), very rich in high molecular weight compounds, was relatively low for the organisms tested (clams and microalgae). However, although concentrations of individual PAHs in aquatic environments are usually much lower than concentrations that are acutely toxic to aquatic organisms, sublethal effects can be produced (Albers 2003). The results presented in this work show the status of the quality of the sediments 2 years after the accidental spill by linking sublethal responses measured in the fish exposed to oilcontaminated sediments with chemical data determined in sediments. Materials and Methods Sediment Bioassays Approach Toxicity tests were carried out using juveniles of Sparus aurata obtained from an aquaculture farm and transported to the laboratory where the fish spent 1 month to acclimatize. S. aurata was selected because is a common species along the Spanish coast. Its biology is well known, having been used in previous pollution studies (DelValls et al. 1998a), and it is easy to acclimatize to laboratory conditions. The sea water used during the acclimatization period and the bioassay was clean marine water. A baseline of 10 randomly chosen individuals were weighed to provide data for feeding calculations. After the acclimatization period, the fish had a weight that averaged 4 € 1 g. Approximately 4 L of sediment from the negative control (BC) and the other stations (Ga1, Ga2, Ga3, TM) were placed in replicate 25-L glass tanks with clean sea water before the beginning of the experiment. After 24 h of particle settling, aeration was provided to maintain adequate oxygen concentrations (greater than 80% saturation). At the beginning of the test, another baseline group of 10 randomly chosen individuals was measured, weighed, anesthetized, and processed for biomarker responses (exposure and effect) to be used as the initial cellular control. Twelve individuals were placed in every tank after checking each tankÕs water quality and were fed 2 or 3 times per day with commercial food (approximately 0.2 g per fish per day of ‘‘Mar Perla T’’ 1.4–2.2 mm). The test was conducted over 2 months, during which time no mortality was recorded. After the exposure period, individuals from each station were anesthetized and processed for histopathological, MTs, and EROD analysis. During the experiment natural photoperiod was selected and constant temperature was maintained (19 € 1C). The physicochemical parameters pH, temperature, oxygen, and salinity were recorded and controlled when necessary to maintain quality control during the test. Water replacement was performed every day by renewing 33% of the water column using a peristaltic pump. The present study was carried out by using sediment samples collected along different littoral areas in the North and the South of Spain. In the North, we chose sampling stations that have been affected by the oil spill in differing degrees and located along the Galician Coast (Ga1, Ga2, Ga3). Another sample was located in the South of Spain, in the Bay of Cdiz (BC) which is considered a pristine area (Riba et al. 2004a) and was used as the negative control reference. An artificial sample (TM) was made by mixing a toxic mud from an accidental mining spill in Spain (Aznalcllar, April 1998) with the clean sediment and used as positive control (Riba et al. 2003). Sediment samples from each station were collected with a 0.025m2 Van Veen grab and placed in a cooler until a sufficient amount of sediment was collected from a particular station (about 30 L). The contents of the cooler were homogenized with a Teflon spoon until no color or textural differences could be detected. The samples were subsampled for physical characterization and chemical quantification. After that, sediment samples were maintained in the cooler at 4C in the dark until used in sediment toxicity tests. Testing occurred within 2 weeks of collection. Sediment was filtered (0.5 mm) prior to the toxicity test in order to remove means interferences such as shells, predators, and other residues. Chemical Analysis Sediment aliquots from each station were dried at room temperature prior to chemical analysis and then gently homogenized. Geochemical -98- C. Morales-Caselles et al. 654 Histological Procedures Organisms from the toxicity tests were analyzed to determine the histopathological damages in different target tissues (liver and gills). When the water was renewed, the survival rate for all tanks was determined. Fish were removed from the tanks after 56 days of exposure time and samples were collected. Fish were anesthetized with 0.1% of 99% pure 2-phenoxyethanol during 5–10 min, then weighed, measured for length, and externally examined. Target tissues (liver and gills) from all of the organisms were obtained by dissection and then fixed in phosphate-buffered 10% formaldehyde (pH 7.2) for 24 h and embedded in paraffin. The histological sections were stained with hematoxylin–eosin and hematoxylin–VOF (Gutirrez 1967). Sections were reviewed by light microscopy (Leitz Laborlux S) and photographed (Sony DKC-CM30). Damage to the tissues was semiquantified by detecting the frequency of the lesions in each detected alteration. Biochemical Analysis Fish were sampled for biochemical analysis, and after dissection, the liver was kept at )80C prior to the homogenization. The samples were homogenized following the procedure developed by Lafontaine et al. (2000). Metallothionein Concentration (MT) Samples obtained to determine metallothionein content were centrifuged at 28,000g for 40 min. The supernatant was added to 0.9 ml of NaCl (0.9%), heated to 95C for 4 min, and centrifuged at 10,000g for 15 min at 4C. Supernatant was stored at )80C prior to MT concentration determinations by Anodic Stripping Voltammetry (Olafson and Olsson 1987) using purified rabbit metallothionein (Sigma-Aldrich). Total protein determination was carried out using the methodology described by Bradford (1976). Concentrations were expressed as lg MT/mg total protein. markers responses; the Tukey test was used as the post-hoc comparison. Also, contamination and toxicity data were linked by factor analysis, and using principal components analysis (PCA) as the extraction procedure, which is a multivariate statistical technique to explore variable distributions (Riba et al. 2003). The original data set used in the analysis included two biomarkers (EROD activity and metallothionein induction), two histopathological indexes (lesions in gills (LIG), and lesions in liver (LIL)), the concentration of different contaminants (PAHs, Cd, Cr, Cu, Ni, Pb, Zn, Hg), and the geochemical matrix characteristics (including total organic carbon and grain size distributions). The objective of PCA is to derive a reduced number of new variables as linear combinations of the original variables. This provides a description of the structure of the data with the minimum loss of information. Results Sediment Contamination Summarized results of total organic carbon, grain size (percent of fine grain <63 lm), concentration of metals and PAHs are shown in Table 1. Of all the stations, the negative control (BC) showed the lowest values of most of contaminants. In general, it is observed that the concentration of PAHs in the area of Galicia (Ga3>Ga2>Ga1) was higher than those measured in the toxic mud and the sediments from the Bay of Cdiz (not detected). The toxic mud, used as positive control, showed high levels of metals in comparison to the other sample sites. These chemical data can be compared to international sediment quality guidelines (SQGs) that account for the chemical contaminants levels associated with biological effect (DelValls et al. 2004). In Table 1, the contaminants that exceed any SQG are highlighted. The letter that appears with the number indicates which SQG is surpassed. Biomarker Responses Mixed Function Oxidase Assay (EROD) After homogenization of the samples, EROD samples were centrifuged at 10,000g for 30 min, and the supernatant was used for the EROD activity determination and the total protein content described by Bradford (1976). Mixed function oxygenase activity was measured using the adapted EROD assay (Gagn and Blaise 1993). Briefly, 50 ll of supernatant (homogenate 10,000g for 30 min), 10 lM 7ethoxyresorufin, and 10 mM reduced NADPH in 100 mM KH2PO4 buffer (pH 7.4). The reaction was started by the addition of NADPH, was allowed to proceed for 60 min at 30C, and stopped by the addition of 100 ll of 0.1 M NaOH. The 7-hydroxyresorufin was determined fluorometrically using 520 nm (excitation) and 590 nm (emission) filters. 7-Hydroxyresorufin concentration in the samples was achieved through a standard calibration curve developed with concentrations of 7-hydroxyresorufin. Results were expressed as pmol/mg total protein. Statistical Analysis Analysis of variance was performed in order to determine significant differences (p < 0.05; p < 0.01) among sites in relation to the bio- The basal level of metallothioneins measured in liver on day 0 of exposure was 20.1 lg)1 mg)1 and was lower than the levels of this biomarker after 56 days of exposure; the measures show that metallothionein levels in liver were significantly different (p < 0.5; p < 0.01) between fishes exposed to control and those exposed to other sediment (Figure 1). These differences were more significant for the station Ga3 and TM (p < 0.01) than for the other two stations located in the area of Galicia, Ga1, Ga2 (p < 0.05). EROD activity determined in the liver of juveniles of S. aurata on day 0 was 0.3 pmol mg)1 min)1. Results after 56 days of exposure are higher than basal levels and showed low values in fish exposed to sediment samples with absence or low levels of total PAHs (TM and BC, respectively) and were significantly different (p < 0.05) from stations affected to a different degree by the oil spill (Ga#) (Figure 1). The fish from these stations present high values of EROD activity and high levels of PAHs in their sediment (Ga1, Ga2, and Ga3). These relationships increase when the concentration of PAHs in sediments increases (Ga3 > Ga2 > Ga1). The EROD activity in liver of fish exposed to sediments from station Ga2 and Ga3 showed a significant difference (p < 0.01) between the control -99- 655 Tanker Oil Spill Toxicity Testing Using Sparus aurata Table 1. Values of total organic carbon (TOC) (% dry weight), fines (% dry weight), and the concentration of contaminants (polycyclic aromatic hydrocarbons (PAHs) and metals) in sediment samples (concentrations are expressed in mg kg)1 dry weight) )1 PAHs (mg kg ) Metals (mg kg)1) Contaminant BC Ga1 Ga2 Ga3 TOC Fines Total PAHs Fluorene Acenaphthene Naphthalene Phenanthrene Anthracene Fluoranthene Pyrene Benzo[a]anthracene Chrysene Benzofluoranthene Benzo[e]pyrene Benzo[a]pyrene Perilene Dibenzo[ah]anthracene Indene[123-cd]pyrene Benzo[ghi]perilene Cd Cr Cu Ni Pb Zn Hg 1.07 1.04 n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 0.92 0.10 6.98 0.06 2.28 21.3 n.d. 0.60 0.06 0.19 0.08 0.06 0.31 0.10 0.02 0.12 0.09 0.05 0.08 0.11 0.08 0.05 0.03 0.01 0.02 0.01 0.16 n.d. 12.8 1.71 2.73 14.7 n.d. 1.19 0.03 2.12 0.13 0.17 0.63 0.15 0.03 0.18 0.13 0.09 0.12 0.18 0.13 0.09 0.05 0.02 0.02 0.02 0.05 2.00 0.65 0.42 1.14 3.95 0.01 2.00 0.01 5.10 0.35 0.27 1.40 1.36 0.18 0.10 0.39 0.20 0.39 0.06 0.16 0.10 0.04 0.02 0.02 0.06 n.d. 1.51 1.19 0.66 1.26 6.45 n.d. a,c a,c a,c a,c c a,c a,d a,d a,d c c c c c TM a a,d a,d a,d a,d,e a,c c a,c c c 1.00 10.1 n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 5.40 a,d 3.28 210 a,d 8.50 790 b,d,e 2181b,d,e 5.61 b,d,e a ERL, Effect Range-Low (NOAA 1999). ERM, Effect Range-Median (NOAA 1999). c ISQG, Interim sediment quality guideline (CCM 1999). d PEL, Probable effect level (CCM 1999). e SQG for San Francisco Bay (Long et al. 1989). Notes: Not detected is expressed by n.d. b treatment. Also, those from station Ga1 were significantly different from control treatment but with different value of the statistical p (0.05). For metallothioneins, Tukey test results set the five stations in three homogeneous groups according to the differences of averages among the sites. The first group includes only BC, which is the negative control; the second group is constituted by Ga1, Ga2, and Ga3; and the third group includes TM, which is the positive control. For EROD activity, there are three homogeneous groups set by the Tukey test results. The first group includes BC and TM, both negative and positive control, which do not present significant differences; the second group is constituted by Ga1 (p < 0.05) and Ga2 (p < 0.01); and the third group includes Ga3 (p < 0.01). Histopathological Approaches The organisms analyzed on day 0 did not present histopathological damages. Different alterations were observed in target tissues (gills and liver) of fish exposed to sediment collected after 56 days of exposure in the different stations, mainly in gills, which showed shortening of secondary lamellae, hyper- trophy, and hyperplasia, necrosis, and loss of epithelial cells in Ga# and TM; fusion of the secondary lamellae above all in Ga3 and TM; and presence of edematous areas in the distal portion of lamellae in Ga#. Also, liver showed lesions: vacuolization of hepatocytes, necrosis, and decrease of the zymogen granules of the exocrine pancreas in Ga# and TM. In general, an increase of cytoplasmic basophilia was detected in the liver and exocrine pancreas of all exposed fish related to the increase of PAHs. An example of some of these lesions is shown in Figure 2. These lesions have been previously recorded as related to contaminants bound to sediments in S. aurata (DelValls et al. 1998a) and in other fish species such as Solea senegalensis (Riba et al. 2004b, 2004c). As previously reported by DelValls et al. (1998a) and based on the damage observed in the different tissues, histopathological alterations were evaluated semiquantitatively in the fishes exposed to the different stations by ranking the frequency of lesions measured in a total number of 6 individuals: – (0 individuals), +/) (1 individual), + (2 individuals), ++/+ (3 individuals), ++ (4 individuals), +++/++ (5 individuals), and finally the maximum is associated with the presence of a disease in the total number of individuals, +++ (6 individuals sampled). Gills were shown to be the most damaged tissue, showing different lesions mainly in Ga# -100- C. Morales-Caselles et al. Metalothioneins/Total proteins(μg/mg) 656 Discussion 120 ** 100 80 ** 60 * * Ga1 Ga2 40 20 0 BC Ga3 T.M. ERODactivity (pmol/mg/min ) 3.0 ** 2.5 2.0 ** 1.5 * 1.0 0.5 0.0 BC Ga1 Ga2 Ga3 T.M. Fig. 1. Results of metallothionein concentration (mean and SD) in lg/mg of protein and EROD activity (mean and SD) in pmol/mg/min of protein in liver samples of S. aurata collected at 56 days of the experiment in sediments sampled in the Bay of Cdiz (BC), Galicia coast (Ga#), and toxic mud (TM) treatments. Asterisks indicate significant differences among the biomarker induction in the stations and the negative control (**p < 001, *p < 005) and TM. An average of this semiquantitative evaluation of the frequency of the lesions measured from the different replicate results is shown in Table 2. General indexes of lesion (lesion index in gills [LIG] and lesion index in liver [LIL]) were calculated for each tissue as an average value of the fish damage semiquantified (Figure 3). Fish exposure to sediment samples produced lesion damage related to the increase of the concentrations of contaminants (PAHs in Ga# and high levels of metals in TM) in the sediments selected in the bioassay. The lesions identified in all the tissues analyzed were almost always present in animals exposed to sediments from stations Ga2 and Ga3. Evaluations of histology of gills and liver revealed clear significant differences (p < 0.05) between the negative control of toxicity and the Ga3 station and the toxic mud. The severity of the lesions detected in the tissues of fish exposed to sediments collected in Bay of Cdiz was lower than those measured in the area of Galicia. Results show the lowest indexes in the Bay of Cdiz (BC), which were significantly different (p < 0.05) from the values from Galicia (Ga#) and toxic mud (TM). The index of lesions measured for gills (LIG) in Galicia increase with the presence of PAHs in the sediment samples (Ga3 > Ga2 > Ga1). The LIL results show that TM has the highest index related to liver lesions. To link the set of data obtained, the original variables from chemical concentration and sublethal responses were analyzed by factor analysis, using PCA as the extraction procedure, which is a multivariate statistical technique (MAA) to explore variable (chemical concentration, n = 25; toxicity data, n = 4) distributions. The factor analysis was performed on the correlation matrix, and the variables were autoscaled (standardized) so as to be treated with equal importance (Riba et al. 2004a). The applications of MAA to the original 29 variables indicate that they can be grouped in two new factors. These factors explain 88.4% of the variance in the original data set. Negative values of sorted rotated factor loadings (negative salience) are as important as positive values (positive salience). In the present study, we selected to interpret a group of variables as those associated with a particular component where loading was 0.40 or higher (Table 3). This approximates ComreysÕ cutoff of 0.55 (Comreys 1973) for a good association between an original variable and a factor, and also takes into account discontinuities in the magnitudes of loadings approximating the original variables. The first principal factor, #1, is predominant and accounts for 62.4% of the variance; it explains the toxicity of individual PAHs and combines the concentrations of PAHs (fluorene, acenaphthene, naphthalene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzofluoranthene, benzo[e]pyrene, benzo[a]pyrene, perilene, dibenzo[ah]anthracene, indene[123-cd]pyrene, benzo[ghi]perilene) in sediment, the total organic carbon, all the indexes of histopathological lesions (gills, LIG; and liver, LIL), and the EROD activity. The second factor, #2, accounts for 26.1% of the variance; it explains the toxicity associated with the metals in sediment combining, with negative loading, the chemical concentrations of the metals Cd, Cr, Cu, Ni, Pb, Zn, and Hg with the grain size with all the indexes of lesions (gills, LIG; and liver, LIL) and with the induction of metallothioneins (MTs). Figure 4 shows the influence of both factors in the five different stations. Factor 1, with positive loading, is defined as the toxic responses of the fish to PAHs bound to sediments; thus, station Ga2 (0.44) and especially Ga3 (1.48) show the significant prevalence of this factor, whereas this factor does not affect station Ga1, and both controls positive (TM) and negative (BC). The definition of Factor 2 as the toxic responses of the fish to metals bound to sediment only has prevalence in the positive control (TM); the negative loading of the toxic responses and the metals concentration in sediment implies that the prevalence of these factors in the station is associated with negative factor scores. Furthermore, a linear relationship can be observed in the scores of this factor from BC to Ga3, which confirms the increase of toxicity when PAHs increase in sediments. It is estimated that about 63,000 tons of heavy fuel oil were lost from the single- hull tanker Prestige. Although a large quantity of this fuel was collected and removed from the coast, a large amount likely settled down at the bottom of the sea covered with sediment reaching the littoral area of the Galician coast after the first months of the spill (Albaiges and Bayona 2003). In the present study, we have aimed to assess the impact of this enrichment in littoral sediments collected in different affected areas and 2 years after the oil spill using juveniles of -101- 657 Tanker Oil Spill Toxicity Testing Using Sparus aurata Fig. 2. Example of histological sections associated with contaminants bound to sediments used in the Sparus aurata sediment toxicity test. (a) Gills from fish exposed to referent sediment showing primary lamellae and secondary lamellae arising from these, parallel with them and perpendicular to the filament axis BC (H & E ·10). (b) Hypertrophy and hyperplasia of the secondary lamellae Ga3 (H & E ·25). (c) Liver from control fish showing the exocrine pancreas around the blood vessels. Parenchymatous distribution of the hepatocytes in cords around the sinusoids BC (H & E ·25). (d) Hepatocytes and exocrine pancreas alteration TM (H & VOF ·25). D: decrease of the zymogen granules; H: hypertrophy and hyperplasia; L: loss of epithelial cells; V: vacuolization of hepatocytes Table 2. Frequency of lesions detected in microscopic abnormalities of individuals of juveniles of the fish Sparus aurata sampled in the Bay of Cdiz (BC), Galicia coast (Ga#) and toxic mud (TM) treatments on day 56 of exposure Samples zones Organ Histopathology BC Ga1 Ga2 Ga3 TM Gills Hypertrophy/hyperplasia Fusion of secondary lamellae Shortening of secondary lamellae Edematous areas or aneurysm in distal portion of lamellae Necrosis and lost of cells epithelial Increase of lipid vacuoles in the hepatocytes Increase of cytoplasmic basophilia of hepatocytes Necrosis and decrease of the zymogen granules of exocrine pancreas +/) + + +/++ + +/) +/) ) +++ +/++ +/++ ++/+++ +/++ + + +/) ++ ++ +/++ ++/+++ +/++ + ++ + +++ +/++ +/++ +++ ++ + + +/) +/++ + +/++ +/++ ++ ++ +/) + Liver (0 individuals), +/) (1 individual), + (2 individuals), ++/+ (3 individuals), ++ (4 individuals), +++/++ (5 individuals) and finally the maximum is associated with the presence of a disease in the total number of individuals, +++ (6 individuals sampled). the fish S. aurata by means of different sublethal endpoints such as histopathological lesions, metallothionein induction, and EROD activity. Previous studies have shown how in water the toxicity of individual PAHs increases as molecular weight (MW) increases up MW 202 and beyond it; solubility reduces and so does lethal toxicity, but sublethal effects can result (Albers 2003). In the present study, it has been shown that the Galician sediments (mainly Ga2 and Ga3) analyzed present levels of PAHs with low MW (fluorene, acenaphthene, naphthalene, phenanthrene, anthracene), medium MW (pyrene), and high MW (benzo[a]anthracene, chrysene, benzo[a]pyrene, dibenzo[ah]anthracene), higher than some of the SQGs proposed by international agencies. Furthermore, all individual PAHs seem to have induced hepatic EROD and to produce histopathological damage; it is quite difficult to determine which of the individual PAHs is the main pollutant that has caused the biological effects (explained by factor 1 in the MAA); however, it can be concluded that PAHs are the compounds that are producing the adverse effects to the fishes. The significant differences of EROD induction between Ga# (Ga1, p < 0.05; Ga2 and Ga3, p < 0.01) show a strong relationship with the concentration of PAHs in the Galician sediments (Ga1, Ga2, and especially in Ga3)—impacted by the oil spill—and the histopathological lesions in gills and liver, studied in the MAA. Despite differences in the induction of EROD among these Galician samples, the validity of this biomarker of contamination was shown. twbIn the absence of fish mortality, other research on the impact of the ‘‘Sea Empress’’ oil spill in the UK in 1996 (Edwards and White 1999) showed the possibility of sublethal and chronic effects using a variety of techniques such as EROD activity. In these studies, there was evidence of high levels of EROD activity in the sites exposed to oil constituents in comparison with the control sites. There are other studies, carried out using biomarkers as EROD activity, that -102- C. Morales-Caselles et al. 658 Table 3. Sorted rotated factor loadings (pattern) of 29 variables for the two principal factors resulting from the multivariate analysis of results obtained from the bioassay with juveniles of Sparus aurata 1,4 1,2 * LIG 1 * * * 0,8 0,6 0,4 0,2 0 BC Ga1 Ga2 Ga3 TM 1,4 1,2 * LIL 1 * 0,8 * * 0,6 0,4 0,2 0 BC Ga1 Ga2 Ga3 TM Fig. 3. General indexes of lesions (mean and SD) measured in gills (LIG) and liver (LIL) of Sparus aurata juveniles exposed to sediments sampled in the Bay of Cdiz (BC), Galicia coast (Ga#), and toxic mud (TM) treatments. Asterisks indicate significant differences among the index value in the stations and the negative control (*p < 005) support the conclusion of the persistent exposure of the organisms to hydrocarbons after 10 years of the oil spill caused by the tanker Exxon Valdez in Alaska in 1989 (Jewett et al. 2002), emphasizing the potential for continuing oil availability to biota. The ability of fish to metabolize many PAHs makes the use of EROD induction for biomonitoring purposes more beneficial than analytical measurements of PAH uptake, providing a sensitive chemical exposure information many years after a contamination event (Whyte et al. 2000). The histopathological analysis showed histomorphological alterations that have been previously reported in this organism when affected by sediment contamination caused by metals and organic compounds (DelValls et al. 1998a; Riba et al. 2004b, 2004c; Ortiz et al. 1999; Au 2004) such as hyperplasia and hypertrophy of gills, and alterations in hepatocytes and exocrine pancreas (i.e., increased cytoplasmic basophilia and vacuolization, necrosis, loss of zymogen granules, etc.). An increase of cytoplasmic basophilia was generally detected in liver and exocrine pancreas of all exposed fish. This fact could be related to a decreased protein synthesis (Sarasquete and Gutirrez 2005), and possibly related to necrotic focus. Moreover, loss of cytoplasmic hepatic glycogen is an early toxic response and may cause an apparent increase in cytoplasmic basophilia (Vethaak and Wester 1996). In general, contaminants can produce osmoregulatory, acid–base, or hemodynamic dysfunctions, and it was proposed that such symptoms are secondary to toxin interactions with specific transport steps or membrane-bound receptors (Evans 1987). Results show that LIG is always higher than LIL in all of the stations; this could be explained by the affirmation that fish gill is a multifunctional organ sensitive to chemicals in water, because gill filaments and lamellae provide a very large sur- % Variance Factor 1 62.4 Factor 2 26.1 TOC Fines Fluorene Acenaphthene Naphthalene Phenanthrene Anthracene Fluoranthene Pyrene Benzo[a]anthracene Chrysene Benzofluoranthene Benzo[e]pyrene Benzo[a]pyrene Perilene Dibenzo[ah]anthracene Indene[123-cd]pyrene Benzo[ghi]perilene Cd Cr Cu Ni Pb Zn Hg MT EROD IGG IGL 0.78 — 0.96 0.97 0.97 0.88 0.90 0.63 0.95 0.97 0.95 0.43 0.93 0.92 0.83 0.91 0.83 0.95 — — — — — — — — 0.98 0.79 0.50 — )0.93 — — — — — — — — — — — — — — — — )0.91 )0.88 )0.95 )0.95 )0.96 )0.96 )0.96 )0.97 — )0.54 )0.74 face area for direct and continuous contact with contaminants in water. Fish gill and liver are highly sensitive to pollutant exposure; however, as previously indicated (Arellano et al. 1999), these pointed histopathological alterations are, in general, nonspecific effects, meaning that they are responsive to a variety of pollutants, and therefore only indicative of the general quality of the environment rather than specific types of pollutants (Au 2004). The increase of lipid vacuoles (small size) present in the hepatocytes can indicate an alteration of lipid metabolism or a partial change in their morphology, or in that of lysosomes (Arellano et al. 1999; Segner and Storch 1985). The cause–effect relationships and detailed mechanisms leading to the development of most pathological symptoms are not generally clear. Nevertheless, certain hepatic lesions in fish have been well correlated with contaminant exposure (Au 2004). Lamellar fusion of gills could be a protective effect for diminishing the amount of vulnerable gill surface area (Mallat 1985). The comparison between chemical analysis and the different toxic response (biomarkers of exposure and of effect at different levels) is a useful tool to determine the quality of the studied sediments. The importance of the use of chronic bioassays that provide long-term information on the effects of the exposure to a toxic compound has been proved, because a compound cannot reflect a considerable lethal toxicity, but it is able to produce lesions at different levels to the organism exposed. -103- 659 Tanker Oil Spill Toxicity Testing Using Sparus aurata 2.0 1.0 Ga1 Ga1 Ga2 0.0 0.0 -1.0 BC Ga3 Ga2 Score Score 1.0 Ga3 -1.0 TM BC -2.0 -2.0 TM Factor 2 Factor 1 Despite the repercussion of the spill in the biota, shown as a decrease of the abundance of the microfauna (Junoy et al. 2005), previous studies have shown that there was not an important toxic effect in different marine organisms (clams and microalgae) exposed to samples of the sediments and their elutriates associated with the spill caused by the tanker ‘‘Prestige’’ (MariÇo-Balsa et al. 2003). The bioassay using juveniles of the fish S. aurata showed results sensitive enough to determine the hazard associated with this oil-contaminated sediment, displaying good correlation between the toxicity and the contaminant levels using a sublethal set of measurements including both biomarkers of exposure and effect. This study demonstrates the necessity to monitor the impact of the spill on sediment quality in the areas affected. Furthermore, it shows that a subchronic test using a sensitive and sublethal endpoint is a powerful tool to identify the risk associated with the enrichment of PAHs in affected sediments. The higher sensitivity of this bioassay compared to the acute tests previously used indicates the need to incorporate this kind of approach as part of a more complete and integrated study based on a weight-of-evidence approach, as previously recommended by some authors (Carballeira 2003). Acknowledgments. The described work was supported by a Grant funded by the Ministry of Education and Science VEM2003-20563. Carmen Morales-Caselles thanks the Ministry of Education and Science for funding her research fellowship (FPU). We thank the members of the ICMAN-CSIC for their support and help. References Adams WJ, Kimerle RA, Barnett JW (1992) Sediment quality and aquatic life assessment. Environ Sci Technol 26:1865–1875 Albaigs J, Bayona JM (2003) La huella del fuel. Ensayos sobre el <<Prestige>>. Fundacin Santiago Rey Fernndez-LaTorre, pp 80–103 Albers PH (2003) Petroleum and individual polycyclic aromatic hydrocarbons. In: Hoffman DJ, Rattner BA, Burton GA, Cairns J (eds) Handbook of ecotoxicology. Lewis Publishers, Boca Raton, FI Chapt 14 Arellano JM, Storch V, Sarasquete C (1999) Histological changes and copper accumulation in liver and gills of the Solea senegalensis. 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Dis Aquat Org 26:99–116 Whyte JJ, Jung RE, Schmitt CJ, Tillit DE (2000) Ethoxyresorufin-Odeethylase (EROD) activity in fish as a biomarker of chemical exposure. Crit Rev Toxicol 30:347–570 -105- Environ Monit Assess (2007) 131:211–220 DOI 10.1007/s10661-006-9469-1 Kinetic of Biomarker Responses in Juveniles of the Fish Sparus aurata Exposed to Contaminated Sediments Carmen Morales-Caselles & Natalia Jiménez-Tenorio & Inmaculada Riba & Carmen Sarasquete & T. Ángel DelValls Received: 17 May 2006 / Accepted: 22 August 2006 / Published online: 14 December 2006 # Springer Science + Business Media B.V. 2006 Abstract Sediments in the National Park of the Atlantic Islands (Galicia, Spain) were affected by the spill of the tanker Prestige (November, 2002) and still present high levels of Polycyclic aromatic hydrocarbons. The adverse effects associated with the contaminants in sediments were tested using a chronic bioassay, exposing juveniles of the fish Sparus aurata (seabream). A toxicokinetic approach is proposed to evaluate sediment quality by linking chemical and C. Morales-Caselles : N. Jiménez-Tenorio : I. Riba : C. Sarasquete Consejo Superior de Investigaciones Científicas (CSIC), Instituto de Ciencias Marinas de Andalucía (ICMAN), Polígono Río San Pedro s/n, 11510 Puerto Real, Cádiz, Spain C. Morales-Caselles : I. Riba : T. Á. DelValls UNITWIN/UNESCO/WiCoP. Departamento de Química Física, Facultad de Ciencias del Mar y Ambientales, Polígono Río San Pedro s/n, 11510 Puerto Real, Cádiz, Spain C. Morales-Caselles : C. Sarasquete : T. Á. DelValls Unidad Asociada Universidad de Cádiz-Calidad Ambiental y Patología (UCA-CSIC), Polígono Río San Pedro s/n, 11510 Puerto Real, Cádiz, Spain ecotoxicological data along the time. Sediment samples were physicochemically characterized and the concentration of contaminants (Polycyclic aromatic hydrocarbons – PAHs – and metals) was measured. Fishes were exposed to contaminated sediments, and samples from different tissues were collected every 15 days throughout the 60 days that lasted the experiment. A biomarker of exposure (ethoxyresorufin O-deethylase activity – EROD activity) and a biomarker of effect (histopathology) were analyzed during the exposure period. Results show a relationship between the biomarkers and the concentrations in sediments of polycyclic aromatic hydrocarbons—PAHs. Besides, the toxicokinetic approach links biomarkers response providing information about the relationship between the detoxification process and the damages observed in the different tissues. The frequency of the histological damage is highest when the EROD activity slightly decreases in accordance with the mechanism of detoxification of this enzymatic system against PAHs and other organic contaminants. Keywords EROD activity . Histopathology . PAHs . Prestige . Oil spill 1 Introduction C. Morales-Caselles (*) Departamento Química Física, Facultad Ciencias del Mar y Ambientales, Polígono Río San Pedro s/n, 11510 Puerto Real, Cádiz, Spain e-mail: [email protected] The heavy fuel oil spill from the tanker Prestige on November 2002 affected more than 1,000 km of coast, from the North of Portugal up to the South-east -107- 212 Environ Monit Assess (2007) 131:211–220 of France, being the Galician Coast the most damaged. The composition of this fuel was a mixture of saturated hydrocarbons, aromatic hydrocarbons, resins and asphaltenes, being most of the Polycyclic aromatic hydrocarbons—PAHs—of an intermedium-high molecular weight (Albaigés & Bayona, 2003; Blanco, Prego, Azpíroz, Fernández-Domínguez, 2006). The formation of the emulsions and the generation of tars induced processes of sedimentation, so that 1 year after the accident the marine sediments reached PAHs concentrations which were 10 times higher than those registered before the spill (IEO, 2003). The use of biomarkers in fish which are indicative of PAHs exposure may provide an early warning of potential ecosystem degradation, contaminant bioavailability, and the defence responses of exposed organisms (Goksøyr et al., 1996; Goksøyr & Förlin, 1992; Reynolds et al., 2003). Interest in the effects of environmental stressors on health and alterations in fish and other marine organisms has increased in recent years, and in particular, histological and cellular alterations have been observed in marine fish from polluted coastal waters and estuaries (Malins et al., 1984; Stein et al., 1992). The capacity of many pollutants to alter different cells, tissues or organs has led to design histopathological techniques in order to evaluate the effects of contaminants (Lowe, 1988; Sarasquete, Muñoz-Cueto, Arellano, & González de Canales, 1997). On the other hand, the relation between contaminated environments and fish alterations has been proved by different authors (Ortiz, González de Canales, & Sarasquete, 2003; Husoy, Myers, & Goksoyr, 1996; Martín-Díaz, Tuberty, McKenney, Sales, & DelValls, 2005; Myers, Willis, Husoy, Goksoyr, & Collier, 1995; Ortiz, González de Canales, Sarasquete, 1999; Sarasquete et al., 2002). The cytochromes P-450-1A (CYP1A) are of special interest in ecotoxicology, due to their role in the biotransformation and bioactivation of different organic xenobiotics (dioxins, PAHs, PCBs). The complex CYP1A turns by monooxygenation, determined lipophilic xenobiotics, in more water-soluble metabolites, helping its detoxification. The EROD measurement in fish is considered a monitoring instrument of pollution exposure and an indicator of potential future problems in the health of fish populations (Carballeira, 2003). According to other authors (Moore & Simpson, 1992; Pacheco & Santos, 2002), the information provided by each biomarker individually is of limited relevance, as there is a considerable likelihood of misinterpretation; thus, biomarkers are best used as selected batteries of tests rather than individually. Furthermore, the study of the behaviour of various biomarkers along the time (toxicokinetic approach) may lead to a substantial improvement in the knowledge of integrated fish toxic response (Pacheco & Santos, 2002). In the present study a bioassay using the fish Sparus aurata was conducted by exposing the individuals to environmental sediment samples collected in areas affected by the Prestige oil spill (November 2002) in the National Park of the Atlantic Islands two years after the Prestige oil spill. The main objectives of this study were: (1) to characterize the metals and PAHs contamination in sediments from the selected areas in the Galician Coast and compare them to a pristine area in the Gulf of Cádiz; (2) to determine the sediment toxicity through the study of the two biomarkers selected along the time; (3) to determine and compare the sediment quality of the different areas of the study by linking the contamination data and the biological effects, establishing a mechanism of detoxification and proposing a toxicokinetic approach. 2 Material and Methods 2.1 Approach The area selected to carry out this study was the “Cíes” islands located in the national park of the Atlantic Islands which has a high ecological value. These islands played an important role during the Prestige oil spill, since they operated as a natural barrier against the entry of fuel in the “Rías Bajas” (Galician Southern coast). Three stations (Ga1, Ga2 and Ga3), whose sediments were affected in different degree by the oil spill of the tanker Prestige, were selected in the internal face of the Archipelago (Figure 1). Another sample was located in the South of Spain, in the Bay of Cádiz (BC) which is considered a clean area (Riba, Forja, Gómez-Parra, & DelValls, 2004b) and was used as the reference station. Sediment samples from each of the stations were collected with a 0.025 m2 Van Veen grab and were homogenized with a Teflon® spoon until no colour or textural differences could be detected. The samples -108- Environ Monit Assess (2007) 131:211–220 213 Figure 1 Map of the locations of the area selected to perform the study. Ga1, Ga2 and Ga3 are located in the Atlantic Islands in the Galician Coast affected by the oil spill related to the Prestige tanker (November, 2002), whereas the reference station (BC) is located in the Bay of Cádiz in the South of Spain (not affected by oil spills). were subsampled for physical characterization and chemical quantification. After that, sediment samples were maintained at 4 °C in the dark until use in sediment toxicity tests (no more than 2 weeks). Sediment was filtered (1 mm) prior to the toxicity test in order to remove means interferences as shells, predators and other residues. FIAS coupled with a Perkin-Elmer 4100 ZL spectrophotometer. Results are expressed as mg kg−1 dry sediment. The analytical procedures were checked using reference material (MESS-1 NRC and CRM 277 BCR) and comply with the certified values in over a 90%. Polycyclic aromatic hydrocarbons (PAHs) were analyzed by using a gas chromatography equipped with an electron capture detector (ECD) (U.S. Environmental Protection Agency SW-846 Method 8270) (US EPA, 1984); briefly, dried samples were soxhlet extracted with n-hexane for 18 h, and the extracts were isolated by column chromatography on Florisil-alumino-silica. PAHs were eluted and their fractions were dried in a rotatory evaporator and redissolved in isooctane. Aromatic fractions were analyzed on a Hewlett-Packard (HP) 5890 Series II gas chromatograph coupled with HP 5970 mass spectrometer. Chromatographic resolution was achieved with a 30 m×0.250 mm DB-5 capillary column, which has a 0.25 μm film thickness, with helium as carrier gas. Quality control was carried out using NRC-CNRC HS-6 sediment reference material. The analytical procedures comply with the certified values in over a 90%. 2.2 Chemical analysis Sediment aliquots from each station were dried at room temperature prior to chemical analysis and then gently homogenized. Geochemical matrix characteristics were studied analyzing organic carbon (TOC) concentration and sediment grain size. For sediment grain size an aliquot of wet sediment was analyzed using a laser particle size Fristch (model Analysette 22) following the method reported by DelValls, Blasco, Sarasquete, Forja, and Gómez-Parra (1998). Organic carbon content was determined using the method of Gaudette, Flight, Torner, and Folger (1974) with El Rayis (1985) modification. Sediments were digested for trace metal analysis, as described by Loring and Rantala (1992). Zn, and Cu concentrations in the extracts were determined with a Perkin-Elmer 2100 flame atomic absorption spectrophotometer. Cd, Cr, Ni and Pb were measured by graphite furnace atomic absorption spectrophotometry (Perkin-Elmer 4100 ZL), while concentrations of Hg were determined by means of Perkin-Elmer MHS- 2.3 Sediment bioassay Juveniles of S. aurata were obtained in an aquaculture farm and were transported to the laboratory where the -109- 214 Environ Monit Assess (2007) 131:211–220 fish spent one month to acclimatize before the bioassay. S. aurata was selected because is a common specie in the Spanish coast, its biology is well known, has been used in previous pollution studies (DelValls et al., 1998) and is easy to acclimatize to laboratory conditions. Sediment (approximately 4 l) from the negative control (BC) and the stations Ga1, Ga2, and Ga3 were placed in replicate in 25-l glass tanks with clean sea water before the beginning of the experiment. After 24 h of particle setting, aeration was provided to maintain adequate oxygen concentrations (higher than 80% saturation). A baseline group of 10 randomly chosen individuals were measured, weighed, anaesthetized, and processed for biomarkers responses (exposure and effect) to be used as the initial cellular control. After checking the tanks water quality, twelve individuals (with a weight averaged 4±1 g) were placed in every tank and were fed two or three times per day. The test was conducted during 2 months, no mortality was recorded, and every 15 days six individuals from each station were anaesthetized and processed for histopathological and EROD analysis. During the experiment natural photoperiod was selected and temperature was maintained constant (19±1 °C). Physicochemical parameters (ammonia, pH, temperature, oxygen and salinity) were recorded and controlled when necessary to maintain quality control during the test. Water replacement was performed every day to avoid increasing levels of ammonia, and the survival rate for all tanks was determined. General indexes of histological lesions were calculated for each tissue (lesion index in gills [LIG] and lesion index in liver [LIL]) as an average value of the fish damage semi_quantified as previously reported (Morales-Caselles, Jiménez-Tenorio, González de Canales, Sarasquete, DelValls, 2006; Riba, CasadoMartínez, Blasco, DelValls, 2004a; Riba et al., 2004b; Riba, González de Canales, Forja, & DelValls, 2004c). The semiquantification was performed by ranking the frequency of lesions measured in a total number of six individuals: − (zero individuals), +/− (one individual), + (two individuals), ++/+ (three individuals), ++ (four individuals), +++/++ (five individuals) and finally the maximum is associated with the presence of alterations in the total number of individuals, +++ (six individuals sampled). 2.5 Biochemical analysis Fish were sampled for biochemical analysis, and after dissection, livers were kept at −80 °C prior to the homogenization. The samples were homogenized following the procedure developed by Lafontaine et al. (2000). After homogenization of the samples, EROD samples were centrifuged at 10,000×g for 30 min, and the supernatant was used for the EROD activity determination and the total protein content described by Bradford (1976). EROD assay was performed following the methodology described by Gagné and Blaise (1993). Briefly, 50 μl of supernatant (homogenate 10,000×g for 30 min), 10 μM 7ethoxyresorufin and 10 mM reduced NADPH in 100 mM KH2PO4 buffer (pH 7.4). The reaction was started by the addition of NADPH, being allowed to proceed for 60 min at 30 °C, and stopped by the addition of 100 μl of 0.1 M NaOH. The 7hydroxyresorufin was determined fluorometrically using 535 nm (excitation) and 580 nm (emission) filters. 7-Hydroxyresorufin concentration in the samples was achieved through an standard calibration curve developed with concentrations of 7-hydroxyresorufin. Results were expressed as picomoles per milligram Total protein (Martín-Díaz, 2004). 2.4 Histological procedures Individual of the fish S. aurata proceeding from the toxicity tests were analyzed to determine the histopathological damages in gills. Fish were removed from the tanks at 15, 30, 45 and 60 days of exposure time and samples were collected. Fish were anaesthetized with 0.1% 2-phenoxyethanol 99% during 5– 10 min; then weighed, measured in length and externally examined. Liver and gills from all the organisms were obtained by dissection and then fixed in phosphate buffered 10% formaldehyde (pH 7.2) for 24 h and embedded in paraffin. The histological sections were stained with Haematoxylin–Eosin and Haematoxylin–VOF (Gutiérrez, 1967). Sections were reviewed by light microscopy Leitz Laborlux S and photographed (Sony DKC-CM30). 3 Results and Discussion Table I shows the summarized results of total organic carbon, grain size (% of fine grain <63 μm), -110- Environ Monit Assess (2007) 131:211–220 Table I Values of total organic carbon (% dry weight), fines (% dry weight) and the concentration of contaminants (PAHs and metals) in sediment samples (concentrations are expressed in mg kg−1 dry weight) 215 Contaminant −1 PAHs (mg kg ) Metals (mg kg−1) Not detected is expressed by n.d. Table adapted from Morales-Caselles et al. (2006). TOC Fines (<63 μm) Total PAHs Fluorene Acenafphthene Naphthalene Phenanthrene Anthracene Fluoranthene Pyrene Benzo[a]anthracene Chrysene Benzofluoranthene Benzo[e]pyrene Benzo[a]pyrene Perilene Dibenzo[ah]anthracene Indene[123-cd]pyrene Benzo[ghi]perilene Cd Cr Cu Ni Pb Zn Hg concentration of metals (Cd, Cr, Cu, Ni, Pb, Zn, Hg) and PAHs (Fluorene, Acenafphthene, Naphthalene, Phenanthrene, Anthracene, Fluoranthene, Pyrene, Benzo[a]anthracene, Chrysene, Benzofluoranthene, Benzo[e]pyrene, Benzo[a]pyrene, Perilene, Dibenzo [ah]anthracene, Indene[123-cd]pyrene, Benzo[ghi] perilene) in the different sediment used in the test (Riba et al., 2004a). Sediments from the reference station (BC) show low values of metals while PAHs were not detected. The highest values of PAHs have been measured in sediments from the station Ga3 (5.10 mg kg−1 dry weight) followed by the station Ga2 (2.12 mg kg−1 dry weight) and Ga1 (0.19 mg kg−1 dry weight). The concentration of metals in sediments from the stations located in Galicia is similar to those measured in the reference station (BC). Previous studies pointed out the possible amount of some metals concentration such as Ni, V, Cu, Pb and Zn (Albaigés & Bayona, 2003; CSIC, 2003; Prego & Cobelo-García, 2003, 2004) from the oil spill although they were not observed at high levels in our study. BC Ga1 Ga2 Ga3 1.07 1.04 ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND 0.92 0.10 6.98 0.06 2.28 21.3 ND 0.60 0.06 0.19 0.08 0.06 0.31 0.10 0.02 0.12 0.09 0.05 0.08 0.11 0.08 0.05 0.03 0.01 0.02 0.01 0.16 ND 12.8 1.71 2.73 14.7 ND 1.19 0.03 2.12 0.13 0.17 0.63 0.15 0.03 0.18 0.13 0.09 0.12 0.18 0.13 0.09 0.05 0.02 0.02 0.02 0.05 2.00 0.65 0.42 1.14 3.95 0.01 2.00 0.01 5.10 0.35 0.27 1.40 1.36 0.18 0.10 0.39 0.20 0.39 0.06 0.16 0.10 0.04 0.02 0.02 0.06 ND 1.51 1.19 0.66 1.26 6.45 ND Figure 2 shows the values of the EROD activity measured in liver samples of the S. aurata exposed to sediments treatments throughout 60 days. In general, EROD activity increases with the presence of PAHs in the sediment samples (Ga3>Ga2>Ga1>BC). Several studies agree that the use of EROD induction in fish is particularly well suited for detection of PAH exposure, because parent compounds may often not be detected in tissues (Whyte, Jung, Schmitt, & Tillit, 2000). The study of the behaviour of EROD activity during the exposure period for Ga3 shows that EROD activity increases significantly at the beginning of the experiments until day number 15 (2.4 pmol/mg/min of protein) and maximum levels are reached (2.9 pmol/mg/min of protein) on day 30. The measures of this biomarker in the liver of the organisms exposed to sediments from Ga1 and Ga2 show a lower increase than in the case of exposure to sediment in Ga3 and reach the maximum later than Ga3, the day 45 (about 1.7 pmol/mg/min of protein for both curves). In the course of the experiment the -111- 216 Environ Monit Assess (2007) 131:211–220 EROD activity (pmol mg-1 min-1) BC Ga1 2.0 2.0 1.5 1.5 1.0 1.0 0.5 0.5 0.0 0.0 0 15 30 45 60 0 15 EROD activity (pmol mg-1 min-1) Ga2 30 45 60 45 60 Ga3 2.5 3.5 3.0 2.0 2.5 1.5 2.0 1.0 1.5 1.0 0.5 0.5 0.0 0.0 0 15 30 45 60 0 15 30 time (days) time (days) Figure 2 EROD activity in picomoles per milligram per minute of protein in liver samples of S. aurata exposed to sediments from Galicia (Ga#) and control (BC) during the 60 days of bioassay. EROD activity for Ga3 – which is the station with the greatest amount of PAHs in their sediments, 5.1 mg kg−1 dry weight – is always higher than the EROD activity for Ga1 and Ga2. These sites (Ga1 and Ga2) show a similar behaviour along the time. For all the stations it is shown a slight decrease of the induction of this biomarker of exposure after the day 30 for Ga3 and after day 45 for the other three stations (including the reference station). The histological alterations observed in target tissues (gill and liver) of fish exposed to sediment collected along the 60 days in the different stations were mainly in gills, which showed shortening of secondary lamellae, presence of edematous areas in distal portion of lamellae, hypertrophy and hyperplasy, necrosis and lost of cells epithelial in the organisms exposed to the Galician sediments; fusion of the secondary was detected specially in organisms exposed to sediments from Ga3. Liver showed lesions such as vacuolization of hepatocytes, necrosis and decrease of the zymogen granules of the exocrine pancreas in the organisms exposed to the Galician sediments. In general, an increase of cytoplasmic basophilia was detected in the liver and exocrine pancreas of all exposed fish that seems related to the increase of PAHs. In Figures 3 and 4 the summarized results of the histopathological alteration are shown as the index of lesions. The index for gills (LIG) increases with the presence of PAHs in the sediment samples (Ga3> Ga2>Ga1>BC) and, in general, LIG increases along the time of exposure (Figure 3). The value of LIG is maximum the day 60 of the experiment and the highest frequency corresponds to the damages observed in the gills of the organisms exposed to sediment from Ga3 (LIG=2.6), followed by Ga2 -112- Ga1 BC 3.0 4.0 2.5 3.0 LIG 2.0 1.5 2.0 1.0 1.0 0.5 0.0 0.0 0 15 30 45 0 60 15 Ga2 30 45 60 Ga3 4.0 3.0 2.5 3.0 LIG 2.0 2.0 1.5 1.0 1.0 0.5 0.0 0.0 0 15 30 45 60 0 time (days) 15 30 45 60 EROD activity (pmol mg-1 min-1) 217 EROD activity (pmol mg-1 min-1) Environ Monit Assess (2007) 131:211–220 time (days) Figure 3 The General Index of Lesions measured in the fish Sparus aurata for gills (LIG) along the period of exposure to the sediments are represented by bars. EROD activity in picomoles per milligram per minute of protein in liver samples of S. aurata along the duration of the experiment for the control (BC) and Galician (Ga#) sites is represented by curves. (LIG=1.9) and Ga1 (LIG=1.1). A similar behaviour can be observed for the index of lesions determined in liver (LIL), where Ga3 presents the highest value (Ga3: LIL=1.3; Ga2: LIL=1.1; Ga1: LIL=0.8; all of them evaluated at the end of the exposure period, after 60 days). The values of LIG were higher than LIL throughout the whole bioassay for all the stations. Gill is a multifunctional organ sensitive to chemicals in water, since gill filaments and lamellae provide a very large surface area for direct and continuous contact with contaminants in water. The EROD activity is used as a biomarker of exposure to lipophilic organic contaminants and measures the enzymatic activity of the phase I catalyzed by the complex CYP1A; the complex CYP1A transforms some lipophilic xenobiotics in metabolites more water soluble, so that they are easier to excrete. However, some of these new compounds are highly reactive and more toxic than the original contaminant, and they might interact with biological macromolecules (Parkinson, 1995) producing lesions. In the fishes exposed to sediments from the station Ga3, it seems that there is a first phase where EROD activity is induced (days 0–30) while there are some histopathological damages. When the activity reaches a maximum and begins to decrease (days 30–60), the histopathological alterations continue increasing and the frequency of the lesions is higher. This mechanism of induction of histopathological damages when hepatic EROD decreases can be shown in the three stations affected by the Prestige oil spill, although it is produced faster and with higher intensity and frequency in the organisms exposed to sediments from Ga3, which also shows the highest PAHs concentra-113- Ga1 BC 3.0 2.5 2.5 2.0 LIL 2.0 1.5 1.5 1.0 1.0 0.5 0.5 0.0 0.0 0 15 30 45 0 60 15 LIL Ga2 30 45 60 Ga3 2.5 3.0 2.0 2.5 2.0 1.5 1.5 1.0 1.0 0.5 0.5 0.0 0.0 0 15 30 45 60 0 time (days) 15 30 45 60 EROD activity (pmol mg-1 min-1) Environ Monit Assess (2007) 131:211–220 EROD activity (pmol mg-1 min-1) 218 time (days) Figure 4 The General Index of Lesions measured in the fish Sparus aurata for liver (LIL) along the period of exposure to the sediments are represented by bars. EROD activity in picomoles per milligram per minute of protein in liver samples of S. aurata along the duration of the experiment for the control (BC) and Galician (Ga#) sites is represented by curves. tion in sediment. This behaviour could be related to the production of toxic metabolites as secondary products in the detoxification process where the EROD activates. It seems that when EROD activity stabilizes or disappears from the cells, the tissues get more defenceless to organic compounds (in this case PAHs), and histopathological damages are caused with more intensity and frequency. Galicia were the chemicals responsible for the measured adverse effects (biomarkers of exposure and effect). The toxicokinetic approach used in this study proposes a mechanism that can explain the histopathological damage associated with the exposure of fish to environmental samples contaminated by PAHs from an oil spill (Prestige, 2002). It gives us the possibility to compare entire curves of behaviour instead of numerical data (endpoint). Besides, it permits to understand better the kinetic of the toxicity based on the role of a detoxification system such as the CYP1A complex. It has been proved the importance of the use of chronic bioassays which provide long-term information of the effects of the exposure to a toxic compound analyzed in environmental samples. 4 Conclusions This study shows that the comparison between chemical analysis and the different toxic responses (biomarkers of exposure and effect) is a useful tool to determine the quality of the studied sediments that were affected by the oil spill. The results obtained demonstrate that PAHs analyzed in sediments from Acknowledgments The described work was partially supported by Grant funded by the Ministry of Education and -114- Environ Monit Assess (2007) 131:211–220 219 Science VEM2003-20563. Carmen Morales Caselles was funded by the Ministerio de Ciencia y Tecnología (FPU) of Spain. Thanks are due to the CIS from Santiago de Compostela and to the members of the ICMAN-CSIC for their help during sampling and analysis of the sediments. to contaminants by caging in Sorfjorden, Norway. Aquatic Toxicology, 36, 53–74. IEO (2003). El vertido del Prestige. Situación un año después del accidente. Informe numero 24 (pp. 1–29). Madrid: IEO. Lafontaine, Y., Gagné, F., Blaise, C., Costan, G., Gagnon, P., & Chan, H. M. (2000). Biomarkers in zebra mussels (Dreissena polymorpha) for the assessment and monitoring of water quality of the St. Lawrence River (Canada). Aquatic Toxicology, 50, 51–70. Loring, D. H., & Rantala, R. T. T. (1992). Methods for the geochemical analyses of marine sediments and suspended particulate matter. Earth-Science Revisions, 32, 235–283. Lowe, W. R. (1988). Sentinel species and sentinel bioassay. In McCarthy, J. F. & Shugart, L. R. 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Critical Reviews in Toxicology, 30(4), 347–570. -116- RoleȱofȱbiomarkersȱtoȱassessȱoilȬcontaminatedȱsedimentȱqualityȱ usingȱtoxicityȱtestsȱwithȱclamsȱandȱcrabsȱȱ CarmenȱMoralesȬCaselles§,§§§,ȱM.ȱLauraȱMartínȬDíaz§,§§§,ȱInmaculadaȱ Riba§,§§§,ȱCarmenȱSarasquete§,ȱT.ȱÁngelȱDelValls§§,§§§ȱȱ ȱ§ȱInstitutoȱdeȱCienciasȱMarinasȱdeȱAndalucíaȱ(ICMANȬCSIC),ȱAvda.ȱRepúblicaȱ Saharauiȱs/n,ȱPuertoȱRealȱ11510,ȱCádiz,ȱSpainȱ §§ȱUNESCOȱUNITWIN/UNICOP,ȱFacultadȱdeȱCienciasȱdelȱMarȱyȱAmbientales,ȱ UniversidadȱdeȱCádiz,ȱPolígonoȱRíoȱSanȱPedroȱs/n,ȱPuertoȱRealȱ11510,ȱCádiz,ȱSpain.ȱ §§§ȱUnidadȱAsociadaȱdeȱCalidadȱAmbientalȱyȱPatologíaȱ(CSICȱ&ȱUCA),ȱAvda.ȱ RepúblicaȱSaharauiȱs/n,ȱPuertoȱRealȱ11510,ȱCádiz,ȱSpain.ȱ Abstractȱ ȱAȱ 28Ȭdayȱ bioassayȱ wasȱ conductedȱ withȱ twoȱ invertebrateȱ speciesȱ withȱ differentȱfeedingȱhabits,ȱtheȱclamȱRuditapesȱphilippinarumȱandȱtheȱshoreȱcrabȱ Carcinusȱ maenas.ȱ Theȱ purposeȱ ofȱ theȱ studyȱ wasȱ toȱ assessȱ theȱ qualityȱ ofȱ sedimentsȱ affectedȱ byȱ oilȱ spillsȱ inȱ differentȱ areasȱ ofȱ ȱ theȱ Spanishȱ Coast.ȱ Theȱ organismsȱ wereȱ exposedȱ toȱ environmentalȱ samplesȱ ofȱ oilȬcontaminatedȱ sedimentsȱduringȱfourȱweeks,ȱandȱafterȱtheȱexperimentȱaȱsuiteȱofȱbiomarkersȱofȱ exposureȱ wasȱ measured:ȱ theȱ phaseȱ Iȱ detoxificationȱ systemȱ wasȱ assessedȱ byȱ EthoxyresorufinȱOȬdeethylaseȱ(EROD)ȱactivity;ȱglutathioneȬSȬtransferaseȱ(GST)ȱ isȱ aȱ phaseȱ IIȱ detoxificationȱ enzymeȱ butȱ isȱ alsoȱ implicatedȱ inȱ oxidativeȱ stressȱ events;ȱglutathioneȱperoxidaseȱ(GPX),ȱglutathioneȱreductaseȱ(GR)ȱandȱtheȱferricȱ reducingȱ abilityȱ ofȱ plasmaȱ (FRAP)ȱ assayȱ wereȱ analyzedȱ toȱ determineȱ theȱ antioxidantȱ activityȱ ofȱ theȱ tissues.ȱ Theȱ biomarkerȱ resultsȱ wereȱ correlatedȱ withȱ theȱchemicalȱcompoundsȱboundȱtoȱsedimentsȱ(PAHs,ȱPCBs,ȱZn,ȱCd,ȱPb,ȱCu,ȱNi,ȱ Co,ȱV)ȱandȱaȱprincipalȱcomponentȱanalysisȱwasȱcarriedȱoutȱwithȱtheȱpurposeȱofȱ linkingȱallȱtheȱvariables,ȱandȱtoȱdetectȱthoseȱcontaminatedȱsedimentsȱpotentiallyȱ harmfulȱ toȱ theȱ biota.ȱ Resultsȱ showedȱ inductionȱ ofȱ biomarkersȱ inȱ bothȱ invertebrateȱ speciesȱ andȱ significantȱ differencesȱ (pȱ <ȱ 0.05;ȱ pȱ <ȱ 0.01)ȱ wereȱ ȱEnvironmentalȱToxicologyȱandȱChemistryȱ(aceptado) - 117 - establishedȱamongȱsedimentsȱaffectedȱbyȱdifferentȱspills.ȱTheȱuseȱofȱtheȱselectedȱ biomarkersȱ togetherȱ withȱ theȱ sedimentȱ chemicalȱ analysisȱ assessesȱ theȱ bioavailabilityȱofȱcontaminantsȱandȱhasȱprovenȱtoȱbeȱaȱsuitableȱtoolȱtoȱmonitorȱ theȱenvironmentalȱqualityȱofȱsedimentsȱaffectedȱbyȱoilȱspills.ȱ Keywords:ȱPAHs,ȱtoxicity,ȱbioassay,ȱoilȱspill,ȱWOEȱ 1.ȱIntroductionȱ Theȱ presenceȱ ofȱ persistentȱ pollutantsȱ relatedȱ toȱ oilȱ spillsȱ suchȱ asȱ PAHsȱ andȱ PCBsȱ andȱ toxicȱ metalsȱ (Cd,ȱ Pb,ȱ Zn,ȱ Cu,ȱ Ni,ȱ Co,ȱ V,ȱ etc)ȱ inȱ differentȱ compartmentsȱ ofȱ theȱ marineȱ environmentȱ hasȱ becomeȱ aȱ majorȱ threatȱ toȱ theȱ healthȱofȱmarineȱecosystemsȱdueȱtoȱaccumulationȱofȱtheirȱresiduesȱinȱtheȱtissuesȱ ofȱ marineȱ organismsȱ [1].ȱ Biomarkersȱ haveȱ beenȱ shownȱ toȱ beȱ usefulȱ toolsȱ inȱ characterizingȱtheȱhealthȱstatusȱofȱanimalsȱfromȱaffectedȱareas,ȱwhereȱcomplexȱ mixturesȱ ofȱ pollutantsȱ areȱ usuallyȱ presentȱ [2,ȱ 3,ȱ 4].ȱ Biomarkersȱ presentȱ theȱ inherentȱ capacityȱ toȱ detectȱ earlyȱ biologicalȱ effectsȱ withinȱ theȱ organismȱ andȱ toȱ monitorȱtheȱtemporalȱprogressionȱ(orȱregression)ȱofȱtheȱdisturbanceȱofȱvariousȱ levelsȱ ofȱ biologicalȱ organizationȱ [5].ȱ Underȱ controlledȱ conditionsȱ inȱ theȱ laboratory,ȱitȱisȱrelativelyȱstraightforwardȱtoȱstandardiseȱbiomarkerȱassaysȱandȱ toȱ regulateȱ theȱ chemicalȱ exposuresȱ thatȱ organismsȱ receive,ȱ soȱ thatȱ causeȬeffectȱ andȱindeed,ȱexposureȬrelationships,ȱcanȱbeȱestablishedȱ[6].ȱ Theȱfluctuationȱofȱdifferentȱbiomarkersȱinȱresponseȱtoȱdifferentȱtoxicantsȱ providesȱaȱpatternȱofȱresultsȱwhichȱcanȱgiveȱcluesȱasȱtoȱtheȱtypeȱofȱpollutantȱthatȱ isȱ causingȱ theȱ observedȱ effectȱ [6].ȱ Biomarkersȱ haveȱ beenȱ previouslyȱ usedȱ toȱ assessȱ oilȱ spillȱ episodesȱ [5,ȱ 7,ȱ 8,ȱ 9].ȱ Inȱ theȱ presentȱ studyȱ aȱ suiteȱ ofȱ biomarkersȱ wasȱchosenȱinȱorderȱtoȱinvestigateȱbiologicalȱresponsesȱofȱorganismsȱexposedȱtoȱ oilȬcontaminatedȱ sedimentsȱ fromȱ theȱ Galicianȱ Coastȱ (NWȱ Spain),ȱ acutelyȱ affectedȱ byȱ aȱ fuelȱ spillȱ (Prestige,ȱ 2002),ȱ andȱ theȱ Bayȱ ofȱ Algecirasȱ (Sȱ Spain),ȱ chronicallyȱ affectedȱ byȱ differentȱ spills.ȱ Ethoxyresorufinȱ OȬdeethylaseȱ (EROD)ȱ - 118 - wasȱ selectedȱ asȱ theȱ phaseȱ Iȱ detoxificationȱ enzymeȱ implicatedȱ inȱ monooxygenationȱ reactionsȱ ofȱ dioxinsȱ andȱ PAHs.ȱ GlutathioneȬSȬtransferaseȱ (GST)ȱ isȱ aȱ phaseȱ IIȱ detoxificationȱ enzymeȱ butȱ isȱ alsoȱ implicatedȱ inȱ oxidativeȱ stressȱ events,ȱ whileȱ glutathioneȱ peroxidaseȱ (GPX)ȱ andȱ glutathioneȱ reductaseȱ (GR)ȱ wereȱ chosenȱ asȱ antioxidantȱ enzymesȱ togetherȱ withȱ theȱ ferricȱ reducingȱ abilityȱ ofȱ plasmaȱ (FRAP)ȱ assay.ȱ Theȱ combinationȱ ofȱ biologicalȱ responsesȱ andȱ chemicalȱdataȱofȱtheȱsedimentȱhelpsȱidentifyȱtheȱintegratedȱimpactȱofȱchemicalȱ contaminationȱonȱorganisms.ȱManyȱauthorsȱagreeȱthatȱsedimentȱqualityȱisȱbestȱ determinedȱbyȱintegratingȱtheȱinformationȱobtainedȱfromȱmeasuresȱofȱchemicalȱ concentrationȱandȱfromȱspecificȱtestsȱtoȱdetermineȱsedimentȱtoxicityȱ[10,ȱ11].ȱȱ Theȱ purposeȱ ofȱ thisȱ workȱ isȱ toȱ testȱ theȱ suitabilityȱ ofȱ usingȱ aȱ setȱ ofȱ biomarkersȱinȱtwoȱinvertebrateȱspecies,ȱtheȱclamȱRuditapesȱphilippinarumȱandȱ theȱ crabȱ Carcinusȱ maenas,ȱ inȱ orderȱ toȱ assessȱ theȱ environmentalȱ qualityȱ ofȱ sedimentsȱ affectedȱ byȱ oilȱ spills.ȱ Toȱ achieveȱ thisȱ objectiveȱ theȱ selectedȱ biomarkersȱ wereȱ linkedȱ withȱ theȱ concentrationȱ ofȱ contaminantsȱ inȱ theȱ sedimentsȱandȱtheȱresultsȱareȱdiscussed.ȱȱ 2.ȱMaterialȱandȱmethodsȱ 2.1.ȱApproachȱ Theȱsedimentsȱemployedȱinȱtheȱpresentȱstudyȱwereȱcollectedȱinȱtwoȱareasȱ ofȱ theȱ Spanishȱ coastȱ affectedȱ byȱ oilȱ spills.ȱ Theȱ areaȱ ofȱ theȱ Galicianȱ coastȱ (NWȱ Spain)ȱsufferedȱtheȱacuteȱimpactȱofȱtheȱPrestigeȱoilȱspillȱinȱ2002ȱwhereasȱtheȱBayȱ ofȱAlgecirasȱ(SȱSpain)ȱisȱcontinuouslyȱaffectedȱbyȱminorȱspills,ȱincludingȱoilȱandȱ otherȱ contaminantsȱ fromȱ industriesȱ andȱ dischargesȱ fromȱ commercialȱ shippingȱ activitiesȱ[12].ȱAȱreferenceȱsiteȱwithȱnoȱorganicȱpollutionȱwasȱselectedȱinȱtheȱBayȱ - 119 - ofȱCádizȱ(SȱSpain).ȱThisȱsiteȱhasȱbeenȱwidelyȱvalidatedȱasȱaȱreferenceȱareaȱ[9,ȱ12,ȱ 13,ȱ14].ȱTheȱ10ȱselectedȱstudyȱsitesȱareȱshownȱinȱFigureȱ1.ȱ ȱ ȱ ȱ Atlantic Islands National Park • D72 •FIG •D59 ƒA1ƒA2 ƒA3 Ría de CormeLaxe ȱ ȱ Spain ȱ ȱ •GR3’ •GR4 Bay of Cádiz •P1 ȱ •CA1 ȱ Bay of Algeciras N E W S ȱ Figureȱ1.ȱMapȱofȱtheȱcoastalȱareaȱofȱGaliciaȱshowingȱtheȱlocationsȱofȱtheȱ samplingȱ stations.ȱ FIG,ȱ D59ȱ andȱ D72ȱ refersȱ toȱ theȱ stationsȱ locatedȱ inȱ theȱ Ciesȱ Islandȱ inȱ theȱ Atlanticȱ Islandȱ NationalȱParkȱ andȱA1,ȱA2ȱandȱA3ȱtoȱthoseȱinȱ theȱ BayȱofȱCormeȬLaxe.ȱTheȱstationsȱlocatedȱinȱtheȱBayȱofȱAlgecirasȱareȱGR3’,ȱGR4ȱ andȱP1.ȱTheȱstationȱCAȱlocatedȱinȱtheȱBayȱofȱCadizȱcorrespondsȱtoȱtheȱsedimentȱ usedȱasȱreference.ȱ 2.2.ȱBioassaysȱ Theȱ clamȱ Ruditapesȱ philippinarumȱ andȱ theȱ crabȱ Carcinusȱ maenasȱ wereȱ obtainedȱfromȱanȱaquacultureȱfarmȱandȱwereȱkeptȱunderȱlaboratoryȱconditionsȱ - 120 - inȱtanksȱwithȱcontinuousȱwaterȱreplacementȱduringȱ10ȱdaysȱforȱacclimation.ȱ25Ȭ Lȱ tanksȱ wereȱ employedȱ toȱ performȱ theȱ bioassayȱ withȱ crabs,ȱ whereasȱ 11ȬLȱ aquariumsȱ wereȱ selectedȱ toȱ carryȱ outȱ theȱ experimentȱ withȱ clams.ȱ Sedimentȱ collectedȱinȱtheȱstudyȱsitesȱwasȱplacedȱinȱreplicateȱinȱtheȱtanks:ȱ4ȱLȱofȱsedimentȱ wasȱputȱinȱtheȱ25ȬLȱglassȱtanksȱandȱ2ȱLȱofȱsedimentȱsampleȱwasȱplacedȱinȱtheȱ 11ȬLȱ aquariums.ȱ Cleanȱ seaȱ waterȱ wasȱ thenȱ addedȱ andȱ afterȱ particleȱ settling,ȱ aerationȱ wasȱ providedȱ toȱ maintainȱ adequateȱ oxygenȱ concentrationsȱ (greaterȱ thanȱ 80%ȱ saturation).ȱ Subsequently,ȱ theȱ organismsȱ wereȱ transferredȱ toȱ theȱ tanks,ȱ theȱ laboratoryȱ conditionsȱ wereȱ controlled,ȱ theȱ temperatureȱ wasȱ keptȱ atȱ 19±1ºCȱ andȱ theȱ naturalȱ photoperiodȱ wasȱ maintained.ȱ Theȱ bioassaysȱ wereȱ performedȱinȱduplicateȱandȱlastedȱ28ȱdays;ȱoverȱthisȱtimeȱtheȱwaterȱinȱtheȱtanksȱ wasȱreplacedȱandȱtheȱcrabsȱwereȱfedȱeveryȱweekȱwithȱaȱmixedȱdietȱofȱmusselsȱ orȱfish,ȱwhileȱtheȱclamsȱwereȱfedȱȱwithȱanȱalgaeȱpreparation.ȱ 2.3.ȱBiochemicalȱanalysisȱ Afterȱ 28ȱ daysȱ ofȱ theȱ exposureȱ periodȱ aȱ surveyȱ wasȱ carriedȱ outȱ andȱ theȱ hepatopancreasȱ (inȱ crabs)ȱ andȱ digestiveȱ glandȱ (inȱ clams)ȱ wereȱ extractedȱ andȱ keptȱ atȱ Ȭ80ºCȱ priorȱ toȱ homogenization.ȱ Theȱ samplesȱ wereȱ homogenizedȱ accordingȱtoȱȱtheȱprocedureȱdevelopedȱbyȱLafontaineȱetȱal.ȱ[15].ȱ Followingȱ homogenization,ȱ theȱ samplesȱ wereȱ centrifugedȱ atȱ 10,000gȱ forȱ 30ȱmin,ȱandȱtheȱsupernatantȱwasȱusedȱforȱtheȱbiomarkerȱdetermination.ȱMixedȱ functionȱ oxygenaseȱ activity,ȱ whichȱ isȱ theȱ firstȱ modeȱ ofȱ detoxificationȱ ofȱ manyȱ organicȱ pollutants,ȱ wasȱ measuredȱ usingȱ theȱ adaptedȱ ERODȱ assayȱ [16].ȱ Theȱ FRAPȱassayȱallowsȱaȱmeasureȱofȱtheȱantioxidantȱcapacityȱandȱwasȱcarriedȱoutȱasȱ describedȱbyȱBenzieȱandȱStrainȱ[17].ȱTheȱantioxidantȱGlutathioneȬSȬtransferaseȱ (GST)ȱ activityȱ wasȱ determinedȱ byȱ monitoringȱ theȱ rateȱ ofȱ conjugationȱ ofȱ glutathioneȱ (GSH)ȱ toȱ 1ȬchloroȬ2,4Ȭdinitrobenzeneȱ (CDNB)ȱ atȱ 340ȱ nmȱ [18].ȱ Theȱ - 121 - oxidationȱ ofȱ 1ȱ mMȱ NADPHȱ byȱ Glutathioneȱ Reductaseȱ activityȱ (GR)ȱ inȱ theȱ presenceȱofȱ10ȱmMȱoxidizedȱglutathioneȱwasȱalsoȱmonitoredȱatȱ340ȱnmȱ[18].ȱTheȱ phaseȱ IIȱ metabolizingȱ enzymeȱ Glutathioneȱ Peroxidaseȱ activityȱ (GPX)ȱ wasȱ measuredȱaccordingȱtoȱMcFarlandȱetȱal.ȱ[18].ȱAllȱtheȱbiomarkerȱresponsesȱwereȱ normalizedȱtoȱtheȱtotalȱproteinȱcontentȱ[19].ȱ 2.4.ȱChemicalȱanalysisȱ Theȱ analysesȱ ofȱ PAHsȱ andȱ PCBsȱ wereȱ carriedȱ outȱ accordingȱ toȱ USEPAȱ SWȬ846ȱ Methodȱ 827C78082.ȱ Briefly,ȱ followingȱ recommendationsȱ byȱ Ribaȱ etȱ al.ȱ [20],ȱ driedȱ samplesȱ wereȱ Soxhletȱ extractedȱ withȱ nȬhexaneȱ forȱ 18ȱ h,ȱ andȱ theȱ extractsȱ wereȱ isolatedȱ byȱ columnȱ chromatographyȱ onȱ Florisileȱ aluminoȬsilica.ȱ Theȱ PCBsȱ andȱ PAHsȱ wereȱ elutedȱ andȱ theirȱ fractionsȱ wereȱ driedȱ inȱ aȱ rotatingȱ evaporatorȱandȱreȬdissolvedȱinȱisooctane.ȱTheȱaromaticȱfractionsȱwereȱanalyzedȱ usingȱȱaȱHewlettȱPackardȱ(HP)ȱ5890ȱSeriesȱIIȱgasȱchromatographerȱcoupledȱwithȱ anȱ HPȱ 5970ȱ massȱ spectrometer.ȱ Theȱ PAHsȱ wereȱ analyzedȱ byȱ GCȬMSȱ usingȱ selectedȱ ionȱ monitoringȱ (SIM).ȱ Analysisȱ ofȱ PCBsȱ suchȱ asȱ AROCLORȱ 1242ȱ andȱ AROCLORȱ 1260ȱ wasȱ performedȱ usingȱ theȱ sameȱ instrumentȱ withȱ anȱ electronȱ captureȱ detectorȱ (GC/ECD).ȱ Forȱ bothȱ setsȱ ofȱ organicȱ chemicals,ȱ PAHsȱ andȱ AROCLOR,ȱ theȱ analyticalȱ procedureȱ showedȱ agreementȱ withȱ theȱ certifiedȱ valuesȱofȱmoreȱthanȱ90%.ȱ AȱtraceȱmetalȱanalysisȱwasȱcarriedȱoutȱasȱdescribedȱbyȱCasadoȬMartínezȱ etȱ al.ȱ [21].ȱ Briefly,ȱ 2.5ȱ gȱ ofȱ sedimentsȱ (<0.065ȱ mm)ȱ wereȱ placedȱ inȱ Teflonȱ containersȱandȱwereȱdigestedȱinȱaȱmicrowaveȱovenȱ(400W,ȱ15ȱmin,ȱtwice)ȱwithȱ 2NȱHNO3.ȱTheȱextractsȱwereȱpurifiedȱbyȱpassingȱthemȱthroughȱaȱCȬ18ȱcolumnȱ andȱ metalȱ analysesȱ wereȱ performedȱ byȱ anodicȱ voltamperometryȱ (ȬZn,ȱ Cd,ȱ Pb,ȱ Ni,ȱ Coȱ andȱ CuȬȱ Metrohmȱ Applicationȱ Bulletinȱ Nºȱ 147;ȱ Ȭȱ VȬȱ Metrohmȱ Applicationȱ Noteȱ Nºȱ VȬ81).ȱ Theȱ coldȱ vapourȱ techniqueȱ wasȱ usedȱ forȱ Hgȱ andȱ - 122 - wasȱ quantifiedȱ usingȱ atomicȱ absorptionȱ spectrometry.ȱ Theȱ analyticalȱ proceduresȱwereȱcheckedȱusingȱreferenceȱmaterialȱ(MESSȬ1ȱNRCȱandȱCRMȱ277ȱ BCR)ȱandȱshowedȱaȱrecoveryȱgreaterȱthanȱ90%ȱofȱtheȱcertifiedȱconcentration.ȱ 2.5.ȱStatisticalȱanalysisȱ Theȱ biomarkerȱ resultsȱ wereȱ analyzedȱ withȱ theȱ ANOVAȱ andȱ Tukeyȱ testȱ withȱtheȱaimȱofȱdeterminingȱsignificantȱdifferencesȱ(pȱ<ȱ0.05;ȱpȱ<ȱ0.01)ȱbetweenȱ theȱ resultsȱ obtainedȱ forȱ theȱ referenceȱ siteȱ andȱ theȱ otherȱ samplingȱ sitesȱ (SPSSȱ 11.5).ȱTheȱchemicalȱconcentrationsȱinȱsedimentsȱandȱbiomarkerȱresponsesȱwereȱ correlatedȱ withȱ theȱ Pearsonȱ analysisȱ (pȱ <ȱ 0.05)ȱ inȱ orderȱ toȱ detectȱ relationshipsȱ betweenȱ theȱ variablesȱ (STATISTICAȱ 6.0).ȱ Finallyȱ aȱ multivariateȱ analysisȱ wasȱ carriedȱ outȱ withȱ theȱ purposeȱ ofȱ linkingȱ chemicalȱ andȱ biologicalȱ data;ȱ theȱ principalȱ componentȱ analysisȱ (PCA)ȱ wasȱ usedȱ asȱ theȱ extractionȱ procedureȱ toȱ deriveȱ aȱ reducedȱ numberȱ ofȱ newȱ variablesȱ (factors)ȱ asȱ linearȱ combinationsȱ ofȱ theȱoriginalȱvariablesȱ(STATISTICAȱ6.0)ȱ[22].ȱ 3.ȱResultsȱ 3.1.ȱBiomarkerȱresponsesȱ Theȱbiomarkerȱresponsesȱinȱcrabsȱandȱclamsȱafterȱ28ȱdaysȱofȱexposureȱtoȱ theȱ sedimentȱ samplesȱ areȱ shownȱ inȱ Figureȱ 2.ȱ Theȱ GPXȱ activityȱ resultsȱ (Figureȱ 2.a)ȱshowedȱtheȱlowestȱvaluesȱinȱC.ȱmaenasȱexposedȱtoȱtheȱreferenceȱsediment.ȱ Significantȱdifferencesȱ(pȱ<ȱ0.01)ȱinȱGPXȱinductionȱwereȱdetectedȱbetweenȱcrabsȱ exposedȱtoȱtheȱreferenceȱsedimentȱandȱcrabsȱexposedȱtoȱtestȱsedimentsȱcollectedȱ inȱA2ȱandȱA3ȱinȱCormeȬLaxeȱandȱGR3’ȱinȱtheȱBayȱofȱAlgeciras.ȱTheȱinductionȱofȱ thisȱ biomarkerȱ inȱ clamsȱ didȱ notȱ presentȱ significantȱ differencesȱ betweenȱ treatments.ȱTheȱinductionȱofȱtheȱantioxidantȱbiomarkerȱGRȱ(Figureȱ2.b)ȱinȱcrabsȱ exposedȱtoȱsedimentȱfromȱA1ȱandȱclamsȱfromȱtheȱA2ȱtreatmentȱwasȱȱ - 123 - 17.5 ** 20 ** GR (n m o l/m g /m in ) GPX (nm ol/m g/m in) 30 ** 10 ** 10.5 7.0 3.5 * 0.0 0 Ca1 A1 A2 A3 FIG 59 Ca1 A1 A2 A3 FIG 59 72 GR3' GR4 P1 2500 72 GR3' GR4 P1 1.6 2000 1500 1000 * 500 * 0 Ca1 A1 A2 A3 FIG 59 EROD (pm ol/m g/m in) GST (nm ol/m g/m in) 14.0 ** 1.2 ** 0.8 0.4 * * * 0.0 72 GR3' GR4 P1 * * Ca1 A1 A2 A3 ** * * * ** ** FIG 59 72 GR3' GR4 P1 FRAP (uM /m g/m in) 20.0 ** 16.0 Carcinusȱmaenas 12.0 Ruditapesȱphilippinarumȱ 8.0 * ** * 4.0 * ** ** 0.0 Ca1 A1 A2 A3 FIG 59 72 GR3' GR4 P1 Figureȱ 2.ȱ Generalȱ healthȱ biomarkersȱ forȱ bothȱ invertebrateȱ species,ȱ theȱ clamȱ Ruditappesȱ philippinarumȱ andȱ theȱ crabȱ Carcinusȱ maenas:ȱ glutathioneȱ peroxidaseȱ activityȱ GPXȱ (nmol/min/mgȱ prot),ȱ glutathioneȱ transferaseȱ GSTȱ activityȱ (nmol/min/mgȱ prot),ȱ glutathioneȱ reductaseȱ GRȱ activityȱ (nmol/min/mgȱ prot),ȱferricȱreducingȱabilityȱofȱplasmaȱFRAPȱactivityȱ(ΐM/mg/min)ȱandȱERODȱ activityȱ (pmol/mg/min).ȱ Asterisksȱ indicateȱ significantȱ differencesȱ withȱ theȱ referenceȱtreatmentȱCA1ȱ(*pȱ<ȱ0.05;ȱ**pȱ<ȱ0.01).ȱ ȱ ȱ - 124 - significantlyȱ differentȱ (pȱ <ȱ 0.05ȱ andȱ pȱ <ȱ 0.01ȱ respectively)ȱ fromȱ theȱ referenceȱsite;ȱonȱtheȱotherȱhandȱcrabsȱexposedȱtoȱsedimentȱfromȱFIGȱandȱclamsȱ exposedȱ toȱ GR3’ȱ presentedȱ significantȱ differencesȱ (pȱ <ȱ 0.05)ȱ andȱ lowerȱ valuesȱ thanȱ theȱ referenceȱ siteȱ CA.ȱ Inȱ relationȱ toȱ ȱ theȱ phaseȱ Iȱ detoxificationȱ system,ȱ clamsȱfromȱallȱtreatmentsȱshowedȱsignificantȱdifferencesȱwithȱtheȱreferenceȱsiteȱ inȱERODȱactivityȱ(Figureȱ2.d);ȱtheseȱdifferencesȱwereȱgreaterȱ(p<0.01)ȱforȱthoseȱ clamsȱthatȱhadȱbeenȱexposedȱtoȱtheȱsedimentsȱcollectedȱinȱtheȱBayȱofȱAlgecirasȱ (GR3’,ȱ GR4ȱ andȱ P1).ȱ ȱ ERODȱ inductionȱ inȱ crabsȱ fromȱ A1,ȱ A2ȱ inȱ CormeȬLaxe,ȱ GR3’ȱandȱGR4ȱinȱtheȱBayȱofȱAlgecirasȱwasȱalsoȱsignificantlyȱdifferentȱfromȱtheȱ referenceȱ stationȱ (pȱ <ȱ 0.05).ȱ Theȱ antioxidantȱ activityȱ obtainedȱ fromȱ theȱ FRAPȱ assayȱ(Figureȱ2.e)ȱshowedȱsignificantȱdifferencesȱbetweenȱȱcrabsȱexposedȱtoȱA2ȱ (pȱ<ȱ0.05),ȱA3ȱ(pȱ<ȱ0.05),ȱFIGȱ(pȱ<ȱ0.05),ȱP1ȱ(pȱ<ȱ0.01)ȱandȱtheȱreferenceȱsite;ȱinȱtheȱ caseȱ ofȱ clams,ȱ GR3’ȱ (pȱ <ȱ 0.01),ȱ GR4ȱ (pȱ <ȱ 0.01)ȱ andȱ D72ȱ (pȱ <ȱ 0.05)ȱ presentedȱ significantȱ differencesȱ toȱ theȱ referenceȱ site,ȱ althoughȱ GR3’ȱ showedȱ higherȱ valuesȱthanȱCAȱwhereasȱGR4ȱandȱD72ȱpresentedȱlowerȱvalues.ȱȱ 3.2.ȱChemicalȱanalysisȱ ResultsȱofȱtheȱchemicalȱanalysisȱareȱshownȱinȱTable1.ȱSedimentsȱfromȱtheȱ referenceȱ siteȱ didȱ notȱ presentȱ organicȱ contaminationȱ whereasȱ sedimentsȱ fromȱ theȱ Bayȱ ofȱ Algecirasȱ (GR3’ȱ >ȱ GR4ȱ >ȱ P1),ȱ chronicallyȱ affectedȱ byȱ differentȱ spillȱ andȱ CormeȬLaxeȱ (A1ȱ >ȱ A2ȱ >ȱ A3)ȱ presentedȱ higherȱ concentrationsȱ ofȱ PAHsȱ inȱ theirȱ sedimentsȱ thanȱ sitesȱ fromȱ theȱ Ciesȱ Islandȱ (59ȱ >ȱ FIGȱ >72).ȱ ȱ ȱ Inȱ general,ȱ chemicalȱanalysisȱdoesȱnotȱpresentȱaȱprevailingȱtendencyȱinȱtheȱconcentrationȱofȱ metalsȱamongȱsedimentsȱfromȱtheȱdifferentȱareas.ȱSamplesȱcollectedȱinȱtheȱsiteȱ GR3ȱfromȱtheȱBayȱofȱAlgecirasȱpresentedȱtheȱhighestȱvaluesȱofȱNiȱ(74.7ȱmgȱKgȬ1),ȱ whereasȱ Zn,ȱ andȱ Pbȱ presentsȱ theirȱ maximumsȱ inȱ sedimentsȱ fromȱ theȱ areaȱ ofȱ CormeȬLaxeȱ(A1ȱandȱA3).ȱȱȱ - 125 - Tableȱ 1.ȱ Concentrationȱ ofȱ PAHsȱ andȱ PCBsȱ (ΐgȱ kgȬ1ȱ dryȱ weight)ȱ andȱ metalsȱ(mgȱkgȬ1ȱdryȱweight)ȱinȱtheȱsedimentȱsamplesȱusedȱinȱtheȱbioassays.ȱ ȱȱ Reference CormeȬLaxeȱ CíesȱIslandȱ BayȱofȱAlgecirasȱ ȱȱ Ca1ȱ A1ȱ A2ȱ A3ȱ FIGȱ 59ȱ 72ȱ GR3ȇȱ GR4ȱ P1ȱ PAHsȱ n.d.ȱ 820ȱ 558ȱ 537ȱ 257ȱ 370 239ȱ 2961ȱ 802ȱ PCBsȱȱ n.d.ȱ 2.28ȱ 4.29ȱ 2.60ȱ n.d.ȱ 6.52 4.76ȱ 22.0ȱ 1.75ȱ 0.84 Znȱȱ 21.3ȱ 244ȱ 31.8ȱ 65.7ȱ 76.2ȱ 43.4 37.5ȱ 138ȱ 35.3ȱ 56.7 Cdȱȱ 0.92ȱ n.d.ȱ n.d.ȱ n.d.ȱ n.d.ȱ n.d. n.d.ȱ 0.17ȱ 0.10ȱ 0.12 Pbȱ 2.28ȱ 14.3ȱ 4.25ȱ 44.0ȱ 26.6ȱ 9.13 6.54ȱ 21.6ȱ 6.21ȱ 12.3 Cuȱȱ 6.98ȱ 19.1ȱ n.d.ȱ 22.1ȱ 18.9ȱ n.d. 31.6ȱ 5.01ȱ 3.67ȱ 75.2 Niȱȱ 0.06ȱ 7.03ȱ 5.61ȱ 9.39ȱ 12.0ȱ 6.88 5.02ȱ 74.7ȱ 13.1ȱ 13.3 Coȱȱ 3.40ȱ 0.67ȱ 0.37ȱ 1.21ȱ 0.52ȱ n.d. 0.87ȱ 12.8ȱ 5.59ȱ n.d. Vȱȱ 80.0ȱ 5.94ȱ 2.34ȱ 13.4ȱ n.d.ȱ n.d. n.d.ȱ 26.1ȱ n.d.ȱ 6.84 641ȱ 3.3.ȱCorrelationȱbetweenȱvariablesȱ A correlation analysis was conducted in order to detect relationships between the presence of contaminants in the sediments and the induction of biomarkers in the invertebrates exposed to the same as biological mechanisms to defend against these compounds. Significant correlations (p < 0.05 and p < 0.01) were observed between sediment contamination and biological responses in the organisms exposed (table 2). Similarly, significant associations (p < 0.05 and p < 0.01) were observed between organic contaminants (PAHs and PCBs) bound to sediments, the metals Ni and Co and the induction of EROD activity in both clams and crabs after the 28-dayexposure time. ȱ - 126 - ȱ PAHs PCBs Zn Cd Pb Cu Ni Co V GPX-crab GPX-clam GR-crab GR-clam GST-crab GST-clam EROD-crab EROD-clam FRAP-crab FRAP-clam .791** Cu Ni Co .754* .851** .648* .727* .709* .857** .843** .725* .882** .882** Pb .969** .914** .863** .799** .970** Cd .969** .863** .914** .799** .843** Zn .905** .905** PAHs PCBs .843** .692* .709* .857** .754* .648* .692* .843** .725* .851** .727* .791** GPX GPX GR GR GST GST EROD EROD FRAP FRAP crab clam crab clam crab clam crab clam crab clam - 127 - .970** V Tableȱ 2.ȱ Pearsonȱ correlationȱ (*p<0.05,ȱ **p<0.01)ȱ resultsȱ amongȱ chemicalȱ compoundsȱ boundȱ toȱ sedimentsȱ andȱ biomarkers:ȱ Ethoxyresorufinȱ OȬdeethylaseȱ (EROD)ȱ activity,ȱ glutathioneȬSȬtransferaseȱ (GST)ȱ activity,ȱ glutathioneȱ peroxidaseȱ (GPX)ȱactivity,ȱglutathioneȱreductaseȱ(GR)ȱactivityȱandȱferricȱreducingȱabilityȱofȱplasmaȱ(FRAP)ȱactivity.ȱ Meanwhile, the antioxidant GR and FRAP activity measured in both species was significantly (p < 0.01) correlated with the presence of Zn and Cu in the sediment respectively. A relationship has been shown between the metals V and Cd (p < 0.01) although this association did not present any relationship with the biomarkers studied. 3.4.ȱPrincipalȱcomponentsȱanalysisȱ Basedȱ onȱ correlationsȱ betweenȱ theȱ chemicalȱ andȱ biologicalȱ results,ȱ theȱ principalȱcomponentsȱanalysisȱenablesȱgroupingȱofȱtheȱ19ȱoriginalȱvariablesȱintoȱ 4ȱ newȱ factorsȱ whichȱ accountȱ forȱ 63.3ȱ %ȱ ofȱ theȱ variance.ȱ Theȱ purposeȱ ofȱ thisȱ analysisȱ isȱ ȱ toȱ reduceȱ theȱ numberȱ ofȱ variablesȱ withȱ theȱ minimumȱ lossȱ ofȱ informationȱinȱorderȱtoȱsimplifyȱtheȱinterpretationȱofȱtheȱresults.ȱInȱtheȱpresentȱ study,ȱitȱwasȱdecidedȱtoȱinterpretȱaȱgroupȱofȱvariablesȱasȱbeingȱassociatedȱwithȱ aȱ particularȱ componentȱ whereȱ theȱ loadingȱ wasȱ 0.30ȱ orȱ higherȱ (Tableȱ 3),ȱ approximatingȱ toȱ Comreys’ȱ cutȬoffȱofȱ0.55ȱ[23]ȱforȱaȱgoodȱassociationȱbetweenȱ anȱ originalȱ variableȱ andȱ aȱ factor.ȱ Factorȱ 1ȱ (31.2ȱ %)ȱ linksȱ theȱ concentrationȱ ofȱ PAHs,ȱ PCBs,ȱ Niȱ andȱ Coȱ inȱ sedimentsȱ withȱ theȱ inductionȱ ofȱ ERODȱ activityȱ inȱ clamsȱ andȱ crabs,ȱ theȱ GPXȱ activityȱ inductionȱ inȱ crabsȱandȱ theȱ FRAPȱ activityȱ inȱ clamsȱafterȱ28ȱdaysȱofȱexposure.ȱTheȱmetalsȱZnȱandȱPbȱinȱsedimentȱareȱrelatedȱ withȱGPXȱandȱGRȱactivitiesȱinȱbothȱcrabsȱandȱclams,ȱGSTȱactivityȱinȱcrabsȱandȱ FRAPȱinductionȱinȱclamsȱasȱdefinedȱbyȱFactorȱ2ȱ(17.3ȱ%).ȱFactorȱ3ȱ(14.9ȱ%),ȱwithȱ negativeȱloading,ȱgroupsȱCuȱwithȱtheȱinductionȱofȱGPXȱandȱFRAPȱactivitiesȱinȱ crabsȱafterȱ28ȱdaysȱofȱexposureȱtoȱtheȱsediments.ȱȱ Afterȱdefiningȱtheȱmeaningȱofȱeachȱfactor,ȱtheȱPCAȱenablesȱȱidentificationȱ ofȱ theȱ importanceȱ ofȱ eachȱ factorȱ atȱ eachȱ studyȱ siteȱ byȱ usingȱ theȱ factorȱ score.ȱ Figureȱ3ȱshowsȱtheȱFactorȱscoreȱatȱeachȱofȱtheȱstations.ȱTheȱinfluenceȱofȱFactorȱ1,ȱ relatedȱ withȱ theȱ biomarkerȱ responseȱ ofȱ theȱ organicȱ contaminantsȱ (PAHsȱ andȱ PCHs),ȱandȱtheȱmetalsȱCoȱandȱNiȱinȱsediments,ȱisȱprevalentȱinȱtheȱstationsȱGR3’ȱ (2.66)ȱandȱGR4ȱ(0.57)ȱfromȱtheȱBayȱofȱAlgeciras;ȱFactorȱ2,ȱwhichȱexplainsȱtheȱȱ - 128 - Tableȱ 3.ȱ Sortedȱ rotatedȱ factorȱ loadingsȱ ofȱ 19ȱ variablesȱ forȱ theȱ threeȱ principalȱ factorsȱ resultingȱ fromȱ theȱ multivariateȱ analysisȱ ofȱ resultsȱ obtainedȱ fromȱ theȱ chemicalȱ analysisȱ andȱ theȱ biomarkerȱ responsesinȱ crabsȱ andȱ clams:ȱ EthoxyresorufinȱOȬdeethylaseȱ(EROD)ȱactivity,ȱglutathioneȬSȬtransferaseȱ(GST)ȱ activity,ȱ glutathioneȱ peroxidaseȱ (GPX)ȱ activity,ȱ glutathioneȱ reductaseȱ (GR)ȱ activityȱandȱferricȱreducingȱabilityȱofȱplasmaȱ(FRAP)ȱactivity.ȱ ȱȱ ȱȱ PAHsȱ PCBsȱ Znȱ Cdȱ Pbȱ Cuȱ Niȱ Coȱ Vȱ GPXȬcrabȬ28ȱ GPXȬclamȬ28ȱ GRȬcrabȬ28ȱ GRȬclamȬ28ȱ GSTȬcrabȬ28ȱ GSTȬclamȬ28ȱ ERODȬcrabȬ28ȱ ERODȬclamȬ28ȱ FRAPȬcrabȬ28ȱ FRAPȬclamȬ28ȱ FACTORȱ1ȱ FACTORȱ2ȱ FACTORȱ3ȱ 31.23%ȱ 17.25%ȱ 14.85%ȱ ņȱ ņȱ 0.80ȱ ņȱ 0.34ȱ ņȱ ņȱ ņȱ ņȱ 0.38ȱ 0.31ȱ 0.82ȱ 0.34ȱ 0.73ȱ ņȱ ņȱ ņȱ ņȱ 0.44ȱ 0.95ȱ 0.91ȱ ņȱ ņȱ ņȱ ņȱ 0.95ȱ 0.91ȱ ņȱ 0.48ȱ ņȱ ņȱ ņȱ ņȱ ņȱ 0.86ȱ 0.85ȱ ņȱ 0.42ȱ ȱ ȱ ȱ - 129 - ņȱ ņȱ ņȱ ņȱ ņȱ Ȭ0.49ȱ ņȱ ņȱ ņȱ Ȭ0.30ȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ Ȭ0.59ȱ ņȱ 3.0 GR3' ȱ Factor 1 2.0 ȱ 1.0 GR4 ȱ 0.0 A2 -1.0 A3 A1 Ca1 FIG 59 P1 72 ȱ ȱ 3.0 A1 ȱ Factor 2 1.5 A2 GR3' A3 0.0 P1 ȱ FIG Ca1 59 -1.5 72 ȱ GR4 -3.0 ȱ 3.0 Ca1 ȱ Factor 3 2.0 1.0 A3 A1 ȱ GR3' GR4 0.0 -1.0 -2.0 A2 ȱ 59 72 FIG ȱ P1 Figureȱ3.ȱFactorȱloadingsȱforȱtheȱthreeȱprincipalȱfactorsȱresultingȱfromȱtheȱ multivariateȱanalysisȱofȱresultsȱobtainedȱfromȱtheȱchemicalȱanalysisȱandȱtheȱ suiteȱofȱbiomarkers.ȱ - 130 - relationshipȱ betweenȱ theȱ contentȱ ofȱ Znȱ andȱ Pbȱ inȱ theȱ sedimentȱ andȱ theȱ biomarkerȱ responsesȱ inȱ clamsȱ andȱ crabs,ȱ presentsȱ aȱ positiveȱ loadingȱ inȱ theȱ stationsȱA1ȱ(2.02),ȱA2ȱ(0.36)ȱandȱA3ȱ(0.46)ȱfromȱCormeȬLaxeȱandȱGR3`ȱ(0.58)ȱandȱ P1ȱ (0.07)ȱ fromȱ theȱ Bayȱ ofȱ Algeciras.ȱ Finally,ȱ Factorȱ 3,ȱ whichȱ withȱ negativeȱ loadingȱ relatesȱ Cuȱ withȱ someȱ biomarkerȱ responsesȱ (GPXȱ andȱ FRAPȱ inductionȱ inȱ crabs)ȱ showsȱ aȱ prevalenceȱ (negativeȱ scores)ȱ inȱ theȱ stationsȱ fromȱ theȱ Ciesȱ IslandsȱFIGȱ(Ȭ0.88),ȱ59ȱ(Ȭ0.46),ȱ72ȱ(Ȭ0.16),ȱandȱA2ȱ(Ȭ0.38)ȱfromȱCormeȬLaxeȱandȱP1ȱ (Ȭ1.40)ȱfromȱtheȱBayȱofȱAlgeciras.ȱ 4.ȱDiscussionȱȱ Theȱ presentȱ studyȱ analysesȱ theȱ relationshipȱ betweenȱ biomarkerȱ responsesȱinȱorganismsȱexposedȱtoȱsedimentsȱcontaminatedȱbyȱoilȱspillsȱȱinȱNWȱ andȱSȱSpainȱandȱtheirȱchemicalȱcontent.ȱTwoȱinvertebrateȱspeciesȱwithȱdifferentȱ feedingȱhabitsȱhaveȱbeenȱemployedȱinȱthisȱresearchȱasȱbioindicatorȱspecies,ȱtheȱ shoreȱcrabȱCarcinusȱmaenasȱandȱtheȱclamȱRuditapesȱPhilippinarum.ȱȱ Despiteȱ theȱ difficultyȱ ofȱ testingȱ complexȱ mixturesȱ ofȱ contaminants,ȱ theȱ resultsȱ haveȱ shownȱ clearȱ relationshipsȱ betweenȱ theȱ differentȱ antioxidantȱ enzymesȱ inȱ theȱ testedȱ organismsȱ inȱ theȱ presenceȱ ofȱ metals.ȱ Theȱ Phaseȱ Iȱ detoxificationȱ systemȱ measuredȱ byȱ theȱ ERODȱ activityȱ wasȱ relatedȱ toȱ organicȱ contaminantsȱ(PAHsȱandȱPCBs)ȱandȱmetalsȱboundȱtoȱcomplexȱorganicȱmixturesȱ (Niȱ andȱ Co).ȱ Theseȱ contaminants,ȱ especiallyȱ PAHsȱ andȱ Ni,ȱ haveȱ ȱ oftenȱ beenȱ linkedȱtoȱoilȱspills.ȱAntioxidantȱresponseȱ(GPXȱinȱcrabsȱandȱFRAPȱinȱclams)ȱwasȱ alsoȱidentifiedȱforȱtheseȱcompounds.ȱERODȱactivityȱisȱoftenȱusedȱasȱaȱbiomarkerȱ ofȱ exposureȱ toȱ lipophilicȱ organicȱ contaminantsȱ andȱ measuresȱ theȱ enzymaticȱ activityȱ ofȱ ȱ phaseȱ Iȱ catalyzedȱ byȱ theȱ complexȱ CYP1A.ȱ Theȱ complexȱ CYP1Aȱ transformsȱsomeȱlipophilicȱxenobioticsȱintoȱȱmoreȱwaterȬsolubleȱmetabolites,ȱsoȱ thatȱtheyȱareȱeasierȱtoȱexcrete.ȱInductionȱofȱERODȱactivityȱhasȱbeenȱpreviouslyȱ - 131 - reportedȱ inȱ crabsȱ andȱ clamsȱ subsequentȱ toȱ organicȱ pollutantȱ exposureȱ [9,ȱ 15,ȱ 24].ȱ Theȱhighestȱ valuesȱ ofȱERODȱ activityȱ wereȱobtainedȱinȱorganismsȱexposedȱ toȱsedimentsȱfromȱtheȱBayȱofȱAlgeciras,ȱandȱtheȱmultivariateȱanalysisȱlinkedȱthisȱ inductionȱ withȱ organicȱ compoundsȱ (PAHsȱ andȱ PCBs).ȱ Inȱ addition,ȱ theȱ inductionȱofȱantioxidantȱenzymesȱmeasuredȱbyȱtheȱGPXȱandȱFRAPȱanalysisȱwasȱ linkedȱ withȱ organicȱ contaminantsȱ inȱ sedimentsȱ byȱ Factorȱ 1;ȱ Cheungȱ etȱ al.ȱ [25]ȱ demonstratedȱ thatȱ someȱ PAHsȱ areȱ potentȱ oxidativeȱ stressȱ inducersȱ inȱ theȱ marineȱ mussel,ȱ Pernaȱ viridis,ȱ andȱ obtainedȱ increasingȱ valuesȱ ofȱ antioxidantȱ parameters,ȱ includingȱ GPX.ȱ Manyȱ pollutantsȱ (orȱ theirȱ metabolites)ȱ mayȱ elicitȱ toxicityȱ relatedȱ toȱ oxidativeȱ stress.ȱ Oxygenȱ toxicityȱ canȱ beȱ aȱ potentȱ oxidantȱ capableȱ ofȱ reactingȱ withȱ criticalȱ cellularȱ macromolecules,ȱ possiblyȱ leadingȱ toȱ DNAȱ damageȱ andȱ cellȱ death.ȱ Defenseȱ systemsȱ thatȱ tendȱ toȱ inhibitȱ oxyradicalȱ formationȱincludeȱantioxidantȱenzymesȱsuchȱasȱglutathioneȱreductaseȱ(GR)ȱandȱ glutathioneȱ peroxidaseȱ (GPX)ȱ [9].ȱ Itȱ isȱ wellȱ knownȱ thatȱ GPXȱ transformsȱ organohydroperoxideȱ toȱ alcoholȱ andȱ waterȱ atȱ theȱ expenseȱ ofȱ GSHȱ [26].ȱ Thus,ȱ GPXȱactivityȱisȱlikelyȱtoȱbeȱinfluencedȱbyȱtheȱGSHȱlevelȱandȱGRȱactivity,ȱwhichȱ regulatesȱtheȱlevelȱofȱGSHȱ[25].ȱTheȱresultsȱobtainedȱinȱtheȱmultivariateȱanalysisȱ demonstratedȱaȱrelationshipȱofȱtheȱantioxidantȱbiomarkersȱGPXȱandȱGRȱinȱbothȱ invertebrateȱspeciesȱdueȱtoȱtheȱpresenceȱofȱZnȱandȱPbȱinȱsediments.ȱThisȱmeansȱ thatȱ theseȱ metalsȱ areȱ producingȱ someȱ stressȱ inȱ theȱ exposedȱ organisms,ȱ asȱ isȱ reflectedȱinȱtheȱantioxidantȱresponses.ȱȱ Theȱ inductionȱ ofȱ lipidȱ peroxidationȱ byȱ copperȱ isȱ wellȬknownȱ inȱ otherȱ invertebratesȱ [27],ȱ whichȱ couldȱ explainȱ theȱ connectionȱ betweenȱ Cuȱ andȱ theȱ inductionȱ ofȱ antioxidantȱ enzymesȱ explainedȱ byȱ Factorȱ 3ȱ inȱ theȱ MAA.ȱ Itȱ isȱ importantȱtoȱnoteȱthatȱCuȱbelongsȱtoȱaȱgroupȱofȱmetalsȱthatȱareȱredoxȬactiveȱandȱ areȱ capableȱ ofȱ directlyȱ generatingȱ freeȱ radicalsȱ [28]ȱ whichȱ mayȱ leadȱ toȱ antioxidantȱ defenseȱ responses.ȱ Previousȱ studiesȱ alsoȱ reportedȱ anȱ inductionȱ ofȱ - 132 - GPXȱ activityȱ inȱ Mytilusȱ galloprovincialisȱ exposedȱ toȱ copperȱ inȱ controlledȱ conditionsȱ orȱ toȱ complexȱ mixturesȱ ofȱ metalsȱ inȱ fieldȱ conditionsȱ [29].ȱ Theȱ inductionȱ ofȱ FRAPȱ activityȱ inȱ crabsȱ andȱ clamsȱ seemsȱ toȱ beȱ ȱ lessȱ relevantȱ thanȱ otherȱbiomarkersȱrelatedȱtoȱoxidativeȱstress,ȱalthoughȱtheȱcorrelationsȱobserved,ȱ especiallyȱ withȱ metals,ȱ suggestȱ theȱ importanceȱ ofȱ analyzingȱ aȱ groupȱ ofȱ biomarkersȱratherȱthanȱsingleȱuse.ȱȱȱ GSTȱ activityȱ inductedȱ inȱ crabsȱ hasȱ beenȱ relatedȱ toȱ Znȱ andȱ Pbȱ contaminationȱinȱtheȱmultivariateȱanalysisȱofȱFactorȱ2.ȱGlutathioneȱtransferasesȱ phaseȱIIȱdetoxificationȱenzymesȱwhichȱutilizeȱglutathioneȱ(GSH)ȱasȱaȱsubstrateȱ inȱ reactionsȱ whichȱ permitȱ theȱ biotransformationȱ andȱ disposalȱ ofȱ exogenousȱ compoundsȱ [30];ȱ theȱ inductionȱ ofȱ GSTȱ activityȱ inȱ Carcinusȱ maenasȱ hasȱ beenȱ previouslyȱrelatedȱwithȱmetalȱcontaminationȱ[9].ȱȱ Theȱ resultsȱ obtainedȱ inȱ theȱ presentȱ studyȱ showedȱ theȱ activationȱ ofȱ differentȱdefenceȱsystemsȱinȱbothȱtheȱorganismsȱtested.ȱThisȱwasȱmainlyȱrelatedȱ withȱ anȱ inputȱ ofȱ chronicȱ fuelȱ oilȱ contaminationȱ intoȱ theȱ studiedȱ sediments,ȱ predominantlyȱ inȱ theȱ Bayȱ ofȱ Algeciras,ȱ ȱ followedȱ byȱ CormeȬLaxe,ȱ whichȱ wasȱ affectedȱbyȱanȱacuteȱoilȱimpact;ȱtheseȱresultsȱcorrespondȱwithȱhistopathologicalȱ damageȱobservedȱinȱtheȱtissueȱofȱcrabsȱandȱclamsȱunderȱlaboratoryȱconditionsȱ exposedȱ toȱ theseȱ sedimentsȱ (personalȱ observations).ȱ Theȱ Niȱ andȱ Coȱ sedimentȱ contentȱcorrelatesȱwithȱtheȱorganicȱcontaminantsȱwhichȱareȱusualȱinȱtheȱcaseȱofȱ hydrocarbonȱcontaminationȱepisodes.ȱȱZnȱandȱPbȱmetalȱcontaminationȱwasȱalsoȱ detectedȱinȱtheȱareaȱofȱCormeȬLaxeȱandȱtheȱBayȱofȱAlgecirasȱȱ,ȱproducingȱstressȱ inȱtheȱanimalsȱexposed;ȱbesides,ȱaȱsourceȱofȱCuȱinȱCíesȱandȱAlgecirasȱwasȱlinkedȱ withȱ antioxidantȱ responsesȱ inȱ theȱ organismsȱ tested.ȱ Theȱ presenceȱ ofȱ metalsȱ inȱ theseȱ areasȱ suggestsȱ ȱ thatȱ otherȱ alternativeȱ sourcesȱ ofȱ contaminantsȱ shouldȱ beȱ investigatedȱapartȱfromȱtheȱPrestigeȱoilȱspill.ȱȱ - 133 - Bothȱ speciesȱ employedȱ inȱ theȱ presentȱ study,ȱ theȱ clamȱ Ruditapesȱ philippinarumȱ andȱ theȱ crabȱ Carcinusȱ maenas,ȱ haveȱ biochemicallyȱ respondedȱ toȱ theȱ contaminationȱ presentȱ inȱ theȱ sediments.ȱ Allȱ theȱ biomarkersȱ presentedȱ higherȱ valuesȱ inȱ theȱ digestiveȱ glandȱ ofȱ clamsȱ thanȱ inȱ theȱ hepatopancreasȱ ofȱ crabs,ȱexceptȱforȱGST.ȱTheȱuseȱofȱtwoȱinvertebrateȱspeciesȱwithȱdifferentȱfeedingȱ habitsȱ allowsȱ aȱ moreȱ completeȱ studyȱ ofȱ theȱ biologicalȱ effectsȱ ofȱ contaminantsȱ boundȱ toȱ sediments.ȱ Accordingȱ toȱ otherȱ authorsȱ [31,ȱ 32],ȱ theȱ informationȱ providedȱ byȱ eachȱ biomarkerȱ individuallyȱ isȱ ofȱ limitedȱ relevance,ȱ asȱ thereȱ isȱ aȱ considerableȱlikelihoodȱofȱmisinterpretation;ȱthus,ȱbiomarkersȱareȱbestȱusedȱasȱ selectedȱ batteriesȱ ofȱ testsȱ ratherȱ thanȱ individually.ȱ Inȱ addition,ȱ combiningȱ chemicalȱ analysisȱ withȱ suitesȱ ofȱ biomarkersȱ addressesȱ theȱ needȱ forȱ moreȱ pragmaticȱ environmentalȱ assessmentȱ techniquesȱ linkingȱ environmentalȱ degradationȱ withȱ itsȱ causesȱ [2].ȱ Theȱ higherȱ sensitivityȱ ofȱ sublethalȱ bioassaysȱ comparedȱ toȱ acuteȱ toxicityȱ testsȱ indicatesȱ theȱ advantagesȱ ofȱ incorporatingȱ thisȱ approachȱasȱpartȱofȱaȱmoreȱcompleteȱandȱintegratedȱstudyȱbasedȱonȱaȱweightȬ ofȬevidenceȱapproach,ȱasȱpreviouslyȱrecommendedȱbyȱsomeȱauthorsȱ[8,ȱ9,ȱ33].ȱ 5.ȱConclusionsȱȱ Inȱ theȱ presentȱ study,ȱ anȱ evaluationȱ hasȱ beenȱ carriedȱ outȱ ofȱ theȱ environmentalȱqualityȱofȱcoastalȱareasȱaffectedȱbyȱdifferentȱcontaminantsȱ.ȱTheȱ biomarkersȱ haveȱ demonstratedȱ thatȱ theyȱ areȱ activatedȱ dependingȱ onȱ theȱ kindȱ andȱlevelȱofȱcontaminationȱandȱhaveȱprovenȱtoȱbeȱaȱsuitableȱtoolȱtoȱassessȱoilȬ contaminatedȱsediments.ȱTheȱclamȱRuditapesȱphilippinarumȱandȱtheȱcrabȱCarcinusȱ maenasȱ haveȱ demonstratedȱ theȱ importanceȱ ofȱ usingȱ differentȱ speciesȱ ofȱ organismsȱ whenȱ assessingȱ environmentalȱ managementȱ andȱ haveȱ ȱ respondedȱ satisfactorilyȱȱtoȱtheȱcontaminationȱpresentȱinȱtheȱsediments,ȱdemonstratingȱtheȱ bioavailabilityȱ ofȱ organicȱ andȱ inorganicȱ contaminantsȱ relatedȱ toȱ oilȱ spills.ȱ Theȱ - 134 - applicationȱofȱtheȱmethodologyȱinȱtwoȱareasȱaffectedȱinȱdifferentȱmannersȱbyȱoilȱ spillsȱ(acutely:ȱGalicianȱcoastȱandȱchronically:ȱBayȱofȱAlgeciras)ȱhasȱshownȱhowȱ biomarkersȱ areȱ activatedȱ inȱ diverseȱ waysȱ dependingȱ onȱ theȱ sourceȱ ofȱ theȱ pollutants.ȱ Thisȱstudyȱhasȱdemonstratedȱtheȱimportantȱroleȱthatȱbiomarkersȱplayȱasȱ partȱofȱtheȱWeightȱofȱEvidenceȱApproachȱ(WOE)ȱandȱitsȱuseȱinȱtheȱassessmentȱ ofȱoilȱspillsȱisȱstronglyȱrecommended.ȱȱ 6.ȱAcknowledgementsȱ Theȱ workȱ describedȱ wasȱ partlyȱ supportedȱ byȱ theȱ projectsȱ VEM2003Ȭ 20563/INTER,ȱ andȱ CTM2005Ȭ07282ȬC03Ȭ01/TECNOȱ financedȱ byȱ theȱ Spanishȱ EducationȱandȱScienceȱ Ministryȱ andȱ byȱ CISȱ fundedȱ byȱ theȱ Ministryȱ ofȱ Environment.ȱ Carmenȱ MoralesȬCasellesȱthanksȱtheȱMinistryȱofȱEducationȱandȱScienceȱforȱfundingȱherȱ researchȱ fellowshipȱ (FPU).ȱ Weȱ areȱ gratefulȱ forȱ theȱ supportȱ andȱ helpȱ ofȱ theȱ membersȱofȱtheȱCISȱandȱtheȱICMANȬCSIC.ȱSpecialȱthanksȱareȱgivenȱtoȱAntonioȱ Moreno,ȱJuditȱKalmanȱandȱtheȱErasmusȱstudentȱAurelian.ȱThanksȱareȱgivenȱtoȱ theȱCSLMȱforȱtheȱEnglishȱrevisionȱandȱtoȱtheȱreviewersȱwhoȱhaveȱcontributedȱtoȱ theȱimprovementȱofȱtheȱmanuscript.ȱȱ 7.ȱReferencesȱȱȱȱ [1]ȱ Sarkarȱ A,ȱ Rayȱ D,ȱ Shrivastavaȱ AN.ȱ 2006.ȱ Molecularȱ biomarkers:ȱ theirȱ significanceȱ andȱapplicationȱinȱmarineȱpollutionȱmonitoring.ȱEcotoxicologyȱ15:ȱ333Ȭ340.ȱ - 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138 - [26]ȱ Thomasȱ JP,ȱ Maiorinoȱ M,ȱ Ursiniȱ F,ȱ Girottiȱ AW.ȱ 1990.ȱ Protectiveȱ actionȱ ofȱ phospholipidȱ hydroperoxideȱ glutathioneȱ peroxidiseȱ againstȱ membraneȬ damagingȱlipidȱperoxidation.ȱJournalȱofȱBiologicalȱChemistryȱ265:ȱ454–461.ȱ [27]ȱ Viarengoȱ A.ȱ 1989.ȱ Heavyȱ metalsȱ inȱ marineȱ invertebrates:ȱ mechanismsȱ ofȱ regulationȱandȱtoxicityȱatȱcellularȱlevel.ȱRevȱAquatȱSciȱ1:295–317.ȱ [28]ȱErcalȱN,ȱGurerȬorhanȱH,ȱAykinȬBurnsȱN.ȱ2001.ȱToxicȱmetalsȱandȱoxidativeȱstressȱ partȱIȱ:ȱmechanismsȱinvolvedȱinȱmetalȬinducedȱoxidativeȱdamage.ȱCurrȱTopȱMedȱ Chemȱ1:ȱ29Ȭ539.ȱ [29]ȱ Regoliȱ F,ȱ Principatoȱ G.ȱ 1995.ȱ Glutathione,ȱ glutathioneȬdependentȱ andȱ ntioxidantȱ enzymesȱinȱmussel,ȱMytilusȱgalloprovincialis,ȱexposedȱtoȱmetalsȱunderȱfieldȱandȱ laboratoryȱconditions:ȱimplicationsȱforȱtheȱuseȱofȱbiochemicalȱbiomarkers.ȱAquatȱ Toxicolȱ31:ȱ143–164.ȱ [30]ȱ ContrerasȬVergaraȱ CA,ȱ HarrisȬValleȱ C,ȱ SoteloȬMundoȱ RR,ȱ YepizȬPlascenciaȱ G.ȱ 2004.ȱ AȱmuȬclassȱglutathioneȱ SȬtransferaseȱfromȱtheȱmarineȱshrimpȱLitopenaeusȱ vannamei:ȱMolecularȱcloningȱandȱactiveȬsiteȱstructuralȱmodelling.ȱJȱBiochemȱMolȱ Toxicȱ18:ȱ245ȱ–ȱ252.ȱ [31]ȱMooreȱMN,ȱSimpsonȱMG.ȱ1992.ȱMolecularȱandȱcellularȱpathologyȱinȱenvironmentȱ impactȱassessment.ȱAquatȱToxicolȱ22.ȱ313.ȱ [32]ȱPachecoȱM,ȱȱSantosȱMA.ȱ2002.ȱBiotransformation,ȱgenotoxic,ȱandȱhistopathologicalȱ effectsȱ ofȱ environmentalȱ contaminantsȱ inȱ Europeanȱ eelȱ (Anguillaȱ anguillaȱ L.).ȱ EcotoxicolȱEnvironȱSafȱ53:ȱ331–347.ȱ [33]ȱCarballeiraȱA.ȱ2003.ȱConsiderationsȱinȱtheȱdesignȱofȱaȱmonitoringȱprogramȱofȱtheȱ biologicalȱeffectsȱofȱtheȱPrestigeȱoilȱspill.ȱCiencȱMarȱ29:ȱ123–139.ȱ - 139 - - 140 - VitellogeninȱvariationȱinȱtheȱcrabȱCarcinusȱmaenasȱexposedȱtoȱ sedimentsȱaffectedȱbyȱoilȱspillsȱ(Spain)ȱ C.ȱMoralesȬCaselles1,2*,ȱM.ȱL.ȱMartínȬDíaz1,2,ȱI.ȱRiba1,2,ȱT.ȱÁ.ȱDelValls1,2ȱ §ȱ1ȱInstitutoȱdeȱCienciasȱMarinasȱdeȱAndalucía.ȱUnidadȱAsociadaȱdeȱCalidadȱAmbientalȱ yȱPatologíaȱ(CSICȱ&ȱUCA);ȱȱPolígonoȱRíoȱSanȱPedroȱs/n.ȱ11510ȱPuertoȱRealȱ(Cádiz).ȱ España.ȱ CátedraȱUNESCO/UNITWIN/WiCop.ȱFacultadȱdeȱCienciasȱdelȱMarȱyȱAmbientales.ȱ 2ȱ UniversidadȱdeȱCádiz.ȱȱPolígonoȱRíoȱSanȱPedroȱs/n.ȱ11510ȱPuertoȱRealȱ(Cádiz).ȱ España.ȱ Abstractȱ Inȱtheȱpresentȱstudyȱtheȱinductionȱofȱvitellogeninȱhasȱbeenȱstudiedȱasȱaȱ biomarkerȱ ofȱ exposureȱ inȱ crabsȱ inȱ orderȱ toȱ assessȱ itsȱ relationshipȱ withȱ contaminantsȱ boundȱ toȱ sedimentsȱ [Zn,ȱ Pb,ȱ Cu,ȱ Ni,ȱ Co,ȱ Vȱ andȱ polyaromaticȱ hydrocarbonsȱ(PAHs)]ȱaffectedȱbyȱdifferentȱoilȱspillsȱinȱSpain.ȱTwoȱdifferentȱ28Ȭ daysȱ bioassaysȱ haveȱ beenȱ carriedȱ outȱ bothȱ underȱ fieldȱ andȱ laboratoryȱ conditionsȱ byȱ exposingȱ theȱ crabȱ Carcinusȱ maenasȱ toȱ contaminatedȱ sedimentȱ samples.ȱForȱtheȱfieldȱapproachȱtheȱorganismsȱwereȱlabelledȱandȱkeptȱinȱcagesȱ locatedȱ inȱ theȱ studyȱ sitesȱ duringȱ theȱ exposureȱ period.ȱ Inȱ theȱ experimentȱ conductedȱ underȱ laboratoryȱ conditionsȱ sedimentȱ fromȱ theȱ stationsȱ wasȱ collectedȱandȱcarriedȱtoȱtheȱlaboratoryȱwhereȱlabelledȱcrabsȱwereȱplacedȱinȱ20ȱLȱ tanksȱ withȱ theȱ sedimentȱ samples.ȱ Forȱ bothȱ bioassaysȱ haemolymphȱ wasȱ extractedȱ fromȱ theȱ individualsȱ theȱ dayȱ 0ȱ andȱ 28ȱ ofȱ exposureȱ toȱ determineȱ theȱ variationȱinȱtheȱlevelsȱofȱvitellogeninȱafterȱtheȱbioassay.ȱTheȱSpanishȱsedimentsȱ selectedȱ forȱ thisȱ studyȱ hadȱ beenȱ affectedȱ inȱ aȱ differentȱ wayȱ byȱ oilȱ spills;ȱ theȱ GalicianȱCoastȱ(NWȱSpain)ȱwasȱacutelyȱimpactedȱbyȱtheȱaccidentȱofȱtheȱtankerȱ Prestigeȱ (2002)ȱ whereasȱ theȱ Bayȱ ofȱ Algecirasȱ (Southȱ Spain)ȱ suffersȱ chronicallyȱ fromȱ continuousȱ inputȱ ofȱ differentȱ contaminantsȱ fromȱ shipsȱ andȱ industriesȱ locatedȱinȱtheȱarea,ȱincludingȱoilȱspills.ȱResultsȱshowȱaȱrelationshipȱbetweenȱȱ ȱPremioȱSecotoxȱ07ȱ“Bestȱoralȱpresentationȱofȱyoungȱscientist”ȱȱ ȱJournalȱofȱEnvironmentalȱScienceȱandȱHealth:ȱPartȱAȱ(enviado) - 141 - vitellogeninȱ inductionȱ andȱ contaminants.ȱ Theȱ variationȱ ofȱ vitellogeninȱ concentrationȱ wasȱ relatedȱ toȱ theȱ presenceȱ ofȱ PAHsȱ andȱ theȱ metalsȱ Pb,ȱ Niȱ andȱ Cuȱ inȱ theȱ sediment,ȱ whichȱ occurredȱ mainlyȱ inȱ theȱ treatmentsȱ fromȱ theȱ Bayȱ ofȱ Algeciras.ȱ Inȱ thisȱ sense,ȱ theȱ studyȱ showsȱ aȱ partialȱ recoveryȱ inȱ theȱ sedimentȱ qualityȱ inȱ theȱ Galicianȱ Coastȱ threeȱ yearsȱ afterȱ theȱ spill,ȱ whereasȱ theȱ Bayȱ ofȱ Algecirasȱisȱsignificantlyȱmoreȱpollutedȱthanȱtheȱsedimentsȱstudiedȱinȱtheȱareaȱ ofȱGalicia.ȱȱȱȱȱȱȱȱȱ Keywords:ȱȱvitellogenin,ȱoilȱspill,ȱecotoxicity,ȱinvertebrate,ȱPAHsȱ 1.ȱIntroductionȱ Sediments,ȱ asȱ anȱ importantȱ partȱ ofȱ theȱ ecosystem,ȱ areȱ oftenȱ studiedȱ toȱ assessȱenvironmentalȱquality.ȱComplexȱmixturesȱofȱcontaminantsȱhoweverȱcanȱ beȱexaminedȱwithȱdifficulty,ȱthusȱtheȱstudyȱofȱbothȱchemicalȱandȱtoxicologicalȱ effectsȱ turnsȱ outȱ toȱ beȱ aȱ suitableȱ toolȱ toȱ achieveȱ theȱ objectivesȱ proposedȱ inȱ sedimentȱ qualityȱ assessment.ȱ Biomarkersȱ canȱ beȱ definedȱ asȱ measurementsȱ ofȱ bodyȱ fluids,ȱ cellsȱ orȱ tissuesȱ thatȱ indicateȱ inȱ biochemicalȱ orȱ cellularȱ termsȱ theȱ presenceȱ ofȱ contaminantsȱ orȱ theȱ magnitudeȱ ofȱ theȱ hostȱ responseȱ toȱ suchȱ contaminantsȱ [1] .ȱ Combiningȱ chemicalȱ analysisȱ withȱ suitesȱ ofȱ biomarkersȱ addressesȱ theȱ needȱ forȱ moreȱ pragmaticȱ environmentalȱ assessmentȱ techniquesȱ linkingȱenvironmentalȱdegradationȱwithȱitsȱcausesȱ[2].ȱȱ Theȱ chemicalsȱ introducedȱ intoȱ theȱ environmentȱ haveȱ theȱ potentialȱ toȱ interactȱ withȱ neuroȬendocrineȱ signalingȱ cascades,ȱ resultingȱ inȱ signalȱ perturbationsȱ [3] .ȱ Suchȱ alteredȱ signalingȱ canȱ resultȱ inȱ modificationsȱ toȱ development,ȱ maturation,ȱ reproduction,ȱ andȱ otherȱ neuroȬendocrineȬregulatedȱ processesȱ thatȱ hinderȱ populationȱ sustainabilityȱ [4] .ȱ Laboratoryȱ studiesȱ haveȱ demonstratedȱ theȱ susceptibilityȱ ofȱ crustaceansȱ toȱ toxicantsȱ andȱ fieldȱ studiesȱ haveȱ revealedȱ evidenceȱ ofȱ endocrineȱ disruptionȱ amongȱ variousȱ crustaceanȱ populationsȱ[5].ȱ - 142 - Dueȱ toȱ theirȱ biologicalȱ andȱ ecologicalȱ characteristicsȱ crabsȱ areȱ suitableȱ organismsȱ forȱ useȱ inȱ ecotoxicologicalȱ studiesȱ [6] .ȱ Inȱ theȱ presentȱ studyȱ vitellogeninȱ (VTG)ȱ isȱ usedȱ asȱ aȱ biomarkerȱ toȱ assessȱ theȱ toxicityȱ causedȱ byȱ oilȱ spillsȱ onȱ theȱ crabȱ Carcinusȱ maenas.ȱ Vitellogenesisȱ isȱ aȱ processȱ byȱwhichȱ femaleȱ crustaceansȱ produceȱ andȱ sequesterȱ nutrientsȱ intoȱ developingȱ oocytesȱ [7] .ȱ Vitellogeninȱ isȱ aȱ proteinȱ producedȱ inȱ theȱ hepatopancreasȱ andȱ transportedȱ throughȱtheȱhaemolymphȱtoȱtheȱovary,ȱwhereȱitȱentersȱintoȱgrowingȱoocytesȱ [7].ȱ Theȱ inhibitionȱ orȱ stimulationȱ ofȱ vitellogeninȱ levelsȱ inȱ haemolymphȱ couldȱ provideȱaȱusefulȱindicatorȱofȱdirectȱrepercussionsȱonȱtheȱreproductiveȱcapacityȱ inȱtheȱfemaleȱcrabsȱ[8].ȱ Theȱ aimȱ ofȱ thisȱ studyȱ wasȱ toȱ investigateȱ theȱ relationshipȱ betweenȱ contaminatedȱsedimentsȱwithȱtheȱinductionȱofȱvitellogeninȱinȱtheȱcrabȱCarcinusȱ maenasȱ byȱ exposingȱ theȱ organismsȱ toȱ sedimentsȱ fromȱ theȱ Galicianȱ Coastȱ (NWȱ Spain),ȱ threeȱ yearsȱ afterȱ anȱ oilȱ spillȱ (Prestige),ȱ andȱ sedimentsȱ fromȱ theȱ Bayȱ ofȱ Algecirasȱ (Sȱ Spain),ȱ chronicallyȱ impactedȱ byȱ spillsȱ ofȱ differentȱ contaminantsȱ includingȱ oilȱ spills.ȱ Exposuresȱ wereȱ performedȱ underȱ fieldȱ andȱ laboratoryȱ conditionsȱ withȱ theȱ purposeȱ ofȱ studyȱ theȱ similaritiesȱ andȱ differencesȱ ofȱ bothȱ methodologies.ȱȱ 2.ȱMaterialȱandȱmethodsȱ Theȱsedimentsȱselectedȱforȱthisȱstudyȱwereȱaffectedȱinȱaȱdifferentȱwayȱbyȱ oilȱspills;ȱtheȱGalicianȱCoastȱ(NWȱSpain)ȱwasȱacutelyȱimpactedȱbyȱtheȱaccidentȱ ofȱtheȱtankerȱPrestigeȱ(2002)ȱwhereasȱtheȱBayȱofȱAlgecirasȱ(SȱSpain)ȱchronicallyȱ suffersȱ continuousȱ inputȱ ofȱ differentȱ contaminantsȱ comingȱ fromȱ shipsȱ andȱ industriesȱlocatedȱinȱtheȱarea,ȱincludingȱoilȱspills.ȱFigureȱ1ȱshowsȱtheȱlocationȱofȱ theȱstudyȱsites.ȱ ȱ - 143 - ȱ ƒF ƒE ƒD Atlantic Islands National Park C A B Ría de CormeLaxe Spain GR3 GR4 P1 Bay of Algeciras N W E S ȱ Figureȱ 1.ȱ Mapȱ ofȱ ȱ studyȱ sites:ȱ theȱ coastalȱ areaȱ ofȱ Galiciaȱ showingȱ theȱ locationsȱ ofȱ theȱ samplingȱ stations.ȱ A,ȱ Bȱ andȱ Cȱ refersȱ toȱ theȱ stationsȱ locatedȱ inȱ theȱCiesȱIslandȱinȱtheȱAtlanticȱIslandȱNationalȱParkȱandȱD,ȱEȱandȱFȱtoȱthoseȱinȱ theȱ Bayȱ ofȱ CormeȬLaxe.ȱ Theȱ stationsȱ locatedȱ inȱ theȱ Bayȱ ofȱ Algecirasȱ areȱ GR3,ȱ GR4ȱandȱP1.ȱ 2.1.ȱSedimentȱsamplingȱandȱcharacterizationȱȱ Sedimentsȱfromȱtheȱselectedȱsitesȱwereȱcarriedȱtoȱtheȱlaboratoryȱandȱwereȱ sampledȱforȱphysicalȱcharacterizationȱandȱchemicalȱquantification.ȱTheȱanalysesȱ ofȱ PAHsȱ wereȱ carriedȱ outȱ accordingȱ toȱ USEPAȱ SWȬ846ȱ Methodȱ 827C78082ȱ [9].ȱ Forȱtraceȱmetalȱanalysesȱ(Zn,ȱPb,ȱCu,ȱNi,ȱCo,ȱV),ȱtheȱsedimentsȱwereȱdigestedȱasȱ describedȱ byȱ Loringȱ andȱ Rantalaȱ [10]ȱ andȱ thenȱ measuredȱ byȱ atomicȱ absorptionȱ spectrophotometryȱ (AAS).ȱ Organicȱ carbonȱ contentȱ wasȱ determinedȱ usingȱ theȱ - 144 - methodȱ ofȱ Gaudetteȱ etȱ al.ȱ [11]ȱ withȱ theȱ Elȱ Rayisȱ [12]ȱ modification.ȱ Forȱ sedimentȱ grainȱ size,ȱ anȱ aliquotȱ ofȱ wetȱ sedimentȱ wasȱ analyzedȱ usingȱ aȱ Fristchȱ laserȱ particleȱsizerȱ(modelȱAnalysetteȱ22)ȱfollowingȱtheȱmethodȱreportedȱbyȱDelVallsȱ andȱChapmanȱ[13].ȱ 2.2.ȱToxicityȱtestsȱ Intermoultȱ femalesȱ crabsȱ wereȱ collectedȱ fromȱ aȱ cleanȱ siteȱ inȱ theȱ Gulfȱ ofȱ Cádizȱandȱwereȱacclimatizedȱforȱtwoȱweeksȱinȱtheȱlaboratory.ȱAfterȱthatȱperiodȱ theȱsedimentȱsamplesȱwereȱplacedȱinȱ20ȬLȱaquariumsȱandȱseaȱwaterȱwasȱaddedȱ (1:4).ȱAerationȱwasȱprovidedȱafterȱtheȱsedimentȱhadȱsettledȱdown.ȱCrabsȱwereȱ labelledȱandȱaȱnumberȱofȱthemȱwereȱplacedȱinȱtheȱaquariumsȱinȱtheȱlaboratoryȱ (8ȱperȱaquarium)ȱandȱinȱtheȱcagesȱwhichȱwereȱtransferredȱtoȱtheȱstudyȱsites.ȱTheȱ bioassaysȱrunȱinȱreplicateȱandȱlastedȱ28ȱdays.ȱ 2.3.ȱVitellogeninȱdeterminationȱ Haemolymphȱsamplesȱwereȱtakenȱfromȱtheȱbaseȱofȱaȱwalkingȱlegȱusingȱaȱ syringeȱ theȱ daysȱ 0ȱ andȱ 28ȱ ofȱ theȱ bioassay.ȱ Theȱ samplesȱ wereȱ transferredȱ toȱ microcentrifugeȱtubesȱandȱwereȱkeptȱintoȱliquidȱnitrogenȱbeforeȱstoringȱthemȱinȱ theȱ Ȭ80ȱ ºCȱ freezer.ȱ Vitellogeninȱ determinationȱ wasȱ performedȱ usingȱ aȱ directȱ EnzymeȬLinkedȱ Inmunosorbentȱ Assayȱ (ELISA)ȱ adaptedȱ fromȱ Paterakiȱ andȱ Stratakisȱ .ȱ Theȱ 96Ȭwellȱ microtiterȱ platesȱ wereȱ coatedȱ withȱ theȱ standardȱ [14] solutions,ȱ purifiedȱ VTGȱ (0,ȱ 22,ȱ 10,ȱ 20,ȱ 50,ȱ 75ȱ andȱ 100ȱ ngȱ 100ȱ ΐLȬ1)ȱ andȱ haemolymphȱsamplesȱfromȱeachȱcrabȱ(200ȱΐL).ȱAȱpolyclonalȱantibodyȱraisedȱinȱ rabbitsȱ againstȱ C.ȱ maenasȱ VTGȱ couldȱ identifyȱ vitellogeninȱ concentrations.ȱ Theȱ plateȱwasȱreadȱatȱ405ȱnmȱandȱVTGȱstandardsȱwereȱfitȱtoȱaȱlinearȱregressionȱ(R2ȱ=ȱ 0.96;ȱ slopeȱ =ȱ 0.144).ȱ 28Ȭdayȱ VTGȱ resultsȱ wereȱ normalizedȱ withȱ theȱ 0Ȭdayȱ VTGȱ concentrationsȱ([VTG*]ȱ=ȱ[28ȬdaysȱVTG]ȱ–ȱ[0ȬdaysȱVTG])ȱprovidingȱtheȱamountȱ ofȱproteinsȱthatȱfluctuatesȱduringȱ28ȱdaysȱofȱexposure.ȱ - 145 - 2.4.ȱStatisticalȱanalysisȱ Contaminationȱ andȱ VTG*ȱ dataȱ wereȱ linkedȱ byȱ factorȱ analysis,ȱ usingȱ principalȱ componentsȱ analysisȱ (PCA)ȱ asȱ theȱ extractionȱ procedureȱ (STATISTICA®);ȱthisȱisȱaȱmultivariateȱstatisticalȱtechniqueȱforȱexploringȱvariableȱ distributionsȱ ȱ Theȱ objectiveȱ ofȱ PCAȱ isȱ toȱ deriveȱ aȱ reducedȱ numberȱ ofȱ newȱ variablesȱ asȱ linearȱ combinationsȱ ofȱ theȱ originalȱ variables.ȱ Thisȱ providesȱ aȱ descriptionȱofȱtheȱstructureȱofȱtheȱdataȱwithȱtheȱminimumȱlossȱofȱinformationȱ[9].ȱ 3.ȱResultsȱandȱdiscussionȱ 3.1.ȱChemicalȱanalysisȱ Sedimentsȱ wereȱ mainlyȱ contaminatedȱ byȱ PAHs,ȱ andȱ theȱ samplesȱ fromȱ theȱ Bayȱ ofȱ Algeciras,ȱ continuouslyȱ affectedȱ byȱ oilȱ spills,ȱ turnedȱ outȱ toȱ beȱ theȱ mostȱ contaminatedȱ byȱ theseȱ compoundsȱ (Tableȱ 1).ȱ Onȱ theȱ otherȱ hand,ȱ resultsȱ doȱ notȱ showȱ aȱ prevailingȱ tendencyȱ inȱ theȱ concentrationȱ ofȱ metalsȱ amongȱ sedimentsȱ fromȱ theȱ differentȱ areas.ȱ Highȱ levelsȱ ofȱ Znȱ wereȱ detectedȱ inȱ theȱ stationsȱA,ȱCȱ(CiesȱIsland)ȱandȱFȱ(CormeȬLaxe)ȱfromȱGalicia,ȱwhereasȱCuȱlevelsȱ wereȱhighȱP1ȱandȱNiȱinȱGR3,ȱbothȱstationsȱlocatedȱinȱtheȱBayȱofȱAlgeciras.ȱȱ ȱ ȱ ȱ ȱ ȱ - 146 - Tableȱ 1.ȱ Valuesȱ ofȱ totalȱ organicȱ carbonȱ (%dryȱ weight),ȱ finesȱ (%ȱ ofȱ dryȱ sedimentȱ<ȱ63ȱmm)ȱandȱtheȱconcentrationȱofȱcontaminantsȱ(metalsȱ(mgȱkg_1ȱdryȱ weight);PAHsȱ andȱ PCBsȱ (mgȱ kg_1ȱ dryȱ weight))ȱ inȱ sedimentȱ samplesȱ fromȱ Galiciaȱ(CíesȱIsland:ȱA,ȱB,ȱC;ȱandȱCormeȬLaxe:ȱD,ȱE,ȱF)ȱandȱAlgecirasȱBayȱ(GR3,ȱ GR4ȱandȱP1).ȱNotȱdetectedȱisȱexpressedȱbyȱn.d.ȱ Stationsȱ Aȱ Bȱ Cȱ Dȱ Eȱ Fȱ GR3ȱ GR4ȱ P1ȱ O.C.ȱ Finesȱ 0.28ȱ 4.32ȱ 0.26ȱ 2.81ȱ 0.30ȱ 2.76ȱ 0.31ȱ 3.79ȱ 0.37ȱ 5.50ȱ 0.65ȱ 5.95ȱ 2.15ȱ 69.4ȱ 3.19ȱ 59.3ȱ 3.86ȱ 35.4ȱ Znȱȱ 377ȱ 91.0ȱ 164ȱ 25.0ȱ 19.9ȱ 271ȱ 138ȱ 35.3ȱ 56.7ȱ Pbȱȱ 1.50ȱ 0.90ȱ 0.85ȱ 3.70ȱ 7.30ȱ 5.90ȱ 21.6ȱ 6.21ȱ 12.3ȱ Cuȱȱ 5.20ȱ 1.40ȱ 1.40ȱ 0.70ȱ 0.43ȱ 4.20ȱ 5.01ȱ 3.67ȱ 75.2ȱ Niȱȱ 13.3ȱ 2.40ȱ 4.50ȱ 1.70ȱ 1.50ȱ 5.70ȱ 74.7ȱ 13.1ȱ 13.3ȱ Coȱȱ 0.30ȱ 0.20ȱ 0.10ȱ 0.34ȱ 0.35ȱ 0.36ȱ 12.8ȱ 5.59ȱ n.d.ȱ Vȱȱ 0.70ȱ 0.80ȱ 0.60ȱ 2.00ȱ 2.10ȱ 3.40ȱ 26.1ȱ n.d.ȱ 6.84ȱ PAHȱ 108ȱ 67.0ȱ n.d.ȱ 38.0ȱ 52.0ȱ 323ȱ 3150ȱ 802ȱ 641ȱ ȱ 3.2.ȱȱVitellogeneninȱanalysisȱ Resultsȱ ofȱ vitellogeninȱ concentrationȱ inȱ haemolymphȱ decreasedȱ inȱ theȱ majorityȱ ofȱ theȱ treatmentsȱ afterȱ 28ȱ daysȱ ofȱ exposureȱ (Fig.ȱ 2).ȱ Theȱ declineȱ wasȱ detectedȱmainlyȱinȱtheȱlaboratoryȱtestsȱwhereasȱcagedȱcrabsȱpresentedȱaȱlowerȱ variationȱinȱtheȱvitellogeninȱlevelsȱafterȱtheȱexposureȱperiod.ȱThisȱcouldȱbeȱdueȱ toȱtheȱfactȱthatȱunderȱcagedȱcrabsȱinȱfieldȱwereȱsubjectedȱtoȱtheȱenvironmentalȱ conditionsȱsuchȱasȱchangesȱinȱtheȱvariablesȱandȱcurrentsȱwhatȱmayȱdecreaseȱtheȱ availabilityȱofȱtheȱcontaminants.ȱOrganismsȱexposedȱtoȱsedimentsȱfromȱtheȱBayȱ ofȱ Algecirasȱ (GR3,ȱ GR4ȱ andȱ P1)ȱ sufferedȱ theȱ highestȱ variationsȱ inȱ vitellogeninȱ levels.ȱ ȱ - 147 - 1.2 1.0 VTG 0.8 0.6 0.4 0.2 0.0 A B C D E F A-c B-c C-c D-c E-c F-c GR4 P1 GR3 GR4-c P1-c GR3-c treatments ȱ Figureȱ 2.ȱ Levelsȱ ofȱ vitellogeninȱ (ngȱ 100mLȬ1)ȱ inȱ haemolymphȱ ofȱ crabsȱ exposedȱtoȱsedimentsȱfromȱGaliciaȱ(CíesȱIsland:ȱA,ȱB,ȱC;ȱandȱCormeȬLaxe:ȱD,ȱE,ȱ F)ȱ andȱ Algecirasȱ Bayȱ (GR3,ȱ GR4ȱ andȱ P1);ȱ samplesȱ fromȱ theȱ cagedȱ organismsȱ haveȱtheȱsuffixȱ“–c”.ȱTheȱresultsȱshownȱmatchȱwithȱtheȱdayȱ0ȱ(dottedȱbar)ȱandȱ dayȱ28ȱ(stripedȱbar)ȱofȱexposure.ȱ 3.3.ȱStatisticalȱanalysisȱ Theȱvariablesȱ(O.C.,ȱfines,ȱZn,ȱPb,ȱCu,ȱNi,ȱCo,ȱV,ȱPAHs,ȱandȱVTG)ȱwereȱ autoscaledȱ (standardized)ȱ soȱ asȱ toȱ beȱ treatedȱ withȱ equalȱ importanceȱ [15].ȱ Theȱ applicationȱ ofȱ theȱ PCAȱ toȱ theȱ originalȱ 10ȱ variablesȱ indicatesȱ thatȱ theyȱ canȱ beȱ groupedȱ inȱ twoȱ newȱ factorsȱ whichȱ explainȱ aȱ 72%ȱ ofȱ theȱ totalȱ varianceȱ inȱ theȱ originalȱ dataȱ set.ȱ Aȱ groupȱ ofȱ variablesȱ asȱ thoseȱ associatedȱ withȱ aȱ particularȱ componentȱwhereȱtheȱloadingȱwasȱ0.30ȱorȱhigherȱwasȱinterpretedȱ(Tableȱ2).ȱTheȱ firstȱ principalȱ factor,ȱ #1ȱ isȱ predominantȱ (50%)ȱ andȱ itȱ groupsȱ theȱ variationȱ ofȱ vitellogeninȱconcentrationȱinȱtheȱhaemolymphȱofȱtheȱcrabsȱwithȱtheȱpresenceȱofȱ PAHsȱandȱtheȱmetalsȱPb,ȱNiȱandȱVȱinȱtheȱsedimentȱandȱitsȱassociationȱwithȱtheȱ organicȱcarbonȱandȱgrainȱsize.ȱFactorȱ#2ȱ(22%),ȱshowsȱtheȱrelationshipȱbetweenȱ - 148 - theȱgrainȱsizeȱandȱtheȱtotalȱorganicȱcarbonȱinȱtheȱsedimentsȱwithȱtheȱpresenceȱofȱ Pb,ȱCuȱandȱCoȱandȱtheȱlinkȱwithȱtheȱvariationȱinȱvitellogeninȱlevels.ȱ Theȱ influenceȱ ofȱ theȱ twoȱ factorsȱ atȱ theȱ 18ȱ treatmentsȱ isȱ reflectedȱ byȱ theȱ FactorȱscoreȱatȱtheseȱtreatmentsȱandȱisȱshownȱinȱFigureȱ3.ȱFactorȱ1ȱwhichȱshowsȱ theȱ relationshipȱ ofȱ theȱ vitellogeninȱ variationȱ andȱ theȱ contaminationȱ byȱ PAHs,ȱ Pb,ȱ Niȱ andȱ Vȱ hasȱ aȱ mainȱ prevalenceȱ inȱ theȱ stationsȱ fromȱ theȱ Bayȱ ofȱ Algecirasȱ GR3ȱandȱGR4ȱbothȱinȱlaboratoryȱandȱfieldȱexposures.ȱFactorȱ#2,ȱwhichȱlinksȱtheȱ variationȱ ofȱ vitellogeninȱ concentrationȱ withȱ theȱ metalsȱ Pb,ȱ Cuȱ andȱ Co,ȱ itȱ isȱ mainlyȱprevalentȱinȱ theȱstationsȱGR4ȱandȱP1,ȱlaboratoryȱandȱcagedȱexposures,ȱ inȱ theȱ Bayȱ ofȱ Algeciras.ȱ Treatmentsȱ fromȱ theȱ Galicianȱ Coastȱ didȱ notȱ presentȱ positiveȱloadingȱinȱtheȱfactorȱscores.ȱ Tableȱ 2.ȱ Sortedȱ rotatedȱ factorȱ loadingsȱ (pattern)ȱ ofȱ 10ȱ variablesȱ forȱ theȱ twoȱprincipalȱfactorsȱresultingȱfromȱtheȱmultivariateȱanalysisȱofȱresultsȱobtainedȱ fromȱtheȱchemicalȱanalysisȱandȱtheȱvitellogeninȱdetermination.ȱ FACTOR1 FACTOR2 ȱȱ ņȱ ņȱ Znȱȱ Pbȱȱ 0.84ȱ 0.32ȱ ņȱ Cuȱȱ 0.95ȱ ņȱ Niȱȱ 0.93ȱ ņȱ Coȱȱ 0.95ȱ ņȱ Vȱȱ 0.54ȱ ņȱ PAHȱ 0.97ȱ %C.O.ȱ 0.53ȱ 0.80ȱ %finesȱ 0.91ȱ 0.33ȱ VTGȱ 0.37ȱ 0.56ȱ ȱ ResultsȱobtainedȱinȱtheȱStatisticalȱanalysisȱhaveȱshownȱthatȱtheȱrangeȱofȱ variationȱofȱtheȱvitellogeninȱconcentrationȱinȱtheȱhaemolymphȱofȱtheȱcrabsȱwasȱ relatedȱtoȱtheȱPAHsȱandȱtheȱmetalsȱPb,ȱNi,ȱCu,ȱCoȱandȱV.ȱAlthoughȱVȱandȱCoȱȱ - 149 - 3 GR3' GR3'-c Factor 1 2 GR4 1 GR4-c 0 -1 A B C D E F A-c B-c C-c D-c E-c P1 F-c P1-c -2 4 P1 3 P1-c Factor 2 2 1 GR4 GR4-c 0 -1 A B C D E F A-c B-c C-c D-c E-c F-c GR3' GR3'-c -2 Figureȱ 3.ȱ Estimatedȱ factorȱ scoresȱ forȱ theȱ twoȱ factorsȱ inȱ eachȱ ofȱ theȱ 18ȱ cases.ȱTheȱfactorȱscoresȱquantifyȱtheȱprevalenceȱofȱeachȱfactorȱforȱeveryȱstationȱ andȱ isȱ usedȱ toȱ establishȱ theȱ definitionȱ ofȱ eachȱ factor.ȱ Samplesȱ fromȱ theȱ cagedȱ organismsȱhaveȱtheȱsuffixȱ“–c”.ȱ areȱ includedȱ inȱ theȱ definitionsȱ ofȱ factorȱ #1ȱ andȱ 2ȱ respectively,ȱ theyȱ appearȱ inȱ lowȱ concentrationsȱ inȱ theȱ sedimentsȱ whatȱ meansȱ thatȱ probablyȱ theȱ correlationȱisȱdueȱtoȱbasalȱlevelsȱofȱtheseȱmetalsȱinȱtheȱenvironmentȱandȱdoȱnotȱ supposeȱ contamination.ȱ Previousȱ studiesȱ showedȱ aȱ relationshipȱ betweenȱ vitellogeninȱ andȱ metalsȱ ,ȱ althoughȱ inȱ thatȱ caseȱ thereȱ wasȱ aȱ vitellogeninȱ [16] inductionȱ alongȱ theȱ timeȱ ofȱ exposure,ȱ whereasȱ inȱ theȱ presentȱ caseȱ ofȱ studyȱ vitellogeninȱ decreasedȱ inȱ theȱ majorityȱ ofȱ theȱ treatments.ȱ Otherȱ studiesȱ ȱ [17] suggestedȱ thatȱ metalsȱ mayȱ interfereȱ withȱ theȱ ovarianȱ cycleȱ inȱ Carcinusȱ maenasȱ and,ȱtherefore,ȱwithȱtheȱreproductionȱofȱthisȱspecies.ȱPrecedingȱinvestigationsȱinȱ fishesȱ [18],ȱconsideredȱthatȱlowȱvitellogeninȱlevelsȱinȱfemalesȱcouldȱbeȱindicativeȱ ofȱ pollutionȱ inducedȱ dysfunctionȱ atȱ theȱ reproductiveȱ endocrineȱ systemȱ level.ȱ AlterationsȱinȱvitellogeninȬlikeȱproteinȱlevelsȱwereȱobservedȱinȱmusselsȱexposedȱ - 150 - toȱ organicȱ pollutantsȱ [19]ȱ whereasȱ studiesȱ withȱ femaleȱ clamsȱ exposedȱ toȱ PAHȱ contaminationȱ presentedȱ lowȱ levelsȱ ofȱ alkaliȬlabileȱ phosphateȱ whichȱ positiveȱ correlatesȱwithȱvitellogeninȱ[20].ȱȱ 4.ȱConclusionsȱ Inȱ theȱ presentȱ studyȱ aȱ decreaseȱ ofȱ vitellogeninȱ concentrationȱ inȱ haemolymphȱfromȱtheȱcrabȱCarcinusȱmaenasȱexposedȱtoȱcontaminatedȱsedimentsȱ wasȱ detectedȱ afterȱ 28ȱ daysȱ ofȱ exposure.ȱ Theȱ variationȱ ofȱ vitellogeninȱ concentrationȱ wasȱ relatedȱ toȱ theȱ presenceȱ ofȱ PAHsȱ andȱ theȱ metalsȱ Pb,ȱ Niȱ andȱ Cuȱ inȱ theȱ sediment,ȱ whichȱ occurredȱ mainlyȱ inȱ theȱ treatmentsȱ fromȱ theȱ Bayȱ ofȱ Algecirasȱ(chronicallyȱaffectedȱbyȱoilȱspills)ȱwhereasȱtheȱGalicianȱCoastȱ(acutelyȱ impactedȱ byȱ anȱ oilȱ spill)ȱ didȱ notȱ presentȱ thisȱ association.ȱ Thisȱ pointsȱ toȱ aȱ recoveryȱofȱtheȱareaȱaffectedȱbyȱtheȱoilȱspill.ȱAlthoughȱbothȱfieldȱandȱlaboratoryȱ testsȱ presentedȱ theȱ sameȱ trendsȱ inȱ vitellogeninȱ variations,ȱ theȱ responseȱ wasȱ lowerȱ underȱ fieldȱ conditionsȱ whichȱ meansȱ thatȱ laboratoryȱ testsȱ resultedȱ toȱ beȱ moreȱsensitiveȱthanȱfieldȱstudiesȱinȱorderȱtoȱassessȱsedimentȱtoxicity.ȱ 5.ȱAcknowledgementsȱ Theȱ workȱ describedȱ wasȱ partlyȱ supportedȱ byȱ theȱ projectsȱ VEM2003Ȭȱ 20563/INTER,ȱ andȱ CTM2005Ȭ07282ȬC03Ȭ01/TECNOȱ financedȱ byȱ theȱ Spanishȱ Educationȱ andȱ Scienceȱ Ministryȱ andȱ byȱ CISȱ fundedȱ byȱ theȱ Ministryȱ ofȱ Environment.ȱ Carmenȱ MoralesȬCasellesȱ thanksȱ theȱ Ministryȱ ofȱ Educationȱ andȱ Scienceȱ forȱ fundingȱ herȱ researchȱ fellowshipȱ (FPU).ȱ Dr.ȱ Ribaȱ thanksȱ theȱ I3pȱ programȱ forȱ supportingȱ herȱ participationȱ inȱ thisȱ research.ȱ Inmaculadaȱ Ribaȱ thanksȱtheȱCSICȱforȱherȱI3Pȱcontract.ȱWeȱareȱgratefulȱforȱtheȱsupportȱandȱhelpȱofȱ theȱ membersȱ ofȱ theȱ CISȱ andȱ theȱ ICMANȬCSIC.ȱ Specialȱ thanksȱ areȱ givenȱ toȱ - 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153 - [16]ȱ MartínȬDíaz,ȱ M.L.,ȱ VillenaȬLincoln,ȱ A.,ȱ Lamber,ȱ S.,ȱ Blasco,ȱ J.,ȱ DelValls,ȱ T.A.ȱ Anȱ integratedȱ approachȱ usingȱ bioaccumulationȱ andȱ biomarkerȱ measurementsȱ inȱ femaleȱshoreȱcrab,ȱCarcinusȱmaenas.ȱChemosphere.ȱ2005,ȱ58,ȱ615Ȭ626.ȱ [17]ȱ Elumalai,ȱ M.,ȱ Antunes,ȱ C.,ȱ Guilhermino,ȱ L.ȱ Alterationsȱ ofȱ reproductiveȱ parametersȱ inȱ theȱ crabȱ Carcinusȱ maenasȱ afterȱ exposureȱ toȱ metals.ȱ Water.ȱ Air.ȱ Soil.ȱPollut.ȱ2005,ȱ160,ȱ245Ȭ258.ȱ [18]ȱ Kime,ȱ D.E.,ȱ Nash,ȱ J.P.,ȱ Scott,ȱ A.P.ȱ Vitellogenesisȱ asȱ aȱ biomarkerȱ ofȱ reproductiveȱ disruptionȱbyȱxenobiotics.ȱAquaculture.ȱ1999,ȱ177,ȱ345Ȭ352.ȱ [19]ȱOrtizȬZarragoitia,ȱM.,ȱCajaraville,ȱM.P.ȱBiomarkersȱofȱexposureȱandȱreproductionȬ relatedȱ effectsȱ inȱ musselsȱ exposedȱ toȱ endocrineȱ disruptors.ȱ Arch.ȱ Environ.ȱ Contam.ȱToxicol.ȱ2006,ȱ50,ȱ361Ȭ369.ȱȱ [20]ȱ Gagnè,ȱ F.,ȱ Blaise,ȱ C.,ȱ Pellerin,ȱ J.,ȱ GauthierȬClerc,ȱ S.ȱ Alterationȱ ofȱ theȱ biochemicalȱ propertiesȱ ofȱ femaleȱ gonadsȱ andȱ vitellinsȱ inȱ theȱ clamȱ Myaȱ arenariaȱ atȱ contaminatedȱsitesȱinȱtheȱSaguenayȱFjord.ȱMar.ȱEnviron.ȱRes.ȱ2002,ȱ53,ȱ295Ȭ310.ȱ ȱȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱȱ - 154 - AȱmultibiomarkerȱapproachȱusingȱtheȱpolychaeteȱArenicolaȱ marinaȱtoȱassessȱoilȱcontaminatedȱsedimentsȱȱ CarmenȱMoralesȬCaselles1,ȱCeriȱLewis2,ȱTamaraȱGalloway2,ȱInmaculadaȱRiba1,ȱ T.ȱÁngelȱDelVallsȱ1ȱ 1 ȱUnidadȱAsociadaȱdeȱCalidadȱAmbientalȱyȱPatologíaȱ(CSICȱ&ȱUCA)ȱinstitutoȱ deȱCienciasȱMarinasȱdeȱAndalucíaȱ(ICMANȬCSIC),ȱUNESCOȱUNITWIN/WiCopȱ Avda.ȱRepúblicaȱSaharauiȱs/n,ȱPuertoȱRealȱ11510,ȱCádiz,ȱSpainȱ 2 SchoolȱȱofȱBiosciences,ȱHatherlyȱLaboratories,ȱUniversityȱofȱExeter,ȱPrinceȱofȱWalesȱ Road,ȱExeter,ȱUK,ȱEX4ȱ4PS.telȱ(44)ȱ1392ȱ263436,ȱfaxȱ(44)ȱ1392ȱ263700ȱȱ Abstractȱ Marineȱandȱcoastalȱsedimentsȱcanȱaccumulateȱsubstantialȱconcentrationsȱ ofȱ metalsȱ andȱ hydrocarbons,ȱ yetȱ theȱ consequencesȱ ofȱ thisȱ contaminationȱ forȱ exposedȱ biotaȱ inȱ situȱ canȱ beȱ difficultȱ toȱ establish.ȱ Here,ȱ weȱ examineȱ theȱ hypothesisȱ thatȱ exposureȱ toȱ contaminatedȱ sedimentsȱ canȱ leadȱ toȱ detrimentalȱ effectsȱ toȱ sedimentȱ dwellingȱ species.ȱ Theȱ commonȱ lugwormȱ Arenicolaȱ marinaȱ wasȱ exposedȱ inȱ theȱlaboratoryȱforȱ 14ȱdaysȱ toȱmarineȱ sedimentsȱcollectedȱfromȱ sitesȱofȱcontaminationȱinȱSpainȱandȱEngland.ȱAȱsuiteȱofȱbiomarkersȱofȱsublethalȱ toxicityȱ wasȱ combinedȱ withȱ analyticalȱ chemistryȱ toȱ testȱ forȱ relationshipsȱ betweenȱ sedimentȱ contaminationȱ andȱ effect.ȱ ȱ Moderateȱ toȱ strongȱ correlationsȱ betweenȱorganics,ȱmetalsȱandȱbiologicalȱresponsesȱwereȱobserved,ȱwithȱDNAȱȱ ȱ ȱEnvironementalȱScienceȱandȱTechnology (enȱpreparación) ȱ - 155 - damageȱ asȱ measuredȱ usingȱ theȱ Cometȱ assayȱ formingȱ theȱ largestȱ contributionȱ towardsȱ theȱ observedȱ differences.ȱ Theȱ responseȱ ofȱ wormsȱ fromȱ sitesȱ experiencesȱdifferentȱcontaminationȱloadsȱwereȱclearlyȱdistinguishable.ȱTheȱuseȱ ofȱ A.ȱ marinaȱ inȱ thisȱ wayȱ providesȱ aȱ sensitive,ȱ holisticȱ approachȱ toȱ sedimentȱ toxicityȱ assessment,ȱ enablingȱ comparisonsȱ betweenȱ chronically,ȱ andȱ acutelyȱ pollutedȱsitesȱtoȱbeȱquantifiedȱandȱrecoveryȱofȱtheseȱsitesȱtoȱbeȱcharted.ȱȱ 1.ȱIntroductionȱ Anȱ integratedȱ approachȱ toȱ marineȱ pollutionȱ monitoring,ȱ thatȱ combinesȱ theȱ traditionalȱ chemicalȱ analysesȱ withȱ laboratoryȱ andȱ fieldȱ basedȱ toxicityȱ testing,ȱisȱbecomingȱincreasinglyȱimportantȱinȱgainingȱbetterȱassessmentsȱofȱtheȱ pollutionȱprocessȱinȱtheȱmarineȱandȱcoastalȱenvironmentȱ(Chapman.,ȱ2007).ȱTheȱ waterȱ frameworkȱ directiveȱ (WFD)ȱ requiresȱ memberȱ statesȱ toȱ assessȱ theȱ ecologicalȱ qualityȱ statusȱ (EQS)ȱ ofȱ waterȱ bodiesȱ andȱ toȱ achieveȱ “goodȱ waterȱ status”ȱ forȱ allȱ Europeanȱ watersȱ byȱ 2015ȱ (EEC,ȱ 2000).ȱ Interestȱ isȱ thereforeȱ focusedȱ onȱ developingȱ assessmentȱ toolsȱ toȱ monitorȱ littoralȱ ecosystemsȱ followingȱ theȱ WFDȱ requirements.ȱ ȱ Biomarkersȱ haveȱ beenȱ shownȱ toȱ beȱ usefulȱ toolsȱinȱcharacterizingȱtheȱhealthȱstatusȱofȱanimalsȱfromȱimpactedȱareas,ȱwhereȱ complexȱ mixturesȱ ofȱ pollutantsȱ areȱ usuallyȱ presentȱ (Gallowayȱ etȱ al.,ȱ 2002;ȱ Gallowayȱetȱal.,ȱ2004).ȱTheȱcombinationȱofȱchemicalsȱandȱbiomarkersȱasȱpartȱofȱ aȱweightȱofȱevidenceȱ(WOE)ȱapproachȱallowsȱtheȱidentificationȱofȱtheȱimpactȱofȱ chemicalȱ contaminationȱ onȱ differentȱ levelsȱ ofȱ biologicalȱ functionȱ andȱ couldȱ makeȱ aȱ viableȱ additionȱ toȱ routineȱ managementȱ protocolsȱ forȱ protectingȱ theȱ environmentȱ(Gallowayȱetȱal.,ȱ2004)ȱbutȱhasȱrarelyȱbeenȱachievedȱforȱsedimentȱ dwellingȱspecies.ȱSinceȱmanyȱpersistentȱorganicsȱandȱmetalsȱareȱretainedȱwithinȱ sediments,ȱ thisȱ representsȱ aȱ majorȱ knowledgeȱ gapȱ inȱ ecotoxicologicalȱ monitoringȱprogrammesȱofȱtheȱmarineȱenvironment.ȱ - 156 - ȱArenicolaȱ marinaȱ isȱ aȱ commonȱ intertidalȱ polychaeteȱ whichȱ isȱ highlyȱ suitableȱforȱtheȱ biomonitoringȱ ofȱsedimentȬȱboundȱcontaminants:ȱ itȱlivesȱinȱ UȬ shapedȱ burrowsȱ withinȱ theȱ sedimentȱ andȱ ingestsȱ largeȱ volumesȱ ofȱ sedimentȱ whenȱfeeding,ȱthereforeȱisȱcontinuouslyȱexposedȱtoȱanyȱcontaminantsȱpresentȱinȱ theȱ sediment.ȱ Itȱ isȱ availableȱ allȱ theȱ yearȱ round,ȱ oftenȱ inȱ reasonablyȱ highȱ densities,ȱtoleratesȱaȱwideȱrangeȱofȱparticlesȱsizesȱandȱsalinitiesȱandȱhasȱaȱbroadȱ geographicȱrangeȱ(Batȱetȱal.,ȱ1998).ȱArenicolaȱmarinaȱisȱalsoȱanȱimportantȱlinkȱinȱ coastalȱ foodȱ chainȱ playingȱ anȱ importantȱ roleȱ inȱ sedimentȱ communityȱ organizationȱ (Batȱ etȱ al.,ȱ 1998).ȱ Polychaeteȱ wormsȱ areȱ oftenȱ theȱ mostȱ abundantȱ taxaȱ inȱ contaminatedȱ areasȱ andȱ theirȱ capacityȱ toȱ accumulateȱ andȱ metabolizeȱ PAHsȱ mayȱ haveȱ importantȱ effectsȱ onȱ theȱ transportȱ andȱ fateȱ ofȱ PAHsȱ inȱ theȱ marineȱenvironmentȱ(Selckȱetȱal.,ȱ2003).ȱTheȱstudyȱofȱwaterȬsolubleȱmetabolitesȱ inȱ A.ȱ marinaȱ highlightsȱ theȱ presenceȱ ofȱ aȱ PAHȱ metabolisingȱ systemȱ inȱ theȱ organismȱ(Christensenȱetȱal.,ȱ2002).ȱȱDuringȱtheȱpastȱfewȱyearsȱtheȱ10Ȭdayȱacuteȱ sedimentȱassayȱusingȱA.ȱmarinaȱhasȱbeenȱwidelyȱadoptedȱforȱuseȱinȱevaluatingȱ theȱ qualityȱ ofȱ sedimentsȱ (CEFAS,ȱ 1998;ȱ Thainȱ andȱ Bifieldȱ 2002).ȱAlthoughȱ thisȱ bioassayȱ suppliesȱ informationȱ aboutȱ generalȱ health,ȱ itȱ doesȱ notȱ clarifyȱ howȱ orȱ whyȱ theȱ organismsȱ areȱ affected.ȱ Biomarkersȱ studiesȱ inȱ Arenicolaȱ marinaȱ areȱ few,ȱ (Hannamȱ etȱ al.,ȱ 2007;ȱ Lewisȱ etȱ alȱ (inȱ prep)),ȱ however,ȱ someȱ specificȱ andȱ nonȬspecificȱbiomarkersȱhaveȱbeenȱinvestigatedȱinȱotherȱpolychaeteȱspeciesȱ(forȱ example;ȱNereisȱdiversicolorȱ,ȱDurouȱetȱal.,ȱ2007);ȱCapitellaȱcapitataȱ,ȱBachȱetȱal.,ȱ 2005);ȱLaeonoreisȱacuta,ȱ(Montserratȱetȱal.,ȱ2006);ȱTubifexȱtubifexȱ,ȱMoslehȱetȱal.,ȱ 2007);ȱ Sipunclusȱ nudus,ȱ Matozzoȱ etȱ al.,ȱ 2002).ȱ Toȱ date,ȱ theseȱ techniquesȱ haveȱ notȱpreviouslyȱbeenȱcombinedȱtoȱgiveȱaȱmultiȬbiomarkerȱapproachȱtoȱsedimentȱ qualityȱmonitoringȱusingȱaȱsingleȱspecies.ȱ Inȱ theȱ presentȱ study,ȱ weȱ useȱ aȱ novelȱ approachȱ toȱ sedimentȱ toxicityȱ assessment,ȱ whichȱ combinesȱ aȱ multiȬȱ biomarkerȱ approachȱ usingȱ anȱ Arenicolaȱ exposureȱ modelȱ withȱ analyticalȱ chemistryȱ toȱ addressȱ theȱ hypothesisȱ thatȱ - 157 - exposureȱ toȱ contaminatedȱ sedimentsȱ canȱ causeȱ detrimentalȱ biologicalȱ effects.ȱ Marineȱ sedimentsȱwereȱ collectedȱ fromȱsitesȱaroundȱEuropeȱexhibitingȱvaryingȱ degreesȱofȱanthropogenicȱimpactȱandȱincludedȱsitesȱrecoveringȱfromȱtheȱacuteȱ impactsȱ provokedȱ byȱ theȱ tankerȱ Prestigeȱ (2002)ȱ inȱ theȱ Galicianȱ Coastȱ (NWȱ Spain)ȱ(MoralesȬCasellesȱetȱal.,ȱaccepted)ȱandȱanȱareaȱchronicallyȱaffectedȱbyȱoilȱ spillage.ȱSpecificȱquestionsȱincluded:ȱ(1)ȱcanȱaȱsignificantȱrelationshipȱbetweenȱ contaminationȱandȱbiologicalȱresponseȱbeȱshown?ȱ(2)ȱcanȱweȱuseȱthisȱintegratedȱ approachȱtoȱdistinguishȱbetweenȱacutelyȱandȱchronicallyȱimpactedȱsites?ȱ(3)ȱIsȱ thisȱtechniqueȱsensitiveȱenoughȱtoȱchartȱrecovery?ȱ 2.ȱMaterialsȱandȱmethodsȱ 2.1.ȱStudyȱsiteȱ Contaminatedȱ sedimentsȱ fromȱ twoȱ areasȱ ofȱ theȱ Spanishȱ coastȱ wereȱ selected.ȱTheȱAtlanticȱIslandsȱNationalȱParkȱȱisȱlocatedȱinȱfrontȱofȱtheȱmouthȱofȱ theȱ Riasȱ Baixasȱinȱtheȱ GalicianȱCoastȱ(NWȱSpain)ȱandȱ itȱitsȱconsideredȱaȱplaceȱ withȱ highȱ ecologicalȱ revelance.ȱ Theseȱ islandsȱ playedȱ anȱ importantȱ roleȱ inȱ theȱ Prestigeȱ oilȱ spillȱ (November,ȱ 2002)ȱ actingȱ asȱ aȱ barrierȱ thatȱ protectedȱ theȱ coastȱ fromȱtheȱentranceȱofȱspilledȱoil.ȱSedimentsȱfromȱtheȱBayȱofȱAlgecirasȱ(SȱSpain)ȱ haveȱsufferedȱaȱchronicȱimpactȱlastingȱseveralȱdecades,ȱcausedȱbyȱtheȱinputȱofȱ oilȱandȱotherȱcontaminantsȱfromȱtheȱvariousȱindustriesȱȱlocatedȱinȱtheȱareaȱandȱ fromȱ accidentalȱ spillsȱ andȱ deliberateȱ dischargesȱ fromȱ commercialȱ shippingȱ activitiesȱ(MoralesȬCaselles,ȱetȱalȱ2007).ȱ ȱToȱperformȱthisȱstudyȱ3ȱstationsȱwereȱselectedȱinȱtheȱNationalȱParkȱandȱ3ȱ stationsȱinȱtheȱareaȱofȱtheȱBayȱofȱAlgecirasȱ(Figureȱ1).ȱTwoȱreferenceȱsitesȱwereȱ selectedȱtoȱcarryȱoutȱthisȱstudy:ȱinȱtheȱEstuaryȱatȱExmouth,ȱSouthȱDevon,ȱU.K,ȱ andȱ inȱ theȱ Bayȱ ofȱ Cádiz,ȱ Spain.ȱ Theȱ firstȱ wasȱ theȱ siteȱ ofȱ collectionȱ ofȱ Arenicolaȱ marinaȱ specimensȱ whereasȱ theȱ secondȱ wasȱ chosenȱ becauseȱ itȱ hasȱ beenȱ widelyȱ characterizedȱ inȱ previousȱ ecotoxicologicalȱ studiesȱ (DelVallsȱ etȱ al.,ȱ 1998,ȱ - 158 - MoralesȬCasellesȱetȱal.,ȱ2007);ȱinȱaddition,ȱorganicȱcontaminationȱwasȱbelowȱtheȱ detectionȱlimitȱinȱbothȱplaces.ȱ ȱ ȱ Atlantic Islands National Park (Galician Coast) •AC1 Spain •AC2 ȱ N •AC3 E W ȱ United Kingdom S ȱ Bay of Cádiz •CR2 •CR1 •CR3 ȱ Bay of Algeciras •R2 R1• ȱ ȱ Figureȱ 1.ȱ Mapȱ ofȱ generalȱ areasȱ sampledȱ andȱ locationsȱ ofȱ theȱ samplingȱ stationsȱinȱGaliciaȱ(NWȱSpain)ȱandȱtheȱBayȱofȱAlgecirasȱ(SȱSpain)ȱ,ȱbothȱaffectedȱ byȱ oilȱ spills,ȱ andȱ theȱ referenceȱ sitesȱ locatedȱ inȱ theȱ Bayȱ ofȱ Cádizȱ (Sȱ Spain)ȱ andȱ Exmouthȱ(SȱUK).ȱ 2.2.ȱSampleȱcollectionȱandȱbioassayȱ Sedimentȱ samplesȱwereȱ collectedȱandȱ transportedȱtoȱ theȱ laboratoryȱandȱ subȬsampledȱ forȱ physicalȱ characterizationȱ andȱ chemicalȱ quantification.ȱ Afterȱ that,ȱsedimentȱsamplesȱwereȱmaintainedȱinȱtheȱcoolerȱatȱ4ºȱCȱinȱtheȱdarkȱuntilȱ theyȱ wereȱ usedȱ forȱ sedimentȱ toxicityȱ testing,ȱ butȱ forȱ noȱ longerȱ thanȱ 2ȱ weeks.ȱ Arenicolaȱ marinaȱ specimensȱ wereȱ obtainedȱ fromȱ aȱ naturalȱ populationȱ fromȱ aȱ ‘clean’ȱ (http://www.environmentȬagency.gov.uk/)ȱ estuaryȱ atȱ Exmouth,ȱ Southȱ Devon,ȱ U.Kȱ (50º36ȇ57ȇȇNȱ 3º26ȇ40ȇȇW).ȱ Organismsȱ wereȱ placedȱ inȱ 20ȱ Lȱ capacityȱ aquariumsȱ withȱ clean,ȱ filteredȱ (0.5ΐm)ȱ seawaterȱ (FSW)ȱ andȱ sievedȱ sedimentȱ - 159 - (collectedȱinȱtheȱsameȱareaȱasȱtheȱorganisms)ȱandȱwereȱmaintainedȱinȱlaboratoryȱ underȱ controlledȱ conditionsȱ forȱ acclimationȱ (7ȱ days)ȱ untilȱ theȱ startȱ ofȱ theȱ test.ȱ Aerationȱwasȱprovidedȱwithȱaȱ12:12ȱlight:ȱdarkȱphotoperiod.ȱȱȱ Theȱ toxicityȱ testȱ wasȱ conductedȱ inȱ replicateȱ (5)ȱ byȱ exposingȱ individualȱ Arenicolaȱmarinaȱspecimensȱtoȱbulkȱsediment.ȱApproximately,ȱ250ȱgȱofȱsievedȱ(1ȱ mm)ȱ sedimentȱ wasȱ placedȱ inȱ 2ȱ Lȱ beakersȱ withȱ 750ȱ mLȱ ofȱ wellȱ aeratedȱ FSW.ȱȱ TwoȱA.ȱmarinaȱwereȱplacedȱinȱeachȱreplicateȱcontainerȱandȱmaintainedȱatȱ15ȱºCȱ duringȱ theȱ 14ȱ dayȱ exposureȱ period.ȱ Theȱ behaviourȱ andȱ castsȱ assayȱ wasȱ performedȱ afterȱ theȱ exposureȱ period.ȱ afterȱ whichȱ coelomicȱ fluidȱ wasȱ collectedȱ forȱuseȱinȱtheȱcellularȱassays.ȱȱCoelomicȱfluidȱwasȱcarefullyȱwithdrawnȱfromȱtheȱ posteriorȱpartȱofȱeachȱA.ȱmarinaȱspecimenȱusingȱaȱ21Gȱsyringe,ȱandȱstoredȱinȱiceȱ priorȱ toȱ use.ȱ Theȱ wholeȱ bodyȱ wasȱ thenȱ frozenȱ atȱ Ȭ80ȱ ºCȱ forȱ subsequentȱ biochemicalȱ biomarkersȱ analysis.ȱ Wormsȱ wereȱ homogenizedȱ withȱ PBSȱ pHȱ 7.5ȱ andȱcentrifugedȱforȱ30ȱminutesȱatȱ10,000ȱgȱatȱ4ȱºC;ȱsupernatantȱwasȱemployedȱ forȱ biochemicalȱ biomarkersȱ andȱ totalȱ proteinsȱ determinationȱ (Bradfordȱ etȱ al.,ȱ 1976).ȱ Chemicalȱ analysis.ȱ Theȱ analysesȱ ofȱ PAHsȱ andȱ PCBsȱ boundȱ toȱ sedimentsȱ wereȱcarriedȱoutȱaccordingȱtoȱUSEPAȱSWȬ846ȱMethodȱ827C78082ȱ(1994).ȱBrieflyȱ driedȱ samplesȱ wereȱSoxhletȱ extractedȱ withȱ nȬhexaneȱ forȱ 18ȱ h,ȱ andȱ theȱ extractsȱ wereȱisolatedȱbyȱcolumnȱchromatographyȱonȱFlorisileȱaluminoȬsilica.ȱPCBsȱandȱ PAHsȱwereȱ elutedȱ andȱ theirȱ fractionsȱwereȱdriedȱinȱaȱ rotatingȱevaporatorȱandȱ reȬdissolvedȱ inȱ isooctane.ȱ Aromaticȱ fractionsȱ wereȱ analyzedȱ onȱ aȱ HewlettePackardȱ(HP)ȱ5890ȱSeriesȱIIȱgasȱchromatographerȱcoupledȱwithȱanȱHPȱ 5970ȱ massȱ spectrometer.ȱ PAHsȱ wereȱ analyzedȱ byȱ GCȬMSȱ usingȱ selectedȱ ionȱ monitoringȱ (SIM).ȱ Analysisȱ ofȱ PCBsȱ asȱ AROCLORȱ 1242ȱ andȱ AROCLORȱ 1260ȱ wasȱ performedȱ usingȱ theȱ sameȱ instrumentȱ withȱ anȱ electronȱ captureȱ detectorȱ (GC/ECD).ȱ Forȱ bothȱ setȱ ofȱ organicȱ chemicals,ȱ PAHsȱ andȱ AROCLOR,ȱ theȱ - 160 - analyticalȱprocedureȱshowedȱagreementȱwithȱtheȱcertifiedȱvaluesȱofȱmoreȱthanȱ 90%.ȱ TraceȱmetalȱanalysisȱwereȱanalyzedȱasȱdescribedȱbyȱCasadoȬMartínezȱetȱ al.ȱ (2006);ȱ briefly,ȱ 2.5ȱ gȱ ofȱ sedimentsȱ (<0.065ȱ mm)ȱ wereȱ placedȱ inȱ Teflonȱ containersȱ andȱ wereȱdigestedȱinȱmicrowaveȱ(400W,ȱ15ȱmin,ȱtwice)ȱwithȱHNO3ȱ 2N.ȱ Theȱ extractsȱ wereȱ purifiedȱ byȱ passingȱ throughȱ aȱ CȬ18ȱ columnȱ andȱ metalsȱ analysesȱwereȱperformedȱbyȱanodicȱvoltamperimetryȱ(ȬZn,ȱPb,ȱNi,ȱCoȱandȱCuȬȱ MetrohmȱApplicationȱBulletinȱNºȱ147;ȱȬȱVȬȱMetrohmȱApplicationȱNoteȱNºȱVȬ81).ȱ Forȱ Hgȱ theȱ coldȱ vapourȱ techniqueȱ wasȱ usedȱ andȱ wasȱ quantifiedȱ usingȱ atomicȱ absorptionȱ spectrometry.ȱ Theȱ analyticalȱ proceduresȱ wereȱ checkedȱ usingȱ referenceȱ materialȱ (MESSȬ1ȱ NRCȱ andȱ CRMȱ 277ȱ BCR)ȱ andȱ showedȱ aȱ recoveryȱ greaterȱthanȱ90%ȱofȱtheȱcertifiedȱconcentration.ȱ Behaviourȱ andȱ Feedingȱ assay.ȱ Afterȱ 14ȱ daysȱ ofȱ exposureȱ theȱ individualȱ A.ȱ marinaȱ specimensȱ wereȱ transferredȱ toȱ differentȱ beakersȱ containingȱ cleanȱ sedimentȱ(fromȱtheȱreferenceȱsiteȱatȱExmouth)ȱandȱtheȱtimeȱtakenȱforȱthemȱtoȱreȬ buryȱthemselvesȱcompletelyȱwasȱrecorded.ȱWormsȱwereȱtheȱreturnedȱtoȱtheȱtestȱ sedimentȱ beakersȱ andȱ leftȱ forȱ 24ȱ hours;ȱ afterȱ whichȱ castsȱ wereȱ carefullyȱ removed,ȱdriedȱandȱweighed.ȱȱ Cometȱ assay.ȱ Theȱ Cometȱ assayȱ wasȱ performedȱ toȱ detectȱ singleȱ strandȱ DNAȱbreaksȱinȱinvidicualȱcellsȱaccordingȱtoȱtheȱmethodsȱofȱSinghȱetȱal.ȱ(Singh,ȱ 1988)ȱ withȱ modificationsȱ specificȱ forȱ Arenicolaȱ marinaȱ (Lewisȱ etȱ al.,ȱ inȱ prep),ȱ usingȱ alkalineȱconditions.ȱ ȱOneȱ hundredȱcellsȱperȱpreparationȱ wereȱquantifiedȱ usingȱKineticȱCOMETȱSoftware.ȱȱ Phagocytosis.ȱ Phagocytosisȱ activityȱ wasȱ determinedȱ byȱ measuringȱ theȱ uptakeȱ ofȱ fluorescentȱ zymosanȱ particles,ȱ usingȱ trypanȱ blueȱ asȱ aȱ quenchingȱ agentȱ Andersonȱ etȱ alȱ (1995).ȱ Inȱ brief,ȱ 50ȱ ΐLȱ ofȱ coelomicȱ fluidȱ wasȱ pipettedȱ inȱ triplicateȱ wellsȱ ofȱ aȱ microtitreȱ plate;ȱ thenȱ 50ȱ ΐLȱ Flouresceinȱ isothiocyanateȱ (FITC)ȱwasȱaddedȱtoȱtheȱwells.ȱIncubationȱwasȱperformedȱinȱdarkȱforȱ40ȱmin,ȱatȱ - 161 - 21ȱºC.ȱ50ȱΐLȱofȱFluorescenceȱquenchingȱsolutionȱ(1.25ȱmLȱtrypanȱblueȱinȱ1ȱmMȱ citrateȱbufferȱpHȱ4.5)ȱwasȱthenȱaddedȱtoȱtheȱwells,ȱandȱfluorescenceȱmeasuredȱ usingȱ aȱ Hitachiȱ FȬ4500ȱ fluorescenceȱ spectrophotometerȱ Ώex/emȱ 485/535ȱ .ȱ Resultsȱ wereȱcomparedȱtoȱaȱstandardȱcurveȱandȱnormalisedȱtoȱprotein.ȱ Antioxidantȱ status.ȱ Antioxidantȱ statusȱ wasȱ measuredȱ suignȱ theȱ ferricȱ reducingȱabilityȱofȱplasmaȱ(FRAP)ȱassayȱ(BenzieȱandȱStrain,ȱ1996)ȱasȱadaptedȱbyȱ Haggerȱetȱal.,ȱ2005.ȱCoelomicȱfluid,ȱ50ȱΐl,ȱinȱduplicateȱwasȱincubatedȱforȱ10ȱminȱ atȱ 25°Cȱ withȱ 200ȱ ΐLȱ ofȱ FRAPȱ reagentȱ (300ȱ mMȱ acetateȱ bufferȱ pHȱ 3.6,ȱ 2,4,6Ȭ tripyridylȬ5Ȭtriazineȱ (TBTZ),ȱ 20ȱ mMȱ ironȱ chlorideȱ inȱ theȱ ratioȱ 10:1:1ȱ preparedȱ immediatelyȱpriorȱtoȱanalysis)ȱinȱmicrotitreplatesȱandȱtheȱchangeȱinȱabsorbanceȱ atȱ593nmȱnoted.ȱTheȱFRAPȱvalueȱwasȱcalculatedȱrelativeȱtoȱaȱstandardȱcurveȱofȱ Fe(II)ȱ inȱ theȱ rangeȱ 100Ȭ500ȱ ΐmol/lȱ andȱ expressedȱ asȱ changeȱ inȱ absorbanceȱ perȱ mgȱprotein.ȱȱ Thiobarbituricȱacidȱreactiveȱsubstancesȱ(TBARS)ȱassay.ȱTheȱmeasurementȱofȱ TBARSȱ wasȱ performedȱ toȱ evaluateȱ theȱ freeȱ radicalȬmediatedȱ oxidationȱ (modifiedȱ byȱ Camejoȱ etȱ al.,ȱ 1999).ȱ ȱ Malondialdehydeȱ (MDA),ȱ aȱ secondaryȱ productȱ inȱ lipidȱ peroxidationȱ bindsȱ toȱ thiobarbituricȱ acidȱ (TBA)ȱ whichȱ canȱ beȱ measuredȱ spectrophotometrically.ȱ Briefly,ȱ 10ȱ ΐLȱ ofȱ freeȱ radicalȱ scavengerȱ 1ȱ mmolȱ 1Ȭ1ȱ butylatedȱ hydroxytolueneȱ (2,6ȬDiȬ0ȱ tertȬbutylȬ4Ȭmethyphenol)ȱ dissolvedȱ inȱ absoluteȱ ethanolȱ wasȱ addedȱ toȱ theȱ microplateȱ wellsȱ inȱ orderȱ toȱ preventȱ furtherȱ oxidationȱ ofȱ theȱ samples;ȱ 40ȱ ΐLȱ ofȱ homogenateȱ andȱ 200ȱ ΐLȱ phosphateȱbufferedȱsalineȱpHȱ7.4ȱwereȱaddedȱtoȱtheȱwells.ȱ50ȱΐLȱofȱ50ȱ%ȱ(w/v)ȱ trichloroaceticȱ acidȱ andȱ 75ȱ ΐLȱ ofȱ 1.3ȱ %ȱ (w/v)ȱ thiobarbituricȱ acidȱ (TBA)ȱ (dissolvedȱ inȱ 0.3%ȱ (w/v)ȱ NaOH)ȱ wereȱ includedȱ andȱ afterȱ 60ȱ minȱ atȱ 60ȱ ºCȱ incubationȱ theȱ absorbanceȱ wasȱ readȱ atȱ 530ȱ nmȱ andȱ thenȱ againȱ atȱ 630ȱ nm.ȱ Resultsȱ wereȱ comparedȱ toȱ aȱ standardȱ curveȱ preparedȱ usingȱ 1,1,3,3Ȭ tetraethoxypropaneȱ(aȱstabilizedȱformȱofȱMDA)ȱandȱnormalisedȱtoȱprotein.ȱ - 162 - Glutathioneȱ transferaseȱ (GST)ȱ assay.ȱ Theȱ phaseȱ IIȱ metabolizingȱ enzymeȱ GlutathioneȬSȬtransferaseȱ (GST)ȱ wasȱ determinedȱ byȱ monitoringȱ theȱ rateȱ ofȱ conjugationȱofȱglutathioneȱ(GSH)ȱtoȱ1ȬchloroȬ2,4Ȭdinitrobenzeneȱ(CDNB)ȱatȱ340ȱ nmȱ (McFarlandȱ etȱ al.,1999).ȱ Supernatantsȱ wereȱ dilutedȱ (20ȱ ΐLȱ inȱ 1ȱ mLȱ homogenizingȱ buffer)ȱ andȱ placedȱ inȱ theȱ 96ȱ wellsȱ plate.ȱ 0.5ȱ mLȱ 42ȱ mMȱ GSHȱ wereȱ addedȱ toȱ aȱ mixtureȱ containingȱ 0.5ȱ mLȱ 42ȱ mMȱ CDNBȱ (inȱ ethanol)ȱ andȱ CDNBȱassayȱbufferȱ(200ȱmMȱsodiumȱphosphate,ȱpHȱ6.5);ȱimmediatelyȱ200ȱΐLȱofȱ theȱsolutionȱwereȱplacedȱintoȱtheȱwellsȱandȱtheȱplateȱwasȱreadȱatȱ340ȱnmȱeveryȱ 30ȱsecondsȱforȱ3ȱminutes.ȱȱ GlutathioneȱReductaseȱ(GR)ȱassay.ȱTheȱoxidationȱofȱ1ȱmMȱNADPHȱbyȱGRȱ inȱ theȱ presenceȱ ofȱ 10ȱ mMȱ oxidizedȱ glutathioneȱ wasȱ monitoredȱ atȱ 340ȱ nmȱ (McFarlandȱetȱal.,1999).ȱInȱbrief,ȱ20ȱΐLȱofȱsupernatantȱwasȱpipettedȱinȱtriplicateȱ wellsȱ ofȱ aȱ microtitreȱ plate.ȱ Aȱ solutionȱ containingȱ 2.5ȱ mLȱ 10ȱ mMȱ oxidizedȱ glutathione,ȱ 2.5ȱ mLȱ 1mMȱ NADPHȱ andȱ 20ȱ mLȱ GRȱ bufferȱ (200ȱ mMȱ sodiumȱ phosphate,ȱ pHȱ 7.6)ȱ wasȱ preparedȱ andȱ 200ȱ ΐLȱ wereȱ addedȱ toȱ theȱ wells.ȱ Plateȱ wasȱreadȱatȱ340ȱnmȱeveryȱ2ȱminȱforȱ10ȱminȱ Glutathioneȱ Peroxidaseȱ (GPX)ȱ assay.ȱ Theȱ antioxidantȱ GPXȱ activityȱ wasȱ measuredȱ accordingȱ toȱ (McFarlandȱ etȱ al.,1999).ȱ Supernatantsȱ wereȱ dilutedȱ (10ȱ ΐLȱ +ȱ 10ȱ ΐLȱ homogenizingȱ buffer)ȱ andȱ placedȱ inȱ theȱ 96ȱ wellsȱ plate.ȱ Aȱ solutionȱ containingȱ inȱ excessȱ NADPH,ȱ reducedȱ gluthationeȱ andȱ glutathioneȱ reductaseȱ wasȱpreparedȱandȱ200ȱΐLȱwereȱaddedȱtoȱtheȱwells.ȱAfterȱ2ȱminȱincubationȱ50ȱΐLȱ ofȱ 1.25ȱ mMȱ hydrogenȱ peroxideȱ wasȱ pipettedȱ toȱ theȱ wells;ȱ NADPHȱ oxidationȱ wasȱmeasuredȱatȱ340ȱnmȱatȱ10ȱsȱintervalsȱforȱ3ȱmin.ȱȱ Statisticalȱanalysis.ȱDataȱforȱeachȱbiomarkerȱwereȱanalyzedȱusingȱANOVAȱ inȱ orderȱ toȱ determineȱ significantȱ differencesȱ (p<0.05)ȱ amongȱ theȱ resultsȱ obtainedȱ inȱ eachȱ collectionȱ siteȱ andȱ theȱ referenceȱ site.ȱ Correlationȱ betweenȱ chemicalȱconcentrationsȱinȱsedimentsȱandȱbiomarkerȱresponsesȱwasȱcarriedȱoutȱ usingȱaȱSpearmanȱcorrelationȱanalysisȱ(p<0.05).ȱMultivariateȱanalysesȱwereȱalsoȱ - 163 - performedȱ usingȱ theȱ MDS,ȱ SIMPER,ȱ ANOSIMȱ andȱ BIOENVȱ programsȱ ofȱ theȱ PRIMERȱsoftwareȱpackageȱ(PlymouthȱMarineȱLaboratory,ȱUK).ȱȱAȱBrayȬCurtisȱ dissimilarityȱ matrixȱ wasȱ producedȱ fromȱ fourthȱ rootȱ transformedȱ rawȱ abundanceȱ data.ȱ ȱ NonȬmetricȱ MultiȬDimensionalȱ Scalingȱ (nMDS)ȱ wasȱ thenȱ performedȱ toȱ produceȱ twoȬdimensionalȱ ordinationȱ plots.ȱ ȱ Inȱ ordinationȱ plots,ȱ pointsȱ(sites)ȱcloseȱtoȱeachȱotherȱhaveȱsimilarȱbiomarkerȱresponses,ȱwhilstȱthoseȱ farȱ apartȱ areȱ lessȱ similar.ȱ ȱ OneȬwayȱ ANOSIMȱ testsȱ wereȱ usedȱ toȱ testȱ forȱ significantȱ differencesȱ betweenȱ biomarkerȱ responsesȱ inȱ reference,ȱ chronicallyȱ pollutedȱ andȱ acutelyȱ pollutedȱ (i.e.ȱ Prestige)ȱ sites.ȱ ȱ Similarityȱ percentagesȱ (SIMPER)ȱ wereȱ thenȱ usedȱ toȱ identifyȱ theȱ percentageȱ contributionȱ ofȱ eachȱ biomarkerȱ toȱ theȱ multivariateȱ differencesȱ betweenȱ theȱ differentȱ sitesȱ (Clarkeȱ andȱ Warwick,ȱ 1994)ȱ andȱ theȱ BESTȱ (BIOȬENV)ȱ programmeȱ wasȱ usedȱ toȱ determineȱ whichȱ chemicalȱ parametersȱ measuredȱ ‘best’ȱ describeȱ theȱ patternȱ inȱ biomarkerȱ responsesȱ observedȱ inȱ Arenicolaȱ marinaȱ specimensȱ exposedȱ toȱ theȱ differentȱsediments.ȱ 3.ȱResultsȱ 3.1.ȱChemicalȱanalysisȱofȱsedimentsȱȱ Theȱ concentrationȱ ofȱ organicȱ contaminantsȱ (PAHs)ȱ wasȱ muchȱ higherȱ inȱ sedimentsȱcollectedȱinȱtheȱBayȱofȱAlgecirasȱ(CR2ȱ>ȱCR1ȱ>ȱCR3)ȱthanȱinȱtheȱareaȱ ofȱ Galiciaȱ (AC3ȱ >ȱ AC2ȱ >AC1),ȱ whereasȱ theȱ concentrationȱ ofȱ metalsȱ didȱ notȱ presentȱ aȱ clearȱ trendȱ amongȱ sedimentsȱ fromȱ theȱ differentȱ areasȱ (Tableȱ 1).ȱ Theȱ referencesȱ (R1ȱ andȱ R2)ȱ presentedȱ theȱ lowestȱ levelsȱ ofȱ metals,ȱ andȱ noȱ organicȱ contaminationȱwasȱdetected.ȱTheȱpredominantȱPAHȱinȱtheȱsedimentsȱcollectedȱ inȱtheȱNationalȱParkȱwasȱtheȱnaphthaleneȱwhereasȱsedimentsȱlocatedȱinȱtheȱBayȱ ofȱ Algecirasȱ mainlyȱ presentedȱ phenanthrene,ȱ fluorene,ȱ pyreneȱ andȱ benzo[b]fluoranthene.ȱȱȱ - 164 - Tableȱ1.ȱTotalȱPAHs,ȱPCBsȱandȱmetalȱconcentrationȱ(Zn,ȱCd,ȱPb,ȱCu,ȱNi,ȱ Co,ȱHgȱandȱV)ȱȬmgȱKgȬ1ȱdryȱsedimentȬ,ȱpercentageȱofȱfinesȱ(fines)ȱandȱorganicȱ carbonȱ(O.C.)ȱmeasuredȱinȱtheȱsediments.ȱȱn.d:ȱnotȱdetected.ȱ ȱȱ Znȱ Cdȱ Pbȱ Cuȱ C2ȱ 12.4ȱ 0.06 11.6ȱ 17.6ȱ 13.1ȱ 1.8ȱ 3.27 0.15ȱ n.d.ȱ n.d.ȱ 1.22ȱ 22.7ȱ Ca1ȱ 21.3ȱ 0.92 2.28ȱ 6.98ȱ 0.06ȱ 3.40 80.0 n.d.ȱ n.d.ȱ n.d.ȱ 1.07ȱ 2.50ȱ Niȱ Coȱ Vȱ Hgȱ PAH PCBsȱ O.C.ȱ fines GR4ȱ 35.3ȱ 0.10 6.21ȱ 3.67ȱ 13.1ȱ 5.59 n.d. 0.25a 802bȱ 1.75ȱ 3.19ȱ 59.3ȱ GR3ȇȱ 138ȱ 0.17 21.6ȱ 5.01ȱ 74.7a 12.8 26.1 1.04a 3151b 22.0ȱ 2.15ȱ 69.4ȱ P1ȱ 56.7ȱ 0.12 12.3ȱ 75.2aȱ 13.3ȱ n.d. 6.84 0.65a 641bȱ 0.84ȱ 3.86ȱ 35.4ȱ D88ȱ 158aȱ n.d. 17.3ȱ 20.1ȱ 12.4ȱ n.d. n.d. 0.28a 13.0ȱ n.d.ȱ 0.26ȱ 2.35ȱ D79ȱ 107ȱ n.d. 21.0ȱ 39.1aȱ 21.1a 0.30 n.d. 0.09ȱ 80.0ȱ n.d.ȱ 2.08ȱ 65.2ȱ D60ȱ 161aȱ n.d. 43.4ȱ 16.7ȱ 14.7ȱ 0.20 n.d. 0.12ȱ 260ȱ n.d.ȱ 2.07ȱ 50.0ȱ 0.15ȱ 624*ȱ 22.7ȱ Ȭȱ Ȭȱ SQVsȱ 150ȱ 1.2ȱ 46.7ȱ 34ȱ 20.9ȱ Ȭȱ Ȭȱ Chemicalȱ dataȱ wasȱ comparedȱ toȱ internationalȱ sedimentȱ qualityȱ guidelinesȱ (SQGs)ȱ thatȱ specifyȱ theȱ levelsȱ ofȱ chemicalȱ contaminantsȱ associatedȱ withȱbiologicalȱeffectsȱandȱthoseȱexceedingȱrecommendedȱlimitsȱareȱhighlightedȱ inȱ Tableȱ 1.ȱ Followingȱ theȱ recommendationsȱ describedȱ byȱ MacDonaldȱ etȱ al.ȱ (1996),ȱtheȱsedimentsȱfromȱtheȱBayȱofȱAlgecirasȱwouldȱbeȱconsideredȱasȱslightlyȱ pollutedȱ byȱ PAHsȱ andȱ adverseȱ effectsȱ mightȱ beȱ predicted..ȱ Siteȱ AC3ȱ alsoȱ presentȱ aȱ naphthaleneȱ contentȱ higherȱ thanȱ theȱ ERLȱ (160ȱ ΐgȱ kgȬ1)ȱ proposedȱ byȱ NOAAȱ(1999)ȱ(ERL:ȱvaluesȱbelowȱwhichȱbiologicalȱeffectsȱareȱrare).ȱInȱtheȱBayȱ ofȱAlgeciras,ȱsiteȱCR2ȱsurpassedȱtheȱERLȱdefinedȱforȱfluoreneȱ(19ȱΐgȱkgȬ1)ȱwithȱ highȱvaluesȱofȱphenanthreneȱandȱfluoranthene.ȱCR3ȱfromȱtheȱBayȱofȱAlgecirasȱ exceededȱ theȱ guidelineȱ forȱ Cu,ȱ asȱ didȱ AC2ȱ ȱ inȱ Galicia.ȱ Znȱ ERLȱ valueȱ isȱ surpassedȱ byȱ theȱ sedimentsȱ AC1ȱ ȱ andȱ AC3;ȱ Niȱ sedimentȱ concentrationȱ goesȱ aboveȱ theȱ ERLȱ definedȱ inȱ CR2ȱ andȱ AC2ȱ whereasȱ Hgȱ SQGȱ isȱ surpassedȱ byȱ sedimentsȱ fromȱ theȱ Bayȱ ofȱ Algecirasȱ andȱ theȱ treatmentȱ AC1ȱ locatedȱ inȱ theȱ - 165 - Galicianȱ Coast.ȱ PCBsȱ wereȱ onlyȱ detectedȱ inȱ samplesȱ fromȱ theȱ chronicȱ sitesȱ althoughȱlevelsȱwereȱbelowȱtheȱSQGs.ȱ 3.2.ȱBiomarkerȱresponsesȱ AȱsummaryȱofȱallȱtheȱbiomarkersȱresultsȱmeasuredȱinȱArenicolaȱmarinaȱisȱ shownȱ inȱ Figureȱ 2.ȱ Cometȱ resultsȱ obtainedȱ afterȱ 15ȱ daysȱ ofȱ exposureȱ confirmȱ significantlyȱ differencesȱ (p<0.01)ȱ betweenȱ theȱ referenceȱ sitesȱ (R1ȱ andȱ R2)ȱ andȱ theȱ stationsȱ fromȱ theȱ Bayȱ ofȱ Algecirasȱ CR1,ȱ CR2,ȱ CR3ȱ andȱ theȱ sitesȱ AC2ȱ andȱ AC3ȱ locatedȱ inȱ theȱ AINP.ȱ Inȱ theȱ Behaviourȱ assayȱ CR2ȱ wasȱ significantlyȱ differentȱ(p<0.05)ȱtoȱtheȱR1,ȱR2ȱandȱAC1ȱtreatmentsȱwhereasȱtheȱweightȱofȱcastsȱ showedȱ thatȱ AC1ȱ wasȱ significantlyȱ differentȱ (p<0.01)ȱ toȱ allȱ theȱ stations,ȱ includingȱtheȱreferenceȱtreatments.ȱDifferencesȱwereȱstatisticallyȱsignificantȱforȱ theȱ phagocytosisȱ assayȱ althoughȱ responsesȱ presentedȱ aȱ highȱ increaseȱ inȱ variation.ȱNoȱsignificantȱdifferencesȱwereȱdetectedȱinȱFRAP,ȱTBARS,ȱGPX,ȱGSTȱ andȱ GRȱ byȱ usingȱ theȱ ANOVA.ȱ Inȱ general,ȱ treatmentȱ AC1ȱ fromȱ theȱ Galicianȱ Coastȱandȱbothȱreferenceȱsitesȱpresentȱanalogousȱtrends.ȱInȱcontrast,ȱsitesȱfromȱ theȱBayȱofȱAlgecirasȱgenerallyȱpresentȱmoreȱmarkedȱeffectsȱinȱtheȱinhibitionȱorȱ increasingȱofȱtheȱanalyzedȱbiomarkers,ȱespeciallyȱsiteȱCR2.ȱ - 166 - 40 4 3 TBARS FRAP 30 20 10 2 1 0 0 C2 CA1 GR4 GR3 P1 D88 D79 C2 D60 1500 CA1 GR4 GR3 P1 D88 D79 D60 GR3 P1 D88 D79 D60 GR3 P1 D88 D79 D60 12 1200 9 900 GR GST 6 600 3 300 0 0 C2 CA1 GR4 GR3 P1 D88 D79 C2 D60 -300 300 GR4 150 120 Phagocytosis 200 GPX CA1 -3 100 90 60 30 0 C2 CA1 GR4 GR3 P1 D88 D79 D60 0 C2 -100 2500 GR4 5 * * 2000 4 3 1500 casts Time to bury CA1 1000 2 1 500 0 0 C2 C2 CA1 GR4 GR3 P1 D88 D79 D60 * * D79 D60 CA1 GR4 GR3 P1 D88 D79 D60 -1 80 * DNA tail 15-d 60 * * 40 20 0 C2 CA1 GR4 GR3 P1 D88 Figureȱ 2.ȱ Generalȱ healthȱ biomarkers:ȱ glutathioneȱ peroxidaseȱ GPXȱ (nmol/min/mgȱ prot),ȱ glutathioneȱ transferaseȱ GSTȱ (nmol/min/mgȱ prot),ȱ glutathioneȱ reductaseȱ GRȱ (nmol/min/mgȱ prot),ȱ thiobarbituricȱ acidȱ reactiveȱ substancesȱ TBARSȱ (nmol/mgȱ prot),ȱ ferricȱ reducingȱ abilityȱ ofȱ plasmaȱ FRAPȱ - 167 - (ΐM/mg),ȱ phagocytosisȱ (zymosanȱ perȱ mgȱ proteinȱ ȉȱ 106),ȱ behaviourȱ assayȱ (s),ȱ castsȱ assayȱ (g)ȱ andȱ Cometȱ assayȱ (%ȱ DNAȱ inȱ tail)ȱ afterȱ 7ȱ andȱ 15ȱ daysȱ ofȱ exposure.ȱ Comparingȱtheȱbiomarkerȱresponsesȱbetweenȱtheȱdifferentȱsitesȱusingȱtheȱ multivariateȱ ANOSIMȱ (Primerȱ 6ȱsoftware)ȱdemonstratedȱ aȱ significantȱ effectȱofȱ chronicȱpollutionȱonȱtheȱbiomarkerȱresponsesȱofȱArenicolaȱmarinaȱ(Figureȱ3).ȱAnȱ aȱ prioriȱ oneȬwayȱ ANOSIMȱ comparingȱ theȱ biomarkerȱ responsesȱ ofȱ Arenicolaȱ marinaȱexposedȱtoȱ‘clean’ȱreferenceȱsedimentsȱwithȱthoseȱexposedȱtoȱsedimentsȱ fromȱ chronicallyȱ pollutedȱ andȱ acutelyȱ pollutedȱ (Prestige)ȱ sites,ȱ revealsȱ aȱ significantȱ differenceȱ inȱ biomarkerȱ responseȱ betweenȱ theȱ chronicallyȱ pollutedȱ sitesȱ andȱ theȱ otherȱ sitesȱ (Rȱ =ȱ 0.281,ȱ Pȱ =ȱ 0.001).ȱ ȱ Noȱ significantȱ differenceȱ wasȱ observedȱbetweenȱtheȱPrestigeȱaffectedȱsitesȱandȱtheȱtwoȱreferenceȱsitesȱ(Figureȱ 3).ȱ ȱ Similarityȱ percentagesȱ (SIMPER)ȱ wereȱ usedȱ toȱ identifyȱ theȱ percentageȱ contributionȱofȱeachȱbiomarkerȱtoȱtheȱmultivariateȱdifferencesȱbetweenȱallȱsitesȱ (Clarkeȱ andȱ Warwick,ȱ 1994).ȱ ȱ Theȱ cometȱ assayȱ wasȱ foundȱ toȱ makeȱ theȱ largestȱ contributionȱ toȱ theȱ observedȱ differencesȱ betweenȱ theȱ referenceȱ sitesȱ andȱ theȱ chronicallyȱ pollutedȱ sites,ȱ representingȱ 21.62%ȱ ofȱ theȱ dissimilarityȱ betweenȱ sites,ȱwhilstȱtheȱburrowingȱassayȱmadeȱupȱ14.10%ȱofȱtheȱdissimilarityȱbetweenȱ theȱPrestigeȱsitesȱandȱtheȱchronicallyȱpollutedȱsites.ȱ ȱ - 168 - Transform: Fourth root Normalise Resemblance: D1 Euclidean distance site health control chronic Prestige 2D Stress: 0.16 Figureȱ 3.ȱ Twoȱ dimensionalȱ nonȬmetricȱ multidimensionalȱ scalingȱ plotȱ ofȱ theȱ biomarkerȱ responsesȱ forȱ eachȱ Arenicolaȱ marinaȱ specimenȱ exposedȱ toȱ sedimentsȱ fromȱ theȱ differentȱ experimentalȱ sites:ȱ representingȱ ‘clean’ȱ controlȱ sites;ȱ sitesȱ affectedȱ byȱ chronicȱ pollutionȱ andȱ sitesȱ affectedȱ byȱ theȱ Prestigeȱ oilȱ spillȱ(i.e.ȱanȱacuteȱpollutionȱincident).ȱ 3.3.ȱLinkingȱchemicalsȱandȱbiomarkersȱȱ Theȱ chemicalȱ parametersȱ measuredȱ thatȱ bestȱ accountȱ forȱ theȱ patternȱ observedȱ inȱ theȱ biomarkerȱ responsesȱ ofȱ Arenicolaȱ marinaȱ areȱ theȱ sumȱ ofȱ PAHsȱ andȱtheȱPCBsȱ(Figureȱ4,ȱBESTȱanalysis,ȱSpearman’sȱRankȱcorrelationȱcoefficientȱ 0.361).ȱ Aȱ strongȱ positiveȱ relationshipȱ wasȱ observedȱ betweenȱ organicȱ contaminantsȱ(PAHsȱandȱPCBs)ȱwithȱtheȱDNAȱdamageȱ(0.89,ȱ0.79,ȱrespectively),ȱ theȱphagocyticȱresponseȱ(0.90,ȱ0.87,ȱrespectively)ȱandȱtheȱburialȱbehaviourȱ(0.90,ȱ 0.85,ȱrespectively).ȱAȱnegativeȱcorrespondenceȱwasȱdetectedȱwithȱtheȱweightȱofȱ - 169 - ȱ casts.ȱ Onȱ theȱ otherȱ hand,ȱ theȱ phaseȱ IIȱ detoxificationȱ enzymeȱ GSTȱ presentedȱ aȱ negativeȱ relationshipȱ withȱ theȱ organicȱ contaminants,ȱ whereasȱ noȱ correlationȱ wasȱfoundȱwithȱtheȱantioxidantsȱenzymes.ȱȱ 4.ȱDiscussionȱ Theȱ resultsȱ demonstrateȱ howȱ aȱ combinationȱ ofȱ multiȬbiomarkersȱ withȱ analyticalȱchemistryȱcanȱbeȱusedȱtoȱinvestigateȱtheȱtoxicityȱofȱmarineȱsediments,ȱ enablingȱ theȱ differentiationȱ ofȱ sitesȱ showingȱ differentȱ typesȱ ofȱ contamination.ȱ Thereȱ areȱ clearȱ relationshipsȱ inȱ sublethalȱ assaysȱ thatȱ canȱ beȱ relatedȱ toȱ theȱ putativeȱmodeȱofȱtoxicityȱofȱtheȱcontaminants.ȱȱ Phenanthrene,ȱ fluorene,ȱ pyreneȱ andȱ benzo[b]fluorantheneȱ areȱ theȱ predominantȱPAHsȱinȱsedimentsȱfromȱtheȱBayȱofȱAlgecirasȱwhichȱpresentedȱtheȱ highestȱ impactȱ inȱ theȱ organismsȱ exposed.ȱ Theseȱ compoundsȱ areȱ consideredȱ priorityȱ pollutantsȱ byȱ theȱ USEPAȱ onȱ theȱ basisȱ ofȱ theirȱ toxicity,ȱ frequencyȱ ofȱ occurrenceȱandȱpotentialȱforȱhumanȱexposureȱ(MingȬHoȱYu,ȱ2005).ȱItȱisȱknownȱ thatȱ PAHsȱ affectȱ organismsȱ throughȱ toxicȱ actionȱ byȱ theȱ interferenceȱ withȱ cellularȱ membraneȱ functionȱ andȱ inductionȱ ofȱ enzymeȱ systemsȱ associatedȱ withȱ theȱ membraneȱ (Albers,ȱ 2003).ȱ Althoughȱ unmetabolizedȱ PAHsȱ canȱ haveȱ toxicȱ effects,ȱaȱmajorȱconcernȱinȱanimalsȱisȱtheȱabilityȱofȱtheȱreactiveȱmetabolites,ȱsuchȱ asȱ epoxidesȱ andȱ dihydrodiols,ȱ ofȱ someȱ PAHsȱ toȱ bindȱ toȱ cellularȱ proteinsȱ andȱ DNAȱ(Albers,ȱ2003).ȱThisȱcanȱexplainȱtheȱelevationȱinȱDNAȱdamageȱdetectedȱinȱ thoseȱ organismsȱ exposedȱ toȱ sedimentsȱ fromȱ theȱ Bayȱ ofȱ Algeciras.ȱ ȱ Theȱ DNAȱ damageȱobservedȱinȱtheȱlugwormsȱlinksȱtoȱtheȱresultsȱobtainedȱinȱtheȱbehaviourȱ andȱcastsȱassaysȱconfirmingȱtheȱeffectsȱofȱtheȱtoxicantsȱonȱtheȱmetabolismȱandȱ conduct.ȱ Theseȱ resultsȱ areȱ inȱ accordȱ withȱ previousȱ studiesȱ whichȱ usedȱ otherȱ marineȱ speciesȱ andȱ demonstratedȱ thatȱ cometȱ assayȱ isȱ aȱ sensitiveȱ toolȱ forȱ monitoringȱtheȱgenotoxicȱeffectsȱofȱPAHsȱ(PérezȬCadahíaȱetȱal.,ȱ2004).ȱ - 170 - (a) Tra nsform: Fourth root Norma lise Resembla nce: D1 Euclidea n dista nce PAH 400 ch ch 1.6E3 ch ch P ch ch ch ch ch ch ch ch cont P P ch P P contcont P P cont controlcont cont P control cont P P P P P cont P P ch 2.8E3 ch 4E3 2D Stress: 0.16 (b) PCBs Tra nsform: Fourth root Norma lise Resembla nce: D1 Euclidea n dista nce 3 ch ch ch ch 12 P P ch ch ch ch ch ch cont P ch 21 ch P ch P P P cont contcont cont P P P P P cont cont P cont cont P ch ch 30 cont P 2D Stress: 0.16 Figureȱ 4.ȱ ȱ Twoȱ dimensionalȱ nonȬmetricȱ multidimensionalȱ scalingȱ plotsȱ forȱ biomarkerȱ responsesȱ inȱ Arenicolaȱ marinaȱ forȱ theȱ controlȱ sitesȱ (cont);ȱ chronicallyȱ pollutedȱ sitesȱ (ch)ȱ andȱ sitesȱ affectedȱ byȱ theȱ Prestigeȱ oilȱ spillȱ (P),ȱ overlaidȱ withȱ circlesȱ proportionalȱ inȱdiameterȱ toȱtheȱconcentrationȱatȱeachȱsiteȱ ofȱ(a)ȱPAH’sȱandȱ(b)ȱPCB’s.ȱ - 171 - ȱ Exposureȱ toȱ PAHsȱ canȱ leadȱ toȱ theȱ formationȱ ofȱ reactiveȱ oxygenȱ speciesȱ (ROS)ȱ whichȱ canȱ alsoȱ affectȱ immuneȱ functionȱ throughȱ lipidȱ peroxidationȱ andȱ membraneȱ destabilisationȱ ofȱ haemocytesȱ (Diȱ Guilioȱ etȱ al.,ȱ 1989,ȱ Gallowayȱ andȱ Goven,ȱ 2007).ȱ Thisȱ concursȱ withȱ observationsȱ ofȱ phagocyticȱ activityȱ fromȱ previousȱ workȱ withȱ invertebrateȱ speciesȱ (Komiyamaȱ etȱ al.,ȱ 2003).ȱ Theȱ correlationȱ betweenȱ organicȱ contaminantsȱ withȱ theȱ timeȱ ofȱ burrowingȱ inȱ theȱ sedimentȱ suggestsȱ aȱ chemosensoryȱ response,ȱ whereasȱ theȱ weightȱ ofȱ castsȱ decreaseȱseemsȱtoȱbeȱrelatedȱtoȱtheȱfeedingȱinhibitionȱbyȱtheȱpolychaete.ȱPCBsȱ haveȱ beenȱ linkedȱ withȱ PAHsȱ andȱ similarȱ relationshipȱ withȱ biomarkersȱ haveȱ beenȱ established.ȱ Thisȱ pointsȱ toȱ aȱ mixtureȱ ofȱ organicȱ pollutantsȱ whichȱ areȱ affectingȱ theȱ qualityȱ ofȱ sedimentsȱ andȱ supposeȱ anȱ environmentalȱ riskȱ inȱ theȱ areaȱofȱtheȱBayȱofȱAlgeciras.ȱ Theȱ metalȱ contentȱ alsoȱ showedȱ correlationsȱ withȱ theȱ analyzedȱ biomarkers.ȱ Niȱ showsȱ aȱ strongȱ relationshipȱ withȱ DNAȱ damageȱ (0.79),ȱ theȱ phagocyticȱ response,ȱ theȱ burialȱ behaviourȱ andȱ casts.ȱ Copperȱ showedȱ aȱ relationshipȱwithȱtheȱ antioxidantȱactivityȱanalyzedȱinȱtheȱTBARSȱassay,ȱwhichȱ measuresȱoneȱofȱtheȱterminalȱproductsȱinȱtheȱperoxidativeȱbreakdownȱofȱlipids.ȱ Theȱ inductionȱ ofȱ lipidȱ peroxidationȱ byȱ copperȱ isȱ wellȬknownȱ inȱ otherȱ invertebratesȱ (Viarengo,ȱ 1989)ȱ andȱ theȱ TBARSȱ activityȱ hasȱ beenȱ previouslyȱ associatedȱ withȱ Cuȱ (Quiniouȱ etȱ al.,ȱ 2007).ȱ Weakerȱ correlationsȱ wereȱ alsoȱ detectedȱ amongȱ antioxidantȱ biomarkers:ȱ FRAPȱ associatesȱ withȱ GSTȱ andȱ GRȱ whereasȱ TBARSȱ linksȱ withȱ GRȱ activity;ȱ howeverȱ noȱ relationshipsȱ wereȱ observedȱforȱtheȱGPXȱantioxidantȱenzymeȱwithȱotherȱbiomarkersȱorȱpollutants.ȱ Thisȱsuggestsȱcombinedȱregulationȱofȱtheseȱresponses.ȱ AfterȱtheȱPrestigeȱoilȱspillȱinvestigationsȱhaveȱaddressedȱinȱdeterminingȱ theȱ biologicalȱ effectsȱ andȱ environmentalȱ statusȱ afterȱ theȱ accidentȱ byȱ followingȱ - 172 - singleȱ linesȱ ofȱ evidence,ȱ suchȱ asȱ chemicalȱ analysesȱ [(CSIC,ȱ 2003;ȱ Francoȱ etȱ al.,ȱ 2006;ȱGonzálezȱetȱal.,ȱ2006)ȱandȱtoxicityȱincludingȱbiomarkersȱ(MariñoȬBalsaȱetȱ al.,ȱ2003;ȱMartínezȬGómezȱetȱal.,ȱ2006;ȱMarigómezȱetȱal.,ȱ2006)ȱhoweverȱlittleȱhasȱ beenȱdoneȱwithȱtheȱcombinationȱofȱbothȱfieldsȱ(MoralesȬCasellesȱ2006;ȱMoralesȬ Caselles,ȱaccepted2).ȱInȱadditionȱmostȱofȱtheȱbiologicalȱassessmentsȱcarriedȱoutȱ towardsȱtheȱPrestigeȱhaveȱbeenȱconductedȱinȱsitu,ȱunderȱfield;ȱunderȱcontrolledȱ conditionsȱ inȱ theȱ laboratory,ȱ itȱ isȱ relativelyȱ straightforwardȱ toȱ standardiseȱ biomarkerȱ assaysȱ andȱ toȱ regulateȱ theȱ chemicalȱ exposuresȱ thatȱ organismsȱ receive,ȱ soȱ thatȱ causeȬeffectȱ andȱ indeed,ȱ exposureȬrelationships,ȱ canȱ beȱ establishedȱ(Astleyȱetȱal.,ȱ1999).ȱȱ LessȱattentionȱthanȱtheȱplayedȱinȱtheȱPrestigeȱaccidentȱhasȱbeenȱfocusedȱ towardsȱ theȱ chronicȱ pollutionȱ ofȱ theȱ Bayȱ ofȱ Algecirasȱ inȱ recentȱ years.ȱ Theȱ methodologyȱ employedȱ inȱ thisȱ studyȱ hasȱ shownȱ howȱ thisȱ areaȱ isȱ muchȱ moreȱ pollutedȱandȱbiologicalȱeffectsȱonȱkeyȱinvertebratesȱexposedȱtoȱtheirȱsedimentsȱ haveȱ beenȱ demonstrated.ȱ Otherȱ studiesȱ basedȱ onȱ theȱ Exxonȱ Valdezȱ oilȱ spillȱ suggestedȱaȱrecoveryȱyearsȱafterȱtheȱepisodeȱandȱtheȱprevelanceȱofȱtheȱchronicȱ pollutionȱdueȱtoȱtheȱhumanȱandȱindustrialȱactivitiesȱ(BoehmȱandȱPage,ȱ2007).ȱ Researchȱ methodsȱ basedȱ inȱ biomarkersȱ haveȱ notȱ yetȱ beenȱ validatedȱ forȱ applicationȱasȱaȱmonitoringȱmethodȱforȱoilȱspillsȱinȱaȱsystematicȱfashionȱ(Boehmȱ andȱ Page,ȱ 2007).ȱ Theȱ selectedȱ biomarkersȱ analyzedȱ showsȱ importantȱ relationshipsȱ withȱ pollutantsȱ andȱ theȱ proposedȱ methodologyȱ whichȱ integratesȱ differentȱvariablesȱasȱpartȱofȱaȱweightȱofȱevidenceȱapproachȱhasȱdemonstratedȱ toȱbeȱaȱsuitableȱtoolȱinȱoilȱspillȱassessmentsȱcomingȱfromȱdifferentȱsources.ȱ Theȱ bioassayȱ performedȱ withȱ anȱ invertebrateȱ especieȱ thatȱ livesȱ inȱ theȱ sediment,ȱ theȱ polychaeteȱ Arenicolaȱ marina,ȱ resultsȱ toȱ beȱ relativelyȱ simple,ȱ rapid,ȱ economicȱ andȱ appropiateȱ toȱ testȱ theȱ environmentalȱ statusȱ ofȱ anȱ oilȬ - 173 - contamiantedȱ sediment.ȱ Thisȱ organismȱ hasȱ beenȱ oftenȱ usedȱ onȱ monitoringȱ programs;ȱ however,ȱ theȱ applicationȱ ofȱ suitesȱ ofȱ assaysȱ andȱ chemistryȱ areȱ illustratedȱhereȱforȱtheȱfirstȱtimeȱtoȱthisȱpolychaete.ȱTheseȱhaveȱtheȱpotentialȱtoȱ chartȱrecoveryȱafterȱoilȱspillsȱandȱhaveȱallowedȱtheȱdifferentiationȱofȱsitesȱwithȱ differentȱtypesȱofȱcontamination:ȱtheȱacutelyȱ(Prestige)ȱandȱchronicallyȱ(Bayȱofȱ Algeciras)ȱ affectedȱ areasȱ andȱ theȱ referenceȱ sites.ȱ Theȱ Cometȱ assayȱ hasȱ demonstratedȱ toȱ beȱ theȱ mostȱ sensitiveȱ ofȱ theȱ studiedȱ endpoints,ȱ showingȱ importantȱ correlationsȱ withȱ theȱ mainȱ contaminants.ȱ Authorsȱ considerȱ theȱ suitabilityȱ ofȱ theȱ usingȱ theseȱ toolsȱ inȱ assessingȱ environmentalȱ qualityȱ assessmentȱandȱtoȱchartȱrecoveryȱinȱareasȱaffectedȱbyȱoilȱspills.ȱ 5.ȱAcknowledgmentsȱ Supportedȱ byȱ Ministryȱ ofȱ Educationȱ andȱ Scienceȱ grantȱ VEM2003Ȭ20563,ȱ EUȱ FP7ȱ FACEȬiTȱ grantȱ andȱ byȱ CISȱ fundedȱ byȱ theȱ Ministryȱ ofȱ Environment.ȱ Carmenȱ MoralesȬCasellesȱ thanksȱ theȱ Ministryȱ ofȱ Educationȱ andȱ Scienceȱ forȱ fundingȱherȱresearchȱfellowshipȱ(FPU).ȱWeȱareȱgratefulȱforȱtheȱsupportȱandȱhelpȱ ofȱtheȱmembersȱofȱtheȱCISȱandȱtheȱSchoolȱofȱBiologicalȱSciencesȱ(Universityȱofȱ Plymouth).ȱSpecialȱthanksȱareȱgivenȱtoȱChristopherȱPookȱandȱTrevorȱWorsey.ȱȱ 6.ȱReferencesȱ Albersȱ P.H.ȱ Petroleumȱ andȱ individualȱ polycyclicȱ aromaticȱ hydrocarbons.ȱ In:ȱ Hoffmanȱ DJ,ȱ Rattnerȱ BA,ȱ Burtonȱ GA,ȱ Cairnsȱ Jȱ (eds)ȱ Handbookȱ ofȱ ecotoxicology.ȱLewisȱPublishers,ȱBocaȱRaton,ȱFLȱChaptȱ14,ȱ2003.ȱ Anderson,ȱ R.S.,ȱ Mora,ȱ L.M.ȱ Phagocytosis:ȱ aȱ microtiterȱ plateȱ assay.ȱ In:ȱ TechniquesȱinȱFishȱImmunology.ȱImmunologyȱandȱPathologyȱofȱAquaticȱ Invertebrates.ȱSOSȱPublications,ȱFairȱHaven,ȱNJ,ȱUSA.ȱ1995,ȱ109Ȭ112.ȱ - 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179 - Selck,ȱ H.,ȱ Palmqvist,ȱ A.,ȱ Forbes,ȱ V.E.ȱ Uptake,ȱ depuration,ȱ andȱ toxicityȱ ofȱ dissolvedȱandȱsedimentȬboundȱfluorantheneȱinȱtheȱpolychaete,ȱCapitellaȱ sp.I.ȱEnviron.ȱToxicol.ȱChem.ȱ2003,ȱ22,ȱ2354Ȭ2363ȱȱ Thain,ȱ J.E.,ȱ Bifield,ȱ S.ȱ Biologicalȱ effectsȱ ofȱ contaminants:ȱ Sedimentȱ bioassayȱ usingȱ theȱ polychaeteȱ Arenicolaȱ marina.ȱ Techniquesȱ inȱ Marineȱ Environmentalȱ Science,ȱ 2002,ȱ 29,ȱ Internationalȱ Councilȱ forȱ theȱ ExplorationȱofȱtheȱSea,ȱCopenhagen,ȱ1Ȭ17.ȱ USEPA.ȱ Methodsȱ forȱ Assessingȱ theȱ Toxicityȱ ofȱ SedimentȬassociatedȱ Contaminantsȱ withȱ Estuarineȱ andȱ Marineȱ Amphipods.ȱ Unitedȱ Statesȱ EnvironmentalȱProtectionȱAgencyȱ(USEPA).ȱEPA/600/RȬ94/025.ȱ1994.ȱ Viarengoȱ A.ȱHeavyȱ metalsȱinȱ marineȱinvertebratesȱ:ȱmechanismsȱofȱregulationȱ andȱtoxicityȱatȱcellularȱlevel.ȱRevȱAquatȱSciȱ1989;1:295–317.ȱ ȱ - 180 - ȱ Capítuloȱ4.ȱ Evaluaciónȱdeȱefectosȱsubletalesȱinȱsituȱ Laȱ calidadȱ deȱ losȱ ecosistemasȱ costerosȱ seȱ haȱ evaluadoȱ tradicionalmenteȱ siguiendoȱ unaȱ metodologíaȱ clásicaȱ queȱ incluyeȱ elȱ muestreoȱ deȱ especiesȱ autóctonas,ȱelȱestudioȱdeȱlasȱcomunidadesȱbentónicasȱoȱlaȱdeterminaciónȱdeȱlaȱ toxicidadȱ bajoȱ condicionesȱ deȱ laboratorioȱ (Burtonȱ Jrȱ etȱ al.,ȱ 2005).ȱ Estaȱ serieȱ deȱ estudiosȱresultanȱmuyȱútilesȱyȱenȱocasionesȱesenciales,ȱaunqueȱpresentanȱciertasȱ limitacionesȱ(Tablaȱ1)ȱ(ej.ȱChapmanȱetȱal.,ȱ1992;ȱBurtonȱetȱal.,ȱ1996;ȱGrotheȱetȱal.,ȱ 1996).ȱ Elȱ estudioȱ deȱ laȱ toxicidadȱ inȱ situȱ medianteȱ organismosȱ enȱ jaulasȱ proporcionaȱlaȱinformaciónȱqueȱfaltaȱenȱlosȱestudiosȱtradicionalesȱ(BurtonȱJrȱetȱ al.,ȱ2005). Laȱventajaȱprincipalȱdeȱlaȱexposiciónȱdeȱlosȱorganismosȱaȱlosȱsedimentosȱ deȱestudioȱmedianteȱelȱusoȱdeȱjaulasȱradicaȱenȱlaȱobtenciónȱdeȱunaȱinformaciónȱ sobreȱlaȱtoxicidadȱdeȱlosȱsedimentosȱevaluadaȱbajoȱcondicionesȱnoȱcontroladas,ȱ queȱ noȱ sóloȱ permitenȱ estudiarȱ laȱ toxicidadȱ producidaȱ porȱ losȱ contaminantesȱ presentesȱenȱelȱsedimento,ȱsinoȱqueȱpermiteȱevaluarȱelȱefectoȱproducidoȱporȱlasȱ variacionesȱ fisicoquímicasȱ aȱ lasȱ queȱ seȱ veȱ sometidoȱ elȱ medioȱ yȱ queȱ puedenȱ afectarȱaȱlaȱdisponibilidadȱdeȱlosȱcontaminantesȱ(MartínȬDíaz,ȱ2004).ȱAȱpesarȱdeȱ lasȱdificultadesȱdeȱlaȱrealizaciónȱdeȱaproximacionesȱinȱsituȱestasȱpermitenȱllevarȱ aȱ caboȱ unaȱ evaluaciónȱ másȱ realistaȱ deȱ losȱ efectosȱ biológicosȱ producidosȱ porȱ contaminantesȱ delȱ medio.ȱ Ademásȱ esteȱ tipoȱ deȱ estudiosȱ sonȱ capacesȱ deȱ ȱ Ȭȱ181ȱȬȱ Capítuloȱ4 identificarȱ fuentesȱ deȱ poluciónȱ ajenasȱ alȱ sedimentoȱ peroȱ queȱ puedenȱ serȱ laȱ causaȱdeȱalteracionesȱbentónicasȱenȱelȱmedio,ȱyȱnoȱseȱpuedenȱdetectarȱmedianteȱ laȱconsecuciónȱdeȱexperimentosȱdeȱlaboratorioȱaislados. Tablaȱ 4.1.ȱ Ventajasȱ yȱ limitacionesȱ deȱ losȱ métodosȱ tradicionalesȱ deȱ evaluaciónȱdeȱlaȱcalidadȱdeȱecosistemasȱcosterosȱ(segúnȱBurtonȱJrȱetȱal.,ȱ2005)ȱ Metodologíaȱ Ventajasȱ Limitacionesȱprincipalesȱ GuíasȱQuímicasȱ Fácilesȱyȱestandarizadas.ȱ Extrapolacionesȱaȱcampoȱyȱotrasȱ especies.ȱEspecíficasȱdeȱlaȱzona.ȱ Basadasȱenȱestudiosȱdeȱ laboratorio.ȱȱ Biotaȱautóctonaȱ Ampliamenteȱutilizada.ȱ Reflejaȱlosȱefectos.ȱInterésȱ público.ȱ Variabilidad.ȱEfectosȱindirectos.ȱ Causasȱnaturalesȱdeȱestrésȱqueȱ dificultanȱinterpretación.ȱ Ensayosȱdeȱtoxicidadȱenȱ laboratorioȱ Ampliamenteȱutilizados.ȱ Integraȱefectosȱdeȱ contaminantesȱaȱcortoȱplazo.ȱ Estandarizados.ȱȱ Lasȱcondicionesȱnoȱsonȱigualesȱaȱ lasȱnaturalesȱenȱȱcampo.ȱȱ Bioacumulaciónȱ Exposicionesȱrealistas.ȱÚtilesȱ paraȱelaborarȱmodelosȱdeȱ redesȱtróficas.ȱMedidasȱaȱ largoȱplazo.ȱUtilizadasȱ tradicionalmente.ȱ Metabolismoȱyȱexcreciónȱdeȱ algunosȱquímicos.ȱLaȱ aclimatación,ȱȱadaptaciónȱyȱlosȱ metalesȱesencialesȱpuedenȱ confundirȱlaȱinterpretaciónȱdeȱlosȱ efectosȱobservados.ȱȱȱ Enȱelȱcapítuloȱ4ȱseȱpresentanȱcuatroȱartículos,ȱdeȱlosȱcualesȱelȱtrabajoȱX,ȱ XIȱ yȱ XIIȱ muestranȱ losȱ resultadosȱ deȱ medidasȱ deȱ biomarcadoresȱ trasȱ exposicionesȱenȱcampoȱdeȱdosȱespeciesȱdeȱinvertebrados.ȱEnȱprimerȱlugar,ȱenȱelȱ trabajoȱ Xȱ seȱ recogenȱ losȱ resultadosȱ deȱ laȱ instalaciónȱ deȱ jaulasȱ enȱ puntosȱ deȱ estudioȱ delȱ Golfoȱ deȱ Cádizȱ yȱ laȱ Costaȱ deȱ Galicia.ȱ Enȱ esteȱ estudioȱ seȱ seleccionaronȱ dosȱ especiesȱ deȱ invertebradosȱ marinosȱ conȱ hábitosȱ distintosȱ deȱ alimentación,ȱelȱcangrejoȱCarcinusȱmaenasȱyȱlaȱalmejaȱRuditapesȱPhilippinarum.ȱSeȱ realizóȱunaȱexposiciónȱdeȱ28ȱdíasȱtrasȱlosȱcualesȱseȱllevaronȱaȱcaboȱmedidasȱdeȱ biomarcadoresȱ deȱ exposiciónȱ (actividadȱ EROD,ȱ GPX,ȱ GSTȱ yȱ GR)ȱ yȱ unȱ biomarcadorȱ deȱ efectoȱ (histopatología).ȱ Esteȱ experimentoȱ seȱ reprodujoȱ bajoȱ - 182 - Evaluaciónȱdeȱefectosȱsubletalesȱinȱsituȱ condicionesȱ deȱ laboratorioȱ comoȱ seȱ explicaȱ enȱ elȱ Capítuloȱ 3.ȱ Alȱ compararȱ losȱ resultadosȱ obtenidosȱ enȱ esteȱ experimentoȱ inȱ situȱ conȱ elȱ descritoȱ enȱ elȱ capítuloȱ anteriorȱ desarrolladoȱ bajoȱ condicionesȱ deȱ laboratorio,ȱ comprobamosȱ comoȱ laȱ inducciónȱ deȱ losȱ biomarcadoresȱ deȱ exposiciónȱ seȱ dabaȱ mayormenteȱ enȱ losȱ organismosȱ expuestosȱ enȱ jaulasȱ ancladasȱ enȱ laȱ Bahíaȱ deȱ CormeȬLaxe,ȱ enȱ lugarȱ deȱdarseȱenȱlosȱindividuosȱlocalizadosȱenȱlaȱzonaȱdeȱAlgeciras,ȱmientrasȱqueȱlosȱ dañosȱ histopatológicosȱ “seȱ suavizaban”ȱ enȱ lasȱ exposicionesȱ enȱ campo.ȱ Esteȱ hechoȱ puedeȱ significarȱ variasȱ cosas:ȱ a)ȱ que,ȱ enȱ general,ȱ losȱ efectosȱ biológicosȱ bajoȱ condicionesȱ deȱ campoȱ sonȱ menoresȱ queȱ enȱ laboratorio,ȱ debidoȱ aȱ laȱ renovaciónȱ continuaȱ deȱ aguaȱ queȱ disminuyeȱ laȱ biodisponibilidadȱ deȱ losȱ contaminantes;ȱ b)ȱ queȱ lasȱ desembocadurasȱ deȱ losȱ ríosȱ Guadarranqueȱ yȱ PalmonesȱenȱAlgeciras,ȱsujetosȱaȱunȱimportanteȱrégimenȱmareal,ȱsuponganȱunaȱ renovaciónȱ mayorȱ deȱ agua;ȱ c)ȱ queȱ dadaȱ laȱ mezclaȱ complejaȱ deȱ contaminantesȱ noȱmedidosȱenȱesteȱestudioȱpresentesȱenȱlosȱsedimentosȱyȱposiblementeȱtambiénȱ enȱlasȱaguasȱdeȱlaȱBahíaȱdeȱAlgecirasȱseȱdenȱfenómenosȱdeȱsolapamientoȱentreȱ laȱ inducción/inhibiciónȱ deȱ losȱ biomarcadores;ȱ d)ȱ queȱ losȱ factoresȱ abióticosȱ afectenȱsignificativamenteȱaȱlaȱinducciónȱdeȱbiomarcadores,ȱprincipalmenteȱenȱ laȱdesembocaduraȱdeȱlosȱríosȱenȱAlgeciras;ȱe)ȱqueȱlaȱaltaȱpresenciaȱdeȱbateasȱenȱ laȱ Bahíaȱ deȱ CormeȬLaxeȱ supongaȱ unȱ estrésȱ aȱ laȱ biotaȱ debidoȱ aȱ posiblesȱ sustanciasȱcontaminantesȱenȱpiensosȱoȱaȱlaȱaltaȱcargaȱorgánicaȱȱdelȱagua,ȱyȱqueȱ expliquenȱ porȱ tanto,ȱ laȱ notableȱ inducciónȱ deȱ losȱ biomarcadoresȱ deȱ exposiciónȱ observadosȱ bajoȱ condicionesȱ deȱ campoȱ yȱ queȱ noȱ fueronȱ vistosȱ trasȱ losȱ experimentosȱ deȱ laboratorio.ȱ Paraȱ completarȱ esteȱ estudioȱ seȱ realizóȱ unaȱ evaluaciónȱ deȱ laȱ cinéticaȱ deȱ variosȱ biomarcadoresȱ enȱ laȱ almejaȱ Ruditapesȱ Philippinarum,ȱtalȱyȱcomoȱseȱmuestraȱenȱelȱtrabajoȱXI,ȱaclarandoȱdeȱmaneraȱmásȱ efectivaȱ lasȱ posiblesȱ fuentesȱ deȱestrés;ȱasimismo,ȱseȱrealizóȱunȱestudioȱcinéticoȱ deȱlasȱenzimasȱimplicadasȱenȱlaȱdetoxificaciónȱdeȱPAHȱenȱelȱcangrejoȱCarcinusȱ maenasȱ(trabajoȱXII).ȱ Ȭ 183ȱȬ Capítuloȱ4 ȱ ȱ ȱ ȱ boya ȱ aguaȱ ȱ ȱ ȱ ȱ ȱ pesosȱ ȱ ȱ sedimentoȱ anclaje ȱ Figuraȱ 4.1.ȱ Esquemaȱ deȱ anclajeȱ yȱ utilizaciónȱ deȱ jaulasȱ bentónicasȱ utilizadasȱenȱlosȱbioensayosȱenȱcampo.ȱ Elȱúltimoȱtrabajoȱdeȱesteȱcapítulo,ȱXIII,ȱincluyeȱunaȱlíneaȱdeȱestudioȱajenaȱ aȱ losȱ bioensayosȱ peroȱ deȱ granȱ importancia.ȱ Enȱ esteȱ trabajoȱ seȱ evalúaȱ laȱ alteraciónȱdeȱlaȱfaunaȱbentónicaȱdeȱlasȱáreasȱdeȱestudioȱconȱelȱfinȱdeȱrelacionarȱ losȱ efectosȱ deȱ laȱ biotaȱ autóctonaȱ conȱ losȱ contaminantesȱ presentesȱ enȱ losȱ sedimentos.ȱ Deȱ estaȱ maneraȱ seȱ cubreȱ unaȱ deȱ lasȱ líneasȱ clásicasȱ dentroȱ deȱ losȱ estudiosȱ deȱ calidadȱ ambientalȱ deȱ losȱ sedimentos.ȱ Enȱ esteȱ trabajoȱ seȱ observaȱ comoȱ inicialmenteȱ laȱ macrofaunaȱ bentónicaȱ deȱ lasȱ costasȱ gallegasȱ seȱ vioȱ afectadaȱ porȱ elȱ vertidoȱ delȱ petroleroȱ Prestige,ȱ aunqueȱ seȱ describeȱ unaȱ recuperaciónȱimportanteȱqueȱhaȱsidoȱfinalmenteȱcomparadaȱconȱlaȱsituaciónȱdeȱ laȱ biotaȱ deȱ laȱ zonasȱ deȱ estudioȱ localizadasȱ elȱ laȱ Bahíaȱ deȱ Algeciras,ȱ dondeȱ elȱ - 184 - Evaluaciónȱdeȱefectosȱsubletalesȱinȱsituȱ impactoȱ delȱ conjuntoȱ deȱ fuentesȱ contaminantesȱ suponeȱ unȱ impactoȱ ambientalȱ muchoȱmayor.ȱ Bibliografíaȱ BurtonȱJr.,ȱG.A.,ȱGreenberg,ȱM.S.,ȱRowland,ȱ C.D.,ȱ Irvine,ȱ C.A.,ȱ Lavoie,ȱ D.R.,ȱ Brooker,ȱ J.A.,ȱ Delia,ȱ L.M.,ȱ Raymer,ȱ F.N.,ȱ McWilliam.ȱ2005.ȱInȱsituȱexposuresȱusingȱ cagedȱ organisms:ȱ aȱ multiȬcompartmentȱ approachȱ toȱ detectȱ aquaticȱ toxicityȱ andȱ bioaccumulation.ȱ Environ.ȱ Pollut.ȱ 134,ȱ 133–144.ȱ Burton,ȱ G.A.,ȱ Hickey,ȱ C.W.,ȱ DeWitt,ȱ T.H.,ȱ Roper,ȱ D.S.,ȱ Morrisey,ȱ D.J.,ȱ Nipper,ȱ M.,ȱ 1996.ȱ Inȱ situȱ toxicityȱ testing:ȱ teasingȱ outȱ environmentalȱstressors.ȱSETACȱNewsȱ16ȱ (5),ȱ20–22.ȱ Grothe,ȱ D.R.,ȱ Dickson,ȱ K.L.,ȱ ReedȬJudkins,ȱ D.K.,ȱ 1996.ȱ Wholeȱ Effluentȱ Toxicityȱ Testing:ȱ Anȱ Evaluationȱ ofȱ Methodsȱ andȱ Predictionȱ ofȱ Receivingȱ Systemȱ Impacts.ȱ SETACȱPress,ȱBocaȱRaton,ȱFL,ȱpp.ȱ346.ȱ MartínȬDíaz,ȱ L.ȱ 2004.ȱ Determinaciónȱ deȱ laȱ calidadȱ ambientalȱ deȱ sistemasȱ litoralesȱ yȱ deȱ estuarioȱ deȱ laȱ penínsulaȱ ibéricaȱ utilizandoȱ ensayosȱ deȱ campoȱ yȱ laboratorio.ȱTesisȱDoctoral.ȱȱ ȱ ȱ Chapman,ȱ P.M.,ȱ Power,ȱ E.A.,ȱ Burtonȱ Jr.,ȱ G.A.,ȱ 1992.ȱ Integratedassessmentsȱ inȱ aquaticȱ ecosystems.ȱ In:ȱ Burton,ȱ G.A.ȱ (Ed.),Sedimentȱ Toxicityȱ Assessment.ȱ LewisȱPublishers,ȱBocaȱRaton,ȱFL.ȱ ȱ Ȭ 185ȱȬ ȱ ȱ ȱ ȱ Ȭȱ186ȱȬȱ Sublethalȱresponsesȱinȱcagedȱorganismsȱexposedȱtoȱsedimentsȱ affectedȱbyȱoilȱspillsȱ CarmenȱMoralesȬCaselles1,2,*,ȱM.ȱLauraȱMartínȬDíaz1,2,ȱInmaculadaȱRiba1,2,ȱ CarmenȱSarasquete1,ȱT.ȱÁngelȱDelVallsȱ1,2ȱ 1 IȱUnidadȱAsociadaȱdeȱCalidadȱAmbientalȱyȱPatologíaȱ(CSICȱ&ȱUCA)ȱinstitutoȱ deȱCienciasȱMarinasȱdeȱAndalucíaȱ(ICMANȬCSIC),ȱAvda.ȱRepúblicaȱSaharauiȱs/n,ȱ PuertoȱRealȱ11510,ȱCádiz,ȱSpainȱ 2 UNESCOȱUNITWIN/WiCop,ȱFacultadȱdeȱCienciasȱdelȱMarȱyȱAmbientales,ȱ UniversidadȱdeȱCádiz,ȱPolígonoȱRíoȱSanȱPedroȱs/n,ȱPuertoȱRealȱ11510,ȱCádiz,ȱSpain.ȱ Abstractȱ Theȱ currentȱ studyȱ wasȱ performedȱ toȱ determineȱ sublethalȱ responsesȱ inȱ twoȱ invertebrateȱ speciesȱ byȱ usingȱ fieldȱ deploymentsȱ inȱ areasȱ affectedȱ byȱ oilȱ spills,ȱ acuteȱ inȱ theȱ Galicianȱ Coastȱ (NNW,ȱ Spain)ȱ andȱ chronicȱ inȱ theȱ Bayȱ ofȱ Algecirasȱ(SSW,ȱSpain).ȱTheȱorganismsȱemployedȱwereȱtheȱcrabȱCarcinusȱmaenasȱ andȱ theȱ clamȱ Ruditapesȱ philippinarum.,ȱ andȱ duringȱ 28ȱ daysȱ theȱ animalsȱ wereȱ exposedȱ inȱ cagesȱ underȱ fieldȱ conditionsȱ toȱ contaminatedȱ sediments.ȱ Differentȱ biomarkersȱ ofȱ exposureȱ wereȱ determinedȱ afterȱ 28Ȭdayȱ exposure:ȱ ethoxyresorufinȱ OȬdeethylaseȱ (EROD),ȱ phaseȱ Iȱ detoxificationȱ enzyme,ȱ glutathioneȬSȬtransferaseȱ (GST)ȱ phaseȱ IIȱ detoxificationȱ enzymeȱ butȱ alsoȱ implicatedȱ inȱ oxidativeȱ stressȱ events,ȱ glutathioneȱ peroxidaseȱ (GPX)ȱ andȱ glutathioneȱ reductaseȱ (GR),ȱ bothȱ antioxidantȱ enzymes.ȱ Inȱ additionȱ histopathologicalȱ effectsȱ inȱ targetȱ tissuesȱ ofȱ theȱ deployedȱ organismsȱ wereȱ evaluated.ȱ Biomarkersȱ measurementsȱ wereȱ linkedȱ withȱ theȱ concentrationȱ ofȱ chemicalsȱ inȱ theȱ sedimentsȱ inȱ orderȱ toȱ elucidateȱ theȱ type,ȱ sourceȱ andȱ bioavailabilityȱ ofȱ contaminantsȱ producingȱ adverseȱ effectsȱ inȱ theȱ bioindicatorȱ species.ȱResultsȱobtainedȱinȱtheȱpresentȱstudyȱhaveȱshownȱhowȱtheȱapplicationȱ ofȱ theȱ selectedȱ batteryȱ ofȱ biomarkersȱ underȱ fieldȱ bioassaysȱ allowsȱ identifyingȱ alternativeȱ sourcesȱ ofȱ stressȱ thatȱ areȱ notȱ possibleȱ toȱ observeȱ inȱ laboratoryȱ experiments.ȱ Keywords:ȱbiomarker,ȱhistopathology,ȱinvertebrate,ȱtoxicity,ȱcontaminantsȱȱ ȱChemosphereȱ(enviado) - 187 - 1.ȱIntroductionȱ Measurementsȱ ofȱ anȱ organisms’ȱ responseȱ toȱ aȱ pollutantȱ atȱ theȱ biochemicalȱorȱphysiologicalȱlevelȱcanȱdetectȱmoreȱquicklyȱandȱspecificallyȱtheȱ presenceȱ ofȱ toxicȱ compounds,ȱ allowingȱ earlierȱ identificationȱ ofȱ change,ȱ beforeȱ deleteriousȱ effectsȱ reachȱ higherȱ organizationȱ levelsȱ (Montserratȱ etȱ al.,ȱ 2003).ȱ Overȱ theȱ pastȱ decade,ȱ biomarkersȱ haveȱ beenȱ usedȱ increasinglyȱ asȱ diagnosticȱ toolsȱ toȱ investigateȱ sublethalȱ effectsȱ ofȱ toxicȱ exposureȱ andȱ toȱ elucidateȱ theȱ variousȱmodesȱofȱactionȱofȱxenobioticsȱ(DeȱCoenȱetȱal.,ȱ2000).ȱTheȱapplicationȱofȱ biomarkersȱunderȱfieldȱconditionsȱhasȱbeenȱproposedȱbyȱmanyȱauthorsȱinȱorderȱ toȱ assessȱ chronicȱ responsesȱ inȱ aquaticȱ populationsȱ exposedȱ underȱ environmentalȱ realisticȱ conditionsȱ (Suter,ȱ 1993;ȱ Depledgeȱ andȱ Fossi,ȱ 1994;ȱ Deȱ Coenȱ etȱ al.,ȱ 2006;ȱ MartínȬDíazȱ etȱ al.,ȱ inȱ press).ȱ Fieldȱ studiesȱ poseȱ farȱ greaterȱ difficultiesȱdueȱtoȱtheȱcomplexȱandȱfluctuatingȱnatureȱofȱtheȱenvironment,ȱandȱ interactionsȱ amongȱ organismsȱ withinȱ ecologicalȱ communities.ȱ ȱ Theyȱ addressȱ theȱ integratedȱ impactȱ ofȱ anthropogenicȱ andȱ environmentalȱ stressors.ȱ Dataȱ collectedȱ inȱ fieldȱ studiesȱ mayȱ beȱ muchȱ harderȱ toȱ interpretȱ thanȱ dataȱ fromȱ controlledȱ laboratoryȱ experimentsȱ (Astleyȱetȱalȱ1999).ȱ Itȱisȱalsoȱhighlightedȱtheȱ potentialȱ useȱ ofȱ inȱ situȱ assaysȱ toȱ determineȱ theȱ toxicityȱ ofȱ sedimentsȱ usingȱ differentȱ approachesȱ includingȱ cagingȱ animalsȱ (MartínȬDíaz,ȱ 2004).ȱ Sedimentȱ toxicityȱ bioassaysȱ carriedȱ outȱ inȱ theȱ laboratoryȱ areȱ performedȱ underȱ strictlyȱ controlledȱ parametersȱ andȱ thusȱ doȱ notȱ reflectȱ theȱ variabilityȱ inȱ exposureȱ thatȱ mayȱoccurȱinȱnaturalȱsystems.ȱThisȱgivesȱriseȱtoȱuncertaintyȱinȱtheȱextrapolationȱ ofȱ laboratoryȬbasedȱ testȱ resultsȱ toȱ naturalȱ environmentsȱ inȱ sedimentȱ riskȱ assessmentȱ(Sibleyȱetȱal,ȱ1999).ȱ Inȱorderȱtoȱevaluateȱtheȱexposureȱofȱcontaminantsȱrelatedȱtoȱoilȱspillsȱinȱ theȱ organismsȱ usingȱ inȱ situȱ deploymentsȱ andȱ aȱ biomarkerȱ approach,ȱ theȱ objectivesȱwereȱ asȱ follows:ȱ (1)ȱ toȱ testȱtheȱfeasibilityȱofȱaȱsuiteȱofȱbiomarkersȱtoȱ assessȱ theȱ oilȬcontaminatedȱ sedimentȱ qualityȱ (2)ȱ toȱ identifyȱ theȱ contaminantsȱ - 188 - boundȱ toȱ sedimentsȱ whichȱ produceȱ theȱ sublethalȱ effectsȱ inȱ theȱ organismsȱ exposedȱ (3)ȱ toȱ determineȱ theȱ differencesȱ betweenȱ theȱ biologicalȱ responsesȱ associatedȱ withȱ aȱ deploymentȱ toȱ acutelyȱ andȱ chronicallyȱ oilȱ contaminatedȱ sediments.ȱȱ Aȱbatteryȱofȱbiomarkersȱofȱexposureȱofȱearlyȱbiologicalȱeffectsȱwasȱusedȱ inȱorderȱtoȱassessȱsedimentȱtoxicityȱofȱtwoȱcoastalȱareasȱaffectedȱbyȱoilȱspills,ȱtheȱ GalicianȱCoast,ȱacutelyȱimpactedȱbyȱtheȱsinkingȱofȱtheȱtankerȱPrestigeȱ(2002)ȱandȱ theȱ Bayȱ ofȱ Algecirasȱ chronicallyȱ affectedȱ byȱ severalȱ spills.ȱ Twoȱ invertebrateȱ speciesȱwithȱdifferentȱfeedingȱhabitsȱwereȱselectedȱtoȱcarryȱoutȱtheȱassessment,ȱ theȱ crabȱ Carcinusȱ maenasȱ andȱ theȱ clamȱ Ruditapesȱ philippinarum.ȱ Theȱ suiteȱ ofȱ biomarkersȱ employedȱ was:ȱ Ethoxyresorufinȱ OȬdeethylaseȱ (EROD),ȱ phaseȱ Iȱ detoxificationȱenzymeȱimplicatedȱinȱmonooxygenationȱreactionsȱofȱdioxinsȱandȱ PAHs;ȱ glutathioneȬSȬtransferaseȱ(GST)ȱphaseȱIIȱdetoxificationȱenzymeȱbutȱalsoȱ implicatedȱ inȱ oxidativeȱ stressȱ events;ȱ glutathioneȱ peroxidaseȱ (GPX)ȱ andȱ glutathioneȱreductaseȱ(GR),ȱantioxidantȱenzymesȱ(MartínȬDíazȱetȱal.,ȱinȱpress).ȱ Histopathologicalȱalterationsȱinȱtargetȱtissuesȱwereȱalsoȱevaluatedȱbecauseȱitȱhasȱ shownȱtoȱbeȱresponsiveȱandȱsensitiveȱtoȱaȱwideȱrangeȱofȱcontaminantsȱandȱhaveȱ beenȱdevelopedȱandȱrecommendedȱasȱbiomarkersȱforȱmonitoringȱtheȱeffectsȱofȱ pollutionȱ(Au,ȱ2004).ȱ 2.ȱMaterialsȱandȱmethodsȱ 2.1.ȱSitesȱdescriptionȱ TheȱstudyȱwasȱperformedȱinȱtwoȱareasȱofȱtheȱSpanishȱCoast:ȱtheȱGalicianȱ Coastȱ(NWȱSpain)ȱwasȱchosenȱasȱitȱwasȱaffectedȱbyȱtheȱPrestigeȱoilȱspillȱinȱ2002,ȱ whatȱsupposedȱoneȱofȱtheȱmajorȱecologicalȱcatastrophesȱofȱtheȱIberianȱpeninsulaȱ affectingȱ moreȱ thanȱ 1000ȱ kmȱ ofȱ coast;ȱ inȱ thisȱ sense,ȱ theȱ selectedȱ sitesȱ wereȱ locatedȱinȱtheȱCiesȱIslandȱinȱtheȱAtlanticȱIslandȱNationalȱParkȱandȱinȱtheȱBayȱofȱ CormeȬLaxe;ȱ theȱ secondȱ areaȱ ofȱ studyȱ wasȱ theȱ mouthȱ ofȱ theȱ Riverȱ Palmonesȱ - 189 - andȱ Guadarranqueȱ inȱ theȱ Bayȱ ofȱ Algecirasȱ (Sȱ Spain);ȱ thisȱ placeȱ wasȱ selectedȱ becauseȱisȱhighlyȱindustrializedȱandȱthereȱareȱaȱlargeȱnumberȱofȱpetrochemicalȱ activitiesȱ whichȱ compriseȱ severalȱ accidentalȱ oilȱ spills.ȱ Aȱ referenceȱ siteȱ wasȱ selectedȱinȱaȱcleanȱareaȱinȱtheȱBayȱofȱCádizȱ(SȱSpain)ȱ(Ribaȱetȱal.,ȱ2004).ȱTheȱ10ȱ selectedȱ studyȱ sitesȱ areȱ shownȱ inȱ Figureȱ 1:ȱ A,ȱ B,ȱ Cȱ locatedȱ inȱ Cíes,ȱ D,ȱ E,ȱ Fȱ inȱ CormeȬLaxe,ȱ GR3,ȱ GR4ȱ andȱ P1ȱ inȱ theȱ Bayȱ ofȱ Algeciras,ȱ andȱ theȱ referenceȱ siteȱ CAȱ inȱ theȱ Bayȱ ofȱ Cádizȱ widelyȱ characterizedȱ byȱ differentȱ ecotoxicologicalȱ studiesȱ(DelVallsȱetȱal.,ȱ1998,ȱRibaȱetȱal.,ȱ2004,ȱMartínȬDíazȱetȱal.,ȱ2005)ȱ ȱ Atlantic Islands National Park ȱ ƒF ƒE ƒD •C ȱ •A •B Ría de CormeLaxe ȱ Spain ȱ •GR3 •GR4 ȱ •P1 Bay of Algeciras N ȱ E W ȱ •CA S Bay of Cádiz ȱ Figureȱ1.ȱMapȱofȱtheȱcoastalȱareaȱofȱGaliciaȱshowingȱtheȱlocationsȱofȱtheȱ samplingȱstations.ȱA,ȱBȱandȱCȱrefersȱtoȱtheȱstationsȱlocatedȱinȱtheȱCiesȱIslandȱinȱ theȱAtlanticȱIslandȱNationalȱParkȱandȱD,ȱEȱandȱFȱtoȱthoseȱinȱtheȱBayȱofȱCormeȬ Laxe.ȱ Theȱ stationsȱ locatedȱ inȱ theȱ Bayȱ ofȱ Algecirasȱ areȱ GR3,ȱ GR4ȱ andȱ P1.ȱ Theȱ stationȱ CAȱ locatedȱ inȱ theȱ Bayȱ ofȱ Cadizȱ correspondsȱ toȱ theȱ sedimentȱ usedȱ asȱ reference.ȱ - 190 - 2.2.ȱSamplingȱandȱdeploymentȱȱ TheȱclamȱRuditapesȱphilippinarumȱwasȱobtainedȱfromȱanȱaquacultureȱfarmȱ whereasȱtheȱcrabȱCarcinusȱmaenasȱwasȱcaughtȱinȱaȱcleanȱsiteȱlocatedȱinȱtheȱBayȱofȱ Cádizȱ (SW,ȱ Spain)ȱ (Ribaȱ etȱ al.,ȱ 2003).ȱ Theȱ organismsȱ wereȱ transferredȱ toȱ theȱ laboratoryȱ andȱ keptȱ inȱ tanksȱ withȱ continuousȱ waterȱ replacementȱ underȱ controlledȱ conditionsȱ untilȱ theȱ beginningȱ ofȱ theȱ experiment.ȱ Theȱ testȱ animalsȱ wereȱ carefullyȱ transportedȱ toȱ theȱ studyȱ sitesȱ andȱ placedȱ inȱ cagesȱ madeȱ withȱ plasticȱmeshȱ(50cmȱxȱ25cmȱxȱ15cm)ȱdividedȱinȱtwoȱdifferentȱcompartments,ȱoneȱ forȱcrabsȱ(n=20)ȱandȱoneȱforȱclamsȱ(n=40).ȱTheȱcagesȱwereȱpositionedȱwithȱlowȱ tideȱ andȱ wereȱ wedgedȱ intoȱ theȱ sediment.ȱ Theȱ exposureȱ lastedȱ 28ȱ daysȱ duringȱ whichȱ crabsȱ wereȱ fedȱ onceȱ perȱ weekȱ withȱ mixedȱ dietȱ ofȱ musselsȱ orȱ fish.ȱ Sedimentȱ samplesȱ fromȱ theȱ studyȱ sitesȱ wereȱ collectedȱ andȱ transportedȱ toȱ theȱ laboratoryȱwhereȱtheyȱwereȱkeptȱinȱdarkȱatȱ4ºCȱpriorȱtoȱchemicalȱanalysis.ȱ ȱ2.3.ȱBiochemicalȱanalysisȱ Deployedȱcrabsȱandȱclamsȱwereȱcollectedȱandȱdissectedȱafterȱ28ȱdaysȱofȱ exposure;ȱ hepathopancreasȱ (inȱ crabs)ȱ andȱ digestiveȱ glandȱ (inȱ clams)ȱ wereȱ extractedȱ andȱ keptȱ atȱ Ȭ80ºCȱ priorȱ homogenization.ȱ Theȱ samplesȱ wereȱ homogenizedȱ withȱ TrisȬacetateȱ bufferȱ followingȱ theȱ procedureȱ developedȱ byȱ Lafontaineȱetȱal.ȱ(2000).ȱSamplesȱwereȱcentrifugedȱatȱ10,000gȱforȱ30ȱmin,ȱandȱtheȱ supernatantȱ wasȱ usedȱ forȱ theȱ biomarkersȱ determinationȱ andȱ theȱ totalȱ proteinȱ contentȱdescribedȱbyȱBradfordȱ(1976).ȱTheȱphaseȱIIȱmetabolizingȱGlutathioneȬSȬ transferaseȱ(GST)ȱactivityȱwasȱdeterminedȱbyȱmonitoringȱtheȱrateȱofȱconjugationȱ ofȱ glutathioneȱ (GSH)ȱ toȱ 1ȬchloroȬ2,4Ȭdinitrobenzeneȱ (CDNB)ȱ atȱ 340ȱ nm,ȱ methodologyȱ adaptedȱ fromȱ McFarlandȱ etȱ al.ȱ (1999).ȱ Theȱ oxidationȱ ofȱ 1ȱ mMȱ NADPHȱ byȱ Glutathioneȱ Reductaseȱ (GR)ȱ inȱ theȱ presenceȱ ofȱ 10ȱ mMȱ oxidizedȱ glutathioneȱ wasȱ monitoredȱ atȱ 340ȱ nm,ȱ andȱ theȱ methodȱ wasȱ similaryȱ adaptedȱ fromȱ McFarlandȱ etȱ al.ȱ (1999).ȱ Mixedȱ functionȱ oxygenaseȱ activity,ȱ whichȱ isȱ theȱ - 191 - firstȱmodeȱofȱdetoxificationȱofȱmanyȱorganicȱpollutants,ȱwasȱmeasuredȱusingȱtheȱ ERODȱ assayȱ (Gagnèȱ andȱ Blaiseȱ 1993).ȱ Theȱ antioxidantȱ enzymeȱ Glutathioneȱ Peroxidaseȱ (GPX)ȱ wasȱ measuredȱ accordingȱ toȱ McFarlandȱ etȱ al.ȱ (1999).ȱ Biomarkersȱresultsȱwereȱnormalizedȱwithȱtheȱproteinȱcontent.ȱ 2.4.ȱBiomarkerȱofȱeffect:ȱHistopathologyȱ Gillsȱ andȱ digestiveȱ glandȱ tissuesȱ ofȱ theȱ organismsȱ wereȱ fixedȱ inȱ phosphateȱ bufferedȱ 10%ȱ formaldehydeȱ (pHȱ 7.2)ȱ forȱ histopathologyȱ determination.ȱ Afterȱ dehydrationȱ inȱ gradedȱ concentrationsȱ ofȱ ethanol,ȱ theȱ samplesȱ wereȱ embeddedȱ inȱ paraffinȱ wax.ȱ Histologicalȱ sectionsȱ ofȱ 6ȱ toȱ 8ȱ ΐmȱ thicknessȱwereȱstainedȱwithȱHaematoxylin–ȱEosinȱandȱHaematoxylin–VOFȱ[15].ȱ Sectionsȱ wereȱ reviewedȱ byȱ lightȱ microscopyȱ Leitzȱ Laborluxȱ Sȱ andȱ photographedȱ(SonyȱDKCȬCM30).ȱ 2.5.ȱChemicalȱanalysisȱ Theȱ analysesȱ ofȱ PAHsȱ andȱ PCBsȱ boundȱ toȱ sedimentsȱ wereȱ carriedȱ outȱ accordingȱ toȱ USEPAȱ SWȬ846ȱ Methodȱ 827C78082ȱ (USEPA,ȱ 1994).ȱ Brieflyȱ driedȱ samplesȱ wereȱ Soxhletȱ extractedȱ withȱ nȬhexaneȱ forȱ 18ȱ h,ȱ andȱ theȱ extractsȱ wereȱ isolatedȱ byȱ columnȱ chromatographyȱ onȱ Florisileȱ aluminoȬsilica.ȱ PCBsȱ andȱ PAHsȱ wereȱelutedȱandȱtheirȱfractionsȱwereȱdriedȱinȱaȱ rotatingȱevaporatorȱandȱ reȬdissolvedȱ inȱ isooctane.ȱ Aromaticȱ fractionsȱ wereȱ analyzedȱ onȱ aȱ HewlettePackardȱ(HP)ȱ5890ȱSeriesȱIIȱgasȱchromatographerȱcoupledȱwithȱanȱHPȱ 5970ȱ massȱ spectrometer.ȱ PAHsȱ wereȱ analyzedȱ byȱ GCȬMSȱ usingȱ selectedȱ ionȱ monitoringȱ (SIM).ȱ Analysisȱ ofȱ PCBsȱ asȱ AROCLORȱ 1242ȱ andȱ AROCLORȱ 1260ȱ wasȱ performedȱ usingȱ theȱ sameȱ instrumentȱ withȱ anȱ electronȱ captureȱ detectorȱ (GC/ECD).ȱ Forȱ bothȱ setȱ ofȱ organicȱ chemicals,ȱ PAHsȱ andȱ AROCLOR,ȱ theȱ analyticalȱprocedureȱshowedȱagreementȱwithȱtheȱcertifiedȱvaluesȱofȱmoreȱthanȱ 90%.ȱ - 192 - TraceȱmetalȱanalysisȱwereȱanalyzedȱasȱdescribedȱbyȱCasadoȬMartínezȱetȱ al.ȱ (2006c);ȱ briefly,ȱ 2.5ȱ gȱ ofȱ sedimentsȱ (<0.065ȱ mm)ȱ wereȱ placedȱ inȱ Teflonȱ containersȱ andȱwereȱdigestedȱ inȱ microwaveȱ(400W,ȱ15ȱmin,ȱtwice)ȱwithȱHNO3ȱ 2N.ȱ Theȱ extractsȱ wereȱ purifiedȱ byȱ passingȱ throughȱ aȱ CȬ18ȱ columnȱ andȱ metalsȱ analysesȱwereȱperformedȱbyȱanodicȱvoltamperimetryȱ(ȬZn,ȱCd,ȱPb,ȱNi,ȱCoȱandȱ CuȬȱ Metrohmȱ Applicationȱ Bulletinȱ Nºȱ 147;ȱȬȱVȬȱMetrohmȱApplicationȱNoteȱNºȱ VȬ81).ȱ Forȱ Hgȱ theȱ coldȱ vapourȱ techniqueȱ wasȱ usedȱ andȱ wasȱ quantifiedȱ usingȱ atomicȱabsorptionȱspectrometry.ȱTheȱanalyticalȱproceduresȱwereȱcheckedȱusingȱ referenceȱ materialȱ (MESSȬ1ȱ NRCȱ andȱ CRMȱ 277ȱ BCR)ȱ andȱ showedȱ aȱ recoveryȱ greaterȱthanȱ90%ȱofȱtheȱcertifiedȱconcentration.ȱ 2.6.ȱStatisticalȱanalysisȱ TheȱinductionȱofȱbiomarkersȱofȱresponseȱwasȱanalyzedȱwithȱtheȱANOVAȱ andȱTukeyȱtestȱwithȱtheȱaimȱofȱdeterminingȱsignificantȱdifferencesȱ(pȱ<ȱ0.05;ȱpȱ<ȱ 0.01)ȱ amongȱ theȱ resultsȱ obtainedȱ forȱ theȱ referenceȱ (CA)ȱ siteȱ andȱ theȱ otherȱ samplingȱ sites,ȱ usingȱ theȱ statisticalȱ packageȱ SPSSȱ 11.5.ȱ Multivariateȱ analysisȱ wasȱ carriedȱ outȱ withȱ inȱ anȱ attemptȱ toȱ linkȱ contaminationȱ withȱ adverseȱ biologicalȱmeasurements;ȱtheȱprincipalȱcomponentȱanalysisȱ(PCA)ȱwasȱusedȱasȱ theȱextractionȱprocedureȱtoȱderiveȱaȱreducedȱnumberȱofȱnewȱvariablesȱ(factors)ȱ asȱlinearȱcombinationsȱofȱtheȱoriginalȱvariablesȱ(STATISTICAȱ6.0).ȱ 3.ȱResultsȱandȱdiscussionȱ 3.1.ȱConcentrationȱofȱchemicalsȱinȱtheȱsedimentsȱ Resultsȱ ofȱ theȱ concentrationȱ ofȱ chemicalsȱ inȱ theȱ studiedȱ sedimentsȱ areȱ shownȱ inȱ tableȱ 1.ȱ Theȱ highestȱ concentrationȱ ofȱ PAHsȱ wasȱ foundȱ inȱ theȱ sedimentsȱ fromȱ GR3ȱ (2961ȱ mgȱ KgȬ1ȱ dryȱ sediment)ȱ locatedȱ inȱ theȱ Bayȱ ofȱ Algeciras,ȱfollowedȱbyȱsedimentsȱfromȱtheȱstationȱFȱ(820ȱmgȱKgȬ1ȱ dryȱsediment)ȱ locatedȱinȱCormeȬLaxeȱandȱGR4ȱ(802ȱmgȱKgȬ1ȱdryȱsediment)ȱandȱP1ȱ(641ȱmgȱKgȬ1ȱȱ - 193 - Tableȱ1.ȱTotalȱPAHs,ȱPCBsȱandȱmetalȱconcentrationȱ(Zn,ȱCd,ȱPb,ȱNi,ȱCoȱandȱV)ȱȬ mgȱKgȬ1ȱdryȱsedimentȬȱmeasuredȱinȱtheȱsedimentsȱfromȱGalicia:ȱAtlanticȱIslandsȱ NationalȱParkȱ(A,ȱB,ȱC),ȱCormeȬLaxeȱ(D,ȱE,ȱF);ȱtheȱBayȱofȱAlgecirasȱ(GR3,ȱGR4ȱ andȱ P1)ȱ andȱ theȱ Bayȱ ofȱ Cadizȱ (CA)ȱ usedȱ asȱ theȱ referenceȱ station.ȱ ȱ n.d:ȱ notȱ detected.ȱ ȱȱ PAHsȱ PCBsȱ Znȱ Cdȱ Pbȱ Cuȱ Niȱ Coȱ Vȱ CAȱ n.d.ȱ n.d.ȱ 21.3ȱ 0.92ȱ 2.28ȱ 6.98ȱ 0.06ȱ 3.40ȱ 80.0ȱ Aȱ 257ȱ n.d.ȱ 76.2ȱ n.d.ȱ 26.6ȱ 18.9dȱ 12.0ȱ 0.52ȱ n.d.ȱ Bȱ 370ȱ 6.52ȱ 43.4ȱ n.d.ȱ 9.13ȱ n.d.ȱ 6.88ȱ n.d.ȱ n.d.ȱ Cȱ 239ȱ 4.76ȱ 37.5ȱ n.d.ȱ 6.54ȱ 31.6dȱ 5.02ȱ 0.87ȱ n.d.ȱ Dȱ 537ȱ 2.60ȱ 65.7ȱ n.d.ȱ 44dȱ 22.1dȱ 9.39ȱ 1.21ȱ 13.4ȱ Eȱ 558ȱ 4.29ȱ 31.8ȱ n.d.ȱ 4.25ȱ n.d.ȱ 5.61ȱ 0.37ȱ 2.34ȱ Fȱ 820dȱ 2.28ȱ 243a,b,d n.d.ȱ 14.3ȱ 19.1dȱ 7.03ȱ 0.67ȱ 5.94ȱ GR3ȱ 2961d,eȱ 22.0ȱ 138dȱ 0.17ȱ 21.6ȱ 5.01ȱ GR4ȱ 802dȱ 1.75ȱ 35.3ȱ 0.10ȱ 6.21ȱ 3.67ȱ P1ȱ 641dȱ 0.84ȱ 56.7ȱ 0.12ȱ 12.3ȱ 75.2a,c,d,eȱ 74.7a,d,eȱ 12.8ȱ 26.1ȱ 13.1ȱ 5.59ȱ n.d.ȱ 13.3ȱ n.d.ȱ 6.84ȱ Concentrationȱ thatȱ exceedsȱ theȱ ERLȱ (Effectsȱ RangeȬLow)ȱ definedȱ byȱ NOAAȱ (1999);ȱ bȱ valueȱ thatȱ exceedsȱ theȱ sedimentȱ qualityȱ guidelineȱ suggestedȱ byȱ DelValls&Chapmanȱ (1998);ȱ cȱ concentrationȱwhichȱsurpassȱtheȱguidelineȱdescribedȱbyȱRibaȱetȱal.ȱ(2004);ȱ dȱ valueȱ thatȱexcedsȱtheȱguidelineȱproposedȱbyȱMcDonaldȱetȱal.ȱ(1996);ȱ eȱ concentrationȱthatȱsurpassȱ theȱguidelinesȱdefinedȱbyȱDutchȱagencies,ȱTweedeȱKamer,ȱvergaderjaarȱ(1994–1995).ȱ aȱ ȱ dryȱ sediment)ȱ inȱ theȱ Bayȱ ofȱ Algeciras;ȱ theseȱ couldȱ beȱ consideredȱ asȱ slightlyȱ contaminatedȱ byȱ PAHsȱ andȱ adverseȱ effectsȱ couldȱ beȱ frequentȱ accordingȱ toȱ McDonaldȱ etȱ al.ȱ (1996),ȱ andȱ inȱ theȱ caseȱ ofȱ GR3ȱ theȱ concentrationȱ ofȱ thisȱ contaminantȱ alsoȱ exceedsȱ theȱ guidelineȱ proposedȱ byȱ theȱ Dutchȱ agenciesȱ (Tweedeȱ Kamer,ȱ vergaderjaar,ȱ 1994Ȭ1995);ȱ onȱ theȱ otherȱ handȱ sedimentsȱ fromȱ theȱ Ciesȱ Islandȱ presentȱ theȱ lowestȱ concentrationsȱ ofȱ PAHs,ȱ whereasȱ theseȱ chemicalsȱwereȱnotȱdetectedȱinȱtheȱsamplingȱsiteȱlocatedȱinȱtheȱBayȱofȱCadiz.ȱNoȱ specialȱ patternȱ wasȱ detectedȱ regardingȱ toȱ theȱ concentrationȱ ofȱ metalsȱ inȱ theȱ - 194 - differentȱ sitesȱ ofȱ study;ȱ GR3ȱ andȱ Fȱ exceedsȱ someȱ internationalȱ guidelinesȱ definedȱ forȱ theȱ metalȱ Zn:ȱ GR3ȱ (MacDonaldȱ etȱ al.,ȱ 1996)ȱ andȱ Fȱ (NOAA,ȱ 1999;ȱ DelVallsȱandȱChapman,ȱ1998;ȱMacDonaldȱetȱal.,ȱ1996).ȱAccordingȱtoȱMcDonaldȱ etȱ al.ȱ (1996),ȱ sedimentsȱ fromȱ stationȱ Dȱ exceedȱ theȱ guidelineȱ proposedȱ forȱ Pb.ȱ Sitesȱ Aȱ andȱ Cȱ fromȱ Ciesȱ andȱ D,ȱ Fȱ fromȱ CormeȬLaxeȱ surpassȱ theȱ proposedȱ guidelineȱ describedȱ byȱ McDonaldȱ etȱ al.ȱ (1996)ȱ forȱ Cu,ȱ whereasȱ GR3ȱ exceedsȱ variousȱ guidelinesȱ proposedȱ forȱ thisȱ metalȱ (NOAA,ȱ 1999;ȱ MacDonaldȱ etȱ al.,ȱ 1996;ȱ Tweedeȱ Kamer,ȱ vergaderjaar,ȱ 1994Ȭ1995;ȱ Ribaȱ etȱ al.,ȱ 2004).ȱ GR3ȱ alsoȱ exceedsȱtheȱguidelinesȱforȱNiȱproposedȱbyȱdifferentȱinternationalȱagenciesȱandȱ authorsȱ (NOAA,ȱ 1999;ȱ MacDonaldȱ etȱ al.,ȱ 1996;ȱ Tweedeȱ Kamer,ȱ vergaderjaar,ȱ 1994Ȭ1995).ȱȱ 3.2.ȱBiomarkersȱofȱexposureȱ Meanȱ valuesȱ ofȱ theȱ biomarkersȱ ofȱ exposureȱ determinedȱ inȱ crabsȱ andȱ clamsȱobtainedȱafterȱtheȱ28ȬdȱexposureȱareȱsummarizedȱinȱFigureȱ2.ȱInȱgeneral,ȱ organismsȱdeployedȱinȱtheȱareaȱofȱCormeȬLaxeȱ(D,ȱE,ȱandȱF)ȱpresentȱtheȱhighestȱ inductionȱ ofȱ theȱ biomarkersȱ ofȱ exposure.ȱ GPXȱ activitiesȱ forȱ crabsȱ showȱ significantȱdifferencesȱ(p<0.01)ȱbetweenȱsitesȱD,ȱEȱandȱFȱ(CormeȬLaxe)ȱandȱtheȱ referenceȱstationȱCA,ȱwhereasȱclamsȱexposedȱinȱsiteȱDȱpresentedȱalsoȱsignificantȱ differencesȱ withȱ theȱ referenceȱ stationȱ regardingȱ toȱ thisȱ biomarker.ȱ Differencesȱ obtainedȱ forȱ theȱ phaseȱ IIȱ enzymeȱ GSTȱ measuredȱ inȱ crabsȱ wereȱ significantlyȱ amongȱD,ȱFȱandȱtheȱreferenceȱCA.ȱTheȱantioxidantȱenzymeȱGRȱactivityȱforȱboth,ȱ crabsȱ andȱ clamsȱ resultedȱ significantlyȱ differentȱ fromȱ CAȱ forȱ theȱ threeȱ studyȱ sitesȱlocatedȱinȱCormeȬLaxeȱ(D,ȱEȱandȱF).ȱInȱtheȱcaseȱofȱtheȱERODȱactivityȱwhichȱ accountsȱ forȱ theȱ enzymaticȱ activityȱ occurringȱ inȱ theȱ phaseȱ Iȱ ofȱ detoxification,ȱ significantȱ differencesȱ wereȱ detectedȱ forȱ thoseȱ crabsȱ thatȱ wereȱ placedȱ inȱ theȱ locationsȱBȱ(AINP),ȱDȱ,ȱEȱandȱFȱ(CormeȬLaxe),ȱandȱclamsȱexposedȱtoȱsedimentsȱ fromȱDȱ(CormeȬLaxe)ȱandȱGR3,ȱGR4,ȱP1ȱ(BayȱofȱAlgeciras).ȱȱ - 195 - GPX (nmol/mg/min) 200 ȱ 10000 * ȱ 150 8000 GST (nmol/mg/min) 250 * ȱ 50 * * ȱ * * 6000 4000 2000 ȱ 0 0 ȱ 25 CA A B C D E ȱ F CA GR3 GR4 P1 A B C D E F GR3 GR4 P1 10.0 * * 8.0 ȱ * 15 10 EROD (pmol/mg/min) GR (nmol/mg/min) 20 * * * ȱ * 6.0 4.0 * * * * 0.5 * * * 5 ȱ 0 0.0 CA A B C D E F GR3 GR4 P1 CA A B C D E F GR3 GR4 P1 ȱ Figureȱ 2.ȱ Generalȱ healthȱ biomarkersȱ forȱ bothȱ invertebrateȱ species,ȱ theȱ clamȱ Ruditappesȱ philippinarumȱ andȱ theȱ crabȱ Carcinusȱ maenas:ȱ glutathioneȱ peroxidaseȱ activityȱ GPXȱ (nmol/min/mgȱ prot),ȱ glutathioneȱ transferaseȱ GSTȱ activityȱ (nmol/min/mgȱ prot),ȱ glutathioneȱ reductaseȱ GRȱ activityȱ (nmol/min/mgȱ prot)ȱ andȱ ERODȱ activityȱ (pmol/mg/min).ȱ Asterisksȱ indicateȱ significantȱ differencesȱwithȱtheȱreferenceȱtreatmentȱCAȱ(*pȱ<ȱ0.05;ȱ**pȱ<ȱ0.01).ȱ 3.3.ȱBiomarkersȱofȱeffectȱ Theȱrelationshipȱbetweenȱpollutantsȱandȱpathologiesȱinȱtargetȱtissuesȱhasȱ beenȱ previouslyȱ reportedȱ (OrtizȬDelgadoȱ etȱ al.,ȱ 2007).ȱ Histopathologyȱ resultsȱ showedȱnoȱalterationsȱinȱtheȱorganismsȱfromȱtheȱnegativeȱcontrolȱ(Figureȱ3ȱandȱ Figureȱ4).ȱInȱgeneral,ȱdamageȱinȱcrabsȱandȱclamsȱtissuesȱwereȱlowerȱthanȱthoseȱ detectedȱ inȱ laboratoryȱ deploymentsȱ (personalȱ observations).ȱ Mostȱ ofȱ theȱ - 196 - analyzedȱ organismsȱ showedȱ ȱ severalȱ ȱ histologicalȱ unȬspecificȱ lesionsȱ relatedȱ withȱ symptomsȱ ofȱ generalȱ stress,ȱ includingȱ lossȱ ofȱ digestiveȱ epithelialȱ cells,ȱȱ ruptureȱ ofȱ gillȱ epithelium,ȱ respiratoryȱ lamellarȱ fusionȱ ofȱ lifting,ȱ asȱ wellȱ asȱ haemociticȱ infiltratesȱ orȱ lossȱ ofȱ ȱ connectiveȱ tissueȱ ofȱ theȱ gillsȱ andȱȱ hepatopancreas,ȱ ȱ mostȱ whichȱ canȱ alsoȱ beȱ observedȱ inȱ differentȱ ȱ marineȱȱ invertebrateȱ orȱ vertebrateȱ ȱ ȱ speciesȱ exposedȱ toȱ ȱ differentȱ ȱ inorganicȱ orȱ organicȱ contaminants,ȱ parasiticȱ orȱ infectiousȱ diseases,ȱ nutritionalȱ stress,ȱ orȱ physicoȬ chemicalȱdisordersȱ(RodriguezȱdeȱlaȱRuaȱetȱal.,ȱ2005;ȱOrtizȬDelgadoȱetȱal.,ȱ2007).ȱ Organismsȱ exposedȱ toȱ sedimentsȱ fromȱ theȱ Bayȱ ofȱ Algecirasȱ wereȱ theȱ mostȱ affectedȱfollowedȱbyȱclamsȱandȱcrabsȱexposedȱtoȱsedimentsȱfromȱCormeȬLaxe,ȱ andȱfinallyȱorganismsȱfromȱtheȱCiesȱtreatmentȱwhichȱshowedȱalterationsȱdueȱtoȱ generalȱ environmentalȱ stress.ȱ Theȱ lesionsȱ observedȱ inȱ clamsȱ thatȱ hadȱ beenȱ exposedȱ toȱ sedimentsȱ fromȱ Algecirasȱ duringȱ 28ȱ daysȱ included:ȱ desquamationȱȱ ofȱ ȱ digestiveȱ epithelium,ȱ occlusionȱ ofȱ theȱ ȱ digestiveȱ ȱ ducts,ȱ ȱ haemociticȱ infiltrationsȱandȱweakȱalterationsȱorȱlossȱofȱtheȱȱsupportingȱdigestiveȱconnectiveȱ tissueȱ (hepatopancreas),ȱ ciliarȱ alterations,ȱ lossȱ ofȱ ȱ supportȱ connectiveȱ tissue,ȱȱ andȱ hypertrpophyȱ orȱ fusionȱ ofȱ lamellaeȱ (gills).ȱ Crabsȱ deployedȱ inȱ siteȱ GR3ȱ presentedȱ disruptedȱ pillarȱ cells,ȱ epithelialȱ changes,ȱ desquamationȱ inȱ gillsȱ presenceȱ ofȱ vacuolesȱ inȱ hepathopancreasȱ ofȱ cagedȱ organisms.ȱ Theȱ presenceȱ ofȱ parasitesȱ inȱ someȱ ofȱ theȱ crabsȱ studiedȱ makeȱ moreȱ unclearȱ toȱ determineȱ theȱ causeȱ ofȱ theȱ damages,ȱ inȱ thisȱ sense,ȱ aȱ betterȱ relationshipȱ withȱ pollutantsȱ wasȱ shownȱ inȱ clamsȱ thanȱ crabs.ȱ Organismsȱ fromȱ theȱ referenceȱ siteȱ didȱ notȱ presentȱ alterationsȱinȱtargetȱtissues.ȱȱ ȱ ȱ ȱ ȱ - 197 - ȱ A B C D E F G H ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ Figureȱ 3.ȱ Histologicalȱ sectionsȱ ofȱ gillsȱ andȱ digestiveȱ glandȱ ofȱ theȱ clamȱ Ruditapesȱphilippinarumȱafterȱ28Ȭdȱexposureȱtoȱtheȱsediments:ȱ(A)ȱHistologicalȱ sectionȱ ofȱ aȱ controlȱ gillȱ (dayȱ 0);ȱ (B)ȱ Histologicalȱ sectionȱ ofȱ aȱ controlȱ digestiveȱ glandȱ(dayȱ0);ȱ(C)ȱHistologicalȱsectionȱofȱgillȱfromȱaȱclamȱexposedȱtoȱsedimentsȱ fromȱAINP;ȱ(C)ȱHistologicalȱsectionȱofȱdigestiveȱglandȱfromȱaȱclamȱexposedȱtoȱ sedimentsȱ fromȱ AINP;ȱ (D)ȱ Histologicalȱ sectionȱ ofȱ gillȱ fromȱ aȱ clamȱ exposedȱ toȱ sedimentsȱfromȱCormeȬLaxe;ȱ(E)ȱHistologicalȱsectionȱofȱdigestiveȱglandȱfromȱaȱ clamȱ exposedȱ toȱ sedimentsȱ fromȱ CormeȬLaxe;ȱ (F)ȱ Histologicalȱ sectionȱ ofȱ gillȱ fromȱ aȱ clamȱ exposedȱ toȱ sedimentsȱ fromȱ Algeciras;ȱ (G)ȱ Histologicalȱ sectionȱ ofȱ digestiveȱglandȱfromȱaȱclamȱexposedȱtoȱsedimentsȱfromȱAlgeciras.ȱ ȱ - 198 - ȱ A B C D E F G H ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ Figureȱ 4.ȱ Histologicalȱ sectionsȱ ofȱ gillsȱ andȱ hepathopancreasȱ ofȱ theȱ crabȱ Carcinusȱmaenasȱafterȱ28Ȭdȱexposureȱtoȱtheȱsediments:ȱ(A)ȱHistologicalȱsectionȱ ofȱaȱcontrolȱgillȱ(dayȱ0);ȱ(B)ȱHistologicalȱsectionȱofȱaȱcontrolȱdigestiveȱglandȱ(dayȱ 0);ȱ(C)ȱHistologicalȱsectionȱofȱgillȱfromȱaȱclamȱexposedȱtoȱsedimentsȱfromȱAINP;ȱ (C)ȱHistologicalȱsectionȱofȱhepathopancreasȱfromȱaȱclamȱexposedȱtoȱsedimentsȱ fromȱ AINP;ȱ (D)ȱ Histologicalȱ sectionȱ ofȱ gillȱ fromȱ aȱ clamȱ exposedȱ toȱ sedimentsȱ fromȱ CormeȬLaxe;ȱ (E)ȱ Histologicalȱ sectionȱ ofȱ hepathopancreasȱ fromȱ aȱ clamȱ exposedȱ toȱ sedimentsȱ fromȱ CormeȬLaxe;ȱ (F)ȱ Histologicalȱ sectionȱ ofȱ gillȱ fromȱ aȱ clamȱ exposedȱ toȱ sedimentsȱ fromȱ Algeciras;ȱ (G)ȱ Histologicalȱ sectionȱ ofȱ hepathopancreasȱfromȱaȱclamȱexposedȱtoȱsedimentsȱfromȱAlgeciras.ȱ ȱ - 199 - 3.4.ȱLinkingȱchemicalsȱandȱbiomarkersȱȱ Asȱitȱhasȱbeenȱshownȱabove,ȱinȱtheȱcurrentȱstudyȱtheȱhighestȱactivitiesȱofȱ biomarkersȱofȱexposureȱwhereȱobservedȱinȱthoseȱindividualsȱdeployedȱ“inȱsitu”ȱ inȱ theȱ Bayȱ ofȱ CormeȬLaxe.ȱ Studiesȱ carriedȱ outȱ withȱ theȱ sameȱ organismsȱ andȱ similarȱ sedimentsȱ underȱ laboratoryȱ conditionsȱ (MoralesȬCasellesȱ etȱ al,ȱ submitted)ȱ showedȱ higherȱ biomarkerȱ responsesȱ inȱ organismsȱ exposedȱ toȱ sedimentsȱfromȱtheȱBayȱofȱAlgeciras,ȱmainlyȱdueȱtoȱtheȱconcentrationȱofȱPAHsȱ inȱ theȱ sediments.ȱ Inȱ someȱ occasionsȱ inȱ situȱ exposuresȱ showedȱ greaterȱ toxicityȱ thanȱlaboratoryȱexposuresȱtoȱsedimentsȱfromȱtheȱsameȱsitesȱ(Burtonȱetȱal.,ȱ2005).ȱ Toȱ elucidateȱ theȱ sourceȱ andȱ typeȱ ofȱ contaminantȱ thatȱ isȱ producingȱ theȱ stressȱ toȱ theȱ organismsȱ aȱ multivariateȱ analysisȱ wasȱ performedȱ toȱ linkȱ biomarkersȱ ofȱ exposureȱ withȱ theȱ chemicalsȱ boundȱ toȱ sediments.ȱ Threeȱ newȱ factorsȱwereȱdefinedȱtoȱdescribeȱtheȱ17ȱoriginalȱvariablesȱbyȱexplainingȱaȱ75ȱ%ȱ ofȱ theȱ totalȱ varianceȱ (Tableȱ 2).ȱ ȱ Theȱ mainȱ Factorȱ (29.9ȱ %)ȱ linksȱ theȱ phaseȱ Iȱ detoxificationȱ activityȱ determinedȱ byȱ ERODȱ inȱ clamsȱ andȱ crabs,ȱ theȱ GSTȱ andȱ GPXȱactivityȱinȱclamsȱtoȱtheȱconcentrationȱofȱPbȱinȱtheȱsediment.ȱThisȱfactorȱhasȱ aȱpositiveȱloadingȱprincipallyȱinȱsiteȱDȱfromȱCormeȬLaxeȱandȱfollowedȱbyȱsiteȱAȱ inȱCiesȱ(Figureȱ5).ȱTheȱlowȱscoreȱinȱsiteȱAȱsuggestsȱthatȱPbȱboundȱtoȱsedimentsȱ producedȱ someȱ stressȱ althoughȱ theȱ highȱ prevalenceȱ ofȱ thisȱ factorȱ inȱ siteȱ D,ȱ whichȱ exceedsȱ theȱ sedimentȱ qualityȱ guidelineȱ proposedȱ byȱ McDonaldȱ etȱ alȱ (1996)ȱ forȱ thisȱ contaminantȱ impliesȱ thatȱ thereȱ isȱ aȱ sourceȱ ofȱ Pbȱ whichȱ hasȱ involvedȱtheȱactivationȱofȱ“earlyȱwarning”ȱbiomarkers.ȱPrecisely,ȱtheȱactivationȱ ofȱ aȱ groupȱ ofȱ biomarkersȱ oftenȱ relatedȱ toȱ theȱ defenceȱ againstȱ organicȱ compoundsȱ suggestsȱ thatȱ theȱ metalȱ Pbȱ comesȱ fromȱ anȱ organicȱ sourceȱ suchȱ asȱ hydrocarbons.ȱȱ Onȱ theȱ otherȱ handȱ theȱ factȱ thatȱ theȱ biomarkersȱ ofȱ exposureȱ haveȱ thisȱ significantȱ inductionȱ inȱ theȱ organismsȱ exposedȱ toȱ sedimentsȱ fromȱ theȱ Bayȱ ofȱȱ CormeȬLaxeȱ whichȱ wasȱ notȱ detectedȱ underȱ laboratoryȱ exposuresȱ (MoralesȬ - 200 - Casellesȱetȱal.,ȱsubmitted),ȱcouldȱbeȱrelatedȱtoȱtheȱexistenceȱofȱaȱnonȱmeasuredȱ contaminantȱthatȱmightȱcomeȱfromȱtheȱseaȱwater.ȱInȱthisȱcaseȱaȱpossibleȱsourceȱ couldȱbeȱtheȱpresenceȱofȱcagedȱmusselȱforȱaquacultureȱinȱtheȱproximitiesȱwhatȱ mightȱ supposeȱ anȱ inputȱ ofȱ organicȱ matterȱ thereforeȱ aȱ causeȱ ofȱ stressȱ toȱ theȱ deployedȱ organisms.ȱ Aȱ sourceȱ ofȱ organicȱ matterȱ toȱ theȱ surroundingȱ waterȱ involvesȱ aȱ decreaseȱ inȱ theȱ dissolvedȱ oxygenȱ whichȱ isȱ usedȱ inȱ theȱ oxidationȱ processes.ȱ Theȱ oxygenȱ contentȱ ofȱ waterȱ canȱ beȱ importantȱ inȱ determiningȱ theȱ natureȱandȱtheȱrateȱofȱbothȱchemicalȱandȱbiochemicalȱtransformationsȱ(Walkerȱ etȱal.,ȱ2006).ȱ Tableȱ 2.ȱȱȱSortedȱ rotatedȱ factorȱ loadingsȱofȱ17ȱvariablesȱforȱtheȱthreeȱprincipalȱ factorsȱ resultingȱ fromȱ theȱ multivariateȱ analysisȱ ofȱ resultsȱ obtainedȱ fromȱ theȱ biomarkerȱresponsesȱinȱcrabsȱandȱclamsȱandȱtheȱchemicalȱanalysis.ȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱ ȱ ȱ ȱȱ ȱȱ ȱ GPXȬcrabȱ GPXȬclamȱ GRȬcrabȱ GRȬclamȱ GSTȬcrabȱ GSTȬclamȱ ERODȬcrabȱ ERODȬclamȱ PAHsȱ PCBsȱ Znȱ Cdȱ Pbȱ Cuȱ Niȱ Coȱ Vȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ FACTORȱ1ȱ FACTORȱ2ȱ FACTORȱ3ȱ 29.9ȱ 23.8ȱ 21.1ȱ ņȱ 0.97ȱ ņȱ ņȱ ņȱ 0.91ȱ 0.90ȱ 0.94ȱ ņȱ ņȱ ņȱ ņȱ 0.93ȱ ņȱ ņȱ ņȱ ņȱ ȱ ȱ - 201 - ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ Ȭ0.98ȱ Ȭ0.93ȱ Ȭ0.46ȱ ņȱ ņȱ ņȱ Ȭ0.97ȱ Ȭ0.88ȱ ņȱ 0.93ȱ ņȱ 0.85ȱ 0.82ȱ 0.94ȱ ņȱ ņȱ ņȱ ņȱ ņȱ 0.51ȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ Accordingȱ toȱ theȱ secondȱ factorȱ (23.8ȱ %)ȱ aȱ relationshipȱ isȱ observedȱ betweenȱtheȱorganicȱcontaminantsȱPAHsȱandȱPCBsȱwithȱmetalsȱNi,ȱCoȱandȱZn.ȱ Thisȱ factor,ȱ withȱ negativeȱ loading,ȱ doesȱ notȱ relateȱ theȱ associationȱ ofȱ theseȱ contaminantsȱ withȱ biomarkersȱ andȱ accountsȱ forȱ aȱ contaminationȱ inȱ sedimentsȱ fromȱsitesȱGR3ȱandȱGR4ȱfromȱtheȱBayȱofȱAlgecirasȱandȱFȱinȱCormeȬLaxeȱ(Figureȱ 5).ȱ Biomarkerȱ responsesȱ wereȱ expectedȱ inȱ organismsȱ exposedȱ toȱ theȱ contaminationȱ boundȱ toȱ sedimentsȱ fromȱ Algeciras,ȱ asȱ itȱ wasȱ shownȱ inȱȱ laboratoryȱ studiesȱ (MoralesȬCasellesȱ etȱ al.,ȱ submitted)ȱ howeverȱ biomarkersȱ ofȱ exposureȱ wereȱ generallyȱ low,ȱ mainlyȱ inȱ crabs,ȱ inȱ comparisonȱ withȱ sedimentsȱ fromȱCormeȬLaxe.ȱTheȱfactȱthatȱtheȱareaȱofȱtheȱdeployment,ȱinȱtheȱmouthȱofȱtheȱ riverȱ Guadarranque,ȱ isȱ submittedȱ toȱ theȱ influenceȱ ofȱ naturalȱ tidesȱ couldȱ beȱ aȱ reasonȱ ofȱ easingȱ theȱ bioavailabilityȱ ofȱ contaminantsȱ toȱ theȱ organisms.ȱ Sedimentsȱofȱintertidalȱzonesȱalongȱtheȱseashoreȱexperienceȱfluctuatingȱoxygenȱ levelsȱinȱaccordanceȱwithȱtidalȱmovementsȱ(Walkerȱetȱal.,ȱ2006).ȱAsȱtheȱoxygenȱ contentȱ declines,ȱ thereȱ willȱ beȱ aȱ tendencyȱ forȱ oxidativeȱ transformationsȱ toȱ beȱ replacedȱ byȱ reductiveȱ ones.ȱ Oxidationsȱ byȱ theȱ microsomalȱ monooxygenaseȱ systemȱdependȱuponȱtheȱactivationȱofȱhemoproteinȱmolecularȱoxygenȱ(O2)ȱafterȱ itȱ hasȱ beenȱ boundȱ toȱ anȱ associatedȱ hemoprotein,ȱ cytochromeȱ P450.ȱ (Walkerȱ etȱ al.,ȱ2006).ȱȱ Theȱthirdȱfactorȱ(21.1ȱ%)ȱconnectsȱtheȱconcentrationȱofȱZnȱinȱsedimentsȱtoȱ theȱ biomarkersȱ ofȱ responseȱ relatedȱ toȱ antioxidantȱ activity:ȱ GRȱ inductionȱ inȱ crabsȱandȱclamsȱandȱGSTȱandȱGPXȱactivityȱinȱcrabs.ȱSitesȱD,ȱEȱandȱFȱfromȱtheȱ Bayȱ ofȱ CormeȬLaxeȱ presentȱ theȱ influenceȱ ofȱ thisȱ factorȱ (Figureȱ 5)ȱ whatȱ meansȱ thatȱthisȱareaȱpresentsȱaȱstressȱdueȱtoȱtheȱpresenceȱofȱpollutionȱbyȱZn.ȱPreviousȱ studiesȱhaveȱconsideredȱtheȱBayȱofȱCormeȬLaxeȱasȱnotȱcontaminatedȱandȱhaveȱ attributedȱ theȱ presenceȱ ofȱ metalsȱ toȱ basalȱ levelsȱ (CobeloȬGarcíaȱ etȱ al.,ȱ 2005).ȱ However,ȱ regardingȱ toȱ siteȱ Dȱ whichȱ levelsȱ ofȱ Znȱ surpassȱ severalȱ sedimentȱ qualityȱ guidelinesȱ (tableȱ 1)ȱ anȱ anthropogenicȱ sourceȱ ofȱ thisȱ metalȱ isȱ probablyȱ - 202 - theȱ causeȱ ofȱ theȱ stressȱ shownȱ inȱ theȱ organisms,ȱ mainlyȱ inȱ crabs.ȱ Previousȱ studiesȱ haveȱ shownȱ sublethalȱ responsesȱ inȱ Carcinusȱ maenasȱ exposedȱ toȱ sedimentsȱcontaminatedȱbyȱZnȱ(MartínȬDíazȱetȱal.,ȱ2005).ȱȱ Inȱgeneral,ȱhistopathologicalȱresponsesȱhaveȱshownȱmoderateȱdamageȱinȱ theȱ studiedȱ organismsȱ deployedȱ inȱ CormeȬLaxeȱ whatȱ suggestsȱ aȱ successfulȱ actionȱ ofȱ theȱ antioxidantȱ andȱ detoxificationȱ activities.ȱ However,ȱ defenceȱ mayȱ involveȱaȱtradeȬoffȱbetweenȱproductionȱandȱsurvival:ȱincreasedȱsurvivalȱmayȱbeȱ obtainedȱonlyȱatȱaȱcostȱofȱreducedȱgrowthȱofȱreproductionȱ(Walkerȱetȱal.,ȱ2006).ȱ Inȱ thisȱ sense,ȱ moreȱ attentionȱ shouldȱ beȱ playedȱ toȱ thoseȱ areasȱ affectedȱ byȱ theȱ inputȱ ofȱ contaminantsȱ whichȱ maybeȱ areȱ notȱ producingȱ lethalȱ responsesȱ althoughȱsublethalȱeffectsȱareȱexpectedȱandȱcanȱleadȱtoȱsequentialȱchangesȱandȱ reachȱecosystemȱlevels.ȱ ȱ - 203 - D 3.0 Factor 1 2.0 1.0 A 0.0 -1.0 B Ca1 F GR3'-J P1-J GR4-J C E -2.0 1.5 Ca1 A B C D P1-J E Factor 2 0.0 GR4-J F -1.5 -3.0 GR3'-J 2.0 E F Factor 3 1.0 D 0.0 A B C GR3'-J GR4-J P1-J -1.0 Ca1 -2.0 ȱ Figureȱ5.ȱFactorȱloadingsȱforȱtheȱthreeȱprincipalȱfactorsȱresultingȱfromȱtheȱ multivariateȱ analysisȱ ofȱ resultsȱ obtainedȱ fromȱ theȱ chemicalȱ analysisȱ andȱ theȱ suiteȱofȱbiomarkers.ȱ - 204 - 5.ȱConclusionsȱ Inȱ theȱ presentȱ studyȱ sublethalȱ responsesȱ haveȱ beenȱ analyzedȱ inȱ organismsȱdeployedȱinȱsitesȱaffectedȱbyȱdifferentȱspillsȱinȱtheȱareaȱofȱGaliciaȱandȱ theȱ gulfȱ ofȱ Cádiz.ȱ Inȱ addition,ȱ biomarkersȱ resultsȱ haveȱ beenȱ linkedȱ withȱ chemicalsȱ boundȱ toȱ sedimentsȱ inȱ orderȱ toȱ elucidateȱ theȱ cause,ȱ sourceȱ andȱ bioavailabilityȱofȱadverseȱaffectsȱafterȱexposure.ȱAȱsetȱofȱbiomarkersȱincludingȱ antioxidantȱ andȱ detoxificationȱ activitiesȱ haveȱ beenȱ evaluatedȱ inȱ additionȱ toȱ histopathologicalȱ damagesȱ inȱ targetȱ tissues.ȱ Theȱ useȱ ofȱ twoȱ invertebrateȱ ofȱ species,ȱ theȱ clamȱ Ruditapesȱ philippinarumȱ andȱ theȱ crabȱ Carcinusȱ maenasȱ withȱ differenceȱfeedingȱhabitsȱprovidedȱaȱbetterȱassessmentȱofȱtheȱsubjectȱraised.ȱTheȱ lowestȱ sublethalȱ responsesȱ wereȱ observedȱ inȱ organismsȱ exposedȱ toȱ sedimentsȱ fromȱtheȱCíesȱIslandsȱinȱtheȱAINP,ȱalthoughȱtheȱpresenceȱofȱsomeȱmetalsȱcouldȱ haveȱinducedȱsomeȱstressȱinȱtheȱdeployedȱanimals.ȱThisȱpointsȱtoȱaȱrecoveryȱofȱ theȱareaȱfourȱyearsȱafterȱtheȱPrestigeȱoilȱspillȱalthoughȱtheȱinputsȱofȱsomeȱmetalsȱ areȱ consideredȱ aȱ potentialȱ risk.ȱ Organismsȱ exposedȱ inȱ CormeȬLaxeȱ presentedȱ highȱ levelsȱ ofȱ stressȱ thatȱ wereȱ notȱ observedȱ inȱ laboratoryȱ exposuresȱ (MoralesȬ Casellesȱetȱal.,ȱsubmitted)ȱwhatȱsuggestsȱtheȱimpactȱofȱsourcesȱofȱcontaminants,ȱ notȱonlyȱhydrocarbons,ȱsuchȱasȱtheȱmaterialȱfromȱtheȱaquacultureȱcages.ȱInȱtheȱ caseȱ ofȱ theȱ bayȱ ofȱ Algecirasȱ theȱ toxicȱ effectsȱ ofȱ contaminantsȱ wereȱ probablyȱ diminishȱ byȱ theȱ waterȱ removalȱ ofȱ theȱ tidalȱ fluctuationȱ althoughȱ targetȱ tissuesȱ presentedȱtheȱhighestȱalterationsȱofȱallȱtheȱstudyȱsites.ȱȱ Previousȱstudiesȱagreeȱwithȱtheȱfactȱthatȱinȱsituȱcagedȱorganismȱapproachȱ shouldȱ beȱ usedȱ togetherȱ withȱ otherȱ assessmentȱ methodsȱ suchȱ asȱ laboratoryȱ toxicityȱtestingȱ(Burtonȱetȱal.,ȱ2005).ȱInȱthisȱreportȱitȱhasȱbeenȱshownȱhowȱfieldȱ studiesȱ haveȱ permittedȱ toȱ identifyȱ alternativeȱ sourcesȱ ofȱ stressȱ thatȱ areȱ notȱ possibleȱtoȱobserveȱinȱlaboratoryȱexperiments.ȱTherefore,ȱauthorsȱconsiderȱthatȱ bioassaysȱshouldȱnotȱlimitȱtoȱexperimentalȱdesignsȱunderȱlaboratoryȱconditionsȱ andȱ proposeȱ thatȱ fieldȱ deploymentsȱ provideȱ theȱ lacksȱ regardingȱ toȱ theȱ - 205 - uncontrolledȱ circumstancesȱ ofȱ inȱ situȱ surveysȱ andȱ theȱ excessivelyȱ controlȱ ofȱ laboratoryȱtests.ȱ 6.ȱAknowledgmentsȱ Theȱ workȱ describedȱ wasȱ partlyȱ supportedȱ byȱ theȱ projectsȱ VEM2003Ȭ 20563/INTER,ȱ andȱ CTM2005Ȭ07282ȬC03Ȭ01/TECNOȱ financedȱ byȱ theȱ Spanishȱ Educationȱ andȱ Scienceȱ Ministryȱ andȱ byȱ CISȱ fundedȱ byȱ theȱ Ministryȱ ofȱ Environment.ȱ Carmenȱ MoralesȬCasellesȱ thanksȱ theȱ Ministryȱ ofȱ Educationȱ andȱ Scienceȱ forȱ fundingȱ herȱ researchȱ fellowshipȱ (FPU).ȱ Dr.ȱ Ribaȱ thanksȱ theȱ I3pȱ programȱ forȱ supportingȱ herȱ participationȱ inȱ thisȱ research.ȱ Weȱ areȱ gratefulȱ forȱ theȱsupportȱandȱhelpȱofȱtheȱmembersȱofȱtheȱCISȱandȱtheȱICMANȬCSIC.ȱSpecialȱ 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Contam.ȱToxicol.ȱ37,ȱ236Ȭ241.ȱ Montserrat,ȱJ.M.,ȱGeracitano,ȱL.A.,ȱBianchini,ȱA.ȱCurrentȱandȱfutureȱ perspectivesȱusingȱbiomarkersȱtoȱassessȱpollutionȱinȱaquaticȱecosystems.ȱ CommentsȱToxicol,ȱ2003,ȱ9,ȱ255Ȭ269.ȱ MoralesȬCaselles,ȱ C.,ȱ MartínȬDíaz,ȱ M.L.,ȱ Riba,ȱ I.,ȱ Sarasquete,ȱ C.,ȱ DelValls,ȱ T.A.ȱ (submitted).ȱ Roleȱ ofȱ biomarkersȱ toȱ assessȱ oilȬcontaminatedȱ sedimentȱ qualityȱusingȱtoxicityȱtestsȱwithȱclamsȱandȱcrabs.ȱ NOAA.,ȱ 1999.ȱ Sedimentȱ Qualityȱ Guidelinesȱ developedȱ forȱ theȱ Nationalȱ Statusȱ andȱTrendȱPrograms.ȱȱȱ - 208 - OrtizȬDelgado,ȱ JB.,ȱ Segner,ȱ H.,ȱ Arellano,ȱ J.,ȱ Sarasquete,ȱ C.ȱ 2007.ȱ Histopathologicalȱalterations,ȱERODȱactivity,ȱCYP1Aȱproteinsȱandȱbiliaryȱ metabolitesȱ inȱ seabreamȱ Sparusȱ aurataȱ exposedȱ toȱ benzoȬaȬpyreneȱ Ȭ B(a)PȬ.ȱHistologyȱandȱHistopathology,ȱ22:ȱ417Ȭ432ȱ Rodríguezȱ deȱ laȱ Rua,ȱ A.,ȱ ȱ Arellano,ȱ JM.,ȱ Gonzálezȱ deȱ Canales,ȱ ML.,ȱ Blasco,ȱ J.,ȱ Sarasquete,ȱ C.ȱ 2005.ȱ Accumulationȱ ofȱ copperȱ andȱ histopathologicalȱ alterationsȱinȱȱCrassostreaȱangulata.ȱCienc.ȱMar.ȱ31,ȱ455Ȭ466ȱ Riba,ȱI.,ȱForja,ȱJ.M.,ȱGómezȬParra,ȱA.,ȱDelValls,ȱT.A.,ȱ2004.ȱSedimentȱqualityȱinȱ littoralȱ regionsȱ ofȱ theȱ Gulfȱ ofȱ Cádiz:ȱ aȱ triadȱ approachȱ toȱ addressȱ theȱ influenceȱofȱminingȱactivities.ȱEnviron.ȱPollut.ȱ132,ȱ341Ȭ353.ȱ Riba,ȱ I.,ȱ Zitko,ȱ V.,ȱ Forja,ȱ J.M.,ȱ DelValls,ȱ T.A.,ȱ 2003.ȱ Derivingȱ sedimentȱ qualityȱ guidelinesȱ inȱ theȱ Guadalquivirȱ estuaryȱ associatedȱ withȱ theȱ Aznalcóllarȱ miningȱspill:ȱaȱcomparisonȱofȱdifferentȱapproaches.ȱCienc.ȱMar.ȱ29ȱ Sibley,ȱ P.K.,ȱ Benoit,ȱ D.A.,ȱ Balcer,ȱ M.D.,ȱ Phipps,ȱ G.L.,ȱ West,ȱ C.W.,ȱ ȱ Hoke,ȱ R.A.,ȱȱ Ankley,ȱ G.T.ȱ 1999.ȱ Inȱ situȱ bioassayȱchamberȱforȱassessmentȱofȱsedimentȱ toxicityȱ andȱ bioaccumulationȱ usingȱ benthicȱ invertebrates.ȱ Environ.ȱ Toxicol.ȱChem.ȱ18ȱȱp.ȱ2325ȱȱ SuterȱGW.ȱEcologicalȱRiskȱAssessment.ȱBocaȱRaton,ȱFL,ȱUSA:ȱLewisȱPublishers;ȱ 1993.ȱp.ȱ538.ȱ TweedeȱKamer,ȱvergaderjaar,ȱ1994e1995,ȱEvaluatienotaȱWater,ȱDutchȱstandardsȱ forȱcontaminatedȱsediments,ȱ21ȱ250,ȱ2728.ȱ USEPA,ȱ 1994.ȱ Methodsȱ forȱ Assessingȱ theȱ Toxicityȱ ofȱ SedimentȬassociatedȱ Contaminantsȱ withȱ Estuarineȱ andȱ Marineȱ Amphipods.ȱ Unitedȱ Statesȱ EnvironmentalȱProtectionȱAgencyȱ(USEPA).ȱEPA/600/RȬ94/025.ȱ Walker,ȱ C.H.,ȱ Hopkin,ȱ S.P.,ȱ Sibly,ȱ R.M.,ȱ Peakall,ȱ D.B.ȱ 2006.ȱ Principlesȱ ofȱ Ecotoxicology.ȱCRCȱPressȱBocaȱRaton.ȱ315ȱpp.ȱȱ - 209 - ȱ - 210 - KineticȱofȱbiomarkersȱinȱtheȱclamȱRuditapesȱphilippinarumȱ CarmenȱMoralesȬCaselles†ȱ‡ȱ*,ȱLauraȱMartínȬDíaz†ȱ‡,ȱInmaculadaȱRiba†ȱ‡,ȱ CarmenȱSarasquete†,ȱT.ȱÁngelȱDelValls†ȱ‡ȱ †ȱIȱUnidadȱAsociadaȱdeȱCalidadȱAmbientalȱyȱPatologíaȱ(CSICȱ&ȱUCA)ȱinstitutoȱ deȱCienciasȱMarinasȱdeȱAndalucíaȱ(ICMANȬCSIC),ȱAvda.ȱRepúblicaȱSaharauiȱs/n,ȱ PuertoȱRealȱ11510,ȱCádiz,ȱSpainȱ ‡ȱUNESCOȱUNITWIN/WiCop,ȱFacultadȱdeȱCienciasȱdelȱMarȱyȱAmbientales,ȱ UniversidadȱdeȱCádiz,ȱPolígonoȱRíoȱSanȱPedroȱs/n,ȱPuertoȱRealȱ11510,ȱCádiz,ȱ Spain.ȱ Abstractȱ Theȱ detoxificationȱ andȱ antioxidantȱ systemsȱ inȱ theȱ clamȱ Ruditapesȱ philippinarumȱ wasȱ studiedȱ byȱ analyzingȱ theȱ kineticsȱ ofȱ aȱ setȱ ofȱ biomarkers.ȱ Phaseȱ Iȱ cytochromeȱ P450Aȱ (CYP1A)ȱ levelsȱ wereȱ measuredȱ asȱ digestiveȱ glandȱ ethoxyresorufinȱOȬdeethylaseȱ(EROD)ȱactivityȱandȱbyȱgluthationeȬSȬtransferaseȱ (Phaseȱ II),ȱ whereasȱ antioxidantȱ activityȱ wasȱ evaluatedȱ byȱ theȱ glutationeȱ reductaseȱ (GR)ȱ andȱ glutationeȱ peroxidasaȱ (GPX)ȱ inductions.ȱ Analysesȱ wereȱ performedȱ onȱ clamsȱ exposedȱ toȱ PAHsȱ contaminatedȱ sedimentsȱ underȱ fieldȱ conditionsȱ afterȱ 7,ȱ 14,ȱ 21ȱ andȱ 28ȱ daysȱ ofȱ exposure.ȱ Histopathologicalȱ lesionsȱ wereȱalsoȱdeterminedȱtoȱassessȱtheȱeffectsȱofȱpollutantsȱinȱtargetȱtissuesȱsuchȱasȱ gillsȱ andȱ digestiveȱ glands.ȱ Bioassaysȱ wereȱ performedȱ underȱ fieldȱ conditionsȱ usingȱcontaminatedȱsedimentsȱfromȱtwoȱareasȱofȱtheȱSpanishȱcoastȱaffectedȱbyȱ oilȱ spills.ȱ Sedimentsȱ fromȱ theȱ selectedȱ sitesȱwereȱ chemicallyȱ characterizedȱ andȱ theȱ dataȱ obtainedȱ wereȱ correlatedȱ withȱ theȱ kineticȱ approachȱ ofȱ biomarkers.ȱ Resultsȱ showȱ anȱ importantȱ relationshipȱ betweenȱ theȱ phaseȱ Iȱ andȱ IIȱ detoxificationȱ enzymesȱ inȱ theȱ clamȱ R.ȱ philippinarumȱ whereasȱ hitopathologicalȱ lesionsȱ wereȱ mainlyȱ relatedȱ toȱ generalȱ stress.ȱ Inȱ addition,ȱ toxicityȱ testingȱ followingȱaȱkineticȱapproachȱunderȱfieldȱconditionsȱcanȱbeȱconsideredȱaȱsuitableȱ toolȱ toȱ monitoreȱ theȱ pollutantsȱ impact,ȱ asȱ wellȱ asȱ toȱ detectȱ otherȱ sourcesȱ ofȱ contamination.ȱ ȱȱȱEnvironementalȱToxicologyȱandȱChemistry (enviado) - 211 - Keywords:ȱ oilȱ spill,ȱ sedimentȱ quality,ȱ detoxification,ȱ histopathology,ȱ contaminationȱ 1.ȱIntroductionȱ Biomarkersȱ haveȱ beenȱ shownȱ toȱ beȱ usefulȱ toolsȱ inȱ characterizingȱ theȱ healthȱ statusȱ ofȱ animalsȱ fromȱ impactedȱ areas,ȱ whereȱ complexȱ mixturesȱ ofȱ pollutantsȱ areȱ usuallyȱ presentȱ [1,ȱ 2,ȱ 3,ȱ 4,ȱ 5].ȱ Ecotoxicityȱ studiesȱ basedȱ onȱ biomarkersȱ allowȱ toȱ determineȱ theȱ impactȱ ofȱ environmentalȱ stressorsȱ andȱ toȱ easilyȱfollowȱtheȱevolutionȱofȱtheȱecosystemȱtowardsȱdegradationȱorȱrestorationȱ [6].ȱ EthoxyresorufinȱOȬdeethylaseȱactivityȱ(EROD)ȱrepresentsȱaȱgoodȱmarkerȱ inȱMFOȱ(mixedȬfunctionȱoxygenase),ȱwhichȱisȱtheȱfirstȱmodeȱofȱdetoxificationȱofȱ manyȱ organicȱ pollutantsȱ (polycyclicȱ aromaticȱ hydrocarbonsȱ ȬPAHsȬ,ȱ polychlorinatedȱ biphenylsȱ ȬPCBsȬ).ȱ Theȱ measurementȱ ofȱ ERODȱ activityȱ isȱ successfullyȱ usedȱ asȱ aȱ potentialȱ biomarkerȱ ofȱ exposureȱ toȱ xenobioticȱ contaminantsȱ inȱ marineȱ pollutionȱ monitoring.ȱ GlutathioneȬSȬtransferaseȱ (GST)ȱ representsȱ aȱ phaseȱ IIȱ detoxificationȱ enzymeȱ butȱ alsoȱ implicatedȱ inȱ oxidativeȱ stressȱ events;ȱ aȱ criticalȱ roleȱ forȱ GSTsȱ isȱ obviouslyȱ defenceȱ againstȱ oxidativeȱ damageȱandȱperoxidativeȱproductsȱofȱDNAȱandȱlipidsȱ[7].ȱDueȱtoȱtheȱroleȱthatȱ GSTsȱ playȱ inȱ conjugatingȱ reactiveȱ epoxideȱ speciesȱ andȱ otherȱ electrophiles,ȱ inductionȱofȱtheseȱenzymesȱmustȱbeȱconsideredȱtoȱbeȱbeneficialȱ[7].ȱGlutathioneȱ peroxidasesȱ (GPX)ȱ catalyseȱ mainlyȱ theȱ reductionȱ ofȱ organicȱ peroxidesȱ toȱ alcoholsȱ usingȱ reducedȱ glutathioneȱ [8]ȱ whereasȱ glutathioneȱ reductaseȱ (GR)ȱ isȱ alsoȱusedȱasȱantioxidantȱparameter.ȱInȱaddition,ȱhistopathologicalȱalterationsȱinȱ gillsȱ andȱ digestiveȱ glandsȱ ofȱ bivalveȱ molluscsȱ tissuesȱ haveȱ beenȱ shownȱ toȱ beȱ responsiveȱ andȱ sensitiveȱ toȱ aȱ wideȱ rangeȱ ofȱ contaminantsȱ andȱ haveȱ beenȱ developedȱ andȱ recommendedȱ asȱ biomarkersȱ forȱ monitoringȱ theȱ effectsȱ ofȱ pollutionȱ[9].ȱ - 212 - Theȱaimȱofȱthisȱstudyȱwasȱtoȱassessȱtheȱdetoxificationȱsystemȱofȱtheȱclamȱ Ruditappesȱ philippinarumȱ exposedȱ toȱ oilȬcontaminatedȱ sedimentsȱ underȱ fieldȱ conditionsȱ byȱ analyzingȱ theȱ kineticȱ ofȱ biomarkersȱ ofȱ exposureȱ relatedȱ toȱ theȱ detoxificationȱsystemȱandȱantioxidantȱactivities.ȱ 2.ȱMethodologyȱȱ Theȱ studyȱ sitesȱ chosenȱ inȱ theȱ presentȱ studyȱ haveȱ beenȱ affectedȱ byȱ oilȱ spillsȱbyȱaȱdifferentȱway.ȱTheȱBayȱofȱAlgecirasȱ(SȱSpain)ȱsuffersȱchronicȱeffectsȱ dueȱ toȱ theȱ severalȱ spillsȱ ofȱ oilȱ andȱ otherȱ compoundsȱ thatȱ supposeȱ anȱ inputȱ ofȱ contaminantsȱ inȱ theȱ waterȱ andȱ sedimentȱ ofȱ theȱ zone.ȱ Onȱ theȱ otherȱ hand,ȱ theȱ GalicianȱCoastȱ(NWȱSpain)ȱexperiencedȱoneȱofȱtheȱmajorȱaccidentalȱoilȱspillsȱinȱ Europeȱ whenȱ inȱ Novemberȱ 2002,ȱ theȱ tankerȱ Prestigeȱ startedȱ droppingȱ heavyȱ fuelȱoilȱbeyondȱ66,000ȱtons.ȱThreeȱsitesȱwereȱselectedȱinȱtheȱGalicianȱcoast,ȱtwoȱ inȱ theȱ bayȱ ofȱ CormeȬLaxeȱ (CL1,ȱ CL2)ȱ andȱ oneȱ inȱ theȱ Atlanticȱ Islandȱ Nationalȱ Parkȱ(AINP2);ȱbothȱareasȱwereȱimportantlyȱaffectedȱbyȱtheȱPrestigeȱoilȱspill,ȱandȱ haveȱbeenȱrecoveredȱinȱlastȱfewȱyearsȱ[9].ȱTwoȱstationsȱwereȱalsoȱselectedȱinȱtheȱ mouthȱofȱtheȱriverȱGuadarranqueȱinȱtheȱBayȱofȱAlgecirasȱ(ALG1ȱandȱALG2).ȱAȱ referenceȱsiteȱwasȱselectedȱinȱaȱcleanȱareaȱinȱtheȱBayȱofȱCádizȱ(SȱSpain)ȱ[4]ȱȱ Individualsȱ ofȱ Ruditapesȱ Philippinarumȱ wereȱ obtainedȱ fromȱ anȱ aquacultureȱ farm,ȱ andȱ afterȱ oneȱ weekȱ ofȱ acclimation,ȱ clamsȱ wereȱ deployedȱ inȱ cagesȱ (50cmȱ xȱ 25cmȱ xȱ 15cm)ȱ inȱ theȱ selectedȱ sitesȱ andȱ sedimentȱ samplesȱ wereȱ carriedȱ toȱ theȱ laboratoryȱ toȱ performȱ theȱ chemicalȱ analysis.ȱ Theȱ experimentsȱ lastedȱ28ȱdaysȱandȱsurveysȱwereȱperformedȱweekly.ȱȱ Theȱ analysesȱ ofȱ PAHsȱ andȱ PCBsȱ boundȱ toȱ sedimentsȱ wereȱ carriedȱ outȱ accordingȱ toȱ USEPAȱ SWȬ846ȱ Methodȱ 827C78082ȱ [11].ȱ Brieflyȱ driedȱ samplesȱ wereȱSoxhletȱextractedȱwithȱnȬhexaneȱforȱ18ȱh,ȱandȱtheȱextractsȱwereȱisolatedȱbyȱ columnȱ chromatographyȱ onȱ Florisileȱ aluminoȬsilica.ȱ PCBsȱ andȱ PAHsȱ wereȱ elutedȱandȱtheirȱfractionsȱwereȱdriedȱinȱaȱrotatingȱevaporatorȱandȱreȬdissolvedȱ - 213 - inȱisooctane.ȱAromaticȱfractionsȱwereȱanalyzedȱonȱaȱHewlettePackardȱ(HP)ȱ5890ȱ Seriesȱ IIȱ gasȱ chromatographerȱ coupledȱ withȱ anȱ HPȱ 5970ȱ massȱ spectrometer.ȱ PAHsȱwereȱanalyzedȱbyȱGCȬMSȱusingȱselectedȱionȱmonitoringȱ(SIM).ȱAnalysisȱ ofȱ PCBsȱ asȱ AROCLORȱ 1242ȱ andȱ AROCLORȱ 1260ȱ wasȱ performedȱ usingȱ theȱ sameȱ instrumentȱ withȱ anȱ electronȱ captureȱ detectorȱ (GC/ECD).ȱ Forȱ bothȱ setȱ ofȱ organicȱ chemicals,ȱ PAHsȱ andȱ AROCLOR,ȱ theȱ analyticalȱ procedureȱ showedȱ agreementȱwithȱtheȱcertifiedȱvaluesȱofȱmoreȱthanȱ90%.ȱ TraceȱmetalȱanalysisȱwereȱanalyzedȱasȱdescribedȱbyȱCasadoȬMartínezȱetȱ al.[12];ȱbriefly,ȱ2.5ȱgȱofȱsedimentsȱ(<0.065ȱmm)ȱwereȱplacedȱinȱTeflonȱcontainersȱ andȱ wereȱ digestedȱ inȱ microwaveȱ (400W,ȱ 15ȱ min,ȱ twice)ȱ withȱ HNO3ȱ 2N.ȱ Theȱ extractsȱ wereȱ purifiedȱ byȱ passingȱ throughȱ aȱ CȬ18ȱ columnȱ andȱ metalsȱ analysesȱ wereȱperformedȱbyȱanodicȱvoltamperimetryȱ(ȬZn,ȱPb,ȱNi,ȱCoȱandȱCuȬȱMetrohmȱ ApplicationȱBulletinȱ Nºȱ147;ȱȬȱVȬȱMetrohmȱApplicationȱNoteȱNºȱVȬ81).ȱForȱHgȱ theȱ coldȱ vapourȱ techniqueȱ wasȱ usedȱ andȱ wasȱ quantifiedȱ usingȱ atomicȱ absorptionȱ spectrometry.ȱ Theȱ analyticalȱ proceduresȱ wereȱ checkedȱ usingȱ referenceȱ materialȱ (MESSȬ1ȱ NRCȱ andȱ CRMȱ 277ȱ BCR)ȱ andȱ showedȱ aȱ recoveryȱ greaterȱthanȱ90%ȱofȱtheȱcertifiedȱconcentration.ȱ Testedȱorganismsȱwereȱcollectedȱfromȱcagesȱandȱwereȱdissectedȱtheȱdaysȱ 0,ȱ7,ȱ14,ȱ21ȱandȱ28ȱofȱexposure;ȱtheȱdigestiveȱglandȱwasȱwereȱextractedȱandȱkeptȱ atȱȬ80ºCȱpriorȱhomogenizationȱȱ[1].ȱSamplesȱwereȱcentrifugedȱatȱ10,000gȱforȱ30ȱ min,ȱandȱtheȱsupernatantȱwasȱusedȱforȱtheȱdetoxificationȱactivityȱdeterminationȱ andȱ theȱ totalȱ proteinȱ contentȱ describedȱ byȱ Bradfordȱ [13].ȱ Mixedȱ functionȱ oxygenaseȱ activity,ȱ whichȱ isȱ theȱ firstȱ modeȱ ofȱ detoxificationȱ ofȱ manyȱ organicȱ pollutants,ȱ wasȱ measuredȱ usingȱ theȱ ERODȱ assayȱ [14].ȱ Theȱ oxidationȱ ofȱ 1ȱ mMȱ NADPHȱ byȱ Glutathioneȱ Reductaseȱ activityȱ (GR)ȱ inȱ theȱ presenceȱ ofȱ 10ȱ mMȱ oxidizedȱ glutathioneȱ wasȱ alsoȱ monitoredȱ atȱ 340ȱ nmȱ [15].ȱ Glutathioneȱ Peroxidaseȱactivityȱ(GPX)ȱwasȱmeasuredȱaccordingȱtoȱMcFarlandȱetȱal.ȱ[14].ȱTheȱ phaseȱ IIȱ metabolizingȱ enzymeȱ GlutathioneȬSȬtransferaseȱ (GST)ȱ activityȱ wasȱ - 214 - determinedȱ byȱ monitoringȱ theȱ rateȱ ofȱ conjugationȱ ofȱ glutathioneȱ (GSH)ȱ toȱ 1Ȭ chloroȬ2,4Ȭdinitrobenzeneȱ (CDNB)ȱ atȱ 340ȱ nm,ȱ methodologyȱ adaptedȱ fromȱ McFarlandȱ etȱ al.ȱ [15].ȱ Biomarkersȱ resultsȱ wereȱ normalizedȱ withȱ theȱ proteinȱ content.ȱ Correlationȱ amongȱ chemicalsȱ andȱ biomarkersȱ wereȱ evaluatedȱ byȱ theȱ Pearsonȱanalysisȱ(pȱ<ȱ0.05ȱandȱpȱ<ȱ0.01).ȱȱ Gillsȱandȱliverȱtissuesȱofȱtheȱclamsȱwereȱalsoȱfixedȱinȱphosphateȱbufferedȱ 10%ȱ formaldehydeȱ (pHȱ 7.2)ȱ forȱ histopathologyȱ determinationȱ afterȱ 28ȱ daysȱ ofȱ exposure.ȱ Afterȱ dehydrationȱ inȱ gradedȱ concentrationsȱ ofȱ ethanol,ȱ theȱ samplesȱ wereȱ embeddedȱ inȱ paraffinȱ wax.ȱ Histologicalȱ sectionsȱ ofȱ 6ȱ toȱ 8ȱ ΐmȱ thicknessȱ wereȱstainedȱwithȱHaematoxylin–ȱEosinȱandȱHaematoxylin–VOFȱ[16].ȱSectionsȱ wereȱ reviewedȱ byȱ lightȱ microscopyȱLeitzȱ LaborluxȱSȱandȱ photographedȱ(Sonyȱ DKCȬCM30).ȱ 3.ȱResultsȱ 3.1.ȱChemicalȱanalysisȱȱ Chemicalȱ analysisȱ resultsȱ areȱ shownȱ inȱ tableȱ 1.ȱ Theȱ concentrationȱ ofȱ PAHsȱinȱsedimentsȱisȱhigherȱinȱtheȱsedimentsȱfromȱtheȱBayȱofȱAlgecirasȱlocatedȱ inȱtheȱsiteȱALG1ȱ(2961ȱΐgȱkgȬ1ȱdryȱweight),ȱfollowedȱbyȱthoseȱfromȱCL1ȱ(820ȱΐgȱ kgȬ1ȱ dryȱ weight)ȱ inȱ CormeȬLaxeȱ andȱ ALG2ȱ (802ȱ ΐgȱ kgȬ1ȱ dryȱ weight)ȱ alsoȱ inȱ Algeciras.ȱ Sedimentsȱ fromȱ theȱ AINPȱ presentȱ theȱ lowestȱ PAHsȱ contentȱ inȱ theirȱ sediments.ȱ ALG2ȱ alsoȱ presentedȱ alsoȱ presentedȱ theȱ highestȱ concentrationȱ ofȱ PCBsȱ(22ȱmgȱkgȬ1ȱdryȱweight),ȱCdȱ(0.17ȱmgȱkgȬ1ȱdryȱweight),ȱNiȱ(74.7ȱmgȱkgȬ1ȱdryȱ weight),ȱ Coȱ (12.8ȱ mgȱ kgȬ1ȱ dryȱ weight)ȱ andȱ Vȱ (26.1ȱ mgȱ kgȬ1ȱ dryȱ weight).ȱ Theȱ majorȱ amountȱ ofȱ Znȱ wasȱ foundȱ inȱ sedimentsȱ fromȱ CL1ȱ (244ȱ mgȱ kgȬ1ȱ dryȱ weight),ȱ whereasȱ theȱ highestȱ concentrationȱ ofȱ Pbȱ wasȱ analyzedȱ inȱ sedimentsȱ fromȱCL2ȱ(44ȱmgȱkgȬ1ȱdryȱweight)ȱbothȱsitesȱinȱCormeȬLaxe.ȱCuȱwasȱhigherȱinȱ AINP2ȱ (31.6ȱ mgȱ kgȬ1ȱ dryȱ weight).ȱ ȱ Organicȱ contaminationȱ wasȱ notȱ detectedȱ inȱ - 215 - theȱ referenceȱ siteȱ (CA)ȱ whereasȱ theȱ metalȱ contentȱ inȱ sedimentsȱ wasȱ relativelyȱ low.ȱ Tableȱ 1.ȱ Concentrationȱ ofȱ PAHsȱ andȱ PCBsȱ (ΐgȱ kgȬ1ȱ dryȱ weight)ȱ andȱ metalsȱ (mgȱ kgȬ1ȱ dryȱ weight)ȱ inȱ theȱ sedimentsȱ collectedȱ fromȱ theȱ studyȱ sitesȱ (AINP:ȱ Atlanticȱ Nationalȱ Park,ȱ Galicia;ȱ CL:ȱ CormeȬLaxe,ȱ Galicia;ȱ ALG:ȱ Bayȱ ofȱ Algeciras;ȱCA:ȱByaȱofȱCádiz).ȱn.d.:ȱnotȱdetected.ȱ ȱ ȱȱ PAHsȱ PCBsȱ Znȱ Pbȱ Cuȱ Niȱ Coȱ ȱ AINP2ȱ 239ȱ 4.76ȱ 37.5ȱ 6.54ȱ 31.6ȱ 5.02ȱ 0.87ȱ CL1ȱ 820ȱ 2.28ȱ 244ȱ 14.3ȱ 19.1ȱ 7.03ȱ 0.67ȱ ȱ CL2ȱ 537ȱ 2.60ȱ 65.7ȱ 44.0ȱ 22.1ȱ 9.39ȱ 1.21ȱ ȱ ALG1ȱ 2961ȱ 22.0ȱ 138ȱ 21.6ȱ 5.01ȱ 74.7ȱ 12.8ȱ ALG2ȱ 802ȱ 1.75ȱ 35.3ȱ 6.21ȱ 3.67ȱ 13.1ȱ 5.59ȱ CAȱ n.dȱ n.d.ȱ 21.3ȱ 2.28ȱ 6.98ȱ 0.06ȱ 3.40ȱ ȱ 3.2.ȱBiomarkersȱofȱexposureȱ Biomarkerȱ responsesȱ ofȱ deployedȱ animalsȱ areȱ summarizedȱ inȱ Figureȱ 1ȱ andȱ Figureȱ 2.ȱ Clamsȱ deployedȱ inȱ sitesȱ locatedȱ inȱ theȱ Galicianȱ Coastȱ presentedȱ anȱ initialȱ increaseȱ ofȱ GPXȱ inductionȱ duringȱ theȱ firstȱ weekȱ ofȱ exposureȱ (significantlyȱdifferentȱtoȱtheȱreferenceȱCA,ȱpȱ<ȱ0.01)ȱwhileȱtheȱfollowingȱweeksȱ theȱ activityȱ reachedȱ basalȱ levelsȱ exceptȱ forȱ siteȱ CL2ȱ whichȱ continuedȱ risingȱ showingȱaȱmaximumȱafterȱ28ȱdaysȱ(significantlyȱdifferentȱtoȱtheȱreferenceȱCA,ȱpȱ <ȱ 0.01).ȱ Theȱ behaviourȱ ofȱ thisȱ biomarkerȱ inȱ organismsȱ collectedȱ fromȱ cagesȱ placedȱ inȱ theȱ Bayȱ ofȱ Algecirasȱ wasȱ similarȱ toȱ thoseȱ fromȱ theȱ referenceȱ site,ȱ althoughȱ differencesȱ wereȱ significantȱ (pȱ <ȱ 0.01).ȱ Theȱ GRȱ activityȱ showedȱ significantȱ(pȱ<ȱ0.01)ȱdifferencesȱtoȱtheȱreferenceȱCAȱȱforȱtheȱsamplesȱcollectedȱinȱ theȱ Galicianȱ Coast;ȱ thisȱ biomarkerȱ presentedȱ anȱ increaseȱ alongȱ theȱ exposureȱ periodȱinȱclamsȱfromȱCormeȬLaxeȱwhereasȱtheȱotherȱstudyȱsitesȱpresentsȱsimilarȱ - 216 - inductionȱasȱtheȱreferenceȱsite,ȱexceptȱforȱaȱpeakȱdetectedȱinȱtheȱclamsȱfromȱtheȱ AINPȱ whichȱ appearedȱ afterȱ 14ȱ daysȱ ofȱ deploymentȱ (significantlyȱ differentȱ toȱ theȱreferenceȱCA,ȱpȱ<ȱ0.01).ȱALG2ȱalsoȱshowedȱsignificantȱdifferencesȱ(pȱ<ȱ0.05)ȱ toȱ CAȱ theȱ lastȱ dayȱ ofȱ survey.ȱ Duringȱ theȱ firstȱ weekȱ ofȱ experimentȱ theȱ GSTȱ activityȱ increasedȱ especiallyȱ inȱ clamsȱ collectedȱ inȱ theȱ Galicianȱ Coastȱ (significantlyȱ differentȱ toȱ theȱ referenceȱ CA,ȱ pȱ <ȱ 0.01);ȱ aȱ secondȱ maximumȱ wasȱ observedȱ inȱ theȱ lastȱ surveyȱ inȱ siteȱ CL2.ȱ Aȱ peakȱ wasȱ detectedȱ afterȱ 21ȱ daysȱ inȱ clamsȱ collectedȱ fromȱ ALG1ȱ inȱ theȱ Bayȱ ofȱ Algeciras.ȱ ERODȱ activityȱ alsoȱ presentedȱ anȱ intialȱ inductionȱ duringȱ theȱ firstȱ weekȱ ofȱ exposureȱ forȱ organismsȱ deployedȱ inȱ sitesȱ fromȱ theȱ Galicianȱ Coastȱ althoughȱ theȱ generalȱ patternȱ wasȱ toȱ estabilizeȱalongȱtheȱtime,ȱshowingȱsimilarȱresultsȱtheȱlastȱdayȱofȱtheȱexperiment.ȱ Significantȱdifferencesȱ(pȱ<ȱ0.01)ȱwithȱtheȱreferenceȱsiteȱCAȱwhereȱobservedȱforȱ allȱstudyȱsites.ȱȱ ȱ ȱ ȱ ȱ ȱ ȱ - 217 - 20 CL1 CL2 AINP2 ALG1 ALG2 CA GR (nmol/min/mg) 15 10 5 0 0 5 10 15 20 25 30 20 25 30 time (d) 30 CL1 CL2 AINP2 ALG1 ALG2 CA GPX (nmol/min/mg) 25 20 15 10 5 0 0 5 10 15 time (d) Figureȱ1.ȱGPXȱandȱGRȱactivitiesȱ(nmol/min/mgȱprotein)ȱmeasuredȱinȱtheȱ digestiveȱglandȱofȱR.ȱphilippinarumȱexposedȱalongȱ28ȱdaysȱtoȱoilȱcontaminatedȱ sedimentsȱ (AINP:ȱ Atlanticȱ Nationalȱ Park,ȱ Galicia;ȱ CL:ȱ CormeȬLaxe,ȱ Galicia;ȱ ALG:ȱBayȱofȱAlgeciras)ȱunderȱfieldȱconditionsȱ - 218 - 7000 CL1 CL2 AINP2 ALG1 ALG2 CA 6000 GST (nmol/min/mg) 5000 4000 3000 2000 1000 0 0 5 10 15 20 25 30 time (d) 10 CL1 CL2 AINP2 ALG1 ALG2 CA EROD (pmol/min/mg) 8 6 4 2 0 0 5 10 15 20 25 30 time (d) Figureȱ 2.ȱ GSTȱ (nmol/min/mgȱ protein)ȱ andȱ ERODȱ (pmol/mg/min)ȱ activitiesȱ inȱ theȱ digestiveȱ glandȱ ofȱ R.ȱ philippinarumȱ exposedȱ alongȱ 28ȱ daysȱ toȱ oilȱcontaminatedȱsedimentsȱ(AINP:ȱAtlanticȱNationalȱPark,ȱGalicia;ȱCL:ȱCormeȬ Laxe,ȱGalicia;ȱALG:ȱBayȱofȱAlgeciras)ȱunderȱfieldȱconditions.ȱ ȱ - 219 - 3.3.ȱBiomarkersȱofȱeffectȱȱ Afterȱ 28ȱ daysȱ ofȱ exposureȱ toȱ theȱ sedimentsȱ clamsȱ presentedȱ differentȱ alterationsȱ inȱ targetȱ tissuesȱ (gillsȱ andȱ gut).ȱ Mostȱ ofȱ theȱ analyzedȱ organismsȱ showȱ lesionsȱ relatedȱ withȱ generalȱ stress,ȱ includingȱ lossȱ ofȱ epithelialȱ cells,ȱ lamellaeȱ separationȱ andȱ haematiticȱ reaction.ȱ Organismsȱ exposedȱ toȱ sedimentsȱ fromȱtheȱBayȱofȱAlgecirasȱwereȱtheȱmostȱaffectedȱfollowedȱbyȱclamsȱexposedȱtoȱ sedimentsȱ fromȱ CormeȬLaxe,ȱ andȱ finallyȱclamsȱfromȱtheȱCiesȱtreatmentȱwhichȱ showedȱalterationsȱdueȱtoȱgeneralȱenvironmentalȱstress.ȱȱ 4.ȱDiscussionȱ Theȱfluctuationȱofȱdifferentȱbiomarkersȱinȱresponseȱtoȱdifferentȱtoxicantsȱ providesȱaȱpatternȱofȱresultsȱwhichȱcanȱgiveȱcluesȱasȱtoȱtheȱtypeȱofȱpollutantȱthatȱ isȱ causingȱ theȱ observedȱ effectȱ [17].ȱ Inȱ general,ȱ resultsȱ obtainedȱ inȱ thisȱ studyȱ showedȱ anȱ inductionȱ ofȱ GPX,ȱ GSTȱ andȱ ERODȱ activityȱ presentedȱ aȱ maximumȱ afterȱ theȱ firstȱ 7ȱ daysȱ ofȱ exposure,ȱ whereasȱ GRȱ showsȱ anȱ increaseȱ alongȱ theȱ deploymentȱ period.ȱ Correlationsȱ amongȱ biomarkersȱ (tableȱ 2)ȱ wereȱ significantȱ forȱtheȱinductionȱofȱtheȱdetoxificationȱsystemȱdeterminedȱbyȱERODȱactivityȱandȱ theȱantioxidantȱenzymesȱGRȱandȱGPXȱȱtheȱdayȱ7ȱofȱexposure.ȱThisȱpointsȱtoȱtheȱ factȱ thatȱ organismsȱ respondedȱ toȱ environmentalȱ stressorsȱ mainlyȱ duringȱ theȱ firstȱ daysȱ ofȱ deployment.ȱ Theȱ correlationsȱ observedȱ indicatedȱ aȱ relationshipȱ amongȱ organicȱ contaminantsȱ (PAHsȱ andȱ PCBs)ȱ andȱ metalsȱ Niȱ andȱ Coȱ inȱ theȱ sediments,ȱalthoughȱnoȱlinksȱwereȱdetectedȱwithȱbiomarkers.ȱAȱconnectionȱwasȱ detectedȱ betweenȱ Pbȱ andȱ theȱ inductionȱ ofȱ detoxificationȱ andȱ antioxidantȱ enzymesȱ (GPX,ȱ GSTȱ andȱ ERODȱ activities)ȱ afterȱ 28ȱ daysȱ ofȱ exposure.ȱ Theȱ Pbȱ originȱ inȱ pollutingȱ oilȱ wasȱ corroboratedȱ byȱ otherȱ authorsȱ [18];ȱ thereȱ isȱ oftenȱ aȱ strongȱrelationshipȱbetweenȱleadȱconcentrationsȱinȱsoilȱandȱparentȱmaterialȱ[19],ȱ soȱthisȱcompoundȱcouldȱbeȱrelatedȱtoȱanȱorganicȱcontaminationȱassociatedȱwithȱ aȱsourceȱofȱhydrocarbonsȱnotȱlinkedȱtoȱtheȱPAHsȱboundȱsediment,ȱandȱwhichȱisȱȱ - 220 - 0.118ȱ Ȭ0.297ȱ 0.9141ȱ 0.7991ȱ Ȭ0.109ȱ Ȭ0.002ȱ 0.411ȱ Ȭ0.238ȱ Ȭ0.192ȱ Ȭ0.044ȱ 0.129ȱ Ȭ0.124ȱ 0.016ȱ 0.079ȱ 0.869ȱ Ȭ0.255ȱ Ȭ0.317ȱ 0.025ȱ Ȭ0.117ȱ 0.458ȱ 0.214ȱ Ȭ0.149ȱ 0.9691ȱ 0.8631ȱ Ȭ0.209ȱ Ȭ0.245ȱ 0.299ȱ Ȭ0.185ȱ Ȭ0.345ȱ Ȭ0.269ȱ Ȭ0.042ȱ Ȭ0.133ȱ Ȭ0.208ȱ Ȭ0.117ȱ 0.758ȱ Ȭ0.144ȱ Ȭ0.479ȱ Ȭ0.208ȱ Ȭ0.313ȱ 0.272ȱ Znȱ Pbȱ Cuȱ Niȱ Coȱ GPXȱ7ȱ GPXȱ14ȱ GPXȱ21ȱ GPXȱ28ȱ GRȱ7ȱ GR14ȱ GRȱ21ȱ GRȱ28ȱ GSTȱ7ȱ GSTȱ14ȱ GSTȱ21ȱ GSTȱ28ȱ ERODȱ7ȱ ERODȱ14ȱ ERODȱ21ȱ ERODȱ28ȱ 0.088ȱ 0.275ȱ 1ȱ PCBsȱ 0.041ȱ Ȭ0.198ȱ Ȭ0.024ȱ 0.421ȱ 0.170ȱ 0.817ȱ 0.148ȱ 0.094ȱ 0.128ȱ 0.125ȱ Ȭ0.035ȱ 0.414ȱ 0.068ȱ 0.485ȱ 0.294ȱ 0.492ȱ 0.187ȱ 0.335ȱ 0.020ȱ 0.266ȱ 1ȱ 0.275ȱ 0.458ȱ 0.9051ȱ 1ȱ 0.9051ȱ PAHsȱ Znȱ PCBsȱ Ȭ0.100ȱ 0.225ȱ 0.7931ȱ Ȭ0.421ȱ Ȭ0.304ȱ 0.047ȱ Ȭ0.190ȱ 0.143ȱ 0.8111ȱ 0.085ȱ 0.817ȱ 0.257ȱ Ȭ0.22ȱ Ȭ0.206ȱ Ȭ0.548ȱ Ȭ0.095ȱ Ȭ0.185ȱ Ȭ0.522ȱ Ȭ0.261ȱ Ȭ0.258ȱ 0.056ȱ Ȭ0.239ȱ Ȭ0.406ȱ Ȭ0.293ȱ 0.053ȱ Ȭ0.236ȱ 0.121ȱ 0.138ȱ Ȭ0.166ȱ 0.383ȱ Ȭ0.277ȱ Ȭ0.279ȱ 0.8821ȱ 1ȱ Ȭ0.123ȱ 0.260ȱ 0.335ȱ 0.9141ȱ 0.9691ȱ Niȱ 0.702ȱ Ȭ0.640ȱ Ȭ0.078ȱ 0.172ȱ 0.061ȱ Ȭ0.203ȱ Ȭ0.131ȱ 0.076ȱ 0.8741ȱ 0.171ȱ 0.310ȱ Ȭ0.299ȱ Ȭ0.052ȱ Ȭ0.342ȱ Ȭ0.123ȱ 1ȱ 0.129ȱ 0.020ȱ Ȭ0.297ȱ Ȭ0.149ȱ Cuȱ 0.475ȱ 0.059ȱ 0.213ȱ 0.059ȱ 0.260ȱ 0.129ȱ 1ȱ 0.266ȱ 0.118ȱ 0.214ȱ Pbȱ 0.215ȱ Ȭ0.144ȱ Ȭ0.323ȱ Ȭ0.583ȱ Ȭ0.073ȱ 0.746ȱ Ȭ0.182ȱ Ȭ0.307ȱ Ȭ0.312ȱ Ȭ0.044ȱ Ȭ0.274ȱ Ȭ0.566ȱ Ȭ0.231ȱ 0.114ȱ Ȭ0.423ȱ Ȭ0.431ȱ 1ȱ 0.8821ȱ Ȭ0.342ȱ 0.059ȱ 0.187ȱ 0.7991ȱ 0.8631ȱ Coȱ 0.860 ȱ 0.949 ȱ Ȭ0.152ȱ Ȭ0.310ȱ Ȭ0.321ȱ 0.641ȱ 0.455ȱ 0.816ȱ 0.8221ȱ Ȭ0.611ȱ 0.176ȱ Ȭ0.858ȱ 0.8372ȱ 0.9341ȱ 0.105ȱ 0.743ȱ Ȭ0.400ȱ Ȭ0.029ȱ 0.738ȱ Ȭ0.176ȱ 0.392ȱ 0.894ȱ Ȭ0.907ȱ Ȭ0.028ȱ 0.388ȱ 1ȱ 0.581ȱ Ȭ0.212ȱ 0.114ȱ 0.383ȱ 0.31ȱ 0.475ȱ 0.485ȱ 0.411ȱ 0.299ȱ GPXȱ 21ȱ 0.26ȱ 0.416ȱ 0.559ȱ 0.496ȱ 0.7782ȱ 0.483ȱ 0.137ȱ 0.767ȱ 0.321ȱ 0.628ȱ Ȭ0.482ȱ 0.699ȱ 1 0.124ȱ 1 0.27ȱ 1ȱ 0.581ȱ 0.675ȱ 0.675ȱ Ȭ0.423ȱ Ȭ0.277ȱ Ȭ0.299ȱ 0.059ȱ 0.294ȱ Ȭ0.002ȱ Ȭ0.245ȱ GPXȱ 14ȱ Ȭ0.212ȱ 1ȱ Ȭ0.431ȱ Ȭ0.279ȱ Ȭ0.052ȱ 0.213ȱ 0.492ȱ Ȭ0.109ȱ Ȭ0.209ȱ GPXȱ 7ȱ 221 0.7401ȱ 0.919ȱ 0.095ȱ 0.305ȱ 0.9061ȱ Ȭ0.013ȱ Ȭ0.583ȱ 0.067ȱ 0.366ȱ 0.744ȱ Ȭ0.115ȱ 0.274ȱ 1ȱ 0.388ȱ 0.124ȱ 0.27ȱ Ȭ0.231ȱ Ȭ0.166ȱ 0.076ȱ 0.125ȱ 0.138ȱ 0.321ȱ 0.861ȱ Ȭ0.242ȱ 0.635ȱ 0.459ȱ 0.9881ȱ 0.199ȱ 0.221ȱ 0.568ȱ 0.6912ȱ 0.579ȱ 0.345ȱ 0.586ȱ 1ȱ 0.274ȱ Ȭ0.323ȱ Ȭ0.768ȱ Ȭ0.146ȱ 0.473ȱ Ȭ0.035ȱ Ȭ0.417ȱ 0.347ȱ 0.9471ȱ Ȭ0.003ȱ Ȭ0.926ȱ 1ȱ 0.586ȱ Ȭ0.115ȱ Ȭ0.907ȱ 0.699ȱ 0.9491ȱ Ȭ0.028ȱ Ȭ0.274ȱ Ȭ0.239ȱ Ȭ0.712ȱ 0.917ȱ 0.757ȱ Ȭ0.846ȱ 0.529ȱ 0.595ȱ Ȭ0.192ȱ Ȭ0.389ȱ 0.685ȱ 1ȱ Ȭ0.926ȱ 0.345ȱ 0.744ȱ 0.894ȱ 0.767ȱ Ȭ0.482ȱ Ȭ0.044ȱ 0.056ȱ 0.121ȱ 0.061ȱ Ȭ0.035ȱ Ȭ0.203ȱ 0.129ȱ Ȭ0.042ȱ GRȱ 21ȱ Ȭ0.044ȱ Ȭ0.269ȱ GRȱ 14ȱ Ȭ0.566ȱ Ȭ0.406ȱ Ȭ0.131ȱ 0.414ȱ 0.171ȱ 0.068ȱ Ȭ0.192ȱ Ȭ0.345ȱ GRȱ 7ȱ 0.8741ȱ Ȭ0.238ȱ Ȭ0.185ȱ GPXȱ 28ȱ 0.081ȱ 0.843ȱ 0.06ȱ 0.662ȱ 0.114ȱ 0.528ȱ 0.223ȱ 0.403ȱ 1ȱ 0.685ȱ Ȭ0.003ȱ 0.579ȱ 0.366ȱ 0.392ȱ 0.137ȱ 0.628ȱ Ȭ0.312ȱ Ȭ0.258ȱ Ȭ0.236ȱ 0.172ȱ 0.128ȱ Ȭ0.124ȱ Ȭ0.133ȱ GRȱ 28ȱ Ȭ0.158ȱ Ȭ0.479ȱ 0.014ȱ 0.638ȱ 0.035ȱ 0.495ȱ 0.412ȱ 1ȱ 0.403ȱ Ȭ0.8242ȱ 0.056ȱ 0.416ȱ 0.523ȱ Ȭ0.6792ȱ 0.193ȱ 1ȱ 0.412ȱ 0.223ȱ Ȭ0.192ȱ 0.347ȱ Ȭ0.389ȱ 0.568ȱ 0.9471ȱ Ȭ0.583ȱ Ȭ0.40ȱ 0.559ȱ 0.483ȱ Ȭ0.182ȱ Ȭ0.185ȱ Ȭ0.522ȱ Ȭ0.640ȱ 0.148ȱ 0.079ȱ Ȭ0.117ȱ GSTȱ 14ȱ 0.691 ȱ 2 0.067ȱ Ȭ0.176ȱ 0.496ȱ 0.7782ȱ Ȭ0.307ȱ Ȭ0.261ȱ 0.053ȱ Ȭ0.078ȱ 0.094ȱ 0.016ȱ Ȭ0.208ȱ GSTȱ 7ȱ Ȭ0.087ȱ 0.382ȱ 0.5ȱ Ȭ0.984ȱ 0.077ȱ 1ȱ 0.193ȱ 0.495ȱ 0.528ȱ 0.595ȱ Ȭ0.417ȱ 0.221ȱ Ȭ0.013ȱ 0.743ȱ 0.738ȱ 0.416ȱ 0.746ȱ 0.817ȱ Ȭ0.293ȱ 0.702ȱ 0.817ȱ 0.869ȱ 0.758ȱ GSTȱ 21ȱ 0.523ȱ 0.6772ȱ 0.818ȱ Ȭ0.166ȱ 0.27ȱ 1ȱ Ȭ0.314ȱ Ȭ0.863ȱ 0.455ȱ 1ȱ 0.270ȱ Ȭ0.984ȱ Ȭ0.6792ȱ 0.077ȱ 0.638ȱ 0.662ȱ Ȭ0.846ȱ 0.473ȱ 0.988 ȱ 1 0.305ȱ Ȭ0.858ȱ 0.8372ȱ 0.9341ȱ Ȭ0.583ȱ Ȭ0.548ȱ Ȭ0.19ȱ 0.085ȱ 0.421ȱ Ȭ0.317ȱ Ȭ0.479ȱ EROD 7ȱ 0.035ȱ 0.114ȱ 0.529ȱ Ȭ0.035ȱ 0.199ȱ 0.9061ȱ 0.105ȱ Ȭ0.029ȱ 0.26ȱ Ȭ0.073ȱ Ȭ0.095ȱ 0.143ȱ 0.8111ȱ 0.17ȱ Ȭ0.255ȱ Ȭ0.144ȱ GSTȱ 28ȱ Ȭ0.211ȱ 0.904ȱ 1ȱ 0.455ȱ Ȭ0.166ȱ 0.500ȱ 0.416ȱ 0.014ȱ 0.060ȱ 0.757ȱ Ȭ0.146ȱ 0.459ȱ 0.095ȱ 0.455ȱ 0.8221ȱ 0.176ȱ Ȭ0.323ȱ Ȭ0.206ȱ Ȭ0.421ȱ 0.047ȱ Ȭ0.024ȱ 0.025ȱ Ȭ0.208ȱ Ȭ0.932ȱ 1ȱ 0.904ȱ Ȭ0.863ȱ 0.818ȱ 0.382ȱ 0.056ȱ Ȭ0.479ȱ 0.843ȱ 0.917ȱ Ȭ0.768ȱ 0.635ȱ 0.919ȱ 0.641ȱ 0.816ȱ Ȭ0.611ȱ Ȭ0.144ȱ Ȭ0.22ȱ Ȭ0.10ȱ Ȭ0.304ȱ Ȭ0.198ȱ Ȭ0.117ȱ Ȭ0.313ȱ 1ȱ Ȭ0.932ȱ Ȭ0.211ȱ Ȭ0.314ȱ 0.6771ȱ Ȭ0.087ȱ Ȭ0.8241ȱ Ȭ0.158ȱ 0.081ȱ Ȭ0.712ȱ Ȭ0.323ȱ Ȭ0.242ȱ 0.7402ȱ Ȭ0.321ȱ Ȭ0.31ȱ Ȭ0.152ȱ 0.215ȱ 0.257ȱ 0.225ȱ 0.7931ȱ 0.041ȱ 0.088ȱ 0.272ȱ ERODȱ ERODȱ ERODȱ 14ȱ 21ȱ 28ȱ 7,ȱ14,ȱ21ȱandȱ28ȱcorrespondȱtoȱtheȱsamplingȱdate 3 PAHsȱ peroxidaseȱ(GPX)ȱactivity,ȱglutathioneȱreductaseȱ(GR),ȱglutathioneȬSȬtransferaseȱ(GST)ȱactivityȱandȱEthoxyresorufinȱOȬdeethylaseȱ(EROD)ȱactivity.ȱ 2 ȱ Tableȱ2.ȱPearsonȱcorrelationȱ(*p<0.05,ȱ**p<0.01)ȱresultsȱamongȱchemicalȱcompoundsȱboundȱtoȱsedimentsȱandȱbiomarkers:ȱglutathioneȱ 1 producingȱ theȱ activiationȱ ofȱ theseȱ defenceȱ systems.ȱ Leadȱ isȱ notȱ essentialȱ toȱ metabolismȱandȱitȱisȱ highlyȱ toxicȱ forȱbiota,ȱthisȱtoxicityȱisȱdeterminedȱbyȱtheirȱ abilityȱ toȱ regulateȱ anomalousȱ concentrations,ȱ throughȱ variousȱ detoxificationȱ mechanismsȱ[20].ȱTheȱcorrelationȱshownȱbetweenȱPbȱandȱbiomarkersȱoccursȱinȱ theȱ dayȱ 28ȱ whatȱ suggestsȱ thatȱ itȱ isȱ afterȱ thisȱ periodȱ whenȱ theȱ metalȱ becameȱ bioreactiveȱtoȱtheȱstudiedȱbiomarkers.ȱȱ Inȱ general,ȱ theȱ behaviourȱ ofȱ GSTȱ wasȱ similarȱ toȱ ERODȱ inȱ mostȱ ofȱ theȱ casesȱ whatȱ suggestsȱ aȱ relationshipȱ amongȱ theseȱ phaseȱ Iȱ andȱ IIȱ detoxificationȱ biomarkers.ȱ Theȱ firstȱ increaseȱ ofȱ theȱ biomarkersȱ ofȱ effectȱ denotesȱ anȱ initialȱ activationȱ ofȱ theȱ detoxificationȱ systemȱ whichȱ isȱ inhibitedȱ inȱ subsequentlyȱ surveys.ȱWhenȱthereȱisȱanȱincreaseȱonȱtheȱCYPȱ450ȱcontent,ȱthereȱisȱnecessarilyȱ anȱ incrementȱ ofȱ metabolitesȱ toȱ beȱ conjugatedȱ withȱ phaseȱ IIȱ enzymes,ȱ thusȱ preventingȱ cellȱ damage;ȱ whenȱ theseȱ waterȱ solubleȱ compoundsȱ areȱ conjugatedȱ withȱphaseȱIIȱenzymes,ȱGSTȱmayȱinterveneȱ[21].ȱȱ Previousȱstudiesȱwithȱotherȱorganismsȱhaveȱobservedȱbothȱincreaseȱandȱ decreaseȱ ofȱ GPXȱ activityȱ inȱ fieldȱ surveysȱ [7];ȱ resultsȱ obtainedȱ inȱ thisȱ investigationȱ showȱ anȱ initialȱ fluctuationȱ ofȱ thisȱ biomarkerȱ (increaseȱ inȱ theȱ GalicianȱCoastȱandȱdecreaseȱinȱtheȱBayȱofȱAlgeciras)ȱfollowedȱbyȱaȱestabilizationȱ exceptȱforȱsiteȱCL2ȱinȱCormeȬLaxe.ȱȱ Theȱ activationȱ ofȱ GRȱ playsȱ aȱ fundamentalȱ roleȱ inȱ theȱ faceȱ ofȱ oxidativeȱ stressȱ maintainingȱ theȱ properȱ redoxȱ statusȱ ofȱ glutathione,ȱ whichȱ isȱ importantȱ bothȱ asȱ cofactorȱ ofȱ severalȱ antioxidantȱ enzymesȱ andȱ asȱ indirectȱ scavengerȱ ofȱ oxyradicalsȱ [22].ȱ Inȱ theȱ presentȱ studyȱ organismsȱ exposedȱ toȱ sedimentsȱ fromȱ CormeȬLaxeȱ presentȱ aȱ continuousȱ inductionȱ ofȱ thisȱ biomarkerȱ suggestingȱ theȱ presenceȱofȱaȱchronicȱsourceȱofȱstressȱwhichȱisȱnotȱrelatedȱtoȱtheȱcontaminantsȱ measuredȱinȱtheȱsediments,ȱbutȱprobablyȱrelatedȱtoȱtheȱstressȱproducedȱbyȱtheȱ presssureȱ ofȱ theȱ musselȱ raftsȱ [23]ȱ whichȱ mayȱ produceȱ negativeȱ impactsȱ toȱ theȱ organismsȱexposed.ȱȱ - 222 - Biomarkerȱ fluctuationsȱ wereȱ relativelyȱ lowȱ inȱ siteȱ CAȱ inȱ comparissionȱ withȱ theȱ otherȱ studyȱ sites,ȱ whatȱ confirmsȱ theȱ feasabilityȱ ofȱ thisȱ locationȱ asȱ referenceȱ siteȱ inȱ ecotoxicologicalȱ studies.ȱ Higherȱ biomarkerȱ responsesȱ wereȱ expectedȱinȱorganismsȱexposedȱtoȱtheȱcontaminationȱboundȱtoȱsedimentsȱfromȱ theȱ Bayȱ ofȱ Algeciras,ȱ asȱ itȱ wasȱ shownȱ inȱ laboratoryȱ studiesȱ [24]ȱ howeverȱ biomarkersȱ ofȱ exposureȱ wereȱ generallyȱ lowȱ inȱ comparisonȱ withȱ organismsȱ exposedȱ toȱ sedimentsȱ fromȱ CormeȬLaxe.ȱ Inȱ theȱ caseȱ ofȱ theȱ cagedȱ organismsȱ locatedȱinȱtheȱmouthȱofȱtheȱriverȱGuadarranqueȱtheȱvariationsȱofȱabioticȱfactorsȱ dueȱtoȱtheȱinfluenceȱofȱtidesȱcouldȱaffectȱtheȱactivityȱofȱtheȱstudiedȱbiomarkers.ȱ Previousȱstudiesȱhaveȱdemonstratedȱtheȱfluctuationsȱofȱdetoxificationȱenzymesȱ inȱresponseȱtoȱchangesȱofȱtemperatureȱandȱsalinityȱ[21].ȱ Theȱ histopahologicalȱ syntomsȱ ofȱ stressȱ agreeȱ withȱ theȱ presenceȱ ofȱ contamiantsȱ notȱ onlyȱ inȱ theȱ sedimentȱ butȱ alsoȱ inȱ theȱ waterȱ inȱ theȱ areasȱ ofȱ CormeȬLaxeȱ andȱ Algeciras.ȱ Organismsȱ deployedȱ inȱ theȱ AINPȱ presentedȱ slightȱ reversibleȱ lesionsȱ relatedȱ withȱ generalȱ stressȱ butȱ notȱ withȱ contaminants.ȱ Theȱ lesionsȱ wereȱ similarȱ toȱ theȱ tissuesȱ fromȱ organismsȱ exposedȱ toȱ sedimentsȱ fromȱ theȱreferenceȱstationȱinȱtheȱBayȱofȱCádiz.ȱOnȱtheȱwhole,ȱorganisms’ȱlaboratoryȱ deploymentsȱ (personalȱ observations)ȱ haveȱ concurredȱ inȱ moreȱ incidencesȱ ofȱ lesionsȱ inȱ targetȱ tissuesȱ thanȱ inȱ theȱ fieldȱ exposuresȱ whatȱ suggestsȱ thatȱ theȱ pollutantsȱcomeȱmainlyȱfromȱtheȱsediments;ȱunderȱfieldȱconditionsȱtheȱeffectsȱofȱ theȱcontaminantsȱboundȱtoȱsedimentȱareȱrelievedȱdueȱtoȱtheȱopenȱwaterȱsystemȱ whatȱ diminishȱ bioavailabilityȱ ofȱ contaminants.ȱ Theȱ applicationȱ ofȱ biomarkersȱ underȱfieldȱconditionsȱinvolvesȱmoreȱrealisticȱconditionsȱforȱtheȱexperimentȱ[25,ȱ 26,ȱ27],ȱhoweverȱaȱlotȱofȱuncontrolledȱvariablesȱmayȱaffectȱbiomarkers;ȱpreviousȱ studiesȱagreeȱwithȱtheȱfactȱthatȱinȱsituȱcagedȱorganismȱapproachȱshouldȱbeȱusedȱ inȱ tandemȱ withȱ otherȱ assessmentȱ methodsȱ suchȱ asȱ laboratoryȱ toxicityȱ testingȱ [28].ȱȱ - 223 - 5.ȱConclusionsȱ Inȱ theȱ presentȱ studyȱ aȱ setȱ ofȱ biomarkersȱ involvedȱ inȱ theȱ detoxificationȱ system,ȱ antioxidantȱ ȱ activitiesȱ andȱ oneȱ biomarkerȱ ofȱ effectȱ (histopathology)ȱ wereȱ assessedȱ inȱ theȱ clamȱ Ruditapesȱ philippinarumȱ exposedȱ underȱ fieldȱ conditionsȱ toȱ sedimentȱ samplesȱ affectedȱ byȱ oilȱ spills.ȱ Theȱ setȱ ofȱ theȱ studiedȱ biomarkersȱ presentedȱ anȱ importantȱ inductionȱ duringȱ theȱ firstȱ weekȱ ofȱ deploymentȱ andȱ aȱ connectionȱ ofȱ theȱ phaseȱ Iȱ andȱ IIȱ enzymaticȱ activitiesȱ ofȱ theȱ detoxificationȱ systemȱ inȱ theȱ clamȱ Ruditapesȱ philippinarumȱ wasȱ suggested.ȱ Theȱ toxicityȱ ofȱ Pbȱ boundȱ toȱ sedimentsȱ wasȱ relatedȱ toȱ theȱ inductionȱ ofȱ biomarkersȱ afterȱ 28ȱ daysȱ ofȱ deployment,ȱ whatȱ indicatesȱ theȱ importanceȱ ofȱ carryingȱ outȱ kineticȱ studiesȱ inȱ fieldȱ studiesȱ whereȱ theȱ bioavailabilityȱ ofȱ contaminantsȱ partiallyȱ dependsȱ onȱ abioticȱ parameters.ȱ Inȱ additionȱ theȱ evalluationȱ ofȱ biomarkersȱ alongȱ theȱ timeȱ hasȱ allowedȱ toȱ distinguishȱ differentȱ sourcesȱ ofȱ contaminantsȱnotȱrelatedȱtoȱsediments.ȱȱ Authorsȱ considerȱ thatȱ Ruditapesȱ philippinarumȱ isȱ aȱ suitableȱ speciesȱ inȱ oilȱ contaminatedȱ sedimentsȱ assessmentȱ byȱ includingȱ aȱ setȱ ofȱ antioxidant,ȱ phaseȱ Iȱ andȱ IIȱ detoxificationȱ biomarkersȱ togetherȱ withȱ biomarkersȱ ofȱ effectȱ suchȱ asȱ histopathology;ȱ moreoverȱ toxicityȱ testingȱ followingȱ aȱ kineticȱ approachȱ underȱ fieldȱconditionsȱcontributesȱinȱaȱveryȱeffectiveȱwayȱtoȱmonitoreȱandȱdetermineȱ theȱpollutantsȱeffects,ȱincludingȱthoseȱthatȱhaveȱnotȱbeenȱanalyzed.ȱ 6.ȱAcknowledgementsȱ Theȱ workȱ describedȱ wasȱ partlyȱ supportedȱ byȱ theȱ projectsȱ VEM2003Ȭ 20563/INTER,ȱ andȱ CTM2005Ȭ07282ȬC03Ȭ01/TECNOȱ financedȱ byȱ theȱ Spanishȱ Educationȱ andȱ Scienceȱ Ministryȱ andȱ byȱ CISȱ fundedȱ byȱ theȱ Ministryȱ ofȱ Environment.ȱ Carmenȱ MoralesȬCasellesȱ thanksȱ theȱ Ministryȱ ofȱ Educationȱ andȱ Scienceȱ forȱ fundingȱ herȱ researchȱ fellowshipȱ (FPU).ȱ Dr.ȱ Ribaȱ thanksȱ theȱ I3pȱ programȱ forȱ supportingȱ herȱ participationȱ inȱ thisȱ research.ȱ ȱ Inmaculadaȱ Ribaȱ - 224 - thanksȱtheȱCSICȱforȱherȱI3Pȱcontract.ȱȱWeȱareȱgratefulȱforȱtheȱsupportȱandȱhelpȱ ofȱ theȱ membersȱ ofȱ theȱ CISȱ andȱ theȱ ICMANȬCSIC.ȱ Specialȱ thanksȱ areȱ givenȱ toȱ AntonioȱMorenoȱandȱPabloȱVidal.ȱȱ 7.ȱReferencesȱ [1]ȱ Lafontaineȱ Y,ȱ Gagnéȱ F,ȱ Blaiseȱ C,ȱ Costanȱ G,ȱ Gagnonȱ P,ȱ Chanȱ HM.ȱ 2000.ȱ Biomarkersȱ inȱ zebraȱ musselsȱ (Dreissenaȱ polymorpha)ȱ forȱ theȱ assessmentȱ andȱ monitoringȱ ofȱ waterȱ qualityȱ ofȱ theȱ St.ȱ Lawrenceȱ Riverȱ (Canada).ȱ AquatȱToxicolȱ50:ȱ51Ȭ70ȱȱ [2]ȱMunnsȱWRȱJr,ȱBerryȱWJ,ȱDewittȱTH.ȱ2002.ȱToxicityȱtesting,ȱriskȱassessment,ȱ andȱoptionsȱforȱdredgedȱmaterialȱmanagement.ȱMarȱPollȱBullȱ44:ȱ294Ȭ302.ȱ [3]ȱ Gallowayȱ TS,ȱ Brownȱ RJ,ȱ Browneȱ MA,ȱ Dissanayakeȱ A,ȱ Loweȱ D,ȱ Jonesȱ MB,ȱ Depledgeȱ MH.ȱ 2004.Aȱ multibiomarkerȱ approachȱ toȱ environmentalȱ assessment.ȱEnvironȱSciȱTechnolȱ38:ȱ1723Ȭ1731.ȱ [4]ȱ MartínȬDíazȱ ML,ȱ VillenaȬLincolnȱ A,ȱ Bamberȱ S,ȱ Blascoȱ J,ȱ DelVallsȱ TA.ȱ 2005.ȱ Anȱ integratedȱ approachȱ usingȱ bioaccumulationȱ andȱ biomarkerȱ 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theȱredȱmulletȱ(Mullusȱbarbatus).ȱMarȱPollutȱBullȱ44:ȱ912Ȭ922.ȱ [23]ȱ Oteroȱ XL,ȱ Calvoȱ deȱ Antaȱ RM,ȱ Macíasȱ F.ȱ 2006.ȱ Sulphurȱ partitioningȱ inȱ sedimentsȱ andȱ biodepositsȱ belowȱ musselȱ raftsȱ inȱ theȱ Rıыaȱ deȱ Arousaȱ (Galicia,ȱNWȱSpain).ȱMarȱEnvironȱResȱ61,ȱ305Ȭ325.ȱȱȱ [24]ȱ MoralesȬCasellesȱ C,ȱ MartínȬDíazȱ ML,ȱ Ribaȱ I,ȱ Sarasqueteȱ C,ȱ DelVallsȱ TA.ȱ Roleȱ ofȱ biomarkersȱ toȱ assessȱ oilȬcontaminatedȱ sedimentȱ qualityȱ usingȱ toxicityȱtestsȱwithȱclamsȱandȱcrabs.ȱ(submitted).ȱ - 227 - [25]ȱSuterȱGW.ȱ1993.ȱEcologicalȱRiskȱAssessment.ȱLewisȱPublishers,ȱBocaȱRaton,ȱ FL.ȱ [26]ȱ Depledgeȱ MH,ȱ Fossiȱ MC.ȱ 1994.ȱ Theȱ roleȱ ofȱ biomarkersȱ inȱ environmentalȱ assessmentȱ(2).ȱInvertebrates.ȱEcotoxicologyȱ3:ȱ161Ȭ172.ȱ [27]ȱ Deȱ Coenȱ W,ȱ Robbensȱ J,ȱ Janssenȱ C.ȱ 2006.ȱ Ecologicalȱ impactȱ assessmentȱ ofȱ metallurgicȱ effluentsȱ usingȱ inȱ situȱ biomarkerȱ assays.ȱ Environȱ Pollutȱ 141:ȱ 183Ȭ194.ȱ [28]ȱ Burtonȱ GA,ȱ Greenbergȱ MS,ȱ Rowlandȱ CD,ȱ Irvineȱ CA,ȱ Lavoieȱ DR,ȱ Brookerȱ JA,ȱMooreȱL,ȱRaymerȱDFN,ȱMcWilliamȱRA.ȱ2005.ȱInȱsituȱexposuresȱusingȱ cagedȱ organisms:ȱ aȱ multiȬcompartmentȱ approachȱ toȱ detectȱ aquaticȱ toxicityȱandȱbioaccumulation.ȱEnvironȱPollutȱ134:ȱ133Ȭ144ȱȱ - 228 - AȱkineticȱapproachȱinȱtheȱPAHsȱdetoxificationȱsystemȱinȱaȱmarineȱ invertebrateȱspecie:ȱtheȱcrabȱCarcinusȱmaenasȱ CarmenȱMoralesȬCaselles†ȱ‡ȱ*,ȱLauraȱMartínȬDíaz†ȱ‡,ȱInmaculadaȱRiba†ȱ‡,ȱ CarmenȱSarasquete†,ȱT.ȱÁngelȱDelValls†ȱ‡ȱ †ȱIȱUnidadȱAsociadaȱdeȱCalidadȱAmbientalȱyȱPatologíaȱ(CSICȱ&ȱUCA)ȱinstitutoȱ deȱCienciasȱMarinasȱdeȱAndalucíaȱ(ICMANȬCSIC),ȱAvda.ȱRepúblicaȱSaharauiȱs/n,ȱ PuertoȱRealȱ11510,ȱCádiz,ȱSpainȱ ‡ȱUNESCOȱUNITWIN/WiCop,ȱFacultadȱdeȱCienciasȱdelȱMarȱyȱAmbientales,ȱ UniversidadȱdeȱCádiz,ȱPolígonoȱRíoȱSanȱPedroȱs/n,ȱPuertoȱRealȱ11510,ȱCádiz,ȱ Spain.ȱ Abstractȱ Toȱ testȱ theȱ hypothesisȱ thatȱ invertebratesȱ presentȱ aȱ significantȱ PAHsȬ detoxificationȱ system,ȱ theȱ inductionȱ ofȱ ethoxyresorufinȱ OȬdeethylaseȱ (EROD)ȱ activityȱ andȱ guthationeȬSȬtransferaseȱ (GST)ȱ wasȱ studiedȱ inȱ theȱ crabȱ Carcinusȱ maenas.ȱAȱbioassayȱwasȱperformedȱbyȱexposingȱtheȱorganismsȱtoȱbulkȱsedimentȱ contaminatedȱbyȱPAHsȱunderȱlaboratoryȱandȱfieldȱconditions.ȱSedimentsȱwereȱ collectedȱ andȱ transferredȱ toȱ theȱ laboratoryȱ whereȱ theyȱ wereȱ subsampledȱ forȱ chemicalȱanalysisȱandȱtoxicityȱtest;ȱcrabsȱwereȱkeptȱduringȱ28ȱdaysȱinȱtanksȱwithȱ theȱ collectedȱ sedimentȱ samplesȱ whereasȱ cagedȱ crabsȱ wereȱ alsoȱ placedȱ inȱ theȱ selectedȱ studyȱ sitesȱ duringȱ theȱ sameȱ period.ȱ Samplingȱ wasȱ performedȱ weeklyȱ andȱ hepathopancreasȱ wereȱ homogenizedȱ andȱ centrifugedȱ forȱ theȱ biomarkersȱ determination.ȱ Resultsȱ obtainedȱ showȱ theȱ relationshipȱ betweenȱ theȱ kineticȱ ofȱ theȱ biomarkersȱ measuredȱ inȱ theȱ crabsȱ andȱ theȱ chemicalȱ characteristicsȱ ofȱ theȱ sediment.ȱ Besides,ȱ itȱ demonstratesȱ theȱ capabilityȱ ofȱ theȱ mentionedȱ biologicalȱ systemsȱinvolvedȱinȱtheȱdetoxificationȱofȱPAHsȱtoxicityȱinȱtheȱstudiedȱorganism.ȱȱȱ Keywords:ȱbiomarker,ȱinvertebrate,ȱhistopathology,ȱERODȱactivity,ȱGST.ȱ ȱ ȱȱȱEnvironementalȱToxicologyȱ(enviado) - 229 - 1.ȱIntroductionȱ Theȱ presenceȱ ofȱ aȱ xenobioticȱ compoundȱ inȱ aȱ segmentȱ ofȱ anȱ aquaticȱ ecosystemȱ doesȱ not,ȱ byȱ itself,ȱ indicateȱ injuriousȱ effects.ȱ Connectionsȱ mustȱ beȱ establishedȱ betweenȱ externalȱ levelsȱ ofȱ exposure,ȱ internalȱ levelsȱ ofȱ tissueȱ contaminationȱ andȱ earlyȱ adverseȱ effectsȱ (Vanȱ derȱ Oost,ȱ 2003).ȱ SedimentȬ associatedȱchemicalsȱmayȱorȱmayȱnotȱbeȱbioavailable,ȱandȱthereȱisȱaȱpaucityȱofȱ informationȱ onȱ theirȱ combinedȱ effectsȱ onȱ exposedȱ organismsȱ (Wernerȱ etȱ al.,ȱ 2004).ȱ Aȱ varietyȱ ofȱ molecular,ȱ biochemical,ȱ physiological,ȱ histoȬ cytopathological,ȱ organisimal,ȱ populationȱ andȱ communityȱ responsesȱ mayȱ beȱ usedȱ toȱ identifyȱ exposureȱ toȱ certainȱ chemicals,ȱ provideȱ informationȱ onȱ spatialȱ andȱ temporalȱ changesȱ inȱ theȱ concentrationȱ ofȱ contaminants,ȱ andȱ indicateȱ environmentalȱ qualityȱ orȱ occurrenceȱ ofȱ adverseȱ ecologicalȱ consequences.ȱ (Au,ȱ 2004).ȱ Theȱ useȱ ofȱ biomarkersȱ whichȱ areȱ indicativeȱ ofȱ PAHsȱ exposureȱ mayȱ provideȱ anȱ earlyȱ warningȱ ofȱ potentialȱ ecosystemȱ degradation,ȱ contaminantȱ bioavailability,ȱandȱtheȱdefenceȱresponsesȱofȱexposedȱorganismsȱ(Goksøyrȱetȱal.,ȱ 1996;ȱGoksøyrȱ&ȱFörlin,ȱ1992;ȱReynoldsȱetȱal.,ȱ2003).ȱȱ Theȱ ERODȱ activityȱ isȱ usedȱ asȱ aȱ biomarkerȱ ofȱ exposureȱ toȱ lipophilicȱ organicȱcontaminantsȱsuchȱasȱPAHsȱandȱmeasuresȱtheȱenzymaticȱactivityȱofȱtheȱ phaseȱ Iȱ catalyzedȱ byȱ theȱ complexȱ CYP1Aȱ whichȱ transformsȱ someȱ lipophilicȱ xenobioticsȱinȱmetabolitesȱmoreȱwaterȱsolubleȱ(Bachȱetȱal.,ȱ2005).ȱGlutathioneȬSȬ transferaseȱ (GST)ȱ representsȱ aȱ phaseȱ IIȱ detoxificationȱ enzymeȱ butȱ alsoȱ implicatedȱ inȱ oxidativeȱ stressȱ events;ȱ aȱ criticalȱ roleȱ forȱ GSTsȱ isȱ obviouslyȱ defenceȱ againstȱ oxidativeȱ damageȱ andȱ peroxidativeȱ productsȱ ofȱ DNAȱ andȱ lipidsȱ(VanȱderȱOost,ȱ2003).ȱOnȱtheȱotherȱhandȱtheȱcapacityȱofȱmanyȱpollutantsȱ toȱ alterȱ differentȱ cells,ȱ tissuesȱ orȱ organsȱ hasȱ ledȱ toȱ designȱ histopathologicalȱ techniquesȱ inȱ orderȱ toȱ evaluateȱ theȱ effectsȱ ofȱ contaminantsȱ (Lowe,ȱ 1988;ȱ Sarasqueteȱetȱal.,ȱ1997).ȱ - 230 - Inȱ theȱ presentȱ studyȱ bioassaysȱ underȱ fieldȱ andȱ laboratoryȱ conditionsȱ haveȱbeenȱdevelopedȱtoȱelucidateȱtheȱdetoxificationȱsystemȱinȱtheȱcrabȱCarcinusȱ maenasȱ exposedȱ toȱ sedimentsȱ affectedȱ byȱ oilȱ spills,ȱ byȱ analyzingȱ theȱ kineticȱ ofȱ twoȱ biomarkersȱ ofȱ exposureȱ relatedȱ toȱ theȱ detoxificationȱ systemȱ (ERODȱ andȱ GSTȱactivities)ȱandȱoneȱbiomarkerȱofȱeffectȱ(histopathology).ȱ 2.ȱMaterialȱandȱmethodsȱ 2.1.ȱStudyȱsitesȱ Threeȱ differentȱ areasȱ wereȱ selectedȱ toȱ carryȱ outȱ theȱ bioassays,ȱ twoȱ ofȱ themȱ inȱ theȱ Galicianȱ Coastȱ (NWȱ Spain)ȱ (theȱ Bayȱ ofȱ CormeȬLaxeȱ andȱ theȱ Ciesȱ Island)ȱandȱtheȱotherȱoneȱinȱtheȱBayȱofȱAlgecirasȱ(SȱSpain).ȱInȱtotalȱ9ȱstudyȱsitesȱ wereȱchosen,ȱ3ȱinȱtheȱCiesȱIslandsȱ(A,ȱB,ȱandȱC),ȱ3ȱinȱtheȱBayȱofȱCormeȬLaxeȱ(D,ȱ EȱandȱF)ȱandȱ3ȱinȱtheȱBayȱofȱAlgecirasȱ(GR3,ȱGR4ȱandȱP1).ȱTheȱareaȱofȱGaliciaȱ wasȱ affectedȱ inȱ 2002ȱ byȱ theȱ spillȱ ofȱ theȱ tankerȱ Prestigeȱ whereasȱ theȱ Bayȱ ofȱ Algecirasȱ suffersȱ continuousȱ spillsȱ ofȱ oilȱ andȱ otherȱ compoundsȱ fromȱ theȱ industriesȱandȱtheȱmaritimeȱactivitiesȱofȱtheȱarea.ȱȱ 2.2.ȱChemicalsȱinȱsedimentsȱ ForȱPAHsȱandȱPCBsȱdeterminationȱdriedȱsamplesȱwereȱSoxhletȱextractedȱ withȱ nȬhexaneȱ forȱ 18ȱ h,ȱ andȱ theȱ extractsȱ wereȱ isolatedȱ byȱ columnȱ chromatographyȱ onȱ Florisileȱ aluminoȬsilica.ȱ PCBsȱ andȱ PAHsȱ wereȱ elutedȱ andȱ theirȱfractionsȱwereȱdriedȱinȱaȱrotatingȱevaporatorȱandȱreȬdissolvedȱinȱisooctane.ȱ PAHsȱwereȱanalyzedȱbyȱGCȬMSȱusingȱselectedȱionȱmonitoringȱ(SIM).ȱAnalysisȱ ofȱ PCBsȱ asȱ AROCLORȱ 1242ȱ andȱ AROCLORȱ 1260ȱ wasȱ performedȱ usingȱ theȱ sameȱ instrumentȱ withȱ anȱ electronȱ captureȱ detectorȱ (GC/ECD).ȱ Traceȱ metalȱ analysisȱwereȱanalyzedȱasȱdescribedȱbyȱCasadoȬMartínezȱetȱal.ȱ(2006);ȱsedimentȱ samplesȱwereȱdigestedȱinȱmicrowaveȱ(400W,ȱ15ȱmin,ȱtwice)ȱwithȱHNO3ȱ2N,ȱtheȱ extractsȱ wereȱ purifiedȱ byȱ passingȱ throughȱ aȱ CȬ18ȱ columnȱ andȱ metalsȱ analysesȱ - 231 - wereȱ performedȱ byȱ anodicȱ voltamperimetryȱ (ȬZn,ȱ Cd,ȱ Pb,ȱ Ni,ȱ Coȱ andȱ CuȬȱ MetrohmȱApplicationȱBulletinȱNºȱ147;ȱȬȱVȬȱMetrohmȱApplicationȱNoteȱNºȱVȬ81).ȱ Forȱ Hgȱ theȱ coldȱ vapourȱ techniqueȱ wasȱ usedȱ andȱ wasȱ quantifiedȱ usingȱ atomicȱ absorptionȱspectrometry.ȱȱ 2.3.ȱFieldȱandȱlaboratoryȱbioassaysȱ IntermoultȱfemaleȱCarcinusȱmaenasȱwereȱcollectedȱfromȱaȱcleanȱsiteȱofȱtheȱ BayȱofȱCádizȱ(Ribaȱetȱal.,ȱ2004)ȱfromȱanȱaquacultureȱfarmȱandȱwereȱkeptȱunderȱ laboratoryȱconditionsȱduringȱthreeȱweeksȱforȱacclimatization.ȱAfterȱthatȱperiodȱ theȱ crabsȱ wereȱ placedȱ inȱ cagesȱ whichȱ wereȱ deployedȱ inȱ theȱ studyȱ sitesȱ toȱ conductȱ theȱ fieldȱ bioassay;ȱ simultaneously,ȱ aboutȱ 4ȱ Lȱ ofȱ sedimentȱ fromȱ theȱ referenceȱ siteȱ andȱ theȱ otherȱ stationsȱ wereȱ placedȱ inȱ replicateȱ 25ȬLȱ glassȱ tanksȱ withȱ cleanȱ seaȱ waterȱ beforeȱ theȱ beginningȱ ofȱ theȱ experiment.ȱ Afterȱ particleȱ settling,ȱ aerationȱ wasȱ providedȱ toȱ maintainȱ adequateȱ oxygenȱ concentrationsȱ (greaterȱthanȱ80%ȱsaturation).ȱCrabsȱwereȱalsoȱlocatedȱinȱtheseȱtanksȱcontainingȱ sedimentȱfromȱtheȱdifferentȱstationsȱinȱorderȱtoȱperformȱtheȱtoxicityȱtestȱunderȱ laboratoryȱ conditions.ȱ ȱ Bothȱ bioassaysȱ underȱ laboratoryȱ andȱ fieldȱ conditionsȱ wereȱcarriedȱoutȱduringȱ28ȱdaysȱandȱoverȱthisȱtimeȱcrabsȱwereȱfedȱeveryȱweekȱ withȱ aȱ mixedȱ dietȱ ofȱ musselsȱ orȱ fishȱ whereasȱ waterȱ fromȱ theȱ laboratoryȱ tanksȱ wasȱreplacedȱeveryȱthreeȱdays.ȱ 2.4.ȱBiochemicalȱanalysisȱ Samplingȱwasȱconductedȱeveryȱweekȱduringȱtheȱ28ȱdaysȱofȱtheȱexposureȱ period;ȱ afterȱ dissection,ȱ hepathopancreasȱ wasȱ keptȱ atȱ Ȭ80ºCȱ priorȱ homogenization.ȱ Theȱ samplesȱ wereȱ homogenizedȱ followingȱ theȱ procedureȱ developedȱ byȱ Lafontaineȱ etȱ al.ȱ (2000).ȱ Mixedȱ functionȱ oxygenaseȱ activity,ȱ implicatedȱinȱmonooxygenationȱreactionsȱofȱdioxinsȱandȱPAHs,ȱwasȱmeasuredȱ usingȱ theȱ adaptedȱ Ethoxyresorufinȱ OȬdeethylaseȱ (EROD)ȱ (Gagnèȱ andȱ Blaise,ȱ 1993).ȱ Theȱ phaseȱ IIȱ metabolizingȱ enzymeȱ GlutathioneȬSȬtransferaseȱ (GST)ȱ - 232 - activityȱ wasȱ determinedȱ byȱ monitoringȱ theȱ rateȱ ofȱ conjugationȱ ofȱ glutathioneȱ (GSH)ȱ toȱ 1ȬchloroȬ2,4Ȭdinitrobenzeneȱ (CDNB)ȱ atȱ 340ȱ nmȱ (McFarlandȱ etȱ al.,ȱ 1999).ȱ Gillsȱandȱhepathopancreasȱtissuesȱwereȱfixedȱinȱphosphateȱbufferedȱ10%ȱ formaldehydeȱ (pHȱ 7.2)ȱ forȱ histopathologyȱ determinationȱ afterȱ 28ȱ daysȱ ofȱ exposure.ȱ Afterȱ dehydrationȱ inȱ gradedȱ concentrationsȱ ofȱ ethanol,ȱ theȱ samplesȱ wereȱ embeddedȱ inȱ paraffinȱ wax.ȱ Histologicalȱ sectionsȱ ofȱ 6ȱ toȱ 8ȱ ΐmȱ thicknessȱ wereȱ stainedȱ withȱ Haematoxylin–ȱ Eosinȱ andȱ Haematoxylin–VOFȱ (Gutiérrez,ȱ 1967).ȱ Sectionsȱ wereȱ reviewedȱ byȱ lightȱ microscopyȱ Leitzȱ Laborluxȱ Sȱ andȱ photographedȱ(SonyȱDKCȬCM30).ȱ 3.ȱResultsȱ 3.1.ȱChemicalȱanalysisȱȱ Sedimentsȱ fromȱ theȱ Ciesȱ Islandȱ presentedȱ theȱ lowestȱ concentrationsȱ ofȱ PAHs,ȱwhereasȱtheȱhighestȱconcentrationȱofȱPAHsȱwasȱfoundȱinȱtheȱsedimentsȱ fromȱGR3ȱ(2961ȱmgȱKgȬ1ȱdryȱsediment)ȱlocatedȱinȱtheȱBayȱofȱAlgeciras,ȱfollowedȱ byȱsedimentsȱfromȱtheȱstationȱFȱ(820ȱmgȱKgȬ1ȱ dryȱsediment)ȱlocatedȱinȱCormeȬ Laxe,ȱGR4ȱ(802ȱmgȱKgȬ1ȱ dryȱsediment)ȱandȱP1ȱ(641ȱmgȱKgȬ1ȱ dryȱsediment)ȱinȱtheȱ BayȱofȱAlgeciras.ȱHighȱconcentrationsȱwereȱdetectedȱfor:ȱZnȱinȱGR3ȱ(138ȱmgȱKgȬ 1ȱ dryȱsediment)ȱandȱFȱ(243ȱmgȱKgȬ1ȱ dryȱsediment);ȱPbȱinȱsiteȱDȱ(44ȱmgȱKgȬ1ȱ dryȱ sediment);ȱCu:ȱAȱ(18.9ȱmgȱKgȬ1ȱdryȱsedimentȱ)ȱandȱCȱ(31.6ȱmgȱKgȬ1ȱdryȱsedimentȱ )ȱ fromȱ Ciesȱ andȱ Dȱ (22.1ȱ mgȱ KgȬ1ȱ dryȱ sediment),ȱ Fȱ (19.1ȱ mgȱ KgȬ1ȱ dryȱ sediment)ȱ fromȱCormeȬLaxeȱandȱP1ȱ(75.2ȱmgȱKgȬ1ȱdryȱsediment)ȱfromȱtheȱBayȱofȱAlgeciras;ȱ NiȱinȱsiteȱGR3ȱ(74.7ȱmgȱKgȬ1ȱdryȱsediment).ȱ 3.2.ȱGSTȱandȱERODȱactivitiesȱ AnalysisȱperformedȱinȱcrabsȱexposedȱtoȱsedimentsȱfromȱtheȱCiesȱIslandsȱ showedȱthatȱduringȱ28ȱdaysȱofȱexposureȱERODȱactivityȱunderȱfieldȱconditionsȱ - 233 - keptȱlowȱandȱnoȱsignificantȱdifferencesȱwereȱdetectedȱinȱrelationȱwithȱtheȱdayȱ0.ȱ UnderȱfieldȱconditionsȱcrabsȱdeployedȱinȱsitesȱA,ȱBȱandȱCȱpresentedȱaȱpeakȱinȱ theȱinductionȱofȱthisȱsystemȱafterȱ7ȱȬ14ȱdaysȱofȱtheȱbeginingȱofȱtheȱbioassay;ȱtheȱ activityȱ ofȱ theȱ GSTȱ enzymeȱ wasȱ alsoȱ higherȱ inȱ crabsȱ exposedȱ underȱ fieldȱ conditions,ȱandȱtheȱmaximumȱwasȱobservedȱafterȱ14ȱ–ȱ21ȱdaysȱofȱexposure.ȱȱȱ Theȱenzymesȱactivitiesȱdetectedȱinȱcrabsȱexposedȱtoȱsedimentsȱfromȱtheȱ BayȱofȱCormeȬLaxeȱwasȱhigherȱforȱthoseȱorganismsȱdeployedȱinȱfieldȱthanȱcrabsȱ fromȱ theȱ laboratoryȱ assays.ȱ Theȱ inductionȱ ofȱ ERODȱ andȱ GSTȱ activitiesȱ underȱ controlledȱconditionsȱinȱlaboratoryȱwasȱnotȱsignificantȱcomparedȱwithȱtheȱfieldȱ deploymentsȱwhereȱERODȱactivityȱshowedȱaȱmaximumȱtheȱdayȱ14ȱofȱexposureȱ inȱcrabsȱfromȱsitesȱD,ȱEȱandȱF.ȱGSTȱactivityȱanalyzedȱinȱcrabsȱfromȱcagesȱlocatedȱ inȱ stationȱ Dȱ presentedȱ similarȱ behaviourȱ thanȱ ERODȱ activity,ȱ withȱ aȱ peakȱ ofȱ inductionȱ theȱ dayȱ 14.ȱ Inȱ contrast,ȱ crabsȱ collectedȱ inȱ sitesȱ Eȱ andȱ Fȱ showedȱ aȱ maximumȱofȱinductionȱtheȱdayȱ28ȱofȱexposure,ȱwhichȱcorrespondȱtoȱtheȱlastȱdayȱ ofȱtheȱexperiment.ȱ Crabsȱ exposedȱ toȱ sedimentsȱ fromȱ theȱ Bayȱ ofȱ Algecirasȱ presentedȱ theȱ highestȱvaluesȱofȱERODȱactivityȱinȱlaboratoryȱexposures.ȱInȱtheȱcaseȱofȱsiteȱGR3ȱ whichȱ isȱ theȱ mostȱ contamiantedȱ siteȱ byȱ PAHs,ȱ theȱ maximumȱ inductionȱ wasȱ observedȱ aȱ weekȱ afterȱ theȱ beginingȱ ofȱ theȱ assayȱ inȱ crabsȱ exposedȱ underȱ laboratoryȱ conditions;ȱ aȱ similarȱ behaviourȱ wasȱ followedȱ byȱ theȱ inductionȱ ofȱ GSTȱactivityȱanalyzedȱinȱtheȱsameȱcrabs.ȱAȱmaximumȱonȱofȱERODȱactivityȱwasȱ alsoȱobservedȱtheȱdayȱ14ȱinȱcrabsȱexposedȱinȱlaboratoryȱtoȱsedimentsȱcololectedȱ fromȱ siteȱ P1.ȱ Organismsȱ fromȱ GR4ȱ didȱ notȱ presentȱ significantȱ inductionsȱ ofȱ ERODȱ activityȱ underȱ fieldȱ andȱ laboratoryȱ assaysȱ inȱ comparissionȱ withȱ otherȱ sites.ȱInȱgeneral,ȱunderȱfieldȱdeploymentsȱtheȱinductionȱofȱGSTȱwasȱhigherȱthanȱ inȱcrabsȱfromȱlaboratoryȱassays.ȱAȱpeakȱinȱGSTȱactivityȱwasȱobservedȱtheȱdayȱ21ȱ inȱorganismsȱfromȱGR4ȱandȱdayȱ7ȱforȱcrabsȱcagedȱinȱsiteȱP1.ȱȱ - 234 - A A 1800 12.0 1500 9.0 EROD GST 1200 900 600 6.0 3.0 300 0 0.0 0 7 14 21 28 0 7 B 14 21 28 14 21 28 14 21 28 B 2100 12.0 1800 9.0 EROD GST 1500 1200 900 600 6.0 3.0 300 0 0.0 0 7 14 21 28 0 7 C 4000 8.0 3000 6.0 EROD GST C 2000 4.0 2.0 1000 0.0 0 0 7 14 21 0 28 7 ȱ Figureȱ 1.ȱ GSTȱ (nmol/min/mgȱ protein)ȱ andȱ ERODȱ (pmol/mg/min)ȱ activitiesȱ inȱ theȱ hepatopancreasȱ ofȱ Carcinusȱ maenasȱ exposedȱ alongȱ 28ȱ daysȱ toȱ sedimentsȱ fromȱ theȱ Ciesȱ Islands.ȱ Straigthȱ line:ȱ laboratoryȱ assays;ȱ dottedȱ line:ȱ fieldȱassays.ȱ ȱ ȱ ȱ ȱ ȱ - 235 - ȱ D D ȱ 2400 15.0 2000 12.0 ȱ EROD GST 1600 1200 800 9.0 6.0 3.0 400 ȱ0 0.0 0 7 ȱ 14 21 0 28 7 14 21 28 14 21 28 14 21 28 E E 20.0 ȱ 7500 16.0 6000 12.0 EROD GST 9000 4500 ȱ 3000 8.0 4.0 1500 0.0 0 ȱ 0 0 7 14 21 7 28 F F ȱ 7000 15.0 6000 12.0 ȱ EROD GST 5000 4000 3000 9.0 6.0 2000 3.0 1000 ȱ0 0.0 0 7 14 21 28 0 7 ȱ Figureȱ 2.ȱ GSTȱ (nmol/min/mgȱ protein)ȱ andȱ ERODȱ (pmol/mg/min)ȱ activitiesȱ inȱ theȱ hepatopancreasȱ ofȱ Carcinusȱ maenasȱ exposedȱ alongȱ 28ȱ daysȱ toȱ sedimentsȱfromȱtheȱBayȱofȱCormeȬLaxe.ȱStraigthȱline:ȱlaboratoryȱassays;ȱdottedȱ line:ȱfieldȱassays.ȱ ȱ ȱ ȱ ȱ - 236 - GR3 GR3 4.0 1800 1500 3.0 EROD GST 1200 900 600 2.0 1.0 300 0.0 0 0 7 14 21 0 28 7 2000 1.0 1600 0.8 1200 0.6 800 400 28 14 21 28 14 21 28 0.4 0.2 0 0.0 0 7 14 21 28 0 7 P1 P1 2000 5.0 1600 4.0 1200 3.0 EROD GST 21 GR4 EROD GST GR4 14 800 400 2.0 1.0 0 0.0 0 7 14 21 28 0 7 ȱ Figureȱ 3.ȱ GSTȱ (nmol/min/mgȱ protein)ȱ andȱ ERODȱ (pmol/mg/min)ȱ activitiesȱ inȱ theȱ hepatopancreasȱ ofȱ Carcinusȱ maenasȱ exposedȱ alongȱ 28ȱ daysȱ toȱ sedimentsȱ fromȱ theȱ Bayȱ ofȱ Algeciras.ȱ Straigthȱ line:ȱ laboratoryȱ assays;ȱ dottedȱ line:ȱfieldȱassays.ȱ ȱ ȱ ȱ ȱ - 237 - 3.3.ȱHistologicalȱlesionsȱ Asȱdesirableȱnoȱalterationsȱwereȱdetectedȱtheȱdayȱ0ȱofȱexposureȱpriorȱtoȱ theȱbeginingȱofȱtheȱtests.ȱAllȱdeployedȱorganismsȱpresentedȱalterationsȱrelatedȱ withȱ generalȱ stress,ȱ suchȱ asȱ ȱ lossȱ ofȱ ȱ connectiveȱ tissueȱ ofȱ theȱ gillsȱ andȱȱ hepatopancreas,ȱ ruptureȱ ofȱ gillȱ epithelium,ȱ andȱ haemociticȱ infiltrates.ȱ Inȱ general,ȱ damageȱ wasȱ higherȱ isȱ sitesȱ fromȱ Algecriasȱ followedȱ byȱ CormeȬLaxeȱ andȱthenȱtheȱCiesȱIslandsȱwhichȱtissuesȱwereȱsimilarȱtoȱcontrols.ȱAlterationsȱinȱ crabsȱ wereȱ lowerȱ underȱ fieldȱ exposuresȱ thanȱ thoseȱ detectedȱ inȱ laboratoryȱ deployments;ȱ noȱ importantȱ lesionsȱ wereȱ detectedȱ exceptȱ forȱ siteȱ GR3ȱ whereȱ diferentȱ alterationsȱ wereȱ observed,ȱ including:ȱ disruptedȱ pillarȱ cells,ȱ epithelialȱ changes,ȱ desquamationȱ inȱ gills,ȱ presenceȱ ofȱ vacuolesȱ inȱ hepathopancreas,ȱ lossȱ ofȱȱsupportȱconnectiveȱtissue,ȱnecrosis,ȱetc.ȱȱȱ 3.4.ȱCorrelationȱamongȱchemicalsȱandȱbiomarkersȱofȱresponseȱ Theȱconcentrationȱofȱ PAHsȱinȱsedimentsȱhasȱbeenȱcorrelatedȱwithȱotherȱ organicȱ chemicalsȱ suchȱ asȱ PCBsȱ andȱ theȱ metalsȱ Cd,ȱ Ni,ȱ Coȱ andȱ V.ȱ Thisȱ substancesȱ hasȱ beenȱ alsoȱ correlatedȱ withȱ theȱ inductionȱ ofȱ ERODȱ activityȱ inȱ crabsȱtheȱdayȱ7ȱandȱ28ȱofȱexposureȱunderȱlaboratoryȱconditions.ȱPbȱwasȱlinkedȱ withȱtheȱinductionȱȱofȱERODȱactivityȱafterȱ28ȱdaysȱofȱfieldȱdeployment,ȱandȱCuȱ wasȱalsoȱrelatedȱtoȱthisȱbiomarkerȱtheȱdayȱ14ȱofȱlaboratoryȱexposure.ȱȱȱ AȱrelationshipȱhasȱbeenȱdetectedȱbetweenȱtheȱinductionȱofȱERODȱactivityȱ inȱcrabsȱfromȱlaboratoryȱbioassaysȱtheȱdaysȱ14ȱandȱ21.ȱAȱsimilarȱcorrelationȱwasȱ observedȱ inȱ ERODȱ activityȱ measuredȱ inȱ crabsȱ fromȱ organismsȱ collectedȱ fromȱ cagesȱtheȱdaysȱ7ȱandȱ14.ȱTheȱinductionȱofȱtheȱphaseȱIIȱdetoxificationȱenzymesȱinȱ crabsȱ afterȱ 28ȱ daysȱ ofȱ exposureȱ underȱ laboratoryȱ andȱ fieldȱ conditionsȱ wereȱ linkedȱ inȱ additionȱ toȱ theȱ inductionȱ ofȱ thisȱ enzymeȱ theȱ dayȱ 21ȱ ofȱ fieldȱ deployment.ȱ - 238 - ȱ ȱ A B ȱ ȱ ȱ C ȱ ȱ ȱ ȱ E F ȱ ȱ ȱ Figureȱ 4.ȱ Histologicalȱ sectionsȱ ofȱ gillsȱ andȱ hepathopancreasȱ ofȱ theȱ crabȱ Carcinusȱmaenasȱafterȱ28Ȭdȱexposureȱtoȱtheȱsediments:ȱ(A)ȱHistologicalȱsectionȱofȱ aȱcontrolȱdigestiveȱglandȱ(dayȱ0);ȱ(B)ȱHistologicalȱsectionȱofȱaȱcontrolȱgillȱ(dayȱ 0);ȱ (C)ȱ Histologicalȱ sectionȱ ofȱ hepathopancreasȱ fromȱ aȱ cramȱ exposedȱ toȱ sedimentsȱ fromȱ GR3’ȱ underȱ fieldȱ conditions;ȱ (D)ȱ Histologicalȱ sectionȱ ofȱ gillȱ fromȱ aȱ crabȱ exposedȱ toȱ sedimentsȱ fromȱ GR3’ȱ underȱ fieldȱ conditions;ȱ (E)ȱ Histologicalȱsectionȱofȱhepathopancreasȱfromȱaȱcramȱexposedȱtoȱsedimentsȱfromȱ GR3’ȱ underȱ laboratoryȱ conditions;ȱ (F)ȱ Histologicalȱ sectionȱ ofȱ gillȱ fromȱ aȱ crabȱ exposedȱtoȱsedimentsȱfromȱGR3’ȱunderȱlaboratoryȱconditions.ȱ ȱ - 239 - Chemicals in sediment Biomarkers (laboratory) Biomarkers (field) -0.26 0.13 -0.03 0.06 -0.14 .96(2) -0.29 -0.11 0.63 0.22 -0.30 -0.17 -0.20 -0.05 -0.50 -0.14 -0.12 -0.27 -0.18 -0.04 .96(2) -0.15 -0.13 .74(1) 0.25 -0.34 -0.18 -0.16 -0.35 -0.55 -0.30 -0.19 Gst 14 Gst 21 Gst 28 Erod 7 Erod 14 Erod 21 Erod 28 Gst 7 Gst 14 Gst 21 Gst 28 Erod 7 Erod 14 Erod 21 Erod 28 0.23 -0.17 0.34 0.31 -0.07 -0.02 -0.38 -0.12 0.23 -0.36 -0.39 -0.43 -0.52 -.7(1) -0.46 -0.33 .74(1) 0.12 0.24 .89(2) 0.26 -0.18 -0.31 -0.15 -0.33 0.22 -0.04 0.08 .86(2) .87(2) .68(1) Cd 0.66 -0.26 -0.13 -0.04 .74(1) 0.45 Gst 7 0.11 0.19 -0.03 0.29 0.22 0.41 0.22 .68(1) 0.04 -0.36 .91(2) .84(2) .78(1) Zn .90(2) 0.41 .86(2) 0.12 -0.22 .97(2) .93(2) .87(2) PCBs PCBs Zn Cd Pb Cu Ni Co V PAHs -0.03 0.24 -0.58 -0.29 -0.19 0.17 0.20 .73(1) -0.16 -0.22 -0.13 0.14 -0.13 -0.12 0.16 0.22 0.08 0.20 0.09 0.50 Pb 0.11 -0.06 -0.49 -0.33 -0.39 0.10 -0.11 -0.08 -0.52 0.66 .94(2) -0.23 0.03 -0.26 -0.23 -0.23 -0.17 -0.34 -0.01 Cu Chemicals in sediment 0.20 -0.16 -0.36 -0.34 -0.34 -0.59 -0.32 -0.19 .69(1) 0.02 -0.09 .99(2) -0.24 -0.12 -0.13 0.52 .93(2) .86(2) Ni biomarkersȱtheȱdaysȱ7,ȱ14,ȱ21ȱandȱ28ȱȱ -0.01 -0.26 -0.20 -0.31 -0.41 -.7(1) -0.29 -0.20 .90(2) -0.23 -0.27 .92(2) -0.25 -0.16 -0.06 0.46 .74(1) Co 0.28 -0.33 -0.41 -0.21 -0.37 -0.29 -0.03 0.21 0.422 -0.17 -0.05 .87(2) 0.04 -0.24 -0.29 0.53 V -0.12 -0.20 -0.29 -0.39 0.13 -0.33 0.27 0.26 0.21 -0.17 -0.40 0.63 -0.21 0.16 0.43 Gst 7 0.54 -0.08 -0.71 -0.29 .90(2) -0.60 -0.33 0.23 -0.11 0.15 -0.13 -0.14 -0.43 - 240 - -0.62 0.42 -0.13 -0.48 0.35 -0.34 -0.03 0.11 -0.04 -0.10 -0.61 -0.18 -0.41 0.32 0.10 -0.33 .73(1) .80(2) -0.02 0.52 0.23 -0.03 -0.22 -0.33 -0.12 -0.20 Gst 14 Gst 21 Gst 28 0.22 -0.23 -0.41 -0.34 -0.37 -0.57 -0.25 -0.20 0.69 0.10 0.22 Erod 7 0.42 -0.22 -0.50 -0.32 -0.31 0.25 -0.26 -0.26 -0.43 .90(1) Erod 14 Biomarkers (laboratory assay) 0.25 0.43 -0.42 -0.30 -0.24 0.04 -0.31 -0.50 -0.40 Erod 21 -0.14 -0.28 0.09 -0.15 -0.34 -.8(1) -0.32 -0.31 Erod 28 -0.36 -0.24 0.14 0.46 0.07 -0.49 0.09 Gst 7 -0.18 -0.08 -0.03 0.27 0.00 -0.15 .84(2) 0.56 0.32 0.12 -0.33 0.21 0.71 0.34 -0.10 Gst 14 Gst 21 Gst 28 .84(1) -0.10 0.25 Erod 7 Biomarkers (field assay) Table1.ȱ Spearmanȱ correlationȱ (1:ȱp<0.05;ȱ2:ȱp<0.01)ȱresultsȱamongȱchemicalȱcompoundsȱ boundȱ toȱ sedimentsȱ andȱ theȱ inductionȱ ofȱ 0.64 0.36 Erod 14 0.50 Erod 21 4.ȱDiscussionȱ Crustaceansȱ haveȱ theȱ highestȱ totalȱ P450ȱ proteinȱ inȱ theȱ hepatopancreas,ȱ butȱalsoȱsignificantȱactivityȱinȱgreenȱgland,ȱgonads,ȱandȱstomachȱ(James,ȱ1989),ȱ howeverȱ Theȱ mechanismsȱ byȱ whichȱ xenobioticsȱ activateȱ geneȱ expressionȱ leadingȱtoȱtheȱincreasedȱproductionȱofȱnewȱproteinsȱsuchȱasȱP450sȱareȱnotȱwellȱ understoodȱ inȱ marineȱ organismsȱ (Snyder,ȱ 2000).ȱ Underȱ laboratoryȱ conditions,ȱ theȱ concentrationȱ ofȱ PAHsȱ inȱ sedimentȱ hasȱ beenȱ positevelyȱ relatedȱ toȱ theȱ inductionȱofȱERODȱactivityȱtheȱdayȱ7ȱandȱ28ȱofȱexposure.ȱThisȱcorrelationȱalsoȱ includesȱ theȱ metalsȱ Ni,ȱ Co,Vȱ andȱ Cdȱ whichȱ couldȱ beȱ expectedȱ dueȱ toȱ theȱ presenceȱofȱaȱcomplexȱmixtureȱofȱcontaminants,ȱspeciallyȱinȱsedimentsȱfromȱtheȱ Bayȱ ofȱ Algeciras.ȱ Underȱ fieldȱ conditionsȱ thisȱ correlationdoesȱ notȱ occurȱ exceptȱ forȱtheȱinductionȱofȱERODȱactivityȱtheȱdayȱ28ȱofȱdeploymentȱwhichȱisȱcorrelatedȱ withȱPb.ȱThisȱmetalȱhasȱbeenȱoftenȱrelatedȱtoȱfuelȱusedȱbyȱoldȱcars;ȱinȱthisȱcaseȱ thisȱ ERODȱ activityȱ couldȱ beȱ alsoȱ relatedȱ toȱ otherȱ organicȱ compoundsȱ notȱ analyzedȱinȱtheȱtotalȱPAHsȱincludedȱinȱthisȱwork.ȱ Relationshipsȱ betweenȱ theȱ sameȱ biomarkerȱ inȱ consequtiveȱ weeksȱ haveȱ beenȱestablihedȱwhatȱindicatesȱthatȱbiomarkersȱfollowȱaȱmechanism.ȱInȱtheȱcaseȱ ofȱ GSTȱ activityȱ correlationȱ haveȱ beenȱ observedȱ betweenȱ laboratoryȱ andȱ fieldȱ assaysȱ showingȱ thatȱ theȱ stressȱ thatȱ causesȱ theȱ activationȱ ofȱ thisȱ enzymeȱ isȱ presentȱinȱbothȱkindȱofȱexposures.ȱȱ Inȱ general,ȱ theȱ fastestȱ inductionȱ ofȱ biomarkersȱ wasȱ obseredȱ inȱ crabsȱ exposedȱ inȱ laboratoryȱ toȱ sedimentsȱ fromȱ siteȱ GR3ȱ withȱ theȱ highestȱ contentȱ ofȱ PAHsȱinȱtheȱsediment.ȱInȱgeneral,ȱȱtheȱotherȱstudyȱsitesȱpresentȱaȱlaterȱinductionȱ ofȱbiomarkersȱandȱnormalyȱERODȱactivityȱpresentȱpeaksȱaboutȱ14ȱdaysȱafterȱtheȱ beginingȱofȱtheȱbioassays,ȱandȱtheȱsameȱhappendsȱtoȱGSTȱactivity;ȱinȱtheȱcaseȱofȱ siteȱEȱandȱFȱtheȱGSTȱactivityȱkeepsȱgrowingȱfindingȱtheȱmaximumȱtheȱlastȱdayȱ ofȱtheȱbioassay.ȱȱȱ - 241 - Differencesȱ hasȱ beenȱ detectedȱ amongȱ theȱ inductionȱ ofȱ biomarkersȱ ofȱ exposureȱ inȱ crabsȱ exposedȱ toȱ theȱ areasȱ ofȱ study.ȱ Inȱ general,ȱ inȱ tehȱ caseȱ ofȱ theȱ studyȱ sitesȱ locatedȱ inȱ theȱ Galiciaȱ Coast,ȱ theȱ inductionȱ ofȱ biomarkersȱ inȱ moreȱ importantȱ inȱ cagedȱ organismsȱ underȱ fieldȱ conditions.ȱ Onȱ theȱ otherȱ handȱ organismsȱ exposedȱ toȱ sedimentsȱ fromȱ theȱ Bayȱ ofȱ Algecirasȱ inȱ laboratoryȱ areȱ highestȱ thanȱ thoseȱ deployedȱ inȱ field.ȱ Resultsȱ observedȱ inȱ histopathologicalȱ analysis,ȱ useȱ asȱ biomarkerȱ ofȱ effect,ȱ indicateȱ thatȱ organismsȱ exposedȱ inȱ laboratoryȱconditionsȱareȱmoreȱdamagedȱthanȱthoseȱinȱfield.ȱȱȱ Previousȱ studiesȱ showedȱ howȱ theȱ diseaseȱ statusȱ inȱ theȱ crabȱ Carcinusȱ maenasȱ mayȱ beȱ usedȱ asȱ aȱ highȬlevelȱ indicatorȱ ofȱ ecosystemȱ health.(Stentifordȱ andȱ Feist,ȱ 2005).ȱ Histopathologicalȱ observationȱ showedȱ thatȱ crabsȱ exposedȱ toȱ sedimentsȱfromȱtheȱBayȱofȱAlgecirasȱunderȱlaboratoryȱconditionsȱwereȱtheȱmostȱ damagedȱfollowedȱbyȱandȱcrabsȱexposedȱtoȱsedimentsȱfromȱtheȱBayȱofȱCormeȬ Laxe,ȱ andȱ finallyȱ organismsȱ fromȱ theȱ Ciesȱ treatmentȱ whichȱ showedȱ mainlyȱ alterationsȱ dueȱ toȱ generalȱ environmentalȱ stress.ȱ Theȱ relationshipȱ betweenȱ pollutantsȱandȱpathologiesȱinȱtargetȱtissuesȱhasȱbeenȱpreviouslyȱreportedȱ(OrtizȬ Delgadoȱ etȱ al.,ȱ 2007).ȱ Inȱ thisȱ case,ȱ underȱ laboratoryȱ conditions,ȱ ȱ theȱ highestȱ amountȱ ofȱ PAHsȱ inȱ theȱ sedimentȱ is,ȱ theȱ mostȱ histologicalȱ lesionsȱ inȱ crabsȱ areȱ observed,ȱ asȱ inȱ theȱ caseȱ ofȱ siteȱGR3ȱfromȱtheȱ Bayȱ ofȱAlgeciras.ȱTheȱ alterationsȱ shownȱinȱcrabsȱexposedȱtoȱsedimentȱfromȱGR3ȱhasȱbeenȱpreviouslyȱobservedȱinȱȱ differentȱ ȱ marineȱ ȱ invertebrateȱ orȱ vertebrateȱ ȱ ȱ speciesȱ exposedȱ toȱ ȱ differentȱȱ inorganicȱ orȱ organicȱ contaminants,ȱ parasiticȱ orȱ infectiousȱ diseases,ȱ nutritionalȱ stress,ȱ orȱ physicoȬchemicalȱ disordersȱ (Rodriguezȱ deȱ laȱ Ruaȱ etȱ al.,ȱ 2005;ȱ OrtizȬ Delgadoȱetȱal.,ȱ2007).ȱ Althoughȱ aȱ causalȱ relationshipȱ mustȱ existȱ betweenȱ exposureȱ toȱ contaminantsȱandȱbiologicalȱeffects,ȱsuchȱaȱcausalȱlinkȱdoesȱnotȱnecessarilyȱholdȱ betweenȱtheȱtwoȱtypesȱofȱbiomarkersȱ(biomarkersȱofȱresponseȱandȱbiomarkersȱ ofȱeffect),ȱexceptȱifȱbiomarkersȱshareȱaȱcommonȱmetabolicȱpathway.ȱ(Lafontaineȱ - 242 - etȱ al.,ȱ ȱ 2000).ȱ Inȱ thisȱ caseȱ histopathologicalȱ lesionsȱ areȱ higherȱ inȱ organismsȱ exposedȱ toȱ theȱ sedimentȱ withȱ theȱ highestȱ contentȱ ofȱ PAHs;ȱ inȱ addition,ȱ theȱ detoxificationȱ sytemȱ inductedȱ byȱ theȱ ERODȱ activityȱ theȱ dayȱ 7ȱ andȱ 28ȱ alsoȱ correlatesȱ withȱ thisȱ contaminant.ȱ Previousȱ studiesȱ withȱ crabsȱ alsoȱ foundȱ relationshipsȱ betweenȱ PAHsȱ andȱ theȱ inductionȱ ofȱ ERODȱ activityȱ (Fossiȱ etȱ al.,ȱ 2000;ȱMartínȬDíazȱetȱal.,ȱ2004)ȱ 5.ȱConclusionsȱ Theȱ followingȱconclusionsȱ canȱbeȱdrawnȱfromȱtheȱresultsȱofȱtheȱpresentȱ study:ȱ 1.ȱ Theȱ concentrationȱ ofȱ PAHsȱ inȱ sedimentsȱ hasȱ beenȱ correlatedȱ toȱ theȱ inductionȱ ofȱ ERODȱ activityȱ inȱ theȱ hepatopancreasȱ ofȱ theȱ exposedȱ crabsȱ underȱ laboratoryȱconditions.ȱȱ 2.ȱ Inȱ theȱ caseȱ ofȱ organismsȱ deployedȱ inȱ cagesȱ inȱ theȱ Bayȱ ofȱ Algeciras,ȱ effectsȱofȱcontaminatnsȱboundȱtoȱsedimentsȱdecreaseȱconsiderablyȱasȱindicatedȱ byȱbiomarkersȱofȱexposureȱandȱeffect.ȱThisȱcouldȱbeȱrelatedȱtoȱaȱdisminutionȱofȱ bioavailabilityȱofȱcontaminantsȱdueȱtoȱtheȱwaterȱremovalȱmainlyȱproduceȱbyȱtheȱ highȱinfluenceȱofȱtides.ȱ 3.ȱ Organismsȱ deployedȱ inȱ theȱ Galicianȱ Coastȱ probablyȱ presentȱ otherȱ sourcesȱ ofȱ stressȱ notȱ relatedȱ toȱ sedimentȱ asȱ itȱ hasȱ beenȱ shownȱ inȱ theȱ lowȱ biomarkerȱ activitiesȱ underȱ laboratoryȱ assaysȱ andȱ higherȱ activitiesȱ underȱ fieldȱ conditions,ȱspeciallyȱinȱcrabsȱdeployedȱinȱtheȱBayȱofȱCormeȬLaxe.ȱHoweverȱtheȱ sourcesȱofȱstressȱdidȱnotproduceȱsignificantȱhistpathologicalȱeffects.ȱ 4.ȱ Theȱ importanceȱ ofȱ carryingȱ outȱ kineticȱ approachesȱ ofȱ biomarkersȱ ofȱ responseȱ inȱ marineȱ invertebrateȱ hasȱ beenȱ shown;ȱ theȱ incorporationȱ ofȱ biomarkersȱ ofȱ effectȱ andȱ chemicalȱ dataȱ inȱ additionȱ toȱ theȱ combinationȱ ofȱ bothȱ - 243 - fieldȱ andȱ laboratoryȱ assaysȱ toȱ theȱ kineticȱ studyȱ helpsȱ toȱ elucidateȱ possibleȱ sourcesȱofȱcontamination.ȱȱ 6.ȱAcknowledgementsȱ Theȱ workȱ describedȱ wasȱ partlyȱ supportedȱ byȱ theȱ projectsȱ VEM2003Ȭ 20563/INTER,ȱ andȱ CTM2005Ȭ07282ȬC03Ȭ01/TECNOȱ financedȱ byȱ theȱ Spanishȱ Educationȱ andȱ Scienceȱ Ministryȱ andȱ byȱ CISȱ fundedȱ byȱ theȱ Ministryȱ ofȱ Environment.ȱ Carmenȱ MoralesȬCasellesȱ thanksȱ theȱ Ministryȱ ofȱ Educationȱ andȱ Scienceȱ forȱ fundingȱ herȱ researchȱ fellowshipȱ (FPU).ȱ Dr.ȱ Ribaȱ thanksȱ theȱ I3pȱ programȱ forȱ supportingȱ herȱ participationȱ inȱ thisȱ research.ȱ ȱ Inmaculadaȱ Ribaȱ thanksȱtheȱCSICȱforȱherȱI3Pȱcontract.ȱWeȱareȱgratefulȱforȱtheȱsupportȱandȱhelpȱofȱ theȱ membersȱ ofȱ theȱ CISȱ andȱ theȱ ICMANȬCSIC.ȱ Specialȱ thanksȱ areȱ givenȱ toȱ AntonioȱMorenoȱandȱPabloȱVidal.ȱȱ 7.ȱReferencesȱ Au,ȱ D.W.T.ȱ ȱ Theȱ applicationȱ ofȱ histoȬcytopathologicalȱ biomarkersȱ inȱ marineȱ pollutionȱmonitoring:ȱaȱreview.ȱMar.Pollut.ȱBull.ȱ48,ȱ2004.ȱ817Ȭ834.ȱ Bach,ȱ L.,ȱ Palmqvist,ȱ A.,ȱ Rasmussen,ȱ L.J.,ȱ Forbes,ȱ V.E.ȱ Differencesȱ inȱ PAHȱ toleranceȱ betweenȱ Capitellaȱ species:ȱ Underlyingȱ biochemicalȱ mechanisms.ȱAquat.ȱToxicol.ȱ2005,ȱ74,ȱ307Ȭ319ȱ CasadoȬMartínezȱ MC,ȱ Bucetaȱ JL,ȱ Forjaȱ JM,ȱ DelVallsȱ A.ȱ 2006.ȱ Interlaboratoryȱ assessmentȱofȱmarineȱbioassaysȱtoȱevaluateȱtheȱenvironmentalȱqualityȱofȱ coastalȱsedimentsȱinȱSpain.ȱI.ȱExerciseȱdescriptionȱandȱsedimentȱquality.ȱ CiencȱMarȱ32ȱ:ȱ121Ȭ128.ȱ Fossi,ȱM.C.,ȱCasini,ȱS.,ȱSavelli,ȱC.,ȱCorbelli,ȱC.,ȱFranchi,ȱE.,ȱMattei,ȱN.,ȱSanchezȬ Hernandez,ȱ J.C.,ȱ Corsi,ȱ I.,ȱ Bamber,ȱ S.,ȱ Depledge,ȱ M.H.ȱ Biomarkerȱ 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brownȱbullhead,ȱAmeiurusȱnebulosus.ȱArchȱEnvironȱContamȱToxicolȱ37:ȱ236Ȭ 241.ȱ Montserrat,ȱ J.M.,ȱ Geracitano,ȱ L.A.,ȱ Bianchini,ȱ A.ȱ Currentȱ andȱ futureȱ perspectivesȱusingȱbiomarkersȱtoȱassessȱpollutionȱinȱaquaticȱecosystems.ȱ CommentsȱToxicol,ȱ2003,ȱ9,ȱ255Ȭ269.ȱ OrtizȬDelgado,ȱ JB.,ȱ Segner,ȱ H.,ȱ Arellano,ȱ J.,ȱ Sarasquete,ȱ C.ȱ 2007.ȱ Histopathologicalȱalterations,ȱERODȱactivity,ȱCYP1Aȱproteinsȱandȱbiliaryȱ metabolitesȱ inȱ seabreamȱ Sparusȱ aurataȱ exposedȱ toȱ benzoȬaȬpyreneȱ Ȭ B(a)PȬ.ȱHistologyȱandȱHistopathology,ȱ22:ȱ417Ȭ432ȱ Reynolds,ȱ W.ȱ J.,ȱ Feist,ȱ S.ȱ W.,ȱ Jones,ȱ G.ȱ J.,ȱ Lyons,ȱ B.ȱ P.,ȱ Sheahan,ȱ D.ȱ A.,ȱ &ȱ Stentiford,ȱ G.ȱ D.ȱ (2003).ȱ Comparisonȱ ofȱ biomarkerȱ andȱ pathologicalȱ responsesȱ inȱ flounderȱ (Platichthysȱ flesusȱ L.)ȱ inducedȱ byȱ ingestedȱ polycyclicȱ aromaticȱ hydrocarbonȱ (PAH)ȱ contamination.ȱ Chemosphere,ȱ 52,ȱ1135–1145.ȱ Riba,ȱI.,ȱForja,ȱJ.ȱM.,ȱGómezȬParra,ȱA.,ȱ&ȱDelValls,ȱT.ȱA.ȱ2004.ȱSedimentȱqualityȱ inȱ littoralȱ regionsȱ ofȱ theȱ Gulfȱ ofȱ Cádiz,ȱ aȱ triadȱ approachȱ toȱ addressȱ theȱ influenceȱofȱminingȱactivities.ȱEnvironmentalȱPollution,ȱ132(2),ȱ341–353.ȱ Rodríguezȱ deȱ laȱ Rua,ȱ A.,ȱ ȱ Arellano,ȱ JM.,ȱ Gonzálezȱ deȱ Canales,ȱ ML.,ȱ Blasco,ȱ J.,ȱ Sarasquete,ȱ C.ȱ 2005.ȱ Accumulationȱ ofȱ copperȱ andȱ histopathologicalȱ alterationsȱinȱȱCrassostreaȱangulata.ȱCienc.ȱMar.ȱ31,ȱ455Ȭ466ȱ Sarasquete,ȱ C.,ȱ MuñozȬCueto,ȱ J.ȱ A.,ȱ Arellano,ȱ J.,ȱ Gonzálezȱ deȱ Canales,ȱ M.ȱ L.ȱ (1997).ȱHistofisiologíaȱeȱhistiopatologíaȱduranteȱelȱdesarrolloȱlarvarioȱdeȱ pecesȱ deȱ interésȱ enȱ acuicultura.ȱ Histofisiologíaȱ eȱ Histopatologíaȱ deȱ especiesȱ marinasȱ deȱinterésȱenȱacuiculturaȱ(pp.ȱ45–66).ȱMadrid:ȱServicioȱ PublicacionesȱCSIC.ȱ - 246 - Snyder,ȱ M.J.ȱ Cytochromeȱ P450ȱ enzymesȱ inȱ aquaticȱ invertebrates:ȱ recentȱ advancesȱandȱfutureȱdirections.ȱAquaticȱToxicologyȱ48ȱ(2000)ȱ529–547.ȱ Stentiford,ȱG.D.,ȱFeist,ȱS.W.ȱAȱhistopathologicalȱsurveyȱofȱshoreȱcrabȱ(Carcinusȱ maenas)ȱ andȱ brownȱ shrimpȱ (Crangonȱ crangon)ȱ fromȱ sixȱ estuariesȱ inȱ theȱ UnitedȱKingdom.ȱJournalȱofȱInvertebrateȱPathologyȱ88ȱ(2005)ȱ136–146.ȱ Vanȱ derȱ Oostȱ R,ȱ Beyerȱ J,ȱ Vermeulenȱ NPE.ȱ 2003.ȱ Fishȱ bioaccumulationȱ andȱ biomarkersȱ inȱ environmentalȱ riskȱ assessment.ȱ Environȱ Toxicolȱ Pharmacolȱ 13:57Ȭ149ȱ Werner,ȱ I.,ȱ Teh,ȱ S.J.,ȱ Datta,ȱ S.,ȱ Lu,ȱ X.,ȱ Young,ȱ T.M.ȱ Biomarkerȱ responsesȱ inȱ Macomaȱ nasutaȱ (Bivalvia)ȱ exposedȱ toȱ sedimentsȱ fromȱ northernȱ Sanȱ FranciscoȱBay.ȱMar.ȱEnviron.ȱRes.ȱ58ȱ(2004)ȱ299–304.ȱȱ ȱ ȱȱ ȱ ȱ - 247 - ȱ - 248 - Aȱcomparativeȱanalysisȱofȱmacrobenthicȱcommunityȱstructureȱinȱ relationȱtoȱdifferentȱoilȱcontaminatedȱsediments:ȱtheȱGalicianȱ Coastȱ(acute,ȱPrestigeȱoilȱspill)andȱtheȱBayȱofȱAlgecirasȱ(chronicȱoilȱ spills).ȱ CarmenȱMoralesȬCaselles1,2,*,ȱAugustoȱCésar2,3,ȱRodrigoȱB.ȱChoueri2,ȱ InmaculadaȱRiba1,2,ȱT.ȱÁngelȱDelValls1,2ȱ 1ȱUnidadȱAsociadaȱdeȱCalidadȱAmbientalȱyȱPatologíaȱ(CSICȱ&ȱUCA)ȱInstitutoȱ deȱCienciasȱMarinasȱdeȱAndalucíaȱ(ICMANȬCSIC),ȱAvda.ȱRepúblicaȱSaharauiȱs/n,ȱ PuertoȱRealȱ11510,ȱCádiz,ȱSpainȱ 2ȱUNESCOȱUNITWIN/WiCop,ȱFacultadȱdeȱCienciasȱdelȱMarȱyȱAmbientales,ȱ UniversidadȱdeȱCádiz,ȱPolígonoȱRíoȱSanȱPedroȱs/n,ȱPuertoȱRealȱ11510,ȱCádiz,ȱSpain.ȱ 3ȱDepartamentoȱdeȱEcotoxicologia,ȱUniversidadeȱSantaȱCecíliaȱ(UNISANTA),ȱRuaȱ OswaldoȱCruz,ȱ266,ȱSantos,ȱSãoȱPaulo,ȱBrazil.ȱ Abstractȱ Theȱmacrobenthicȱfaunaȱandȱchemicalsȱconcentrationsȱinȱsedimentsȱwereȱ examinedȱinȱtheȱGalicianȱCoastȱ(NWȱSpain)ȱalongȱthreeȱyearsȱafterȱtheȱPrestigeȱ oilȱ spillȱ (November,ȱ 2002).ȱ Resultsȱ obtainedȱ pointsȱ toȱ anȱ initialȱ impactȱ toȱ theȱ benthicȱcommunityȱdueȱtoȱtheȱfuelȱoilȱalthoughȱaȱrecoveryȱofȱtheȱenvironmentalȱ qualityȱwasȱobservedȱfourȱyearsȱafterȱtheȱaccident.ȱSelectedȱsitesȱlocatedȱinȱtheȱ GalicianȱCoastȱwereȱcomparedȱtoȱtheȱstatusȱofȱsedimentsȱchronicallyȱaffectedȱbyȱ oilȱ spillsȱ inȱ theȱ Bayȱ ofȱ Algecirasȱ andȱ thoseȱ notȱ affectedȱ inȱ theȱ Bayȱ ofȱ Cadizȱ inȱ orderȱtoȱassessȱtheȱrecuperationȱcapacityȱofȱtheȱecosystemȱafterȱanȱacuteȱimpact.ȱ Theȱ methodologyȱ employedȱ includesȱ univariateȱ analysisȱ usingȱ conventionalȱ communityȱ descriptiveȱ parametersȱ andȱ theȱ numericalȱ contributionȱ ofȱ majorȱ taxonomicȱgroups.ȱResultsȱobtainedȱinȱtheȱareasȱofȱstudyȱhaveȱbeenȱlinkedȱwithȱ theȱ physicochemicalȱ characterizationȱ ofȱ sedimentsȱ withȱ theȱ purposeȱ ofȱ identifyingȱtheȱcauseȱandȱsourceȱofȱcontaminants.ȱ ȱScienceȱofȱtheȱTotalȱEnvironmentȱ(enviado) - 249 - Keywords:ȱ sedimentȱ alteration,ȱ macrobenthicȱ populations,ȱ community,ȱ environmentalȱdegradation,ȱPAHs.ȱȱȱȱ 1.ȱIntroductionȱ TheȱoilȱtankerȱPrestigeȱbrokeȱdownȱinȱtheȱGalicianȱCoastȱ(NWȱSpain)ȱonȱ Novemberȱ 2002ȱ andȱ approximatelyȱ 60ȱ000ȱ tonnesȱ ofȱ heavyȱ fuelȱ oilȱ wereȱ releasedȱ intoȱ theȱ surroundingȱ waters,ȱ resultingȱ inȱ theȱ contaminationȱ ofȱ moreȱ thanȱ 1000ȱ kmȱ ofȱ coastline;ȱ thisȱ accidentȱ supposedȱ oneȱ ofȱ theȱ majorȱ ecologicalȱ catastrophesȱofȱtheȱIberianȱPeninsula.ȱResultsȱofȱworkȱinvestigatingȱtheȱimpactȱ ofȱoilȱspillsȱonȱaȱvarietyȱofȱbiologicalȱcomponentsȱhaveȱconfirmedȱtheȱeffectsȱinȱ aȱwideȱrangeȱofȱhabitatsȱandȱspeciesȱ(Petersonȱetȱal.,ȱ2001).ȱ Theȱ assessmentȱ ofȱ inȱ situȱ alterationȱ ofȱ residentialȱ communityȱ structureȱ hasȱ beenȱ oftenȱ performedȱ toȱ determineȱ theȱ effectsȱ ofȱ pollutantsȱ inȱ theȱ coastalȱ environmentȱ (DelVallsȱ etȱ al.,ȱ 1998a.,ȱ GómezȬGesteiraȱ andȱ Dauvin,ȱ 2005).ȱ Fieldȱ dataȱ onȱ theȱ communitiesȱ livingȱ inȱ theȱ sedimentsȱ allowȱ establishingȱ whetherȱ thereȱisȱobservableȱpollutionȬinducedȱdegradationȱeffectȱinȱtheȱbiotaȱ(Chapmanȱ etȱ al.,ȱ 1991,ȱ Chapman,ȱ 2007).ȱ Threeȱ symptomsȱ ofȱ stressȱ reducedȱ diversity,ȱ retrogressionȱ toȱ opportunisticȱ species,ȱ andȱ reducedȱ sizeȱ ofȱ individualsȱ areȱ documentedȱforȱaȱwideȱvarietyȱofȱnaturalȱandȱanthropogenicȱstressesȱinȱmarineȱ environmentsȱ (Gray,ȱ 1989).ȱ Identificationȱ ofȱ theseȱ symptomsȱ inȱ aȱ benthicȱ assemblageȱ mayȱ signalȱ aȱ changeȱ inȱ environmentalȱ conditionsȱ resultingȱ fromȱ anthropogenicȱ influencesȱ (Newellȱ etȱ al.,ȱ 1999).ȱ Previousȱ studiesȱ (citedȱ inȱ Blanchardȱ etȱ al.,ȱ 2002)ȱ indicatedȱ thatȱ someȱ benthicȱ organismsȱ canȱ respondȱ toȱ nonȬtoxicȱ fractionsȱ ofȱ crudeȱ oilȱ asȱ theyȱ wouldȱ toȱ otherȱ formsȱ ofȱ organicȱ enrichmentȱ (e.g.,ȱ Weston,ȱ 1990)ȱ andȱ thisȱ isȱ suggestedȱ byȱ theȱ responseȱ ofȱ anȱ increaseȱinȱsomeȱpolychaeteȱspecies.ȱ Multivariateȱ analysisȱ appearsȱ toȱ beȱ anȱ especiallyȱ sensitiveȱ toolȱ forȱ detectingȱ changeȱ inȱ theȱ structureȱ ofȱ theȱ faunalȱ communityȱ (Warwickȱ andȱ - 250 - Clarke.,ȱ 1991).ȱ Theȱ integrationȱ ofȱ fieldȱ dataȱ withȱ chemicalsȱ analysisȱ permitsȱ establishingȱtheȱpossibleȱcausesȱandȱsourcesȱofȱtheȱbenthicȱalteration.ȱ Theȱscopeȱofȱthisȱstudyȱisȱtoȱexamineȱtheȱrecoveryȱofȱbenthicȱcommunityȱ afterȱ theȱ Prestigeȱ oilȱ spillȱ andȱ toȱ compareȱ theȱ environmentalȱ statusȱ ofȱ theȱ Galicianȱ Coastȱ afterȱ 4ȱ yearsȱ ofȱ theȱ spillȱ withȱ theȱ macrobenthicȱ structureȱ analyzedȱinȱBayȱofȱAlgecirasȱthatȱisȱchronicallyȱimpactedȱbyȱdifferentȱoilȱspillsȱ andȱwithȱthatȱanalyzedȱinȱtheȱBayȱofȱCadizȱconsideredȱnotȱcontaminatedȱneitherȱ pollutedȱ byȱ thisȱ kindȱ ofȱ activitiesȱ orȱ contaminants..ȱ Theȱ comparativeȱ analysisȱ willȱbeȱcarriedȱoutȱbyȱusingȱunivariateȱandȱmultivariateȱmethods.ȱ 2.ȱMaterialȱandȱmethodsȱ 2.1.ȱSitesȱdescriptionȱ Figureȱ1ȱshowsȱtheȱselectedȱsitesȱinȱtheȱGalicianȱCoastȱ(NWȱSpain)ȱwereȱ locatedȱ inȱ theȱ Ciesȱ Islandȱ (A,ȱ Bȱ andȱ C)ȱ inȱ theȱ Atlanticȱ Islandȱ Nationalȱ Parkȱ (AINP)ȱandȱinȱtheȱBayȱofȱCormeȬLaxeȱ(D,ȱEȱandȱF).ȱBothȱareasȱwereȱimportantlyȱ affectedȱ byȱ theȱ Prestigeȱ oilȱ spillȱ andȱ areȱ consideredȱ ofȱ highȱ ecologicalȱ importance.ȱTheȱsecondȱareaȱofȱstudyȱwasȱtheȱmouthȱofȱtheȱRiverȱPalmonesȱ(P1)ȱ andȱGuadarranqueȱ(GR3ȱandȱGR4)ȱinȱtheȱBayȱofȱAlgecirasȱ(SȱSpain);ȱthisȱplaceȱ wasȱ selectedȱ becauseȱ isȱ highlyȱ industrializedȱ andȱ thereȱ areȱ aȱ largeȱ numberȱ ofȱ petrochemicalȱactivitiesȱwhichȱcompriseȱseveralȱaccidentalȱoilȱspills.ȱAȱreferenceȱ site,ȱCA,ȱwidelyȱcharacterizedȱbyȱdifferentȱecotoxicologicalȱstudiesȱ(DelȱVallsȱetȱ al.,ȱ1998b,ȱRibaȱetȱal.,ȱ2004,ȱMartínȬDíazȱetȱal.,ȱ2005;ȱCesarȱetȱal.ȱ2007;ȱMoralesȬ Casellesȱetȱal.,ȱ2007)ȱwasȱselectedȱinȱaȱcleanȱareaȱinȱtheȱBayȱofȱCádizȱ(SȱSpain).ȱȱ 2.2.ȱSampleȱcollectionȱ Sedimentȱ samplesȱ wereȱ collectedȱ withȱ aȱ 0.025ȱ m2ȱ vanȱ Veenȱ grab.ȱ Onlyȱ grabsȱ thatȱ achievedȱ adequateȱ penetrationȱ (2/3ȱ ofȱ totalȱ volume)ȱ toȱ collectȱ theȱ superficialȱ 5ȱ cmȱ ofȱ theȱ sedimentȱ andȱ thatȱ showedȱ noȱ evidenceȱ ofȱ leakageȱ orȱ - 251 - surfaceȱ disturbanceȱ wereȱ retainedȱ forȱ theȱ study.ȱ Forȱ theȱ benthicȱ infaunalȱ samples,ȱ theȱ entireȱ contentsȱ ofȱ theȱ grabȱ includingȱ overlyingȱ water,ȱ wereȱ wetȱ sievedȱ atȱ theȱ studyȱ siteȱ withȱ aȱ 0.5ȱ mmȱ stainlessȱ steelȱ mesh.ȱ Residuesȱ wereȱ gentlyȱ washed,ȱ placedȱ inȱ polyethyleneȱ bottles,ȱ preservedȱ withȱ 10ȱ %ȱ bufferedȱ formalinȱ andȱ stainedȱ withȱ Roseȱ Bengal.ȱ Sedimentsȱ forȱ chemicalȱ analysesȱ wereȱ collectedȱandȱtransportedȱtoȱaȱcooler.ȱSedimentȱsamplesȱwereȱkeptȱinȱdarkȱatȱ4ȱ ºCȱpriorȱtoȱanalysis.ȱ ȱȱ ȱ ȱ ƒF ƒE ƒD Atlantic Islands National Park ȱ Ría de CormeLaxe •C N •A •B ȱ E W S ȱ Spain ȱ ȱ •GR3 •GR4 •P1 ȱ Bay of Algeciras ȱ •CA ȱ ȱ Bay of Cádiz Figureȱ1.ȱMapȱofȱtheȱcoastalȱareaȱofȱGaliciaȱshowingȱtheȱlocationsȱofȱtheȱ samplingȱstations.ȱA,ȱBȱandȱCȱrefersȱtoȱtheȱstationsȱlocatedȱinȱtheȱCiesȱIslandȱinȱ theȱAtlanticȱIslandȱNationalȱParkȱandȱD,ȱEȱandȱFȱtoȱthoseȱinȱtheȱBayȱofȱCormeȬ Laxe.ȱ Theȱ stationsȱ locatedȱ inȱ theȱ Bayȱ ofȱ Algecirasȱ areȱ GR3,ȱ GR4ȱ andȱ P1.ȱ Theȱ stationȱ CAȱ locatedȱ inȱ theȱ Bayȱ ofȱ Cadizȱ correspondsȱ toȱ theȱ sedimentȱ usedȱ asȱ reference.ȱ - 252 - 2.3.ȱLaboratoryȱanalysisȱ Theȱ organismsȱ collectedȱ inȱ theȱ studyȱ sitesȱ wereȱ separatedȱ fromȱ theȱ remainingȱ sediment,ȱ sortedȱ andȱ identifiedȱ toȱ theȱ lowestȱ possibleȱ taxonȱ levelȱ (speciesȱlevel,ȱorȱfamilyȱinȱcaseȱofȱPolychaeta).ȱIdentificationsȱtoȱtheȱfamilyȱlevelȱ wereȱconsideredȱadequateȱmeasuresȱofȱfaunalȱcompositionȱforȱtheȱpurposesȱofȱ thisȱstudy.ȱ Polycyclicȱ aromaticȱ hydrocarbonsȱ (PAHs)ȱ boundȱ toȱ sedimentsȱ wereȱ analyzedȱ byȱ usingȱ aȱ gasȱ chromatographȱ equippedȱ withȱ massȱ spectrometerȱ (GC/MS)ȱ (USEPA,ȱ 1994).ȱ Brieflyȱ driedȱ samplesȱ wereȱ Soxhletȱ extractedȱ withȱ nȬ hexaneȱforȱ18ȱh,ȱandȱtheȱextractsȱwereȱisolatedȱbyȱcolumnȱchromatographyȱonȱ Florisil®.ȱ PAHsȱ wereȱ elutedȱ andȱ theirȱ fractionsȱ wereȱ driedȱ inȱ aȱ rotatingȱ evaporatorȱandȱreȬdissolvedȱinȱisooctane.ȱAromaticȱfractionsȱwereȱanalyzedȱonȱ aȱHewlettePackardȱ(HP)ȱ5890ȱSeriesȱIIȱgasȱchromatographȱcoupledȱwithȱanȱHPȱ 5970ȱ massȱ spectrometer.ȱ PAHsȱ wereȱ analyzedȱ byȱ GCȬMSȱ usingȱ selectedȱ ionȱ monitoringȱ (SIM).ȱ Theȱ analyticalȱ procedureȱ showedȱ agreementȱ withȱ theȱ certifiedȱvaluesȱofȱmoreȱthanȱ90%.ȱ TraceȱmetalȱwereȱanalyzedȱasȱdescribedȱbyȱCasadoȬMartínezȱetȱal.ȱ(2006);ȱ briefly,ȱ 2.5ȱ gȱ ofȱ sedimentsȱ (<0.065ȱ mm)ȱ wereȱ placedȱ inȱ Teflonȱ containersȱ andȱ wereȱdigestedȱinȱmicrowaveȱ(400W,ȱ15ȱmin,ȱtwice)ȱwithȱHNO3ȱ2N.ȱTheȱextractsȱ wereȱ purifiedȱ byȱ passingȱ throughȱ aȱ CȬ18ȱ columnȱ andȱ metalsȱ analysesȱ wereȱ performedȱbyȱ anodicȱ voltamperimetryȱ(ȬZn,ȱCd,ȱPb,ȱNi,ȱCoȱandȱ CuȬȱMetrohmȱ ApplicationȱBulletinȱ Nºȱ147;ȱȬȱVȬȱMetrohmȱApplicationȱNoteȱNºȱVȬ81).ȱForȱHgȱ theȱ coldȱ vapourȱ techniqueȱ wasȱ usedȱ andȱ wasȱ quantifiedȱ usingȱ atomicȱ absorptionȱ spectrometry.ȱ Theȱ analyticalȱ proceduresȱ wereȱ checkedȱ usingȱ referenceȱ materialȱ (MESSȬ1ȱ NRCȱ andȱ CRMȱ 277ȱ BCR)ȱ andȱ showedȱ aȱ recoveryȱ greaterȱthanȱ90%ȱofȱtheȱcertifiedȱconcentration.ȱ - 253 - OrganicȱcarbonȱcontentȱwasȱdeterminedȱusingȱtheȱmethodȱofȱGaudetteȱetȱ al.ȱ (1974)ȱ withȱ theȱ Elȱ Rayisȱ (1985)ȱ modification.ȱ Forȱ sedimentȱ grainȱ size,ȱ anȱ aliquotȱofȱwetȱsedimentȱwasȱanalyzedȱusingȱaȱFristchȱlaserȱparticleȱsizerȱ(modelȱ Analysetteȱ 22)ȱ followingȱ theȱ methodȱ reportedȱ byȱ DelVallsȱ andȱ Chapmanȱ (1998b).ȱ 2.4.ȱDataȱanalysisȱ Descriptiveȱstatisticsȱwereȱusedȱinȱorderȱtoȱdescribeȱtheȱtheȱmacrobenthicȱ communityȱ atȱ eachȱ site;ȱ univariateȱ methodsȱ includedȱ classicalȱ communityȱ descriptiveȱ parameters,ȱ asȱ speciesȱ richnessȱ (Margaleff’sȱ R),ȱ ShannonȬWienerȱ diversityȱ (H’),ȱ evennessȱ (Pielou’sȱ J),ȱ andȱ Simpson’sȱ dominanceȱ (Dȱ =ȱ 1ȬΏ’)ȱ (GómezȬGesteiraȱandȱDauvin,ȱ2005;ȱChoueriȱetȱal.,ȱsubmitted).ȱSinceȱnumericalȱ contributionȱ ofȱ majorȱ taxaȱ isȱ widelyȱ utilisedȱ toȱ evaluateȱ pollutionȱ effectsȱ (DelValls,ȱ1998a;ȱChapmanȱetȱal.,ȱ1996),ȱanȱabundanceȱanalysisȱwasȱcarriedȱoutȱ byȱ calculatingȱ theȱ proportionȱ ofȱ majorȱ taxa’sȱ (Polychaeta,ȱ Molluscaȱ andȱ Crustacea)ȱabundanceȱtoȱtheȱtotalȱabundanceȱforȱeachȱsample.ȱȱ Multivariateȱ analysisȱ wasȱ carriedȱ outȱ withȱ inȱ anȱ attemptȱ toȱ linkȱ contaminationȱ withȱ benthicȱ alterationȱ parameters;ȱ theȱ principalȱ componentȱ analysisȱ (PCA)ȱ wasȱ usedȱ asȱ theȱ extractionȱ procedureȱ whichȱ isȱ aȱ multivariateȱ statisticalȱ techniqueȱ toȱ exploreȱ variableȱ distributionsȱ (Ribaȱ etȱ al.,ȱ 2003).ȱ Theȱ objectiveȱ ofȱ PCAȱ isȱ toȱ deriveȱ aȱ reducedȱ numberȱ ofȱ newȱ variablesȱ asȱ linearȱ combinationsȱ ofȱ theȱ originalȱ variables.ȱ Thisȱ providesȱ aȱ descriptionȱ ofȱ theȱ structureȱ ofȱ theȱ dataȱ withȱ theȱ minimumȱ lossȱ ofȱ information.ȱ Aȱ hierarchicalȱ classificationȱ techniqueȱ byȱ meansȱ ofȱ aȱ Clusterȱ analysisȱ wasȱ performedȱ toȱ determineȱ theȱ percentageȱ disagreementȱ amongȱ theȱ studyȱ sitesȱ takingȱ intoȱ accountȱtheȱphysicochemicalȱandȱbiologicalȱvariables,ȱresultsȱwereȱdisplayedȱinȱ aȱdendrogram.ȱ ȱ - 254 - 3.ȱResultsȱandȱdiscussionȱ 3.1.ȱ Evolutionȱ ofȱ theȱ benthicȱ communityȱ andȱ chemicalȱ concentrationȱ inȱ sedimentsȱfromȱtheȱGalicianȱcoastȱ(2004Ȭ2006)ȱ Threeȱ surveysȱ wereȱ carriedȱ outȱ inȱ theȱ AINPȱ afterȱ theȱ Prestigeȱ oilȱ spillȱ (2004,ȱ2005ȱandȱ2006)ȱwhereasȱtwoȱ(2005ȱandȱ2006)ȱwereȱperformedȱinȱtheȱBayȱ ofȱ Cormeȱ Laxe.ȱ Theȱ decreaseȱ inȱ theȱ abundanceȱ ofȱ theȱ macroinfaunaȱ observedȱ afterȱtheȱspillȱappearȱtoȱreflectȱtheȱlossesȱdueȱtoȱoilingȱtoxicityȱorȱindirectȱeffectsȱ ofȱ oilingȱ andȱ cleanȬupȱ (Junoyȱ etȱ al.,ȱ 2004).ȱ Tableȱ 1ȱ showsȱ theȱ decreaseȱ inȱ theȱ concentrationȱ ofȱ PAHsȱ inȱ sedimentsȱ 4ȱ yearsȱ afterȱ theȱ Prestigeȱ oilȱ spillȱ inȱ allȱ studyȱ sitesȱ (MoralesȬCasellesȱ etȱ al.,ȱ accepted).ȱ Forȱ allȱ stationsȱ theȱ numberȱ ofȱ speciesȱ increasedȱ fromȱ theȱ firstȱ surveyȱ tillȱ theȱ lastȱ one;ȱ thisȱ increaseȱ wasȱ especiallyȱimportantȱinȱsitesȱBȱandȱCȱfromȱtheȱAINP.ȱTheȱspecificȱrichnessȱalsoȱ increasedȱinȱsitesȱselectedȱinȱtheȱCíesȱIslandsȱwhereasȱitȱkeptȱsimilarȱinȱDȱandȱFȱ andȱdecreasedȱinȱsiteȱEȱfromȱCormeȬLaxe.ȱDiversityȱpresentedȱaȱdiminutionȱinȱ siteȱEȱwhileȱanȱincreaseȱofȱthisȱparameterȱwasȱobservedȱinȱtheȱotherȱstudyȱsites.ȱ Inȱgeneral,ȱallȱstationsȱpresentedȱaȱhighȱpopulationȱofȱpolychaeteȱafterȱtheȱspillȱ whichȱ decreasedȱ alongȱ theȱ timeȱ whereasȱ otherȱ taxonsȱ suchȱ asȱ molluscsȱ andȱ crustaceanȱincreased.ȱItȱisȱknownȱthatȱtheȱabundanceȱofȱopportunisticȱtaxaȱsuchȱ asȱ polychaeteȱ increaseȱ inȱ theȱ presenceȱ ofȱ petroleumȱ hydrocarbonsȱ (Federȱ andȱ Blanchard,ȱ 1998)ȱ whereasȱ declinesȱ inȱ benthicȱ amphipodsȱ alsoȱ occurredȱ followingȱtheȱAmocoȱCadizȱ(Dauvin,ȱ1982)ȱandȱtheȱAegeanȱSeaȱoilȱspillȱ(Parraȱ andȱ LópezȬJamar,ȱ 1997).ȱ Univariateȱ analysesȱ ofȱ benthicȱ dataȱ fromȱ ourȱ studyȱ showedȱ theȱ trendsȱ (i.e.ȱ lowȱ faunalȱ abundance,ȱ relativelyȱ highȱ dominanceȱ andȱ lowȱ diversity)ȱ observedȱ followingȱ oilȱ spillsȱ (Federȱ etȱ al.,ȱ 1998),ȱ whatȱ indicatesȱ thatȱ theȱ environmentȱ wasȱ negativelyȱ impactedȱ byȱ theȱ accidentȱ ofȱ theȱ tankerȱ Prestige;ȱ however,ȱ theȱ variationȱ ofȱ theȱ benthicȱ parametersȱ alongȱ theȱ timeȱ andȱ theȱ diminutionȱ ofȱ theȱ concentrationȱ ofȱ PAHsȱ boundȱ toȱ sedimentsȱ pointsȱ toȱ aȱ - 255 - recoveryȱofȱtheȱenvironmentalȱqualityȱinȱtheȱfollowingȱyearsȱafterȱtheȱoilȱspill,ȱ whatȱhasȱbeenȱconfirmedȱbyȱotherȱauthorsȱ(Serranoȱetȱal.,ȱ2006).ȱȱ Tableȱ1.ȱSummarizedȱresultsȱofȱtheȱconcentrationȱofȱPAHsȱinȱsedimentsȱ theȱ andȱ benthicȱ alterationȱ parametersȱ measuredȱ forȱ theȱ studyȱ ofȱ theȱ environmentalȱ qualityȱ inȱ theȱ Ciesȱ Islandȱ ȱ inȱ theȱ Atlanticȱ Islandȱ nationalȱ Parkȱ 2004Ȭ2006ȱ(firstȱsurvey:ȱAȬ1,ȱBȬ1,ȱCȬ1;ȱsecondȱsurvey:ȱAȬ2,ȱBȬ2,ȱCȬ2;ȱthirdȱsurvey:ȱ AȬ3,ȱBȬ3,ȱCȬ3)ȱandȱtheȱBayȱofȱCormeȬLaxeȱ2005Ȭ2006ȱȱ(secondȱsurvey:ȱDȬ2,ȱEȬ2,ȱ FȬ2;ȱthirdȱsurvey:ȱDȬ3,ȱEȬ3,ȱFȬ3).ȱȱ Stationsȱ AȬ1ȱ AȬ2ȱ AȬ3ȱ BȬ1ȱ BȬ2ȱ BȬ3ȱ CȬ1ȱ CȬ2ȱ CȬ3ȱ DȬ2ȱ DȬ3ȱ EȬ2ȱ EȬ3ȱ FȬ2ȱ FȬ3ȱ Parametersȱmeasuredȱ Moluscaȱ Polychaetaȱ Crustacea PAHȱ Speciesȱȱ Specificȱ Diversity ΐgKgȬ1ȱ Nºȱ richnessȱ %ȱ ȱȱȱ%ȱ %ȱ 390ȱ 3.0ȱ 1.8ȱ 1.5ȱ 0.1ȱ 53.0ȱ 33.3ȱ 119ȱ 5ȱ 12.0ȱ 4.3ȱ 2.4ȱ 21.0ȱ 34.5ȱ 108ȱ 7.09ȱ 28.5ȱ 5.1ȱ 15.3ȱ 20.0ȱ 37.0ȱ 2120ȱ 2ȱ 1.2ȱ 1.0ȱ 0.1ȱ 100.0ȱ 0.1ȱ 366ȱ 12ȱ 5.9ȱ 5.2ȱ 9.9ȱ 56.2ȱ 15.4ȱ 67ȱ 47ȱ 33.9ȱ 5.0ȱ 28.4ȱ 21.5ȱ 41.0ȱ 420ȱ 9.0ȱ 15.3ȱ 2.9ȱ 22.2ȱ 33.3ȱ 33.3ȱ 239ȱ 30.0ȱ 50.9ȱ 4.5ȱ 26.7ȱ 26.7ȱ 43.3ȱ n.d.ȱ 25.0ȱ 42.4ȱ 4.3ȱ 39.1ȱ 21.7ȱ 39.1ȱ 537ȱ 9ȱ 25.7ȱ 2.9ȱ 33.3ȱ 33.3ȱ 33.3ȱ 38ȱ 10ȱ 28.6ȱ 3.0ȱ 30.0ȱ 20.0ȱ 50.0ȱ 558ȱ 12ȱ 66.7ȱ 5.0ȱ 2.0ȱ 30.6ȱ 100.0ȱ 52ȱ 12ȱ 32.1ȱ 3.0ȱ 40.1ȱ 22.2ȱ 51.4ȱ 820ȱ 15ȱ 55.6ȱ 2.3ȱ 40.0ȱ 26.7ȱ 33.3ȱ 323ȱ 13ȱ 48.2ȱ 2.9ȱ 15.4ȱ 23.1ȱ 61.5ȱ Inȱorderȱtoȱelucidateȱifȱthereȱisȱstillȱdegradationȱofȱtheȱenvironmentȱinȱtheȱ GalicianȱCoastȱfourȱyearsȱafterȱtheȱspill,ȱtheȱevaluationȱofȱtheȱsedimentȱquality,ȱ includingȱ physicochemicalȱ andȱ benthicȱ parametersȱ wasȱ comparedȱ withȱ theȱ situationȱofȱtheȱareaȱofȱtheȱbayȱofȱAlgeciras,ȱchronicallyȱaffectedȱbyȱoilȱspills.ȱ ȱ - 256 - 3.2.ȱ Physicochemicalȱ characterizationȱ ofȱ sedimentsȱ fromȱ theȱ Galicianȱ CoastȱandȱtheȱBayȱofȱAlgecirasȱ(2006)ȱ Summarisedȱ resultsȱ forȱ theȱ chemicalȱ dataȱ andȱ physicalȱ characterizationȱ ofȱ theȱ sedimentsȱ areȱ shownȱ inȱ Tableȱ 2.ȱ ȱ Stationsȱ fromȱ theȱ Bayȱ ofȱ Algecirasȱ presentedȱ theȱ highestȱ concentrationsȱ ofȱ organicȱ carbonȱ andȱ finesȱ inȱ theȱ sediments.ȱ Theȱ highestȱ concentrationsȱ ofȱ PAHsȱ wereȱ observedȱ inȱ theȱ stationsȱ locatedȱinȱtheȱBayȱofȱAlgecirasȱwhereasȱGR3ȱpresentedȱtheȱhighestȱvaluesȱofȱPbȱ andȱ Niȱ oftenȱ relatedȱ toȱ hydrocarbons.ȱ Theȱ factȱ thatȱ thereȱ isȱ aȱ petrogenicȱ industryȱclosedȱtoȱthisȱpointȱandȱtheȱpresenceȱofȱbunkeringȱactivitiesȱinȱtheȱBayȱ couldȱexplainȱtheȱinputȱofȱhydrocarbonȱinȱtheȱarea.ȱOnȱtheȱotherȱhandȱneitherȱ theȱreferenceȱstationȱnorȱtheȱsiteȱCȱshowedȱpresenceȱofȱPAHsȱinȱtheirȱsediments.ȱ Noȱ generalȱ patternȱ wasȱ observedȱ forȱ otherȱ contaminantsȱ inȱ theȱ studiedȱ areasȱ fromȱ CormeȬLaxeȱ andȱ Ciesȱ Island.ȱ Inȱ general,ȱ sitesȱ fromȱ theȱ Bayȱ ofȱ Algecirasȱ presentȱtheȱhighestȱcontentȱofȱfinesȱandȱorganicȱcarbonȱinȱtheirȱsediments.ȱȱ 3.3.ȱ Theȱ benthicȱ communityȱ inȱ theȱ Galicianȱ Coastȱ andȱ theȱ Bayȱ ofȱ Algecirasȱ(2006)ȱ Theȱ descriptionȱ ofȱ theȱ benthicȱ communityȱ differsȱ dependingȱ onȱ theȱ sampledȱ area.ȱ Forȱ sedimentsȱ collectedȱ inȱ theȱ referenceȱ stationȱ (CA)ȱ Molluscsȱ wereȱ theȱ bestȱ representedȱ taxonȱ (78.5%)ȱ followedȱ byȱ Polychaeteȱ (12.7ȱ %)ȱ andȱ Crustaceaȱ (8.8ȱ %)ȱ (Figureȱ 2).ȱ Surveysȱ inȱ theȱ Bayȱ ofȱ Algecirasȱ showedȱ aȱ prevalenceȱ ofȱ polychaete,ȱ 45.3ȱ %ȱ inȱ GR4,ȱ 64.4ȱ %ȱ inȱ P1ȱ whereasȱ inȱ GR3ȱ allȱ theȱ communityȱwasȱmadeȱupȱbyȱpolychaete.ȱTheȱdominanceȱdistributionȱofȱtaxaȱinȱ BayȱofȱAlgecirasȱrevealsȱthatȱpollutantȱresistantȱgroups,ȱaccordingȱGrallȱandȱȱ - 257 - 0.30ȱ 0.31ȱ 0.37ȱ 0.65ȱ 2.15ȱ 3.19ȱ 3.86ȱ Cȱ Dȱ Eȱ Fȱ GR3ȱ GR4ȱ P1ȱ 35.4ȱ 59.3ȱ 69.4ȱ 5.95ȱ 5.50ȱ 3.79ȱ 2.76ȱ 2.81ȱ 56.7ȱ 35.3ȱ 138ȱ 271ȱ 19.9ȱ 25.0ȱ 164ȱ 91.0ȱ 12.3ȱ 6.21ȱ 21.6ȱ 5.90ȱ 7.30ȱ 3.70ȱ 0.85ȱ 0.90ȱ 1.50ȱ 75.2ȱ 3.67ȱ 5.01ȱ 4.20ȱ 0.43ȱ 0.70ȱ 1.40ȱ 1.40ȱ 5.20ȱ 13.3ȱ 13.1ȱ 74.7ȱ 5.70ȱ 1.50ȱ 1.70ȱ 4.50ȱ 2.40ȱ 13.3ȱ - 258 - 0.65ȱ 0.25ȱ 1.04ȱ 3.40ȱ 2.10ȱ 2.00ȱ 0.60ȱ 0.80ȱ 0.70ȱ 641ȱ 802ȱ 2961ȱ 323ȱ 52.0ȱ 38.0ȱ n.d.ȱ 67.0ȱ 108ȱ n.d.ȱ 0.26ȱ 377ȱ n.d.ȱ Bȱ 4.32ȱ 0.06ȱ 0.28ȱ 6.98ȱ Aȱ 2.28ȱ 2.50ȱ 1.07ȱ CAȱ 21.3ȱ Finesȱ Znȱ Pbȱ Cuȱ Niȱ Hgȱ PAHȱ Ȭ1 Ȭ1 Ȭ1 Ȭ1 Ȭ1 %ȱ mgKg mgKg mgKg mgKg mgKg ΐgKgȬ1ȱ Physcochemicalȱanalysisȱ studyȱ O.C.ȱ% sitesȱ ȱȱ ȱ ȱ ȱ 4.67ȱ 4.67ȱ 0.67ȱ 13ȱ 12ȱ 10ȱ 25ȱ 47ȱ 7.09ȱ 14ȱ Speciesȱ N.ȱ 1.3ȱ 1.2ȱ 0.0ȱ 48.2ȱ 32.1ȱ 28.6ȱ 42.4ȱ 33.9ȱ 28.5ȱ 2.6ȱ 1.24ȱ 1.29ȱ 0.0ȱ 2.9ȱ 3ȱ 3ȱ 4.3ȱ 5ȱ 5.1ȱ 1.64ȱ 0.68ȱ 0.72ȱ 0.0ȱ 0.20ȱ 0.19ȱ 0.15ȱ 0.06ȱ 0.10ȱ 0.50ȱ 0.66ȱ Specificȱ Diversity Dominanceȱ richness Benthicȱalterationsȱȱ CormeȬLaxeȱ(D,ȱE,ȱF);ȱtheȱBayȱofȱAlgecirasȱ(GR3,ȱGR4ȱandȱP1)ȱandȱtheȱBayȱofȱCadizȱ(CA)ȱusedȱasȱtheȱreferenceȱstation.ȱȱȱ specificȱ richness,ȱ diversityȱ andȱ dominance)ȱ measuredȱ inȱ theȱ sedimentsȱ fromȱ Galicia:ȱ Atlanticȱ Islandsȱ Nationalȱ Parkȱ (A,ȱ B,ȱ C),ȱ Tableȱ2.ȱ TotalȱPAHs,ȱ PCBsȱandȱ metalȱconcentrationȱ(Zn,ȱPb,ȱCu,ȱNi,ȱandȱ Hg)ȱandȱ benthicȱ parametersȱ (numberȱ ofȱ species,ȱ Glémarecȱ(1997)ȱclassification,ȱareȱmoreȱabundant.ȱPolychaetaȱ(Capitellidaeȱandȱ Nereidae)ȱ wasȱ theȱ mostȱ commonȱ taxa,ȱ followedȱ byȱ Molluscaȱ (onlyȱ pollutionȬ resistantȱ species,ȱ asȱ Cerastodermaȱ eduleȱ andȱ Abraȱ tenuis)ȱ (Choueriȱ etȱ al.,ȱ submitted).ȱThisȱpatternȱofȱabundancyȱhasȱbeenȱshownȱinȱareasȱaffectedȱbyȱoilȱ spillsȱ (Parraȱ andȱ LópezȬJamar,ȱ 1997;ȱ Serranoȱ etȱ al.,ȱ 2006).ȱ Otherȱ authorsȱ considerȱ thatȱ theseȱ taxaȱ appearȱ toȱ beȱrespondingȱtoȱmoderateȱenhancementȱofȱ theȱbenthosȱbyȱresidualȱhydrocarbonsȱinȱeffluentsȱasȱaȱfoodȱsourceȱ(Blanchardȱ etȱal.,ȱ2002).ȱCrustaceaȱwasȱtheȱmostȱfrequentȱtaxaȱinȱallȱtheȱsitesȱlocatedȱinȱtheȱ GalicianȱCoast,ȱ37.0ȱ%ȱinȱA,ȱ41.0ȱinȱB,ȱ39.1ȱ%ȱinȱC,ȱ50.0ȱ%ȱinȱD,ȱ51.4ȱ%ȱinȱEȱandȱ 61.5ȱ%ȱinȱF.ȱTheȱhighestȱnumberȱofȱspeciesȱwasȱdetectedȱinȱtheȱsitesȱBȱ(47)ȱandȱCȱ (25)ȱfromȱtheȱCiesȱIslandsȱ(14),ȱfollowedȱbyȱtheȱreferenceȱstationȱ(CA)ȱwhereasȱ theȱ lowestȱ numberȱ wasȱ observedȱ inȱ theȱ Bayȱ ofȱ Algeciras.ȱ Benthicȱ speciesȱ ofȱ slowȱ growthȱ andȱ withȱ slowȱ recoveryȱ capability,ȱ mainlyȱ crustaceansȱ andȱ echinoderms,ȱshowȱaȱhighȱsensitivityȱtoȱoilȱexposureȱ(Serranoȱetȱal.,ȱ2006).ȱWithȱ regardȱtoȱotherȱpopulationȱparameters,ȱspeciesȱrichnessȱrangedȱfromȱ48.2ȱinȱFȱtoȱ 0ȱ inȱ GR3,ȱ whileȱ theȱ highestȱ diversityȱ wasȱ shownȱ inȱ theȱ AINP.ȱ Noȱ significantȱ changesȱ inȱ benthicȱ communityȱ structure,ȱ characterizedȱ byȱ speciesȱ richness,ȱ individualȱ abundance,ȱ andȱ diversityȱ wereȱ determinedȱ afterȱ theȱ Braerȱ oilȱ spillȱ (Kingstonȱ etȱ al.,ȱ 1995)ȱ whatȱ agreesȱ withȱ theȱ affirmationȱ thatȱ fewȱ validȱ generalizationsȱ aboutȱ ecologicalȱ effectsȱ canȱbeȱ appliedȱ toȱ mostȱ spillsȱ (Junoyȱetȱ al.,ȱ2004).ȱNoȱdiversity,ȱthereforeȱnoȱdominanceȱwasȱfoundȱinȱtheȱstationȱGR3ȱinȱ Algeciras.ȱ Changesȱ inȱ meanȱ abundance,ȱ biomass,ȱ orȱ diversityȱ atȱ aȱ stationȱ thatȱ wereȱ unlike,ȱ orȱ outȱ ofȱ phaseȱ with,ȱ theȱ trendsȱ observedȱ forȱ otherȱ stationsȱ (anȱ interactionȱ effect),ȱ indicateȱ possibleȱ influencesȱ byȱ sourcesȱ otherȱ thanȱ naturalȱ factorsȱ (Jewettȱ etȱ al.,ȱ 1999;ȱ Blanchardȱ etȱ al.,ȱ 2002).ȱ However,ȱ lowȱ valuesȱ ofȱ speciesȱ richnessȱ andȱ lowȱ diversityȱ andȱ highȱ dominanceȱ ofȱ fewȱ betterȱ adaptedȱ speciesȱareȱexpectedȱforȱaquaticȱecosystemsȱlikeȱestuariesȱorȱaȱmouthȱofȱaȱriver,ȱ whereȱ theȱ variationȱ ofȱ environmentalȱ conditionsȱ (salinity,ȱ pH,ȱ temperature)ȱ isȱ stressingȱtoȱtheȱbiotaȱ(Choueriȱetȱal.,ȱsubmitted).ȱȱ - 259 - ȱ CA ȱ GR3 8.8% ȱ 12.7% ȱ ȱ 78.5% 100.0% ȱ GR4 P1 ȱ 10.2% 20.3% 25.4% ȱ 34.4% ȱ ȱ 64.4% 45.3% ȱ % Molluscs % Polychaete % Crustacea ȱ Figureȱ 2.ȱ Distributionȱ ofȱ theȱ mainȱ taxaȱ inȱ sedimentsȱ fromȱ stationsȱ selectedȱinȱtheȱGulfȱofȱCádiz.ȱȱ ȱ ȱ ȱ ȱ ȱ ȱ - 260 - ȱ A ȱ B C 9.1% 15.3% 27.7% 28.4% ȱ 20.0% ȱ 41.0% ȱ 21.5% 37.0% ȱ 39.1% 39.1% 21.7% E D F ȱ 15.4% 30.0% ȱ 35.3% 45.2% 50.0% 23.1% ȱ ȱ ȱ 61.5% 20.0% % Molluscs 19.5% % Polychaete % Crustacea Other groups ȱ Figureȱ 3.ȱ Distributionȱ ofȱ theȱ mainȱ taxaȱ inȱ sedimentsȱ fromȱ stationsȱ selectedȱinȱtheȱGalicianȱCoast.ȱ ȱ ȱ ȱ ȱ ȱ ȱ - 261 - 3.4.ȱLinkingȱphysicochemicalȱcharacterizationȱwithȱbenthicȱalterationȱ Aȱprincipalȱcomponentsȱanalysisȱwasȱperformedȱtowardsȱtwoȱobjectives:ȱ toȱelucidateȱifȱtheȱbenthicȱalterationȱwasȱdueȱtoȱpollutantsȱboundȱtoȱsedimentsȱ andȱ toȱ determineȱ whichȱ contaminantsȱ areȱ theȱ causeȱ ofȱ theȱ environmentalȱ impact.ȱȱ Theȱ multivariateȱ analysisȱ showsȱ thatȱ theȱ originalȱ variablesȱ canȱ beȱ groupedȱinȱthreeȱnewȱfactorsȱthatȱexplainȱanȱ89ȱ%ȱofȱtheȱtotalȱvarianceȱ(Tableȱ3).ȱ Theȱ firstȱ factorȱ (58.5ȱ %)ȱ linksȱ theȱ presenceȱ ofȱ Pb,ȱ Niȱ andȱ PAHsȱ boundȱ toȱ sediment,ȱ concentrationȱ ofȱ organicȱ carbonȱ andȱ fines,ȱ withȱ allȱ theȱ parametersȱ relatedȱwithȱtheȱbenthicȱalteration.ȱTheseȱcontaminantsȱareȱusuallyȱcomponentsȱ ofȱ fuelȱ oilsȱ whatȱ suggestȱ thatȱ aȱ sourceȱ orȱ sourcesȱ ofȱ theseȱ compoundsȱ areȱ producingȱ anȱ environmentalȱ impactȱ inȱ someȱ ofȱ theȱ studiedȱ areas.ȱ Thisȱ factorȱ hasȱ mainlyȱ prevalenceȱinȱtheȱ stationȱGR3ȱfromȱtheȱBayȱofȱAlgecirasȱ(Figureȱ4)ȱ meaningȱthatȱthereȱisȱenvironmentalȱdegradationȱinȱthisȱsiteȱdueȱtoȱtheȱinputȱofȱ contaminantsȱ relatedȱ withȱ oilȱ spills.ȱ Theȱ stationȱ GR4ȱ presentsȱ theȱ influenceȱ ofȱ thisȱ factorȱ (inȱ minorȱ degreeȱ thanȱ GR3),ȱ whatȱ alsoȱ meansȱ thatȱ theȱ alterationȱ ofȱ theȱbenthicȱcommunityȱisȱdueȱtoȱtheȱspillsȱofȱoilȱthatȱoftenȱoccurȱinȱthisȱarea.ȱȱ Bothȱ locationsȱ areȱ closeȱ toȱ aȱ petrochemicalȱ industryȱ whatȱ suggestȱ thatȱ thereȱ isȱ aȱ chronicȱ inputȱ fromȱ thisȱ sourceȱ inȱ additionȱ toȱ accidentalȱ spillsȱ andȱ otherȱ activitiesȱ inȱ theȱ Bayȱ ofȱ Algeciras.ȱ Theȱ secondȱ factorȱ (21.0ȱ %)ȱ correlates,ȱ withȱnegativeȱloading,ȱtheȱmetalsȱZnȱandȱHgȱwithȱtheȱpopulationȱofȱmolluscs,ȱ whereasȱ oppositeȱ relationshipȱ areȱ shownȱ amongȱ theseȱ contaminants,ȱ theȱ percentageȱ ofȱ organicȱ carbonȱ inȱ theȱ sedimentȱ andȱ someȱ benthicȱ parametersȱ suchȱasȱtheȱspecificȱrichnessȱandȱtheȱpopulationȱofȱcrustacean.ȱThisȱfactor,ȱcouldȱ beȱ explainedȱ asȱ theȱ potentialȱ stressȱ thatȱ theseȱ contaminantsȱ mightȱ produceȱ toȱ theȱ environmentȱ inȱ thoseȱ sitesȱ withȱ negativeȱ loadingȱ (Figureȱ 4)ȱ withȱ mainlyȱ prevalenceȱofȱstationȱFȱandȱfollowedȱbyȱD,ȱEȱ(CormeȬLaxe)ȱandȱAȱ(CíesȱIsland).ȱ Theȱpositiveȱloadingȱpresentedȱinȱtheȱreferenceȱsiteȱandȱrelatedȱtoȱtheȱalterationȱ - 262 - ofȱ theȱ populationȱ ofȱ crustaceanȱ itȱ isȱ probablyȱ relatedȱ toȱ theȱ highȱ activityȱ ofȱ fishermenȱinȱtheȱareaȱwhoȱcollectȱdifferentȱspeciesȱofȱthisȱtaxon.ȱTheȱthirdȱfactorȱ (9.4ȱ %)ȱ linksȱ theȱ concentrationȱ ofȱ Pbȱ andȱ Cuȱ boundȱ toȱ sedimentȱ withȱ theȱ percentageȱ ofȱ finesȱ andȱ organicȱ carbonȱ inȱ theȱ sedimentȱ andȱ withȱ theȱ benthicȱ alterationsȱ determinedȱ byȱ theȱ specificȱ richnessȱ andȱ theȱ disturbanceȱ ofȱ theȱ populationsȱofȱpolychaetaȱandȱcrustacean.ȱThisȱrelationshipȱindicatesȱthatȱtheseȱ metalsȱareȱproducingȱenvironmentalȱdegradationȱandȱcanȱbeȱconsideredȱaȱriskȱ forȱ theȱ benthicȱ community.ȱ Factorȱ 3ȱ presentsȱ positiveȱ loadingȱ inȱ sitesȱ P1ȱ andȱ GR4ȱfromȱtheȱBayȱofȱAlgecirasȱandȱstationȱFȱinȱCormeȬLaxe.ȱ Tableȱ 3.ȱ Sortedȱ rotatedȱ factorȱ loadingsȱ ofȱ 15ȱ variablesȱ forȱ theȱ threeȱ principalȱ factorsȱ resultingȱ fromȱ theȱ multivariateȱ analysisȱ ofȱ resultsȱ obtainedȱ fromȱtheȱchemicalȱanalysisȱandȱtheȱbenthicȱalterationȱparameters.ȱ ȱȱ ȱȱ Factorȱ1ȱ 58.5ȱ Factorȱ2ȱ 21.0ȱ Factorȱ3ȱ 9.4ȱ Znȱ ņȱ Ȭ0.63ȱ ņȱ Pbȱ 0.86ȱ ņȱ 0.42ȱ Cuȱ ņȱ ņȱ 0.92ȱ Niȱ 0.99ȱ ņȱ ņȱ Hgȱ ņȱ Ȭ0.83ȱ ņȱ PAHȱ 0.98ȱ ņȱ ņȱ O.C.ȱ 0.32ȱ 0.37ȱ 0.84ȱ Finesȱ 0.77ȱ ņȱ 0.44ȱ SpeciesȱN.ȱ 0.99ȱ ņȱ ņȱ Specificȱrichnessȱ 0.44ȱ 0.73ȱ 0.44ȱ Diversityȱ 0.99ȱ ņȱ ņȱ Dominanceȱ 0.99ȱ ņȱ ņȱ Molluscsȱ 0.58ȱ Ȭ0.69ȱ ņȱ Polychaeteȱ Crustaceaȱ 0.87ȱ ņȱ 0.47ȱ 0.55ȱ 0.72ȱ 0.34ȱ - 263 - GR3 3 Factor 1 2 1 GR4 0 A B CA C D E P1 F -1 3 2 CA GR4 Factor 2 1 B P1 GR3 C 0 D -1 E A -2 F -3 3 P1 Factor 3 2 1 GR4 F 0 A -1 CA B D E GR3 C ȱ Figureȱ4.ȱFactorȱloadingsȱforȱtheȱthreeȱprincipalȱfactorsȱresultingȱfromȱtheȱ multivariateȱ analysisȱ ofȱ resultsȱ obtainedȱ fromȱ theȱ chemicalȱ analysisȱ andȱ theȱ benthicȱalterationȱparameters.ȱ - 264 - ResultsȱobtainedȱwithȱtheȱMAAȱindicateȱthatȱfuelȱoilȱisȱnoȱmoreȱaffectingȱ theȱbenthicȱcommunityȱofȱtheȱAINPȱandȱtheȱBayȱofȱCormeȬLaxeȱinȱtheȱGalicianȱ Coast,ȱ whereasȱ sitesȱ evaluatedȱ inȱ theȱ Bayȱ ofȱ Algecirasȱ haveȱ shownȱ aȱ deepȱ impactȱofȱchronicȱoilȱspillsȱwhichȱareȱtheȱcauseȱofȱtheȱimportantȱenvironmentalȱ degradationȱofȱtheȱarea.ȱInȱaddition,ȱalthoughȱnoȱpollutionȱwasȱobservedȱinȱtheȱ referenceȱsiteȱ(CA),ȱtheȱhighȱinfluenceȱofȱfishermenȱcouldȱbeȱconsideredȱaȱthreatȱ forȱ someȱ taxonsȱ suchȱ asȱ crustaceans.ȱ Theȱ presenceȱ ofȱ metalsȱ boundȱ toȱ sedimentsȱmainlyȱinȱAlgecirasȱandȱCormeȬLaxeȱandȱsomeȱsitesȱofȱtheȱAINPȱcanȱ beȱ consideredȱ aȱ riskȱ forȱ theȱ benthicȱ communityȱ andȱ alterationȱ ofȱ theȱ environmentȱcanȱbeȱexpected.ȱ Figureȱ 5ȱ presentȱ theȱ resultsȱ ofȱ theȱ clusterȱ analysisȱ andȱ showsȱ theȱ heterogeneityȱofȱtheȱareasȱofȱstudy.ȱSitesȱfromȱtheȱBaysȱofȱAlgecirasȱandȱCormeȬ Laxeȱ appearȱ furtherȱ fromȱ theȱ referenceȱ siteȱ whereasȱ locationsȱ fromȱ theȱ AINPȱ areȱ groupedȱ closeȱ toȱ theȱ referenceȱ station.ȱ Inȱ thisȱ sense,ȱ theȱ behaviourȱ ofȱ theȱ CiesȱIslandsȱisȱquiteȱsimilarȱtoȱaȱreferenceȱsiteȱwhereasȱsitesȱfromȱCormeȬLaxe,ȱ especiallyȱstationȱFȱpresentsȱanȱenvironmentalȱalterationȱlowerȱbutȱnearerȱtoȱtheȱ degradationȱofȱtheȱBayȱofȱAlgeciras.ȱȱ ȱ Tree Diagram for 10 Cases Single Linkage Percent disagreement 1.01 ȱ 1.00 0.99 ȱ ȱ Linkage Distance ȱ 0.98 0.97 0.96 0.95 0.94 ȱ ȱ 0.93 0.92 GR3 F GR4 P1 E D A B C CA Figureȱ 5.ȱ Classificationȱ treeȱ ofȱ theȱ studyȱ sitesȱ basedȱ onȱ theȱ clusterȱ analysis.ȱTheȱstationȱCAȱcorrespondsȱtoȱtheȱreferenceȱsite.ȱA,ȱBȱandȱCȱrefersȱtoȱ - 265 - theȱstationsȱlocatedȱinȱtheȱCiesȱIslandȱinȱtheȱAtlanticȱIslandȱNationalȱParkȱandȱ D,ȱEȱandȱFȱtoȱthoseȱinȱtheȱBayȱofȱCormeȬLaxe.ȱTheȱstationsȱlocatedȱinȱtheȱBayȱofȱ AlgecirasȱareȱGR3,ȱGR4ȱandȱP1.ȱȱ 4.ȱConclusionsȱȱ Thisȱ reportȱ showsȱ theȱ recoveryȱ ofȱ theȱ benthicȱ communityȱ fromȱ theȱ Galicianȱ Coastȱ fourȱ yearsȱafterȱ theȱspillȱofȱtheȱtankerȱ Prestigeȱ(2002).ȱTheȱdataȱ obtainedȱ wereȱ comparedȱ withȱ thoseȱ fromȱ anȱ areaȱ chronicallyȱ affectedȱ byȱ oilȱ spills,ȱtheȱBayȱofȱAlgecirasȱandȱanȱareaȱnotȱcontaminatedȱinȱtheȱBayȱofȱCadiz.ȱAȱ multivariateȱ analysisȱ wasȱ performedȱ toȱ determineȱ theȱ causeȱ ofȱ theȱ benthicȱ alterations.ȱ Resultsȱ obtainedȱ showȱ aȱ highȱ environmentalȱ degradationȱ inȱ sedimentsȱ fromȱ theȱ Bayȱ ofȱ Algecirasȱ whichȱ suffersȱ theȱ inputȱ ofȱ differentȱ contaminantsȱ butȱ mainlyȱ fuelȱ oil.ȱ Biologicalȱ stressȱ wasȱ alsoȱ observedȱ dueȱ toȱ sourcesȱofȱmetalȱcontaminationȱinȱallȱtheȱstudiedȱareasȱbutȱmainlyȱinȱAlgecirasȱ andȱtheȱBayȱofȱCormeȬLaxe.ȱȱ Theȱ presentȱ studyȱ showsȱ theȱ importanceȱ ofȱ theȱ combinationȱ ofȱ physicochemicalȱ andȱ biologicalȱ dataȱ toȱ estimateȱ theȱ healthȱ statusȱ ofȱ theȱ sediments.ȱBesides,ȱtheȱresultsȱachievedȱsuggestȱthatȱbenthicȱcommunityȱisȱableȱ toȱrecuperateȱaȱfewȱyearsȱafterȱaȱmajorȱoilȱspillȱwhereasȱsedimentsȱaffectedȱbyȱ lowȱalbeitȱcontinuousȱinputsȱpresentȱaȱchronicȱenvironmentalȱdegradation.ȱȱȱȱȱȱȱȱ 5.ȱAknowledgmentsȱ Theȱ workȱ describedȱ wasȱ partlyȱ supportedȱ byȱ theȱ projectsȱ VEM2003Ȭ 20563/INTER,ȱ andȱ CTM2005Ȭ07282ȬC03Ȭ01/TECNOȱ financedȱ byȱ theȱ Spanishȱ Educationȱ andȱ Scienceȱ Ministryȱ andȱ byȱ CISȱ fundedȱ byȱ theȱ Ministryȱ ofȱ Environment.ȱ Carmenȱ MoralesȬCasellesȱ thanksȱ theȱ Ministryȱ ofȱ Educationȱ andȱ Scienceȱ forȱ fundingȱ herȱ researchȱ fellowshipȱ (FPU).ȱ Dr.ȱ Ribaȱ thanksȱ theȱ I3pȱ programȱ forȱ supportingȱ herȱ participationȱ inȱ thisȱ research.ȱ Cesar,ȱ A.ȱ thanksȱ - 266 - CAPES/MECȬBrazilȱ(BEXȬ3238/06Ȭ7)ȱforȱtheȱpostdoctoralȱscholarship.ȱTheȱworkȱ wasȱ partiallyȱ fundedȱ byȱ theȱ Brazilian–Spanishȱ jointȱ projectȱ (CAPESȬBrazilȱ #099/06ȱ andȱ MECȬSpainȱ PHBȱ 2005Ȭ0100ȬPC).ȱ Specialȱ thanksȱ areȱ givenȱ toȱ theȱ membersȱofȱtheȱCIS.ȱȱ 6.ȱReferencesȱ 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MoralesȬCasellesȱC,ȱJiménezȬTenorioȱN,ȱGonzálezȱdeȱCanalesȱML,ȱSarasqueteȱC,ȱ DelVallsȱ TA.ȱ Ecotoxicityȱ ofȱ sedimentsȱ contaminatedȱ byȱ theȱ oilȱ spillȱ associatedȱ withȱ theȱ tankerȱ “Prestige”ȱ usingȱ juvenilesȱ ofȱ theȱ fishȱ Sparusȱ aurata.ȱArchȱEnvironȱConȱToxȱ2006;ȱ51:ȱ652–660.ȱ MoralesȬCasellesȱ C,ȱ Kalmanȱ J,ȱ Ribaȱ I,ȱ DelVallsȱ TA.ȱ Comparingȱ Sedimentȱ QualityȱInȱSpanishȱLittoralȱAreasȱAffectedȱByȱAcuteȱ(Prestige,ȱ2002)ȱAndȱ Chronicȱ(BayȱOfȱAlgeciras)ȱOilȱSpillsȱ.ȱEnvironȱPollutȱ2007;ȱ146:ȱ233Ȭ240.ȱ - 269 - MoralesȬCasellesȱC,ȱRibaȱI,ȱSarasqueteȱC,ȱDelVallsȱTA.ȱUsingȱaȱclassicalȱweightȬ ofȬevidenceȱ approachȱ forȱ 4Ȭyearsȱ monitoringȱ ofȱ theȱ impactȱ ofȱ anȱ accidentalȱoilȱspillȱonȱsedimentȱquality.ȱEnvironȱIntȱ(accepted)ȱ NewellȱRC,ȱSeidererȱLJ,ȱHitchcockȱDR.ȱTheȱimpactȱofȱdredgingȱworksȱinȱcoastalȱ waters:ȱ aȱ reviewȱ ofȱ theȱ sensitivityȱ toȱ disturbanceȱ andȱ subsequentȱ recoveryȱ ofȱ biologicalȱ resourcesȱ onȱ theȱ seaȱ bed.Oceanograpȱ hyȱ andȱ MarineȱBiologyȱAnnualȱReviewȱ1999;ȱ36:ȱ127–178.ȱ Parraȱ S,ȱ LópezȬJamarȱ E.ȱ Cambiosȱ enȱ elȱ cicloȱ temporalȱ deȱ algunasȱ especiesȱ endofaunalesȱ comoȱ consecuenciaȱ delȱ vertidoȱ delȱ petroleroȱ Aegeanȱ Sea.ȱ PublȱEspȱInsȱEspȱOceanogrnȱ1997;ȱ23:ȱ71–82.ȱ Petersonȱ CH.ȱ Theȱ “Exxonȱ Valdez”ȱ oilȱ spillȱ inȱ Alaska:ȱ Acute,ȱ indirectȱ andȱ chronicȱeffectsȱonȱtheȱecosystem.ȱAdvancesȱinȱMarineȱBiologyȱ2001;ȱ39:ȱ1Ȭ 103.ȱ RibaȱI,ȱZitkoȱV,ȱForjaȱJM,ȱDelVallsȱTA.ȱDerivingȱsedimentȱqualityȱguidelinesȱinȱ theȱGuadalquivirȱestuaryȱassociatedȱwithȱtheȱAznalcóllarȱminingȱspill:ȱaȱ comparisonȱofȱdifferentȱapproaches.ȱCiencȱMarȱ2003,ȱ29ȱȱ Ribaȱ I,ȱ Forjaȱ JM,ȱ GómezȬParraȱ A,ȱ DelVallsȱ TA.ȱ Sedimentȱ qualityȱ inȱ littoralȱ regionsȱofȱtheȱGulfȱofȱCádiz:ȱaȱtriadȱapproachȱtoȱaddressȱtheȱinfluenceȱofȱ miningȱactivities.ȱEnvironȱPollutȱ2004;ȱ132:ȱ341Ȭ353.ȱ Serranoȱ A,ȱ Sánchezȱ F,ȱ Preciadoȱ I,ȱ Parraȱ S,ȱ Frutosȱ I.ȱ Spatialȱ andȱ temporalȱ changesȱinȱbenthicȱcommunitiesȱofȱtheȱGalicianȱcontinentalȱshelfȱafterȱtheȱ Prestigeȱoilȱspill.ȱMarȱPollutȱBulȱ2006;ȱ53:ȱ315–331ȱ USEPAȱ 1994.ȱ Methodsȱ forȱ Assessingȱ theȱ Toxicityȱ ofȱ SedimentȬassociatedȱ Contaminantsȱ withȱ Estuarineȱ andȱ Marineȱ Amphipods.ȱ Unitedȱ Statesȱ EnvironmentalȱProtectionȱAgencyȱ(USEPA).ȱEPA/600/RȬ94/025.ȱ - 270 - WarwickȱRM,ȱClarkeȱKR.ȱComparisionȱofȱsomeȱmethodsȱforȱanalysingȱchangesȱ inȱbenthicȱcommunityȱstructure.ȱJȱMarȱBioȱAssȱUKȱ1991;ȱ71:ȱ225Ȭ244.ȱ Westonȱ DP.ȱ Quantitativeȱ examinationȱ ofȱ macrobenthicȱ communityȱ changesȱ alongȱ anȱ organicȱ enrichmentȱ gradient.Marineȱ Ecologyȱ Progressȱ Seriesȱ 1990;ȱ61:ȱ233–244.ȱ - 271 - - 272 - ȱ Capítuloȱ5.ȱ Aplicaciónȱdeȱunȱmétodoȱintegradoȱparaȱlaȱ caracterizaciónȱdeȱsedimentosȱafectadosȱporȱ vertidosȱdeȱpetróleoȱ Enȱ laȱ actualidadȱ sabemosȱ queȱ paraȱ estudiarȱ laȱ calidadȱ ambientalȱ deȱ losȱ sedimentosȱnoȱbastaȱconȱdeterminarȱlosȱnivelesȱdeȱcontaminantesȱpresentesȱenȱ laȱ matriz,ȱ existenȱ aspectos,ȱ talesȱ comoȱ laȱ biodisponibilidadȱ deȱ losȱ contaminantesȱ unaȱ vezȱ incorporadosȱ alȱ sedimento,ȱ laȱ acciónȱ concomitanteȱ deȱ lasȱcondicionesȱfisicoquímicasȱdelȱmedioȱyȱlaȱposibilidadȱdeȱefectosȱsinérgicosȱoȱ antagónicosȱ conȱ otrosȱ contaminantes,ȱ queȱ hacenȱ queȱ estasȱ medidasȱ distenȱ muchoȱdeȱserȱunaȱvaloraciónȱobjetivaȱdeȱlaȱȈsaludȱambientalȈȱdeȱesosȱsistemasȱ (DelValls,ȱ 2006).ȱ Asíȱ puesȱ elȱ riesgoȱ potencialȱ deȱ unaȱ sustanciaȱ químicaȱ dependeráȱdeȱ(Chapman,ȱMasterȱlessons):ȱȱ Bioaccessibilidad:ȱ laȱ fracciónȱ oȱ matrizȱ queȱ potencialmenteȱ puedeȱ resultarȱȱdisponibleȱparaȱelȱorganismo.ȱ Biodisponibilidad:ȱ laȱ sustanciaȱ queȱ inmediatamenteȱ esȱ disponibleȱ paraȱ serȱincorporadaȱporȱlosȱorganismos.ȱ Bioabsorción:ȱLoȱqueȱrealmenteȱesȱincorporadoȱporȱelȱorganismo.ȱ ȱ Ȭȱ273ȱȬȱ Capítuloȱ5 Biorreactividad:ȱ Loȱ queȱ realmenteȱ esȱ capazȱ deȱ causarȱ toxicidadȱ (laȱ fracciónȱbioabsorbidaȱmenosȱlaȱfracciónȱdepurada,ȱsecuestradaȱinternamenteȱoȱ utilizadaȱporȱelȱorganismoȱparaȱcubrirȱsusȱnecesidades)ȱȱ Seȱhanȱaplicadoȱdistintasȱmetodologíasȱparaȱevaluarȱlaȱcalidadȱambientalȱ deȱ sedimentosȱ sinȱ limitarseȱ aȱ losȱ análisisȱ químicos.ȱ Estasȱ aproximacionesȱ incluyenȱ medidasȱ deȱ laȱ bioacumulaciónȱ enȱ organismosȱ seleccionadosȱ comoȱ indicadoresȱdeȱcontaminación,ȱlosȱefectosȱletalesȱy/oȱsubletalesȱobservadosȱtrasȱ laȱ exposiciónȱ deȱ organismosȱ aȱ sedimentosȱ ‘supuestamente’ȱ contaminados,ȱ lasȱ modificacionesȱ deȱ laȱ estructuraȱ deȱ lasȱ comunidadesȱ queȱ produceȱ laȱ contaminación,ȱetc.ȱ(DelValls,ȱ2006).ȱSinȱembargo,ȱcadaȱunaȱdeȱestasȱpropuestasȱ presentaȱsusȱlimitaciones.ȱȱ Conȱelȱfinȱdeȱsuperarȱlasȱlimitacionesȱqueȱpresentanȱlasȱmetodologíasȱseȱ propusoȱ laȱ realizaciónȱ deȱ unȱ estudioȱ integradoȱ enȱ elȱ queȱ seȱ incluyanȱ distintasȱ tecnologíasȱ deȱ formaȱ queȱ hayaȱ unaȱ aproximaciónȱ loȱ másȱ certeraȱ aȱ laȱ realidad.ȱ Paraȱelloȱseȱempleanȱlasȱllamadasȱlíneasȱdeȱevidenciaȱ(linesȱofȱevidence,ȱLOEs)ȱ queȱincluyenȱcadaȱunaȱdeȱlasȱmetodologíasȱaplicadasȱdeȱformaȱindividualȱparaȱ posteriormenteȱ realizarȱ unaȱ integraciónȱ globalȱ deȱ losȱ resultadosȱ dentroȱ delȱ llamadoȱ “Weightȱ ofȱ Evidenceȱ (WOE)ȱ approach”ȱ oȱ “pesoȱ deȱ laȱ evidencia”,ȱ contrarrestandoȱ asíȱ laȱ subjetividadȱ yȱ laȱ arbitrariedad.ȱ Lasȱ conclusionesȱ proporcionadasȱporȱcadaȱmedidaȱindividual,ȱdentroȱdelȱmétodoȱintegrado,ȱsonȱ consideradasȱenȱrelaciónȱconȱlasȱqueȱofrecenȱlosȱotrosȱcomponentesȱdelȱmétodo.ȱ Deȱ estaȱ manera,ȱ seȱ evalúaȱ laȱ correlaciónȱ entreȱ losȱ resultadosȱ obtenidosȱ porȱ técnicasȱ distintasȱ yȱ seȱ disponeȱ deȱ unosȱ resultadosȱ másȱ cercanosȱ aȱ laȱ realidadȱ queȱcuandoȱseȱaplicanȱesasȱmismasȱtécnicasȱdeȱformaȱindividualizadaȱ(DelValls,ȱ 2006).ȱEsteȱtipoȱdeȱmetodologíaȱseȱhaȱaplicadoȱsatisfactoriamenteȱtrasȱepisodiosȱ deȱ vertidosȱ contaminantesȱ (Ej.ȱ DelVallsȱ andȱ Chapman,ȱ 1998;ȱ Chapman,ȱ 2000;ȱ Borgmannȱetȱal.,ȱ2001;ȱRibaȱetȱal.,ȱ2004;ȱLeeȱetȱal.,ȱ2006).ȱȱ - 274 - Métodosȱintegradosȱdeȱlaȱcalidadȱambientalȱȱ Unaȱdeȱlasȱprincipalesȱventajasȱdeȱlaȱutilizaciónȱdeȱunȱmétodoȱintegradoȱ seȱ encuentraȱ enȱ laȱ posibilidadȱ deȱ caracterizarȱ lasȱ llamadasȱ zonasȱ grisesȱ (Ȉgrayȱ zoneȈ).ȱ Enȱ tornoȱ alȱ 70%ȱ deȱ lasȱ áreasȱ litoralesȱ yȱ deȱ estuarioȱ puedenȱ incluirseȱ dentroȱdeȱestosȱecosistemas,ȱqueȱposeenȱunȱgradoȱdeȱpoluciónȱintermedioȱentreȱ lasȱ zonasȱ claramenteȱ alteradasȱ yȱ lasȱ queȱ puedenȱ serȱ consideradasȱ comoȱ noȱ estresadasȱ(DelValls,ȱ2006).ȱȱ ȱ 1)ȱScreeningȱ ȬȱAnálisisȱquímicos Gradienteȱdeȱ contaminación ȬȱToxicidadȱagudaȱ ȱ 2)ȱMétodoȱintegrado:ȱ ȱ Nivelesȱdeȱ contaminantesȱenȱelȱ sedimento Contaminación ȱ Nivelesȱdeȱefectoȱ biológicoȱmedidoȱ ȱ enȱlosȱorganismosȱ autócotonos Nivelesȱdeȱefectoȱ Alteracionȱ bentónicaȱ WOEȱ Toxicidadȱenȱ biológicoȱdeȱtipoȱagudoȱ laboratorioȱ yȱcrónicoȱmedidosȱbajoȱ condicionesȱcontroladasȱ deȱlaboratorioȱ ȱ ȱ ȱ Efectosȱ subletalesȱInȱsitu Nivelesȱdeȱefectoȱbiológicoȱmedidoȱbajoȱ condicionesȱdeȱcampo ȱ Figuraȱ 5.1.ȱ Representaciónȱ esquemáticaȱ delȱ desarrolloȱ delȱ modeloȱ integradoȱ aplicadoȱ paraȱ elȱ seguimientoȱ delȱ impactoȱ delȱ vertidoȱ delȱ petroleroȱ ‘Prestige’ȱ yȱ suȱ comparaciónȱ conȱ laȱ calidadȱ ambientalȱ enȱ zonasȱ afectadasȱ porȱ vertidosȱ deȱ petróleoȱ deȱ tipoȱ crónicoȱ (continuos)ȱ yȱ conȱ ausenciaȱ deȱ influenciaȱ porȱ esteȱ tipoȱ deȱ vertidosȱ (Bahíaȱ deȱ Cádiz).ȱ Enȱ unaȱ primeraȱ faseȱ deȱ aplicaciónȱ delȱ modeloȱseȱdesarrollaȱ laȱfaseȱ inicialȱdeȱ‘screening’ȱconȱlaȱaplicaciónȱdeȱsóloȱ dosȱLOEsȱsobreȱunȱnúmeroȱextensoȱdeȱestaciones.ȱElȱresultadoȱdeȱlaȱaplicaciónȱ deȱ estaȱ primeraȱ faseȱ vaȱ aȱ permitirȱ laȱ selecciónȱ deȱ unȱ númeroȱ menorȱ deȱ estacionesȱ sobreȱ lasȱ queȱ seȱ vaȱ aȱ desarrollarȱ elȱ modeloȱ integradoȱ deȱ formaȱ completa.ȱ Éstaȱ incluyeȱ cuatroȱ líneasȱ deȱ evidencia:ȱ contaminación,ȱ toxicidad,ȱ alteraciónȱ‘inȱsitu’ȱyȱbioacumulaciónȱyȱbiomagnificación.ȱ Ȭ 275ȱȬ Capítuloȱ5 Enȱ esteȱ capítuloȱ seȱ presentanȱ tresȱ trabajosȱ realizadosȱ consecutivamente.ȱ Enȱ elȱ trabajoȱ XIV,ȱ seȱ llevaȱ aȱ caboȱ unȱ estudioȱ integradoȱ deȱ laȱ calidadȱ deȱ losȱ sedimentosȱ delȱ Parqueȱ Nacionalȱ deȱ lasȱ Islasȱ Atlánticasȱ yȱ laȱ Bahíaȱ deȱ CormeȬ Laxeȱ aȱ loȱ largoȱ deȱ tresȱ años.ȱ Paraȱ realizarȱ esteȱ estudioȱ seȱ empleóȱ unaȱ metodologíaȱclásicaȱbasadaȱenȱ3ȱlíneasȱdeȱevidencia:ȱa)ȱAnálisisȱquímicosȱdeȱlosȱ sedimentos,ȱb)ȱToxicidadȱagudaȱbajoȱcondicionesȱdeȱlaboratorio,ȱyȱc)ȱalteraciónȱ inȱ situȱ deȱ laȱ comunidadȱ bentónica.ȱ Esteȱ estudioȱ poneȱ deȱ manifiestoȱ laȱ recuperaciónȱ deȱ laȱ “saludȱ ambiental”ȱ cuatroȱ añosȱ despuésȱ delȱ vertidoȱ delȱ Prestige,ȱ principalmenteȱ enȱ lasȱ islasȱ Cíes,ȱ aunqueȱ detectaȱ ciertaȱ contaminaciónȱ metálicaȱ potencialmenteȱ peligrosaȱ sobretodoȱ enȱ laȱ Bahíaȱ deȱ CormeȬLaxe.ȱ Además,ȱlaȱ aplicaciónȱ deȱunȱ análisisȱdeȱlaȱ varianzaȱaȱ losȱresultadosȱobtenidosȱ enȱlaȱintegraciónȱdeȱlosȱdatosȱpermitióȱestablecerȱdiferenciasȱsignificativasȱentreȱ lasȱestacionesȱdeȱestudio.ȱ Unaȱ vezȱ realizadoȱ elȱ estudioȱ presentadoȱ enȱ elȱ trabajoȱ XIVȱ seȱ decidióȱȱ ampliarȱ elȱ númeroȱ deȱ líneasȱ deȱ evidencia,ȱ manteniendoȱ lasȱ anterioresȱ eȱ incorporandoȱlosȱresultadosȱobtenidosȱenȱlosȱexperimentosȱsubletales,ȱtantoȱenȱ campoȱ comoȱ enȱ laboratorio.ȱ Deȱ estaȱ formaȱ elȱ trabajoȱ XVȱ muestraȱ estaȱ integraciónȱdondeȱseȱhaceȱhincapiéȱenȱlaȱimportanciaȱdelȱusoȱdeȱbiomarcadoresȱ paraȱevaluarȱcalidadȱambientalȱdeȱlosȱsedimentosȱyȱlosȱriesgosȱpotenciales.ȱ Elȱúltimoȱtrabajoȱdelȱcapítulo,ȱelȱXVI,ȱempleaȱlaȱinformaciónȱobtenidaȱaȱ loȱ largoȱ deȱ laȱ tesisȱ doctoralȱ yȱ presentadaȱ enȱ losȱ anterioresȱ capítulosȱ paraȱ darȱ respuestaȱalȱplanteamientoȱinicialȱdelȱestudio,ȱcompararȱlaȱcalidadȱambientalȱdeȱ losȱ sedimentosȱ deȱ dosȱ áreasȱ afectadasȱ porȱ vertidosȱ deȱ petróleo.ȱ Paraȱ elloȱ seȱ llevaȱ aȱ caboȱ unaȱ integraciónȱ completaȱ conȱ diversasȱ líneasȱ deȱ evidenciaȱ paraȱ clarificarȱ elȱ estadoȱ deȱ losȱ sedimentosȱ deȱ laȱ costaȱ gallegaȱ yȱ deȱ laȱ Bahíaȱ deȱ Algeciras.ȱȱȱ - 276 - Métodosȱintegradosȱdeȱlaȱcalidadȱambientalȱȱ Bibliografíaȱ Borgmann,ȱ U.;ȱ Norwood,ȱ W.P.;ȱ Reynoldson,ȱ T.B.;ȱ Rosa,ȱ F.ȱ 2001.ȱ Identifyingȱ causeȱ inȱ sedimentȱ assessments:ȱ bioavailabilityȱ andȱ theȱ Sedimentȱ Qualityȱ Triad.ȱ Can.ȱ J.ȱ Fish.ȱ Aquat.ȱSci.ȱ58:ȱ950Ȭ969ȱ Lee,ȱ M.R.;ȱ Correa,ȱ J.A.;ȱ Seed,ȱ R.ȱ 2006.ȱ Aȱ sedimentȱ qualityȱ triadȱ assessmentȱ ofȱ theȱ impactȱ ofȱ copperȱ mineȱ tailingsȱ disposalȱ onȱ theȱ littoralȱ sedimentaryȱ environmentȱ inȱ theȱ Atacamaȱ regionȱ ofȱ northernȱ Chile.ȱ Mar.ȱPollut.ȱBull.ȱ52:ȱ1389Ȭ1395ȱ Chapman,ȱP.M.ȱ2000.ȱTheȱSedimentȱQualityȱ Triad:ȱ then,ȱ nowȱ andȱ tomorrow.ȱ Int.ȱ J.ȱ Environ.ȱPollut.13:ȱ351Ȭ356ȱ Riba,ȱ I.;ȱ Forja,ȱ J.M.;ȱ GómezȬParra,ȱ A.;ȱ DelValls,ȱ T.A.ȱ 2004.ȱ Sedimentȱ qualityȱ inȱ littoralȱ regionsȱ ofȱ theȱ Gulfȱ ofȱ Cádiz:ȱ aȱ triadȱapproachȱtoȱaddressȱtheȱinfluenceȱofȱ miningȱ activities.ȱ Environ.ȱ Pollut.ȱ 132:ȱ 341Ȭ353ȱ DelValls,ȱT.A.;ȱChapman.ȱ1998.ȱSiteȬspecificȱ sedimentȱ qualityȱ valuesȱ forȱ theȱ golfȱ ofȱ Cádizȱ (Spain)ȱ andȱ Sanȱ Franciscoȱ Bayȱ (USA),ȱ usingȱ theȱ sedimentȱ qualityȱ triadȱ andȱ multivariateȱ análisis.ȱ Cienc.ȱ Mar.ȱ 24:ȱ 313Ȭ336ȱ DelValls,ȱT.A.ȱ2006.ȱDiseñoȱyȱaplicaciónȱdeȱ modelosȱ integradosȱ deȱ evaluaciónȱ deȱ laȱ contaminaciónȱ yȱ susȱ efectosȱ sobreȱ losȱ sistemasȱ marinosȱ yȱ litoralesȱ yȱ laȱ saludȱ humana.ȱ Premioȱ CEPRECO.ȱ Ministerioȱ deȱlaȱPresidencia.ȱEnȱprensa.ȱ ȱ Ȭ 277ȱȬ ȱ ȱ ȱ ȱ ȱ ȱ Ȭȱ278ȱȬȱ UsingȱaȱclassicalȱWeightȬofȬEvidenceȱapproachȱforȱ4Ȭyears’ȱ monitoringȱofȱtheȱimpactȱofȱanȱaccidentalȱoilȱspillȱonȱSedimentȱ Qualityȱ CarmenȱMoralesȬCaselles1,3,*,ȱInmaculadaȱRiba1,3,ȱCarmenȱSarasquete1,3,ȱT.ȱÁngelȱ DelValls2,3ȱ 1 InstitutoȱdeȱCienciasȱMarinasȱdeȱAndalucíaȱ(ICMANȬCSIC),ȱAvda.ȱRepúblicaȱ Saharauiȱs/n,ȱPuertoȱRealȱ11510,ȱCádiz,ȱSpainȱ 2 UNESCOȱUNITWIN/WiCop,ȱFacultadȱdeȱCienciasȱdelȱMarȱyȱAmbientales,ȱ UniversidadȱdeȱCádiz,ȱPolígonoȱRíoȱSanȱPedroȱs/n,ȱPuertoȱRealȱ11510,ȱCádiz,ȱSpain.ȱ 3 ȱUnidadȱAsociadaȱdeȱCalidadȱAmbientalȱyȱPatologíaȱ(CSICȱ&ȱUCA),ȱAvda.ȱRepúblicaȱ Saharauiȱs/n,ȱPuertoȱRealȱ11510,ȱCádiz,ȱSpainȱ Abstractȱ ȱInȱtheȱpresentȱreport,ȱtheȱsuccessfulȱapplicationȱofȱaȱWeightȱofȱevidenceȱ approachȱ (WOE)ȱ toȱ sedimentȱ qualityȱ assessmentȱ duringȱ aȱ fourȱ yearȱ impactȱ periodȱ followingȱ anȱ oilȱ spillȱ isȱ discussed.ȱ Theȱ studyȱ assessesȱ theȱ sedimentȱ qualityȱonȱtheȱGalicianȱCoastȱ(NWȱSpain)ȱwhichȱwasȱimpactedȱbyȱanȱaccidentalȱ spillȱassociatedȱwithȱtheȱsinkingȱofȱtheȱtankerȱPrestigeȱ(2002).ȱTheȱassessmentȱisȱ basedȱ onȱ threeȱ linesȱ ofȱ evidence:ȱ physicochemicalȱ characterizationȱ ofȱ theȱ sediments;ȱdeterminationȱofȱacuteȱtoxicityȱbyȱconductingȱsedimentȱtoxicityȱtestsȱ andȱ benthicȱ alterationȱ includingȱ taxonomicȱ identificationsȱ alongȱ withȱ communityȱ descriptiveȱ statistics.ȱ Theȱ dataȱ obtainedȱ wereȱ integratedȱ usingȱ aȱ WOEȱapproachȱbyȱmeansȱofȱtwoȱdifferentȱmethodologies:ȱȱmultivariateȱanalysisȱ andȱ ANOVAȬbasedȱ pieȱ charts.ȱ Resultsȱ confirmȱ thatȱ PAHsȱ relatedȱ toȱ theȱ Prestigeȱoilȱspillȱareȱtheȱmainȱcontaminantȱassociatedȱwithȱbiologicalȱeffectsȱinȱ theȱareaȱwhichȱhasȱsinceȱrecoveredȱfromȱtheȱinitialȱacuteȱimpact.ȱAlso,ȱtheȱWOEȱ allowedȱ theȱ identificationȱ ofȱ metalȱ contaminationȱ notȱ previouslyȱ describedȱ inȱ theȱ areaȱ responsibleȱ forȱ toxicityȱ inȱ sedimentsȱ analyzed.ȱ Inȱ addition,ȱ theȱ ȱEnvironmentȱInternationalȱ(aceptado) - 279 - methodologyȱproposedȱtoȱlinkȱtheȱ3ȱlinesȱofȱevidenceȱresultsȱshowsȱtheȱuseȱforȱ theȱ firstȱ timeȱ ofȱ anȱ objectiveȱ indiceȱ basedȱ onȱ factorȱ analysisȱ whichȱ allowsȱ pollutionȱ ofȱ theȱ sedimentsȱ studiedȱ toȱ beȱ qualitativelyȱ andȱ quantitativelyȱ evaluatedȱ whileȱ demonstratingȱ theȱ WOEȱ approachȱ toȱ beȱ recommendableȱ inȱ monitoringȱenvironmentalȱquality.ȱȱ Keywords:ȱPAHs,ȱcontamination,ȱtoxicity,ȱWOE,ȱSedimentȱQualityȱTriadȱȱ 1.ȱIntroductionȱ Chemicalȱ measurementsȱ inȱ theȱ environmentȱ provideȱ informationȱ onȱ contaminationȱ (substancesȱ presentȱ whereȱ theyȱ wouldȱ notȱ normallyȱ occur,ȱ orȱ aboveȱnaturalȱbackgroundȱconcentrations),ȱbutȱtheyȱdoȱnotȱprovideȱinformationȱ onȱ pollutionȱ (contaminationȱ thatȱ causesȱ adverseȱ biologicalȱ effectsȱ inȱ theȱ environment)ȱ (Chapman,ȱ 2007).ȱ Chemicalȱ analysesȱ areȱ anȱ importantȱ toolȱ inȱ sedimentȱqualityȱassessment,ȱhoweverȱtheȱinformationȱobtainedȱdoesȱnotȱreportȱ onȱ theȱ consequencesȱ thatȱ chemicalsȱ haveȱ onȱ theȱ organismsȱ exposedȱ toȱ them.ȱ Biologicalȱ effectsȱ establishedȱ basedȱ onȱ laboratoryȱ testsȱ toȱ determineȱ toxicȱ responsesȱ inȱ combinationȱ withȱ fieldȱ dataȱ onȱ theȱ communitiesȱ livingȱ inȱ theȱ sedimentsȱ allowȱ itȱ toȱ beȱ establishedȱ whetherȱ thereȱ isȱ observableȱ pollutionȬ inducedȱdegradationȱeffectȱaȱgivenȱsetȱofȱbiotaȱ(Chapmanȱetȱal.,ȱ1991).ȱȱ Weightȱ ofȱ evidenceȱ (WOE)ȱ investigationsȱ determineȱ possibleȱ ecologicalȱ impactsȱ owingȱ toȱ chemicalsȱ orȱ otherȱ stressorsȱ basedȱ onȱ multipleȱ linesȱ ofȱ evidenceȱ(Chapman,ȱ2007).ȱTheȱclassicalȱSedimentȱQualityȱTriadȱ(SQT)ȱconsistsȱ ofȱ sedimentȱ chemicalȱ analysis,ȱ examinationȱ ofȱ theȱ inȱ situȱ benthicȱ community,ȱ andȱ measurementsȱ ofȱ sedimentȱ toxicityȱ (Borgmannȱ etȱ al.,ȱ 2001).ȱ Theȱ overallȱ studyȱofȱtheseȱthreeȱcomponentsȱprovidesȱanȱassessmentȱofȱtheȱenvironmentalȱ risk.ȱ Theȱ SQTȱ approach,ȱ acceptedȱ internationallyȱ asȱ theȱ mostȱ comprehensiveȱ approachȱ availableȱ forȱ assessingȱ contaminatedȱ sedimentsȱ (Chapmanȱ andȱ McDonald,ȱ 2005),ȱ formsȱ partȱ ofȱ theȱ WOEȱ frameworkȱandȱ isȱ expectedȱ toȱ beȱ anȱ - 280 - integralȱ componentȱ ofȱ largerȬscaleȱ assessmentsȱ (Chapmanȱ andȱ Hollert,ȱ 2006).ȱ Thisȱ methodȱ hasȱ beenȱ successfullyȱ usedȱ toȱ assessȱ sedimentȱ qualityȱ followingȱ contaminantȱ spillȱ episodesȱ (DelVallsȱ andȱ Chapman,ȱ 1998;ȱ Chapman,ȱ 2000;ȱ Borgmannȱetȱal.,ȱ2001;ȱRibaȱetȱal.,ȱ2004;ȱLeeȱetȱal.,ȱ2006).ȱInȱtheȱpresentȱstudyȱthisȱ methodologyȱwasȱperformedȱinȱorderȱtoȱdetermineȱwhetherȱtheȱWOEȱapproachȱ isȱ ableȱ toȱ beȱ usedȱ asȱ aȱ goodȱ toolȱ inȱ assessingȱ sedimentȱ qualityȱ followingȱ theȱ acuteȱ impactȱ ofȱ anȱ accidentalȱ oilȱ spill.ȱ Inȱ additionȱ theȱ suitabilityȱ ofȱ theȱ applicationȱofȱtheȱWOEȱprocedureȱasȱaȱmonitoringȱinstrumentȱinȱenvironmentalȱ riskȱassessmentȱisȱdemonstrated.ȱȱ Theȱ broadȱ aimȱ ofȱ thisȱ studyȱ itȱ isȱ toȱ determineȱ theȱ qualityȱ ofȱ oilȱ spillȱ affectedȱsedimentsȱbyȱapplyingȱaȱcompleteȱmethodology,ȱandȱmoreȱspecificallyȱ toȱaddressȱtheȱfollowingȱ3ȱobjectives:ȱ(a)ȱtoȱmonitorȱtheȱimpactȱofȱanȱaccidentalȱ oilȱ spillȱ usingȱ aȱ WOEȱ approachȱ duringȱ aȱ 4ȱ yearȱ period,ȱ (b)ȱ toȱ improveȱ methodologicalȱaspectsȱinȱtheȱintegrationȱofȱtheȱ3ȬLOEȱresultsȱinȱorderȱtoȱavoidȱ subjectivityȱ therebyȱ definingȱ aȱ newȱ andȱ moreȱ objectiveȱ processȱ ofȱ integration,ȱ andȱ(c)ȱtheȱdeterminationȱofȱpollution,ȱcontaminationȱandȱnoȱimpactȱscenariosȱ forȱtheȱstationsȱselectedȱandȱoverȱtheȱ4ȱyearȱperiod,ȱincludingȱtheȱidentificationȱ ofȱtheȱcontaminantsȱresponsible.ȱȱ 2.ȱMaterialȱandȱmethodsȱ 2.1.ȱApproachȱ Theȱ caseȱ studyȱ employedȱ forȱ theȱ improvementȱ ofȱ theȱ WOEȱ approach,ȱ wasȱ thatȱ ofȱ theȱ impactȱ associatedȱ withȱ theȱ sinkingȱ ofȱ theȱ tankerȱ Prestigeȱ (Novemberȱ2002)ȱwhichȱspiltȱaroundȱ60,000ȱtonsȱofȱheavyȱfuelȬoilȱwithȱtheȱmostȱ affectedȱareaȱbeingȱtheȱGalicianȱCoastȱ(NWȱSpain).ȱAȱfirstȱstudyȱwasȱcarriedȱoutȱ withȱ sedimentȱ samplesȱ collectedȱ inȱ theȱ Atlanticȱ Islandsȱ Nationalȱ Parkȱ (AINP)ȱ - 281 - duringȱ2004,ȱapproximatelyȱoneȱyearȱafterȱtheȱspill.ȱFigureȱ1ȱshowsȱtheȱareaȱofȱ studyȱ andȱ theȱ 10ȱ stationsȱ selectedȱ forȱ theȱ firstȱ surveyȱdescribedȱ inȱ theȱ presentȱ paper,ȱ3ȱstationsȱlocatedȱinȱtheȱOnsȱIslandȱ(D07,ȱD09ȱandȱD18)ȱandȱ7ȱinȱtheȱCiesȱ Islandȱ(D60,ȱD66,ȱD69,ȱD79,ȱFIG,ȱGA1,ȱGA2).ȱ ȱ ȱ Ons •D18 •D07 •D09 ȱ ȱ Ría de Pontevedra ƒE ƒF ƒD ȱ Ría de Corme-Laxe ȱ ȱ Cíes ȱ N ȱ •C •A •GA2/B •FIG •D66 •D79 •GA1 •D60 •D69 Ría de Vigo ȱ ȱ ȱ ȱ Galician Coast Spain Atlantic Ocean Mediterranean Sea ȱ ȱ Figureȱ 1.ȱ Mapȱ ofȱ theȱ coastalȱ areaȱ ofȱ Galiciaȱ (NWȱ Spain)ȱ showingȱ theȱ samplingȱ sitesȱ inȱ theȱ areaȱ ofȱ CormeȬLaxeȱ (D,ȱ Eȱ andȱ F)ȱ andȱ theȱ Atlanticȱ Islandȱ NationalȱParkȱ(Ons:ȱD07,ȱD09ȱandȱD18;ȱCíes:ȱGA1,ȱGA2/B,ȱFIG,ȱD60,ȱD66,ȱD69,ȱ AȱandȱC).ȱȱ - 282 - Subsequentlyȱsurveysȱwereȱdesignedȱforȱmonitoringȱsedimentȱqualityȱatȱ theȱ distinctȱ stationsȱ locatedȱ inȱ theȱ parkȱ andȱ theȱ surroundingȱ areaȱ withinȱ theȱ fourȱyearȱperiod.ȱ4ȱstationsȱwereȱselectedȱinȱtheȱCiesȱIslandȱ(A,ȱB,ȱCȱandȱGA1),ȱ locatedȱinȱtheȱAINP,ȱforȱtheȱperiodȱfromȱtheȱbeginningȱofȱ2004ȱthroughȱtoȱ2006ȱ (3ȱ surveys).ȱ Theȱ resultsȱ obtainedȱ forȱ theȱ firstȱ studyȱ carriedȱ outȱ inȱ theȱ AINPȱ (beginningȱ ofȱ 2004)ȱ suggestedȱ thatȱ theȱ areaȱ andȱ itsȱ surroundsȱ wereȱ probablyȱ significantlyȱ affectedȱ byȱ theȱ spill.ȱ Thisȱ necessitatedȱ theȱ selectionȱ ofȱ aȱ replacementȱ areaȱ onȱ theȱ Galicianȱ Coastȱ forȱ inclusionȱ inȱ theȱ sedimentȱ qualityȱ monitoringȱ study.ȱ 3ȱ stationsȱ (D,ȱ E,ȱ F)ȱ inȱ CormeȬLaxeȱ (Figureȱ 1)ȱ wereȱ selectedȱ andȱtheȱsameȱWOEȱapproachȱappliedȱoverȱ2ȱyears,ȱfromȱ2004/2005Ȭ2005/2006ȱ(2ȱ surveys).ȱ ȱ Theȱ weightȬofȬevidenceȱ approachȱ (WOE)ȱ conductedȱ inȱ thisȱ studyȱ includesȱ threeȱ linesȱ ofȱ evidenceȱ (LOEs)ȱ incorporatingȱ theȱ followingȱ samplingȱ stationȱanalysesȱcarriedȱoutȱforȱeachȱofȱtheȱ3ȱdistinctȱsurveysȱdescribedȱabove:ȱ (a)ȱsedimentȱcontamination:ȱphysicochemicalȱcharacterizationȱofȱtheȱsedimentsȱ byȱ analyzingȱ PAHsȱ benzo(a)anthracene,ȱ perylene,ȱ (acenaphtalene,ȱ benzo(a)pyrene,ȱ benzo(k)fluoranthene,ȱ acenaphtylene,ȱ anthracene,ȱ benzo(b)fluoranthene,ȱ benzo(g,h,i)ȱ chrysene,ȱ dibenzo(a,h)ȱ anthracene,ȱ fenanthrene,ȱfluoranthene,ȱfluorene,ȱindeneȱ(1,2,3,cdȱ)pyrene,ȱnaphthalene,ȱandȱ pyrene),ȱtraceȱmetalsȱ(Zn,ȱPb,ȱCu,ȱNi,ȱCoȱandȱV),ȱgrainȱsizeȱandȱorganicȱcarbonȱ (methodologiesȱdescribedȱinȱMoralesȬCasellesȱetȱal.,ȱ2006);ȱ(b)ȱsedimentȱtoxicity:ȱ byȱ determinationȱ ofȱ acuteȱ toxicity,ȱ performingȱ bioassaysȱ withȱ bulkȱ sedimentȱ suchȱasȱtheȱamphipodȱmortalityȱtestȱwithȱCorophiumȱvolutatorȱ(MoralesȬCasellesȱ etȱ al.,ȱ 2007)ȱ andȱ theȱ polychaetaȱ mortalityȱ assayȱ (CasadoȬMartínezȱ etȱ al.,ȱ inȱ press)ȱwithȱArenicolaȱmarinaȱasȱwellȱasȱtwoȱtestsȱusingȱsedimentȱelutriate,ȱtheseȱ beingȱ theȱ commercialȱ assayȱ Microtox®ȱ (MoralesȬCasellesȱ etȱ al.,ȱ 2007)ȱ andȱ - 283 - embryo–larvalȱseaȱurchinȱbioassayȱ(methodologyȱdescribedȱbyȱFernándezȱetȱal,ȱ 2006;ȱdataȱobtainedȱfromȱFernándezȱetȱal.ȱnotȱpublished);ȱ(c)ȱ‘inȱsituȱalteration’:ȱ Benthicȱ alterationȱ wasȱ selectedȱ andȱ determinedȱ byȱ measuringȱ parametersȱ inȱ situȱ basedȱ onȱ taxonomicȱ identificationsȱ andȱ communityȱ descriptiveȱ statisticsȱ (abundanceȬbiomassȱ analysis,ȱ speciesȱ richness,ȱ diversity,ȱ dominanceȱ andȱ proportionsȱofȱtheȱmajorȱtaxonomicȱgroups)ȱ(DelVallsȱandȱChapman,ȱ1998).ȱ 2.2.ȱDataȱintegrationȱ Theȱ integrationȱ ofȱ allȱ LOEȱ dataȱ obtainedȱ wasȱ performedȱ viaȱ theȱ twoȱ followingȱmethodologies:ȱ(a)ȱaȱmultivariateȱanalysisȱapproachȱbasedȱonȱlinkingȱ allȱ variablesȱ obtainedȱ inȱ determiningȱ theȱ environmentalȱ degradationȱ ofȱ theȱ studiedȱecosystemsȱ(Ribaȱetȱal.,ȱ2004)ȱandȱ(b)ȱaȱrepresentationȱusingȱpieȱchartsȱ usingȱ anȱ ANOVAȱ approachȱ andȱ byȱ meansȱ ofȱ theȱ determinationȱ ofȱ differentȱ factorsȱ(Ribaȱetȱal.,ȱ2004).ȱȱ Theȱ multivariateȱ analysisȱ wasȱ performedȱ usingȱ principalȱ componentsȱ analysisȱ (PCA)ȱasȱtheȱextractionȱ procedure,ȱaȱmultivariateȱstatisticalȱtechniqueȱ forȱexaminingȱvariableȱdistributionsȱ(Ribaȱetȱal.,ȱ2003).ȱTheȱobjectiveȱofȱPCAȱisȱ toȱ deriveȱ aȱ reducedȱ numberȱ ofȱ newȱ variablesȱ asȱ linearȱ combinationsȱ ofȱ theȱ originalȱvariables.ȱThisȱprovidesȱaȱdescriptionȱofȱtheȱstructureȱofȱtheȱdataȱwithȱ minimumȱlossȱofȱinformation.ȱȱȱ Forȱ theȱ representationȱ ofȱ theȱ pieȱ charts,ȱ theȱ factorsȱ obtainedȱ fromȱ theȱ PCAȱ wereȱ subjectedȱ toȱ ANOVAȱ andȱ Tukeyȱ testsȱ whichȱ identifiedȱ significantȱ differencesȱ inȱ sensitivityȱ amongȱ stationsȱ andȱ controlsȱ forȱ eachȱ factor.ȱ Inȱ thisȱ sense,ȱthisȱnewȱmethodologyȱimprovesȱandȱupdatesȱthisȱkindȱofȱdataȱtreatmentȱ previouslyȱreportedȱbyȱRibaȱetȱal.ȱ(2003).ȱ ȱ - 284 - 3.ȱResultsȱandȱdiscussionȱ Summarizedȱ resultsȱ ofȱ theȱ differentȱ surveysȱ areȱ shownȱ inȱ tableȱ 1ȱ andȱ tableȱ 2.ȱ Aȱ firstȱ approachȱ toȱ assessȱ theȱ impactȱ ofȱ theȱ oilȱ spillȱ onȱ theȱ Galicianȱ CoastȱwasȱperformedȱinȱtheȱAINPȱaȱfewȱmonthsȱafterȱtheȱsinkingȱofȱtheȱtanker.ȱ Theȱmultivariateȱanalysisȱwasȱusedȱinȱtheȱdataȱsetȱbyȱduplicateȱtoȱconnectȱandȱ interpretȱ resultsȱ obtainedȱ fromȱ theȱ threeȱ linesȱ ofȱ evidenceȱ investigated.ȱ Theȱ applicationȱ ofȱ theȱ MAAȱ allowsȱ theȱ averagedȱ variablesȱ (relatedȱ toȱ contamination,ȱtoxicityȱandȱalteration)ȱtoȱbeȱgroupedȱinȱaȱnewȱsetȱofȱfactors.ȱInȱ thisȱ studyȱ physicochemicalȱ dataȱ (metalsȱ –Zn,ȱ Pb,ȱ Cu,ȱ Ni,ȱ Hg,ȱ VȬȱ andȱ PAHs),ȱ toxicityȱ(Microtox®ȱ test,ȱamphipodsȱassay,ȱpolychaetesȱtestȱandȱseaȱurchinȱtest)ȱ andȱalterationȱ(numberȱofȱspecies,ȱspeciesȱrichness,ȱdiversityȱandȱproportionsȱofȱ molluscs,ȱpolychaetesȱandȱcrustaceans)ȱwereȱincluded.ȱTheseȱoriginalȱvariablesȱ canȱ beȱ groupedȱ inȱ fourȱ newȱ factorsȱ whichȱ explainȱ 84.0%ȱ ofȱ theȱ originalȱ dataȱ varianceȱ(tableȱ3).ȱNegativeȱvaluesȱobtainedȱinȱtheȱanalysisȱareȱasȱimportantȱasȱ theȱ positiveȱ values.ȱ Valuesȱ associatedȱ withȱ aȱ particularȱ componentȱ forȱ whichȱ loadingȱwasȱ0.40ȱorȱhigherȱwereȱselectedȱtoȱinterpretȱaȱgroupȱofȱvariables.ȱThisȱ approximatesȱComreys’ȱcutȬoffȱofȱ0.55ȱ(1973)ȱcorrespondingȱtoȱaȱgoodȱoriginalȱ variableȱ factorȱ association,ȱ whileȱ takingȱ intoȱ accountȱ discontinuitiesȱ inȱ theȱ magnitudesȱofȱloadingsȱapproximatingȱtheȱoriginalȱvariables.ȱ ȱ ȱ ȱ ȱ ȱ ȱ - 285 - 2.9ȱ 14.78ȱ 85.3ȱ 106.9ȱ Ga1ȱ DȬ07ȱ DȬ09ȱ 55.5ȱ 100.8ȱ 14ȱ 14.7ȱ 113.9ȱ 76.2ȱ 3.95ȱ DȬ18ȱ DȬ60ȱ DȬ66ȱ DȬ69ȱ DȬ79ȱ FIGȱ Ga2ȱ 1.14ȱ 26.3ȱ 29.3ȱ 2.73ȱ 4.1ȱ 30.5ȱ 14ȱ 27.5ȱ 23.4ȱ Pbȱ mgKgȬ1ȱ Znȱ ȱ Cuȱ ȱ ȱ ȱ ȱ 0.65ȱ 18.5ȱ 149.4ȱ 12.8ȱ 16.2ȱ 70.9ȱ 20.8ȱ 159.7ȱ 250.7ȱ 12.8ȱ mgKgȬ1 Niȱ Vȱ Hgȱ 0.42ȱ 11.8ȱ 4.44ȱ 1.71ȱ 4.6ȱ 16.2ȱ 3.44ȱ 11.7ȱ 1.04ȱ 1.71ȱ 1.0ȱ n.d.ȱ 13.7ȱ n.d.ȱ n.d.ȱ 125ȱ 54ȱ 116ȱ 81.2ȱ 1.0ȱ 0.01ȱ 0.04ȱ 0.09ȱ 0.05ȱ 0.06ȱ 0.12ȱ 0.04ȱ 0.07ȱ 0.08ȱ 0.01ȱ mgKgȬ1ȱ mgKgȬ1ȱ mgKgȬ1 PAHȱ 2120ȱ 390ȱ 270ȱ 480ȱ 380ȱ 700ȱ 480ȱ 240ȱ 470ȱ 190ȱ ΐgKgȬ1ȱ 15ȱ 50ȱ 25ȱ 20ȱ 30ȱ 60ȱ 20ȱ 45ȱ 25ȱ 25ȱ 5ȱ 50ȱ 5ȱ 15ȱ 10ȱ 15ȱ 10ȱ 20ȱ 15ȱ 10ȱ 1215ȱ - 286 - 605ȱ 1006ȱ 364ȱ 450ȱ 486ȱ 358ȱ 390ȱ 1694ȱ 1367ȱ 80.0ȱ 4.8ȱ 8.7ȱ 29.8ȱ 5.0ȱ 100.0ȱ 15.8ȱ 100.0ȱ 3.3ȱ 15.0ȱ 2ȱ 3ȱ 8ȱ 7ȱ 6ȱ 12ȱ 24ȱ 12ȱ 17ȱ 17ȱ 1.2ȱ 1.8ȱ 18.6ȱ 4.3ȱ 15.4ȱ 21.1ȱ 18.6ȱ 9.3ȱ 20.5ȱ 14.3ȱ 1ȱ 1.5ȱ 2.552ȱ 2.574ȱ 1.231ȱ 2.386ȱ 4.089ȱ 3.036ȱ 3.76ȱ 4.574ȱ 0.1ȱ 0.1ȱ 50.0ȱ 42.9ȱ 33.3ȱ 25.0ȱ 25.0ȱ 33.3ȱ 23.5ȱ 22.9ȱ 100ȱ 66.66ȱ 37.5ȱ 42.86ȱ 50ȱ 58.33ȱ 62.5ȱ 66.66ȱ 41.17ȱ 42.86ȱ 0.1ȱ 33.3ȱ 12.5ȱ 14.3ȱ 16.7ȱ 0.1ȱ 8.3ȱ 0.1ȱ 17.7ȱ 34.3ȱ ȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱBenthicȱalterationsȱȱȱ_________________ȱ Molusc Polychaet Crustace Corophiumȱ Arenicolaȱ Microtoxȱ Paracentrotusȱ speciesȱ specificȱ Diversityȱ %mortalityȱ %mortalityȱ IC50ȱ %normalȱ Nºȱ richness aȱ%ȱ aȱ%ȱ a%ȱ ȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱChemicalȱanalysisȱ_________________ȱȱȱ ȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱToxicityȱtests_________________ mgKgȬ1ȱ ȱ ȱ Ga1,ȱD60,ȱD66,ȱD69,ȱD79,ȱFIGȱandȱGa2ȱareȱplacedȱinȱtheȱCiesȱIsland).ȱn.d.:ȱnotȱdetected.ȱ studyȱofȱtheȱsedimentsȱqualityȱinȱtheȱAtlanticȱIslandsȱNationalȱParkȱ(D07,ȱD09ȱandȱD18ȱareȱlocatedȱinȱtheȱOnsȱIslandȱwhereasȱ Tableȱ 1.ȱ Summarizedȱ resultsȱ ofȱ chemicalȱ analysis,ȱ theȱ acuteȱ toxicityȱ testsȱ andȱ theȱ alterationȱ parametersȱ forȱ ourȱ firstȱ 76.2ȱ 123.8ȱ 377ȱ 3.95ȱ 12.7ȱ 91ȱ 41.1ȱ 37.5ȱ 164ȱ 65.7ȱ 25ȱ 34ȱ 19.9ȱ 214ȱ 271ȱ AȬ1ȱ AȬ2ȱ AȬ3ȱ BȬ1ȱ BȬ2ȱ BȬ3ȱ CȬ1ȱ CȬ2ȱ CȬ3ȱ DȬ2ȱ DȬ3ȱ EȬ2ȱ EȬ3ȱ FȬ2ȱ FȬ3ȱ 21.2ȱ 13.8ȱ GA1Ȭ2ȱ GA1Ȭ3ȱ 14.78ȱ 5.9ȱ 14.6ȱ 7.3ȱ 4.31ȱ 3.7ȱ 42.5ȱ 0.85ȱ 6.54ȱ 7.13ȱ 0.9ȱ 0.72ȱ 1.14ȱ 1.5ȱ 10.1ȱ 26.3ȱ 2.1ȱ 1.6ȱ 2.9ȱ Pbȱ mgKgȬ1ȱ Znȱ mgKgȬ1ȱ Cuȱ 4.2ȱ 20ȱ 0.43ȱ n.d.ȱ 0.7ȱ 21.4ȱ 1.4ȱ 34.5ȱ 24.9ȱ 1.4ȱ 0.88ȱ 0.65ȱ 5.2ȱ 11.4ȱ 18.5ȱ 2.19ȱ 6.4ȱ 12.8ȱ mgKgȬ1 Niȱ Vȱ Hgȱ 5.7ȱ 7.07ȱ 1.5ȱ 5.66ȱ 1.7ȱ 9.18ȱ 4.5ȱ 5.11ȱ 5.21ȱ 2.4ȱ 1.31ȱ 0.42ȱ 13.3ȱ 11.8ȱ 11.8ȱ 1.65ȱ 0.32ȱ 1.71ȱ 0.36ȱ 0.7ȱ 0.35ȱ 0.38ȱ 0.34ȱ 1.2ȱ 0.1ȱ 0.86ȱ 0.77ȱ 0.2ȱ n.d.ȱ n.d.ȱ 0.3ȱ 0.32ȱ 0.53ȱ n.d.ȱ n.d.ȱ n.d.ȱ 3.4ȱ 5.81ȱ 2.1ȱ 2.33ȱ 2ȱ 13.2ȱ 0.6ȱ n.d.ȱ n.d.ȱ 0.8ȱ 1.01ȱ n.d.ȱ 0.7ȱ n.d.ȱ n.d.ȱ n.d.ȱ n.d.ȱ n.d.ȱ mgKgȬ1ȱ mgKgȬ1ȱ mgKgȬ1 PAHȱ 323ȱ 820ȱ 52ȱ 558ȱ 38ȱ 537ȱ n.d.ȱ 239ȱ 420ȱ 67ȱ 366ȱ 2120ȱ 108ȱ 119ȱ 390ȱ n.d.ȱ 74ȱ 190ȱ ΐgKgȬ1ȱ 20ȱ 40ȱ 17ȱ 36ȱ 10ȱ 30ȱ 17ȱ 28ȱ 33ȱ 20ȱ 23ȱ 50ȱ 23ȱ 22ȱ 25ȱ 10ȱ 15ȱ 15ȱ 17ȱ 40ȱ 17ȱ 35ȱ 39ȱ 40ȱ 22ȱ 28ȱ 36ȱ 28ȱ 35ȱ 50ȱ 28ȱ 10ȱ 5ȱ 0ȱ 5ȱ 5ȱ - 287 - 4398ȱ 2185ȱ 21041ȱ 20827ȱ 3977ȱ 2436ȱ 1801ȱ 4651ȱ 723ȱ 9422ȱ 1523ȱ 605ȱ 5631ȱ 5231ȱ 1006ȱ 19762ȱ 3974ȱ 2486ȱ 76ȱ 30ȱ 85ȱ 35ȱ 55ȱ 67ȱ 85ȱ 68ȱ 46ȱ 88ȱ 79ȱ 20ȱ 79ȱ 87ȱ 95ȱ 97ȱ 89ȱ 85ȱ 48.2ȱ 55.6ȱ 32.1ȱ 66.7ȱ 28.6ȱ 25.7ȱ 42.4ȱ 50.9ȱ 15.3ȱ 33.9ȱ 5.9ȱ 1.2ȱ 28.5ȱ 12.0ȱ 1.8ȱ 39.1ȱ 43.0ȱ 14.3ȱ 2.9ȱ 2.3ȱ 3.0ȱ 5.0ȱ 3.0ȱ 2.9ȱ 4.3ȱ 4.5ȱ 2.9ȱ 5.0ȱ 5.2ȱ 1.0ȱ 5.1ȱ 4.3ȱ 1.5ȱ 6.1ȱ 2.0ȱ 4.6ȱ 15.4ȱ 40.0ȱ 40.1ȱ 2.0ȱ 30.0ȱ 33.3ȱ 39.1ȱ 26.7ȱ 22.2ȱ 28.4ȱ 9.9ȱ 0.1ȱ 15.3ȱ 2.4ȱ 0.1ȱ 34.7ȱ 23.5ȱ 22.9ȱ 23.1ȱ 26.7ȱ 22.2ȱ 30.6ȱ 20.0ȱ 33.3ȱ 21.7ȱ 26.7ȱ 33.3ȱ 21.5ȱ 56.2ȱ 100.0ȱ 20.0ȱ 21.0ȱ 53.0ȱ 18.0ȱ 32.1ȱ 42.9ȱ 61.5ȱ 33.3ȱ 51.4ȱ 100.0ȱ 50.0ȱ 33.3ȱ 39.1ȱ 43.3ȱ 33.3ȱ 41.0ȱ 15.4ȱ 0.1ȱ 37.0ȱ 34.5ȱ 33.3ȱ 40.5ȱ 41.0ȱ 37.1ȱ 48.2ȱ 55.6ȱ 32.1ȱ 66.7ȱ 28.6ȱ 25.7ȱ 42.4ȱ 50.9ȱ 15.3ȱ 33.9ȱ 5.9ȱ 1.2ȱ 28.5ȱ 12.0ȱ 1.8ȱ 39.1ȱ 43.0ȱ 14.3ȱ ȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱBenthicȱalterationsȱȱȱ_________________ȱ Molusc Polychaet Crustace Corophiumȱ Arenicolaȱ Microtoxȱ Paracentrotusȱ speciesȱ specificȱ Diversityȱ %mortalityȱ %mortalityȱ IC50ȱ %normalȱ Nºȱ richness aȱ%ȱ aȱ%ȱ a%ȱ ȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱChemicalȱanalysisȱ_________________ȱȱȱ ȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱToxicityȱtests_________________ GA1Ȭ1ȱ ȱ ȱ Tableȱ2.ȱSummarizedȱresultsȱofȱchemicalȱanalysis,ȱtoxicityȱtestȱandȱbenthicȱalterationȱparametersȱmeasuredȱforȱtheȱstudyȱofȱtheȱ sedimentsȱqualityȱinȱtheȱCiesȱIslandȱȱ2003Ȭ2006ȱ(firstȱsurvey:ȱGA1Ȭ1,ȱAȬ1,ȱBȬ1,ȱCȬ1;ȱsecondȱsurvey:ȱGA1Ȭ2,ȱAȬ2,ȱBȬ2,ȱCȬ2;ȱthirdȱ survey:ȱGA1Ȭ3,ȱAȬ3,ȱBȬ3,ȱCȬ3)ȱandȱCormeȬLaxeȱ2004Ȭ2006ȱȱ(secondȱsurvey:ȱDȬ2,ȱEȬ2,ȱFȬ2;ȱthirdȱsurvey:ȱDȬ3,ȱEȬ3,ȱFȬ3).ȱn.d.:ȱnotȱ detected.ȱ ȱ Tableȱ 3.ȱ Sortedȱ rotatedȱ factorȱ loadingsȱ (pattern)ȱ ofȱ 17ȱ variablesȱ forȱ theȱ fourȱ principalȱ factorsȱ resultingȱ fromȱ theȱ multivariateȱ analysisȱ ofȱ theȱ singleȱ resultsȱ obtainedȱ fromȱ theȱ chemicalȱ analysis,ȱ theȱ acuteȱ toxicityȱ testsȱ andȱ theȱ alterationȱ parametersȱ forȱ theȱ studyȱ of the sediments quality in the Atlantic Islands National Park. ȱȱ FACTORȱ1 FACTORȱ2 FACTORȱ3ȱ FACTORȱ4 ȱȱ 42.21ȱ 23.43ȱ 10.64ȱ 7.73ȱ Znȱ ņȱ ņȱ ņȱ 0.91ȱ Pbȱ ņȱ ņȱ ņȱ 0.81ȱ Cuȱȱ ņȱ ņȱ 0.47ȱ 0.47ȱ Niȱȱ ņȱ ņȱ ņȱ 0.80ȱ Vȱ ņȱ 0.63ȱ ņȱ 0.55ȱ Hgȱ ņȱ 0.32ȱ ņȱ 0.73ȱ PAHsȱ 0.65ȱ 0.54ȱ ņȱ ņȱ Corophiumȱbioassayȱ 0.30ȱ ņȱ ņȱ ņȱ Arenicolaȱbioassayȱ 0.54ȱ 0.59ȱ ņȱ ņȱ Microtoxȱtestȱ ņȱ ņȱ ņȱ ņȱ Paracentrotusȱassayȱ ņȱ 0.90ȱ ņȱ ņȱ Numberȱofȱspeciesȱ 0.89ȱ ņȱ ņȱ ņȱ Specificȱrichnesȱ 0.94ȱ ņȱ ņȱ ņȱ Diversityȱ 0.79ȱ ņȱ ņȱ ņȱ %ȱMoluscaȱ 0.96ȱ ņȱ ņȱ ņȱ %ȱPolychaetaȱ 0.77ȱ 0.48ȱ ņȱ ņȱ %ȱCrustaceaȱ ņȱ 0.91ȱ ņȱ ņȱ ȱ - 288 - Theȱfirstȱprincipalȱfactor,ȱ#1ȱisȱpredominantȱandȱaccountsȱforȱ42.2%ȱofȱtheȱ variance.ȱThisȱfactorȱrepresentsȱtheȱdegradationȱofȱtheȱenvironmentȱassociatedȱ withȱtheȱpresenceȱofȱPAHsȱinȱtheȱsedimentȱbyȱlinkingȱPAHsȱwithȱtheȱtoxicityȱofȱ CorphiumȱandȱtheȱpolychaeteȱArenicolaȱmarinaȱasȱwellȱasȱinfaunaȱalterations.ȱTheȱ secondȱfactorȱexplainsȱ23.4%ȱofȱtheȱvariance;ȱshowingȱtheȱrelationshipȱbetweenȱ theȱ presenceȱ ofȱ PAHsȱ andȱ theȱ metalsȱ Hgȱ andȱ Vȱ inȱ theȱ sedimentȱ withȱ theȱ adverseȱeffectsȱmeasuredȱinȱbothȱtheȱArenicolaȱandȱseaȱurchinȱtestsȱandȱaȱslightȱ alterationȱinȱtheȱcrustaceansȱandȱpolychaeteȱcommunity.ȱTheseȱtwoȱfactorsȱ(#1ȱ andȱ #2),ȱ certainlyȱ appearȱ asȱ aȱ consequenceȱ ofȱ theȱ tankerȱ Prestigeȱ whichȱ spiltȱ hydrocarbonsȱ containingȱ PAHsȱ andȱ affectedȱ theȱ biotaȱ resultingȱ inȱ environmentalȱ degradationȱ althoughȱ Factorȱ #2ȱ representsȱ moreȱ moderateȱ effectsȱthanȱFactorȱ#1;ȱVȱisȱassociatedȱwithȱtheȱspillȱandȱhasȱanȱapparentlyȱminorȱ effectȱonȱbiotaȱwhenȱcomparedȱtoȱPAHs.ȱFactorȱ#3ȱaccountsȱforȱaȱ10.6%ȱofȱtheȱ varianceȱ andȱ isȱ relatedȱ toȱ Cuȱ contaminationȱ whichȱ isȱ notȱ responsibleȱ forȱ biologicalȱ effectsȱ inȱ theȱ environment,ȱ whereasȱ factorȱ #4ȱ (7.7%)ȱ describesȱ theȱ presenceȱ ofȱ metalȱ contaminationȱ (Zn,ȱ Pb,ȱ Cu,ȱ Niȱ ,ȱ Vȱ andȱ Hg)ȱ whichȱ doesȱ notȱ produceȱtoxicȱeffectsȱandȱisȱnotȱproducingȱdegradationȱinȱtheȱenvironment.ȱThisȱ metalȱcontaminationȱmayȱbeȱrelatedȱtoȱbasalȱlevelsȱofȱcontaminantsȱorȱowingȱtoȱ sourcesȱotherȱthanȱtheȱPrestigeȱoilȱspillȱ Figureȱ 2ȱ showsȱ theȱ factors’ȱ scoresȱ forȱ eachȱ ofȱ theȱ 10ȱ studiedȱ stations.ȱ Factorȱ#1ȱdefinedȱasȱrepresentingȱtheȱenvironmentalȱdegradationȱcausedȱbyȱtheȱ PAHsȱ boundȱ toȱ theȱ sedimentsȱ isȱ prevalentȱ inȱ theȱ stationsȱ FIGȱ (1.8)ȱ andȱ GA2ȱ (2.0)ȱindicatingȱhighȱpollutionȱlevelsȱdueȱtoȱPAHsȱinȱtheseȱsites.ȱFactorȱ#2ȱwhichȱ indicatesȱpollutionȱbyȱPAHsȱandȱVȱisȱprevalentȱinȱtheȱstationȱD09ȱ(1.4)ȱfromȱtheȱ Onsȱ islandȱ andȱ D60ȱ (1.2)ȱ andȱ GA2ȱ (1.4)ȱ fromȱ Cies.ȱ Factorȱ #3,ȱ definedȱ asȱ representingȱ Cuȱ contaminationȱ withȱ noȱ effectsȱ hasȱ aȱ positiveȱ loadingȱ inȱ theȱ samplesȱfromȱOnsȱD07ȱ(1.5)ȱandȱD09ȱ(1.2)ȱandȱFIGȱ(0.4),ȱGA1ȱ(0.9)ȱinȱCies,ȱ - 289 - 2.5 ȱ FIG 2.0 GA2 1.5 FACTOR 1 ȱ ȱ 1.0 0.5 0.0 D66 -0.5 ȱ ȱ ȱ -1.0 D09 GA1 FACTOR 2 ȱ D79 D07 2.0 GA2 D09 D60 1.0 0.5 0.0 D07 D18 -0.5 ȱ D69 D60 -1.5 1.5 ȱ D18 D66 -1.0 D69 GA1 D79 -1.5 ȱ 2.0 ȱ D07 1.5 D09 GA1 FACTOR 3 ȱ ȱ 1.0 FIG 0.5 GA2 0.0 -0.5 D69 D18 ȱ D79 -1.0 D60 -1.5 D66 ȱ 2.0 ȱ FACTOR 4 ȱ ȱ D60 1.5 FIG D79 D09 1.0 0.5 D07 0.0 -0.5 D18 ȱ -1.0 D66 D69 GA1 GA2 -1.5 ȱ Figureȱ 2.ȱ Estimatedȱ factorȱ scoresȱ forȱ theȱ fourȱ factorsȱ inȱ eachȱ ofȱ theȱ 10ȱ cases.ȱTheȱfactorȱscoresȱquantifyȱtheȱprevalenceȱofȱeachȱfactorȱforȱeveryȱstationȱ andȱisȱusedȱtoȱestablishȱtheȱdefinitionȱofȱeachȱfactor.ȱ - 290 - whereasȱFactorȱ#4ȱdescribesȱtheȱpresenceȱofȱmetalsȱ(Zn,ȱPb,ȱCu,ȱNi,ȱVȱandȱHg)ȱ inȱtheȱsedimentsȱfromȱOnsȱD07ȱ(0.1)ȱandȱD09ȱ(0.8),ȱCiesȱD60ȱ(1.4),ȱD79ȱ(0.8)ȱandȱ FIGȱ(1.2).Theseȱresultsȱshowȱhowȱinȱ2004ȱtheȱAtlanticȱIslandsȱNationalȱParkȱwasȱ significantlyȱ affectedȱ byȱ theȱ oilȱ spillȱ andȱ theȱ wayȱ inȱ whichȱ stationȱ GA1ȱ hasȱ provedȱtoȱbeȱaȱsuitableȱsiteȱofȱreferenceȱforȱtheȱpresentȱresearch.ȱȱ Factor 1 Factor 2 Factor 4 Factor 3 D07 Factor 1 Factor 2 Factor 4 Factor 3 Factor 2 Factor 4 Factor 3 D09 Factor 1 Factor 2 Factor 4 Factor 3 D60 D18 Factor 1 Factor 2 Factor 1 Factor 2 Factor 4 Factor 3 Factor 4 Factor 3 D66 Factor 1 Factor 2 Factor 1 Factor 2 Factor 4 Factor 3 Factor 4 Factor 3 D79 Factor 1 FIG D69 Factor 1 Factor 2 Factor 4 Factor 3 GA2 ȱ Figureȱ3.ȱPieȱchartsȱrepresentingȱtheȱsignificantȱdifferencesȱofȱtheȱfactorsȱ scoreȱ inȱ everyȱ studyȱ siteȱ –Atlanticȱ Islandsȱ Nationalȱ Parkȱ (2003)Ȭȱ relatedȱ toȱ theȱ referenceȱsiteȱGA1ȱ(black:ȱpȱ<ȱ0.01;ȱgrey:ȱ0.01<ȱpȱ>ȱ0.05;ȱwhite:ȱnotȱsignificantlyȱ differences,ȱ p>0.05).ȱ Factorȱ #1:ȱ PAHsȬpollution;ȱ Factorȱ #2:ȱ PAHsȬHgȬVȬ pollution;ȱ Factorȱ #3:ȱ CuȬcontamination;ȱ Factorȱ #4:ȱ ZnȬPbȬCuȬNiȬVȬHgȬ contamination.ȱȱ - 291 - Withȱ theȱ aimȱ ofȱ identifyingȱ theȱ causeȱ ofȱ pollutionȱ (orȱ lackȱ thereof)ȱ inȱ eachȱstudyȱsite,ȱanȱANOVAȱanalysisȱwasȱconductedȱbyȱusingȱtheȱfactorȱscoresȱ obtainedȱ inȱ theȱ MAA.ȱ Figureȱ 3ȱ showsȱ theȱ pieȱ chartsȱ stemmingȱ fromȱ ANOVAȱ results,ȱusingȱGA1ȱasȱtheȱnegativeȱcontrol.ȱ Inȱ thisȱ firstȱ approachȱ inȱ whichȱ theȱ sedimentȱ statusȱ wasȱ establishedȱ (inȱ 2004)ȱ followingȱ theȱ spill,ȱ significantȱ pollutionȱ causedȱ byȱ PAHsȱ atȱ theȱ stationsȱ FIGȱ andȱ GA2ȱ wasȱ detected.ȱ Pollutionȱ provokedȱ byȱ aȱ mixtureȱ ofȱ PAHsȱ andȱ Vȱ affectingȱ bothȱ theȱ Ons:ȱ D09ȱ andȱ theȱ Ciesȱ Islands:ȱ D60,ȱ FIG,ȱ GA2ȱ wasȱ alsoȱ detected.ȱHighȱlevelsȱofȱpollutionȱwereȱespeciallyȱidentifiedȱinȱtheȱstationȱGA2ȱ onȱtheȱCiesȱisland.ȱAȱsourceȱofȱmetalsȱ(Zn,ȱPb,ȱCu,ȱNi,ȱHgȱandȱV)ȱwasȱidentifiedȱ initially,ȱwhoseȱpresenceȱwasȱthoughtȱnotȱtoȱbeȱinȱconnectionȱwithȱtheȱoilȱspillsȱ butȱ insteadȱ isȱ probablyȱ relatedȱ toȱ backgroundȱ levelsȱ orȱ contaminationȱ whichȱ doesȱ notȱ causeȱ biologicalȱ effects.ȱ Suchȱ levelsȱ appearȱ atȱ D07,ȱ D09ȱ andȱ theȱ stationsȱfromȱCiesȱIslandsȱD60,ȱD79ȱandȱFIG.ȱInȱFIGȱtheȱpresenceȱofȱmetalsȱhasȱ beenȱ correlatedȱ withȱ alterationȱ inȱ oneȱ ofȱ theȱ analyses,ȱ butȱ noȱ toxicityȱ wasȱ exhibited;ȱ perhapsȱ meaningȱ thatȱ alterationȱ ofȱ theȱ macrofaunaȱ wasȱ causedȱ byȱ otherȱ sources,ȱ possiblyȱ physical,ȱ suchȱ asȱ theȱ assessedȱ beachȱ cleaningȱ afterȱ theȱ spill.ȱ Previousȱ studiesȱ haveȱ demonstratedȱ thatȱ theȱ Prestigeȱ oilȱ spillȱ causedȱ Znȱ contaminationȱ inȱ theȱ surroundingȱ waterȱ columnȱ (Pregoȱ andȱ CobeloȬGarcía,ȱ 2003).ȱContaminationȱbyȱcopperȱandȱleadȱwasȱalsoȱobservedȱinȱtheȱuppermostȱ layerȱinȱtheȱshipwreckȱareaȱofȱtheȱNortheastȱAtlanticȱOceanȱ(PregoȱandȱCobeloȬ García,ȱ2004;ȱCobeloȬGarciaȱetȱal.,ȱ2004),ȱhowever,ȱthisȱcontaminationȱwithȱCuȱisȱ notȱlikelyȱtoȱbeȱrelatedȱbecauseȱlevelsȱofȱCuȱinȱtheȱfuelȱoilȱwereȱrelativelyȱlowȱ (3.39ȱ mgȱ KgȬ1)ȱ suggestingȱ Cuȱ inputsȱ fromȱ theȱ nearbyȱ Riaȱ deȱ Vigo.ȱ Previousȱ studiesȱhaveȱshownȱtheȱpresenceȱofȱtraceȱmetalȱcontaminationȱinȱtheȱRias,ȱcloseȱ toȱtheȱAINPȱ(Carballeiraȱetȱal.,ȱ1997;ȱPérezȬLópezȱetȱal.,ȱ2003)ȱthisȱalsoȱpossiblyȱ explainingȱtheȱpresenceȱofȱmetalsȱonȱtheȱCiesȱandȱOnsȱIslands.ȱȱ - 292 - TheȱapplicationȱofȱtheȱWOEȱapproachȱhasȱshownȱthatȱsomeȱmonthsȱafterȱ theȱ spillȱ thereȱ wasȱ aȱ significantȱ impactȱ whichȱ provokedȱ degradationȱ ofȱ theȱ ecosystemȱ inȱ partȱ ofȱ theȱ sedimentȱ fromȱ studyȱ sitesȱ locatedȱ inȱ theȱ Atlanticȱ IslandsȱNationalȱPark.ȱAȱsourceȱofȱmetals,ȱwhichȱinȱsomeȱcasesȱareȱaffectingȱtheȱ environmentȱ orȱ areȱ consideredȱ aȱ potentialȱ riskȱ hasȱ beenȱ detected.ȱ Resultsȱ suggestedȱ thatȱ furtherȱ studiesȱ shouldȱ beȱ doneȱ inȱ orderȱ toȱ clarifyȱ whetherȱ theȱ affectedȱAINPȱandȱsurroundingȱsitesȱhaveȱrecovered.ȱWithȱthisȱaimȱinȱmind,ȱtheȱ WOEȱ investigationsȱ haveȱ beenȱ appliedȱ toȱ selectedȱ sitesȱ inȱ theȱ Ciesȱ Islandȱ (AINP)ȱ andȱ CormeȬLaxe,ȱ withȱ theȱ freshȱ approachȱ ofȱ monitoringȱ overȱ aȱ fourȱ yearȱperiodȱinȱorderȱtoȱassessȱtheȱrecoveryȱofȱanȱareaȱaffectedȱbyȱanȱoilȱspill.ȱȱ Sedimentsȱ fromȱ GA1ȱ turnedȱ outȱ toȱ beȱ theȱ cleanestȱ givenȱ itȱ didȱ presentȱ toxicityȱorȱinȱsituȱalterationȱmakingȱthisȱstationȱanȱappropriateȱselectionȱasȱtheȱ referenceȱ siteȱ inȱ theȱ followingȱ assessments.ȱ Theȱ WOEȬmonitoringȱ focusedȱ onȱ twoȱ areasȱ withȱ theȱ followingȱ proceduresȱ appliedȱ separately:ȱ (a)ȱ assessingȱ theȱ Ciesȱ Islandȱ sedimentȱ qualityȱ monitoringȱ fromȱ theȱ beginningȱ ofȱ 2004ȱ toȱ 2006,ȱ andȱ(b)ȱstudyingȱtheȱCormeȬLaxeȱsedimentȱstatusȱfromȱtheȱendȱofȱ2004ȱtoȱ2006.ȱ Inȱthisȱsense,ȱthisȱstudyȱwasȱdesignedȱtoȱmonitorȱtheȱrecoveryȱorȱpersistenceȱofȱ theȱ pollutionȱ causedȱ byȱ theȱ oilȱ spillȱ overȱ timeȱ usingȱ anȱ improvedȱ WOEȱ approachȱbasedȱonȱtheȱclassicalȱSQT.ȱ 3.1.ȱCíesȱIslandȱ(2004Ȭ2006)ȱ Theȱ sedimentȱ qualityȱ assessmentȱ atȱ theȱ Ciesȱ Islandȱ (AINP)ȱ hasȱ beenȱ carriedȱ outȱ forȱ theȱ sameȱ 3ȱ sitesȱ inȱ distinctȱ samplingȱ campaignsȱ fromȱ 2003ȱ toȱ 2006.ȱResultsȱfromȱtheȱfirstȱsurveyȱ(2004)ȱcorrespondȱtoȱGA1Ȭ1,ȱAȬ1,ȱBȬ1ȱandȱCȬ 1;ȱ dataȱ fromȱ theȱ secondȱ surveyȱ (2004Ȭ2005)ȱ areȱ referredȱ toȱ asȱ GA1Ȭ2,ȱ AȬ2,ȱ BȬ2ȱ andȱCȬ2,ȱwithȱtheȱresultsȱobtainedȱinȱtheȱthirdȱsurveyȱ(2005Ȭ2006)ȱcorrespondingȱ toȱ Ga1Ȭ3,ȱ AȬ3,ȱ BȬ3ȱ andȱ CȬ3.ȱ Theȱ MAAȱ wasȱ carriedȱ outȱ byȱ treatingȱ eachȱ setȱ ofȱ - 293 - dataȱ asȱ anȱ independentȱ caseȱ inȱ orderȱ toȱ trackȱ theȱ monitoringȱ ofȱ theȱ sedimentȱ qualityȱinȱeachȱstation.ȱȱ Inȱ tableȱ 4ȱ theȱ MAAȱ carriedȱ outȱ onȱ originalȱ variableȱ data,ȱ includingȱ replicatesȱisȱshown.ȱTheȱapplicationȱofȱtheȱstatisticalȱanalysisȱshowsȱthatȱtheȱ19ȱ originalȱ variablesȱ canȱ beȱ groupedȱ inȱ fourȱ newȱ factors.ȱ Theseȱ factorsȱ explainȱ 88.5%ȱofȱtheȱoriginalȱdataȱvariance.ȱTheȱfirstȱFactorȱ(#1)ȱaccountsȱforȱ50.75ȱ%ȱofȱ theȱvarianceȱandȱcorrespondsȱtoȱtheȱtoxicityȱandȱinȱsituȱalterationȱdueȱtoȱPAHsȱ andȱ theȱ presenceȱ ofȱ Pbȱ responsibleȱ forȱ environmentalȱ degradationȱ (pollution);ȱ Factorȱ#2ȱ(18.3%)ȱdepictsȱPb,ȱCu,ȱNiȱandȱVȱcontaminationȱforȱwhichȱnoȱtoxicityȱ orȱ otherȱ effectsȱ onȱ biotaȱ isȱ appreciable;ȱ Factorȱ #3ȱ (10.9%)ȱ isȱ alsoȱ relatedȱ toȱ contaminationȱ byȱ Zn,ȱ Pb,ȱ Niȱ andȱ Hgȱ havingȱ noȱ associatedȱ biologicalȱ effectsȱ whileȱ Factorȱ #4ȱ (8.6%)ȱ showsȱ aȱ degreeȱ ofȱ toxicityȱ andȱ environmentalȱ degradationȱdueȱtoȱPAHsȱcontamination.ȱȱ Figureȱ4ȱshowsȱtheȱfactorȱscoresȱinȱtheȱ12ȱcases.ȱFactorȱ#1,ȱwhichȱdefinesȱ pollutionȱdueȱtoȱPAHsȱandȱPb,ȱhasȱaȱpositiveȱloadingȱinȱAȬ1ȱ(2.0)ȱandȱBȬ1ȱ(2.2).ȱ Theseȱ 2ȱ casesȱ correspondȱ toȱ firstȱ samplingȱ carriedȱ outȱ inȱ theȱ Ciesȱ Islands.ȱ Weȱ canȱseeȱhowȱtheȱscoreȱforȱfactorȱ#1ȱatȱtheseȱ2ȱstationsȱ(AȱandȱB)ȱdecreasesȱwithȱ timeȱinȱtheȱfollowingȱsurveys,ȱinȱresponseȱtoȱsedimentȱrecoveryȱfromȱtheȱeffectsȱ ofȱ initialȱ pollutionȱ levelsȱ inȱ theȱ studiedȱ sitesȱ .ȱ Factorȱ #2ȱ andȱ #3ȱ demonstrateȱ contaminationȱbyȱmetalsȱwhichȱwasȱnotȱassociatedȱwithȱdegradationȱinȱmostȱofȱ theȱstations.ȱFactorȱ#4,ȱrelatedȱtoȱPAHȱtoxicity,ȱdecreasesȱinȱtheȱstationsȱBȱandȱCȱ withȱtimeȱalthoughȱslightȱpersistenceȱisȱevidentȱinȱstationȱA.ȱȱ ȱ ȱ ȱ - 294 - Tableȱ 4.ȱ Sortedȱ rotatedȱ factorȱ loadingsȱ (pattern)ȱ ofȱ 17ȱ variablesȱ forȱ theȱ fourȱ principalȱ factorsȱ resultingȱ fromȱ theȱ multivariateȱ analysisȱ ofȱ theȱ singleȱ resultsȱ obtainedȱ fromȱ theȱ chemicalȱ analysis,ȱ theȱ acuteȱ toxicityȱ testsȱ andȱ theȱ alterationȱ parametersȱ forȱ theȱ studyȱ ofȱ theȱ sedimentsȱ qualityȱ inȱ theȱ Ciesȱ Islandȱ 2004Ȭ2006.ȱ ȱȱ ȱȱ Znȱ Pbȱ Cuȱȱ Niȱȱ Vȱȱ Hgȱ PAHȱ Corophiumȱbioassayȱ Arenicolaȱbioassayȱ Microtoxȱtestȱ Paracentrotusȱassayȱ Numberȱofȱspeciesȱ Specificȱrichnesȱ Diversityȱ %ȱMoluscaȱ %ȱPolychaetaȱ %ȱCrustaceaȱ Factorȱ1ȱ 50.73ȱ Factorȱ2ȱ 18.26ȱ Factorȱ3ȱ 10.93ȱ Factorȱ4ȱ 8.62ȱ ņȱ 0.41ȱ ņȱ ņȱ ņȱ ņȱ 0.73ȱ 0.63ȱ ņȱ 0.62ȱ 0.38ȱ 0.91ȱ 0.95ȱ 0.91ȱ 0.97ȱ 0.76ȱ 0.70ȱ ņȱ 0.71ȱ 0.83ȱ 0.43ȱ 0.82ȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ 0.88ȱ 0.32ȱ ņȱ 0.86ȱ ņȱ 0.37ȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ 0.63ȱ 0.72ȱ 0.92ȱ 0.53ȱ 0.89ȱ 0.31ȱ ņȱ ņȱ ņȱ ņȱ 0.57ȱ Figureȱ5ȱshowsȱtheȱprevalenceȱofȱeachȱfactorȱinȱeveryȱstationȱaccordingȱtoȱ theȱstatisticalȱdifferencesȱobtainedȱinȱtheȱANOVAȱanalysis,ȱinȱcomparisonȱwithȱ theȱreferenceȱsite.ȱTheȱprevalenceȱofȱFactorȱ#1ȱandȱFactorȱ#4ȱwhichȱareȱrelatedȱtoȱ PAHsȱ pollutionȱ decreasedȱ inȱ allȱ stationsȱ overȱ theȱ periodȱ 2004Ȭ2006ȱ givingȱ theȱ impressionȱthatȱtheȱAINPȱhasȱbeenȱundergoingȱaȱprocessȱofȱrecoveryȱduringȱtheȱ 4ȱ yearsȱ followingȱ theȱ oilȱ spill.ȱ Onȱ theȱ otherȱ handȱ theȱ significantȱ differencesȱ foundȱforȱFactorȱ#1ȱandȱFactorȱ#2ȱdidȱnotȱreflectȱsuchȱaȱrecoveryȱprocessȱduringȱ thisȱperiod.ȱThisȱisȱperhapsȱrelatedȱtoȱtheȱpersistenceȱofȱmetalȱcontaminationȱinȱ theȱ 3ȱ studyȱ sites,ȱ suggestingȱ thatȱ thisȱ contaminationȱ wasȱ presentȱ priorȱ toȱ theȱ spillȱinȱtheȱstudiedȱarea.ȱȱ - 295 - 3.5 B-1 FACTOR 1 2.5 A-1 1.5 0.5 A-2 GA1-2 -0.5 GA1-1 GA1-3 B-2 A-3 B-3 C-3 C-1 C-2 -1.5 3.0 2.0 A-2 1.0 C-1 C-2 A-1 GA1-1 0.0 GA1-2 -1.0 GA1-3 A-3 B-1 B-2 C-3 B-3 -2.0 3.5 A-3 FACTOR 3 2.5 1.5 A-1 A-2 -0.5 -1.5 C-3 B-3 0.5 B-2 GA1-1 C-1 B-1 GA1-2 GA1-3 C-2 -2.5 2.5 B-1 C-1 FACTOR 4 1.5 A-3 0.5 -0.5 -1.5 C-2 B-2 B-3 GA1-1 C-3 A-2 GA1-2 GA1-3 A-1 -2.5 Oȱ Figureȱ4.ȱEstimatedȱfactorȱscoresȱforȱtheȱfourȱfactorsȱinȱeachȱofȱtheȱ12ȱcasesȱ - 296 - Factor 1 Factor 2 Factor 4 Factor 3 A-1 Factor 1 Factor 2 Factor 4 Factor 3 A-2 Factor 1 Factor 2 Factor 4 Factor 3 Factor 2 Factor 4 Factor 3 A-3 Factor 1 Factor 2 Factor 1 Factor 2 Factor 4 Factor 3 Factor 4 Factor 3 B-1 B-2 Factor 1 Factor 2 Factor 4 Factor 3 C-1 Factor 1 Factor 1 Factor 2 Factor 4 Factor 3 C-2 B-3 Factor 1 Factor 2 Factor 4 Factor 3 C-3 Figureȱ 5.ȱ Pieȱ chartsȱ showingȱ theȱ significantȱ differencesȱ ofȱ theȱ factorsȱ scoreȱ inȱ everyȱ studyȱ siteȱ ȬCiesȱ (2003Ȭ2006)Ȭȱ relatedȱ toȱ theȱ referenceȱ siteȱ GA1ȱ (black:ȱpȱ<ȱ0.01;ȱgrey:ȱ0.01<ȱpȱ>ȱ0.05;ȱwhite:ȱnotȱsignificantlyȱdifferences,ȱp>0.05).ȱ Factorȱ#1:ȱPAHsȬPbȬpollution;ȱFactorȱ#2:ȱPbȬCuȬNiȬVȬcontamination;ȱFactorȱ#3:ȱ ZnȬPbȬNiȬHgȬcontamination;ȱFactorȱ#4:ȱPAHsȬpollution.ȱȱ ȱ ȱ ȱ ȱ - 297 - Onȱ theȱ whole,ȱ theȱ analysisȱ performedȱ inȱ theȱ Ciesȱ Islandȱ forȱ theȱ periodȱ 2004Ȭ2006ȱhasȱshownȱanȱimportantȱdecreaseȱofȱtheȱinitialȱdegradationȱprovokedȱ byȱ theȱ accidentalȱ oilȱ spill.ȱ Atȱ theȱ startȱ ofȱ 2004ȱ initialȱ pollutionȱ dueȱ toȱ PAHsȱ boundȱ toȱ sedimentsȱ wasȱ detectedȱ whichȱ affectedȱ theȱ sedimentȱ qualityȱ inȱ stationsȱ A,ȱ Bȱ andȱ C.ȱ Thisȱ contaminationȱ andȱ itsȱ biologicalȱ effectsȱ decreasedȱ inȱ theȱfollowingȱsurveysȱandȱcurrentlyȱtheseȱsedimentsȱseemȱnotȱtoȱbeȱdegraded.ȱ Theȱpresenceȱofȱmetalsȱcontaminationȱwasȱdetectedȱinȱtheȱstationsȱdespiteȱthisȱ notȱhavingȱproducedȱenvironmentalȱbiologicalȱeffects.ȱItȱisȱpossibleȱtheseȱmetalsȱ mayȱ notȱ beȱ availableȱ toȱ organismsȱ inȱ theirȱ presentȱ form,ȱ butȱ thatȱ ifȱ environmentalȱconditionsȱeventuallyȱchanged,ȱtheyȱmayȱbecomeȱaȱthreatȱforȱtheȱ environment.ȱȱ 3.2.ȱCormeȬLaxeȱ(endȱofȱ2004Ȭ2006)ȱ Theȱsedimentȱqualityȱevaluationȱwasȱperformedȱatȱtheȱsameȱsitesȱduringȱ distinctȱsurveysȱinȱtheȱperiodȱfromȱtheȱendȱofȱ2004ȱtoȱ2006.ȱResultsȱfromȱtheȱfirstȱ surveyȱ(2004Ȭ2005)ȱcorrespondȱtoȱGA1Ȭ2,ȱDȬ2,ȱEȬ2ȱandȱFȬ2;ȱdataȱfromȱtheȱsecondȱ campaignȱareȱreferredȱtoȱasȱGA1Ȭ3,ȱDȬ3,ȱEȬ3ȱandȱFȬ3.ȱȱ Theȱ multivariateȱ approachȱ wasȱ conductedȱ asȱ describedȱ above.ȱ Afterȱ applyingȱ theȱ principalȱ factorsȱ analysisȱ theȱ 17ȱ variablesȱ wereȱ groupedȱ inȱ twoȱ newȱfactorsȱ(tableȱ5).ȱTheseȱfactorsȱexplainȱ62.96ȱ%ȱofȱtheȱoriginalȱdataȱvariance.ȱ Theȱfirstȱfactor,ȱ#1ȱisȱpredominantȱandȱexplainsȱaȱ41.3ȱ%ȱofȱtheȱvariance.ȱItȱlinksȱ theȱpollutionȱcausedȱbyȱPAHsȱandȱmetalsȱ(Zn,ȱPb,ȱCu,ȱNi,ȱVȱandȱHg)ȱboundȱtoȱ sedimentȱ byȱ relatingȱ theseȱ contaminantsȱ withȱ theȱ toxicityȱ (amphipods,ȱ polychaete,ȱ seaȱ urchin)ȱ andȱ alterationȱ (numberȱ ofȱ speciesȱ andȱ percentageȱ ofȱ crustacea).ȱTheȱsecondȱfactor,ȱ#2,ȱexplainsȱ21.6ȱ%ȱofȱtheȱvarianceȱandȱdepictsȱtheȱ relationshipȱ betweenȱ certainȱ metalsȱ (Cuȱ andȱ V)ȱ withȱ alterationȱ (specificȱ richness,ȱ%ȱofȱpolychaete)ȱandȱpotentialȱtoxicityȱ(Microtox®ȱtest).ȱȱ - 298 - Tableȱ 5.ȱ Sortedȱ rotatedȱ factorȱ loadingsȱ (pattern)ȱ ofȱ 17ȱ variablesȱ forȱ theȱ fourȱ principalȱ factorsȱ resultingȱ fromȱ theȱ multivariateȱ analysisȱ ofȱ theȱ singleȱ resultsȱ obtainedȱ fromȱ theȱ chemicalȱ analysis,ȱ theȱ acuteȱ toxicityȱ testsȱ andȱ theȱ alterationȱ parametersȱ forȱ theȱ studyȱ ofȱ theȱ sedimentsȱ qualityȱ inȱ CormeȬLaxeȱ 2004Ȭ2006.ȱ ȱȱ FACTORȱ1ȱ FACTORȱ2ȱ ȱȱ 41.32ȱ Znȱ 0.55ȱ 21.64ȱ ņȱ Pbȱ 0.79ȱ Cuȱȱ 0.70ȱ 0.59ȱ Niȱȱ 0.94ȱ ņȱ Vȱȱ 0.64ȱ Hgȱ 0.88ȱ 0.72ȱ ņȱ PAHȱ 0.89ȱ Corophiumȱbioassayȱ 0.88ȱ Arenicolaȱbioassayȱ 0.83ȱ Microtoxȱtestȱ ņȱ Paracentrotusȱassayȱ 0.72ȱ Numberȱofȱspeciesȱ 0.50ȱ ņȱ Specificȱrichnesȱ Diversityȱ %ȱMoluscaȱ %ȱPolychaetaȱ %ȱCrustaceaȱ ņȱ ņȱ ņȱ ņȱ 0.87ȱ ņȱ ņȱ ņȱ 0.92ȱ ņȱ ņȱ ņȱ ņȱ 0.49ȱ 0.78ȱ ņȱ ȱ Figureȱ 6ȱ showsȱ theȱ factorȱ scoresȱ forȱ theȱ 8ȱ cases.ȱ Factorȱ #1,ȱ whichȱ isȱ definedȱasȱtheȱpollutionȱcausedȱbyȱPAHsȱandȱtheȱmetalsȱZn,ȱPb,ȱCu,ȱNi,ȱVȱandȱ Hg,ȱhasȱaȱpositiveȱloadingȱinȱDȬ2ȱ(1.7),ȱEȬ2ȱ(0.3),ȱFȬ2ȱ(1.5)ȱandȱFȬ3ȱ(0.1).ȱTheȱthreeȱ firstȱcasesȱcorrespondȱtoȱtheȱfirstȱCormeȬLaxeȱsurveyȱ(2004Ȭ2005)ȱwhereasȱFȬ3ȱȱ - 299 - 2.5 D-2 F-2 FACTOR 1 1.5 E-2 0.5 F-3 D-3 -0.5 E-3 GA1-2 GA1-3 -1.5 1.5 D-2 FACTOR 2 0.5 GA1-2 F-2 D-3 -0.5 E-3 F-3 GA1-3 E-2 -1.5 ȱ Figureȱ6.ȱEstimatedȱfactorȱscoresȱforȱtheȱtwoȱfactorsȱinȱeachȱofȱtheȱ8ȱcases.ȱ ȱ ȱ ȱ ȱ ȱ ȱ - 300 - correspondsȱ toȱ theȱ secondȱ stationȱ Fȱ surveyȱ (2005Ȭ2006).ȱ Weȱ canȱ seeȱ howȱ theȱ scoreȱ forȱ factorȱ 1ȱ inȱ D,ȱ E,ȱ andȱ Fȱ decreasedȱ asȱ timeȱ wentȱ on,ȱ whileȱ remainingȱ positiveȱ forȱ stationȱ F,ȱ thisȱ indicatingȱ thatȱ sedimentsȱ fromȱ theseȱ stationsȱ haveȱ recoveredȱ butȱ thatȱ degradationȱ persistsȱ inȱ stationȱ F.ȱ Factorȱ #2ȱ showsȱ metalȱ contaminationȱbyȱCuȱandȱVȱlinkedȱtoȱalterationȱandȱpotentialȱtoxicityȱhavingȱaȱ positiveȱloadingȱforȱDȬ2ȱ(0.8).ȱTheȱfactorȱscoreȱdecreasedȱwithȱtimeȱinȱstationsȱDȱ andȱFȱwhereasȱstationȱEȱpresentedȱanȱincreaseȱdespiteȱitȱnotȱhavingȱaȱpositiveȱ loading.ȱFigureȱ7ȱshowsȱtheȱprevalenceȱofȱeachȱfactorȱinȱeveryȱstationȱaccordingȱ toȱ theȱ statisticalȱ differencesȱ obtainedȱ inȱ theȱ ANOVAȱ analysesȱ inȱ comparisonȱ withȱtheȱreferenceȱsiteȱ(GA1).ȱTheȱsignificantȱdifferencesȱinȱFactorȱ#1ȱcomparedȱ withȱ theȱ referenceȱ stationȱ didȱ notȱ decreaseȱ duringȱ theȱ 2004Ȭ2006ȱ periodȱ withȱ respectȱtoȱtheȱstationsȱD,ȱEȱandȱF,ȱmeaningȱthatȱalthoughȱrecoveryȱwasȱdetectedȱ inȱtheȱMAAȱanalysis,ȱDȱandȱEȱareȱnotȱasȱcleanȱasȱtheȱreferenceȱstation,ȱwhereasȱ siteȱ Fȱ continuedȱ toȱ presentȱ degradationȱ dueȱ toȱ aȱ mixtureȱ ofȱ variousȱ contaminantsȱ includingȱ PAHsȱ andȱ metals.ȱ Onȱ theȱ otherȱ handȱ theȱ potentialȱ pollutionȱ dueȱ toȱ theȱ metalsȱ Cuȱ andȱ Vȱ (Factorȱ #2)ȱ presentȱ inȱ Dȱ andȱ E,ȱ wasȱ notȱ apparentȱ forȱ theȱ finalȱ survey,ȱ insofarȱ asȱ significantȱ differencesȱ comparedȱ withȱ theȱcontrolȱGA1ȱwereȱconcerned.ȱȱ Theȱ CormeȬLaxeȱ studyȱ showedȱ thatȱ theȱ presenceȱ ofȱ bothȱ PAHsȱ andȱ aȱ mixtureȱ ofȱ metalsȱ Zn,ȱ Pb,ȱ Cu,ȱ Ni,ȱ Vȱ andȱ Hgȱ initiallyȱ causedȱ environmentalȱ degradationȱatȱtheȱstationsȱD,ȱEȱandȱF.ȱTheȱrecoveryȱofȱtheȱstationsȱinȱDȱandȱEȱ (MAA)ȱshowȱthatȱtheȱsourceȱofȱtheȱPAHsȱpollutionȱisȱrelatedȱtoȱtheȱPrestigeȱoilȱ spill.ȱHowever,ȱtheȱpresenceȱofȱmetalsȱwithȱdifferentȱcharacteristicsȱfromȱthoseȱ boundȱtoȱtheȱoriginalȱfuelȱoilȱfromȱtheȱPrestige,ȱsuggestȱtheȱpossibleȱexistenceȱofȱ anotherȱ sourceȱ orȱ sourcesȱ ofȱ contaminationȱ inȱ theȱ area.ȱ Previousȱ studiesȱ haveȱ shownȱ thatȱ theȱ neighbouringȱ Riasȱ andȱ coastalȱ watersȱ actȱ asȱ aȱ sourceȱ ofȱ dissolvedȱ andȱ particulateȱ traceȱ metalsȱ (CobeloȬGarcíaȱ etȱ al.,ȱ 2005).ȱ Researchȱ - 301 - resultsȱ obtainedȱ showȱ sedimentsȱ fromȱ theȱ stationsȱ Dȱ andȱ Eȱ toȱ haveȱ recoveredȱ whereasȱdegradationȱremainsȱatȱtheȱFȱsiteȱnearestȱtoȱtheȱcoast,ȱhighlightingȱtheȱ influenceȱ ofȱ theȱ mentionedȱ causesȱ differentȱ thanȱ theȱ Prestige.ȱ Initialȱ potentialȱ degradationȱ causedȱ byȱ Cuȱ andȱ Vȱ wasȱ alsoȱ detected,ȱ althoughȱ notȱ presentȱ forȱ theȱfinalȱsurvey.ȱ ȱ F2 F1 ȱ F2 ȱ D-2 F1 D-3 ȱ F2 F1 F2 ȱ E-2 F1 ȱ E-3 ȱ F2 F2 F1 F1 ȱ F-2 ȱ F-3 Figureȱ 6.ȱ Pieȱ chartsȱ showingȱ theȱ significantȱ differencesȱ ofȱ theȱ factorsȱ scoreȱinȱeveryȱstudyȱsiteȱ–CormeȬLaxeȱ(2004Ȭ2006)Ȭȱrelatedȱtoȱtheȱreferenceȱsiteȱ GA1ȱ (black:ȱ pȱ <ȱ 0.01;ȱ grey:ȱ 0.01<ȱ pȱ >ȱ 0.05;ȱ white:ȱ notȱ significantlyȱ differencesȱ p>0.05).ȱ Factorȱ #1:ȱ PAHsȬZnȬȱ PbȬNiȬCuȬVȬHgȬpollution;ȱ Factorȱ #2:ȱ CuȬVȬ pollution.ȱȱ - 302 - 4.ȱConclusionsȱ TheȱWOEȱapproachȱemployedȱinȱthisȱstudyȱhasȱbeenȱappliedȱtoȱ3ȱlinesȱofȱ evidenceȱ (contamination,ȱ toxicityȱ andȱ alteration)ȱ inȱ addressingȱ 3ȱ distinctȱ objectives.ȱFirstȱofȱallȱaȱrevisionȱofȱtheȱsedimentȱqualityȱfollowingȱtheȱPrestigeȱoilȱ spillȱhasȱbeenȱcarriedȱoutȱinȱtheȱAtlanticȱIslands,ȱanȱareaȱwithȱaȱhighȱecologicalȱ relevance.ȱThisȱwasȱachievedȱbyȱapplyingȱaȱmultivariateȱandȱANOVAȱanalyses.ȱ Inȱ orderȱ toȱ assessȱ theȱdevelopmentȱofȱtheȱqualityȱofȱtheȱsedimentsȱaffectedȱbyȱ theȱ spillȱ aȱ setȱ ofȱ stationsȱ wasȱ studiedȱ usingȱ theȱ sameȱ timeȬdependentȱ methodologyȱ forȱ theȱ Ciesȱ Islandȱ (2004Ȭ2006)ȱ andȱ inȱ CormeȬLaxeȱ (2004Ȭ2006).ȱ Resultsȱ obtainedȱ haveȱ identifiedȱ PAHsȱ relatedȱ toȱ theȱ Prestigeȱ oilȱ spillȱ asȱ theȱ mainȱcontaminantȱinȱtheȱsitesȱstudiedȱonȱtheȱGalicianȱCoast.ȱAȱsourceȱofȱmetalsȱ hasȱbeenȱidentifiedȱinȱtheȱAtlanticȱIslandsȱNationalȱParkȱwhichȱseemsȱnotȱtoȱbeȱ producingȱ biologicalȱ effectsȱ althoughȱ furtherȱ researchȱ ofȱ thisȱ inputȱ ofȱ metalsȱ shouldȱ beȱ carriedȱ outȱ especiallyȱ forȱ theȱ Onsȱ Island.ȱ Inȱ CormeȬLaxeȱ anȱ additionalȱ sourceȱ orȱ sourcesȱ ofȱ aȱ mixtureȱ ofȱ contaminantsȱ wasȱ alsoȱ detected.ȱ Pollutionȱ hasȱ decreasedȱ inȱ recentȱ yearsȱ inȱ bothȱ theȱ Atlanticȱ Islandsȱ Nationalȱ ParkȱandȱCormeȬLaxeȱareasȱ,ȱalthoughȱthereȱisȱstillȱsomeȱdegradationȱpresentȱinȱ someȱareas,ȱparticularlyȱȱinȱCormeȬLaxe.ȱȱȱ TheȱinformationȱobtainedȱinȱthisȱstudyȱhasȱdemonstratedȱthatȱWOEȱisȱaȱ suitableȱ toolȱ forȱ monitoringȱ environmentalȱ riskȱ assessmentȱ allowingȱ sourcesȱ andȱfateȱofȱcontaminantsȱtoȱbeȱdifferentiatedȱinȱadditionȱtoȱtheirȱpotentialȱrisk.ȱ Theȱ innovativeȱ applicationȱ ofȱ theȱ classicalȱ WOEȱ methodologyȱ hasȱ provedȱ usefulȱ inȱ obtainingȱ moreȱ objectiveȱ resultsȱ andȱ itsȱ useȱ isȱ recommendedȱ inȱ theȱ designȱandȱimplementationȱofȱmonitoringȱprogramsȱinȱareasȱthatȱhaveȱsufferedȱ contaminationȱ episodesȱ throughȱ theȱ selectingȱ ofȱ appropriateȱ linesȱ ofȱ evidenceȱ onȱaȱcaseȱbyȱcaseȱbasisȱȱ - 303 - 5.ȱAcknowledgementsȱ Theȱ workȱ describedȱ wasȱ partlyȱ supportedȱ byȱ theȱ projectsȱ VEM2003Ȭ 20563/INTER,ȱ andȱ CTM2005Ȭ07282ȬC03Ȭ01/TECNOȱ financedȱ byȱ theȱ Spanishȱ Educationȱ andȱ Scienceȱ Ministryȱ andȱ byȱ theȱ CISȱ fundedȱ byȱ theȱ Ministryȱ ofȱ Environment.ȱ Carmenȱ MoralesȬCasellesȱ thanksȱ theȱ Ministryȱ ofȱ Educationȱ andȱ Scienceȱforȱ fundingȱherȱ researchȱ fellowshipȱ(FPU).ȱ Specialȱthanksȱareȱgivenȱ toȱ theȱ CISȱ membersȱ forȱ theirȱ supportȱ andȱ helpȱ inȱ theȱ chemicalȱ analysisȱ andȱ theȱ benthicȱ communityȱ information;ȱ authorsȱ thankȱ Nuriaȱ Fernándezȱ forȱ theȱ ParacentrotusȱdataȱandȱherȱhelpȱinȱtheȱfirstȱbioassayȱcarriedȱoutȱwithȱArenicola.ȱ Weȱ appreciateȱ theȱ contributionȱ ofȱ theȱ reviewersȱ andȱ theȱ helpȱ ofȱ Thomasȱ Ransome.ȱ 6.ȱReferencesȱȱȱȱ Borgmann,ȱ U.;ȱ Norwood,ȱ W.P.;ȱ Reynoldson,ȱ T.B.;ȱ Rosa,ȱ F.ȱ Identifyingȱ causeȱ inȱ sedimentȱ assessments:ȱ bioavailabilityȱ andȱ theȱ Sedimentȱ Qualityȱ Triad.ȱ Can.ȱ J.ȱ Fish.ȱAquat.ȱSci.ȱ58:ȱ950Ȭ969;ȱ2001ȱ Carballeira,ȱA.;ȱCarral,ȱE.;ȱPuente,ȱX.M.;ȱVillares,ȱR.;ȱEstadoȱdeȱconservaciónȱdeȱlaȱcostaȱ deȱ Galicia.ȱ Nutrientesȱ yȱ metalesȱ pesadosȱ enȱ sedimentosȱ yȱ organismosȱ intermareales.ȱUniversidadȱdeȱSantiagoȱdeȱCompostela;1997.ȱ CasadoȬMartínez,ȱ M.C.;ȱ Forja,ȱ J.M.;ȱ DelValls,ȱ T.A.ȱ Comparativeȱ toxicityȱ assessmentȱ usingȱtheȱamphipodȱCorophiumȱvolutatorȱandȱtheȱpolychaeteȱArenicolaȱmarinaȱ forȱdredgedȱmaterialȱmanagement.ȱEnvironȱToxicolȱ(inȱpress).ȱ Chapman,ȱ P.M.;ȱ Power,ȱ E.A.;ȱ Dexter,ȱ R.N.;ȱ Andersen,ȱ H.B.ȱ Evaluationȱ ofȱ effectsȱ associatedȱ withȱ anȱ oilȱ platform,ȱ usingȱ theȱ sedimentȱ qualityȱ triad.ȱ Environ.ȱ Toxicol.ȱChem.ȱ10:ȱ407–424;ȱ1991ȱ - 304 - Chapman,ȱP.M.ȱTheȱSedimentȱQualityȱTriad:ȱthen,ȱnowȱandȱtomorrow.ȱInt.ȱJ.ȱEnviron.ȱ Pollut.13:ȱ351Ȭ356;ȱ2000ȱ Chapman,ȱ P.M.;ȱ McDonald,ȱ B.G.ȱ Usingȱ theȱ sedimentȱ qualityȱ TRIADȱ (SQT)ȱ inȱ ecologicalȱriskȱassessment.ȱIn:ȱSmallȬscaleȱFreshwaterȱToxicityȱInvestigations,ȱC.ȱ BlaiseȱandȱJ.F.ȱFèrardȱ(eds).ȱVolȱ2.ȱ305Ȭ329;ȱ2005ȱ Chapman,ȱ P.M.;ȱ Hollert,ȱ H.ȱ Shouldȱ theȱ sedimentȱ qualityȱ Triadȱ becomeȱ aȱ Tetrad,ȱ aȱ PentadȱorȱpossiblyȱevenȱaȱHexad?.ȱJSSȬȱJȱSoilsȱ&ȱSediments.ȱ6:ȱ4Ȭ8;ȱ2006ȱȱȱȱ Chapman,ȱ P.M.ȱ Determiningȱ whenȱ contaminationȱ isȱ pollutionȱ –ȱ Weightȱ ofȱ evidenceȱ determinationsȱforȱsedimentsȱandȱeffluents.ȱEnvion.ȱInt.ȱ33:ȱ492Ȭ501;ȱ2007ȱ CobeloȬGarcía,ȱA.;ȱLabandeira,ȱA.;ȱPrego,ȱR.ȱTwoȱoppositeȱcasesȱofȱmetalȱaccumulationȱ inȱ riaȱ sediments,ȱ Ferrolȱ andȱ CormeȬLaxeȱ (Galicia,ȱ NWȱ Iberianȱ Peninsula).ȱ Cienc.ȱMar.ȱȱ31:ȱ653Ȭ659;ȱ2004ȱ CobeloȬGarcía,ȱA.;ȱLabandeira,ȱA.;ȱPrego,ȱR.ȱMetalȱdistributionsȱandȱtheirȱfluxesȱatȱtheȱ coastalȱboundaryȱofȱaȱsemiȬenclosedȱria.ȱMar.Chem.ȱ97:ȱ277Ȭ292;ȱ2005.ȱ Comreys,ȱA.L.ȱAȱFirstȱCourseȱinȱFactorȱAnalysisȱAcademic.ȱNewȱYorkȱNYȱUSA;ȱ1973.ȱ DelValls,ȱ T.A.;ȱ Chapman.ȱ SiteȬspecificȱ sedimentȱ qualityȱ valuesȱ forȱ theȱ golfȱ ofȱ Cádizȱ (Spain)ȱ andȱ Sanȱ Franciscoȱ Bayȱ (USA),ȱ usingȱ theȱ sedimentȱ qualityȱ triadȱ andȱ multivariateȱanálisis.ȱCienc.ȱMar.ȱ24:ȱ313Ȭ336;ȱ1998ȱ Fernández,ȱ N.;ȱ César,ȱ A.;ȱ González,ȱ M.;ȱ DelValls,ȱ T.A.ȱ Levelȱ ofȱ contaminationȱ inȱ sedimentsȱ affectedȱ byȱ theȱ Prestigeȱ oilȱ spillȱ andȱ impactȱ onȱ theȱ embryoȱ developmentȱofȱtheȱseaȱurchinȱCienc.ȱMar.ȱ32:ȱ421Ȭ427;ȱ2006ȱ Lee,ȱM.R.;ȱCorrea,ȱJ.A.;ȱSeed,ȱR.ȱAȱsedimentȱqualityȱtriadȱassessmentȱofȱtheȱimpactȱofȱ copperȱ mineȱ tailingsȱ disposalȱ onȱ theȱ littoralȱ sedimentaryȱ environmentȱ inȱ theȱ AtacamaȱregionȱofȱnorthernȱChile.ȱMar.ȱPollut.ȱBull.ȱ52:ȱ1389Ȭ1395;ȱ2006.ȱ - 305 - MoralesȬCaselles,ȱC.;ȱJiménezȬTenorio,ȱN.;ȱGonzálezȱdeȱCanales,ȱM.ȱL.;ȱSarasquete,ȱC.;ȱ DelValls,ȱT.ȱA.ȱEcotoxicityȱofȱsedimentsȱcontaminatedȱbyȱtheȱoilȱspillȱassociatedȱ withȱ theȱ tankerȱ “Prestige”ȱ usingȱ juvenilesȱ ofȱ theȱ fishȱ Sparusȱ aurata.ȱ Arch.ȱ Environ.ȱCon.ȱTox.ȱ51:ȱ652–660;ȱ2006.ȱ MoralesȬCaselles,ȱC.;ȱKalman,ȱJ.;ȱRiba,ȱI.;ȱDelValls,ȱT.A.ȱComparingȱSedimentȱQualityȱ InȱSpanishȱLittoralȱAreasȱAffectedȱByȱAcuteȱ(Prestige,ȱ2002)ȱAndȱChronicȱ(Bayȱ OfȱAlgeciras)ȱOilȱSpillsȱ.ȱEnviron.ȱPollut.ȱ146:ȱ233Ȭ240;ȱ2007.ȱ PérezȬLópez,ȱ M.;ȱ Nóvoa,ȱ M.C.;ȱ Alonso,ȱ J.;ȱ GarcíaȬFernández,ȱ M.A.;ȱ Melgar,ȱ M.J.ȱ Nivelesȱdeȱplomoȱyȱcadmioȱenȱaguaȱmarinaȱyȱlapasȱ(PatellaȱvulgataȱL.)ȱdeȱlaȱRíaȱ deȱVigo.ȱRev.ȱToxicol.ȱ20:ȱ19Ȭ22;ȱ2003.ȱ Prego,ȱ R.;ȱ CobeloȬGarcía,ȱ A.ȱ Twentiethȱ centuryȱ overviewȱ ofȱ heavyȱ metalsȱ inȱ theȱ GalicianȱRiasȱ(NWȱIberianȱPeninsula).ȱEnviron.ȱPollut.ȱ121:ȱ425Ȭ452;ȱ2003.ȱ Prego,ȱR.;ȱCobeloȬGarcía,ȱA.ȱCadmium,ȱcopperȱandȱleadȱcontaminationȱofȱtheȱseawaterȱ columnȱonȱtheȱPrestigeȱshipwreckȱ(NEȱAtlanticȱOcean).ȱAnal.ȱChim.ȱActa.ȱ524:ȱ 23Ȭ26;ȱ2004.ȱȱȱ Riba,ȱ I.;ȱ Zitko,ȱ V.;ȱ Forja,ȱ J.M.;ȱ DelValls,ȱ T.A.ȱ Derivingȱ sedimentȱ qualityȱ guidelinesȱ inȱ theȱ Guadalquivirȱ estuaryȱ associatedȱ withȱ theȱ Aznalcóllarȱ miningȱ spill,ȱ Aȱ comparisonȱofȱdifferentȱapproaches.ȱCienc.ȱMar.ȱ29;ȱ2003.ȱ Riba,ȱI.;ȱForja,ȱJ.M.;ȱGómezȬParra,ȱA.;ȱDelValls,ȱT.A.ȱSedimentȱqualityȱinȱlittoralȱregionsȱ ofȱ theȱ Gulfȱ ofȱ Cádiz:ȱ aȱ triadȱ approachȱ toȱ addressȱ theȱ influenceȱ ofȱ miningȱ activities.ȱEnviron.ȱPollut.ȱ132:ȱ341Ȭ353;ȱ2004.ȱ - 306 - Aȱweightȱofȱevidenceȱapproachȱforȱqualityȱassessmentȱinȱ sedimentsȱimpactedȱbyȱanȱoilȱspill:ȱtheȱroleȱofȱaȱnewȱlineȱofȱ evidenceȱusingȱaȱsetȱofȱbiomarkersȱ CarmenȱMoralesȬCaselles1,2,*,ȱInmaculadaȱRiba1,2,ȱCarmenȱSarasquete1,ȱT.ȱÁngelȱ DelValls1,2ȱ 1 ȱUnidadȱAsociadaȱdeȱCalidadȱAmbientalȱyȱPatologíaȱ(CSICȱ&ȱUCA)ȱinstitutoȱdeȱ CienciasȱMarinasȱdeȱAndalucíaȱ(ICMANȬCSIC),ȱAvda.ȱRepúblicaȱSaharauiȱs/n,ȱPuertoȱ Realȱ11510,ȱCádiz,ȱSpainȱ UNESCOȱUNITWIN/WiCop,ȱFacultadȱdeȱCienciasȱdelȱMarȱyȱAmbientales,ȱ 2ȱ UniversidadȱdeȱCádiz,ȱPolígonoȱRíoȱSanȱPedroȱs/n,ȱPuertoȱRealȱ11510,ȱCádiz,ȱSpain.ȱ Abstractȱ Aȱ setȱ ofȱ biomarkersȱ hasȱ beenȱ chosenȱ andȱ analyzedȱ inȱ targetȱ tissuesȱ ofȱ twoȱ invertebrateȱ speciesȱ afterȱ aȱ 28Ȭdȱ exposureȱ toȱ sedimentsȱ fromȱ theȱ Galicianȱ Coastȱ inȱ anȱ attemptȱ toȱ incorporateȱ aȱ newȱ lineȱ ofȱ evidenceȱ (LOE)ȱ toȱ aȱ classicalȱ weightȱ ofȱ evidenceȱ (WOE),ȱ anȱ approachȱ designedȱ toȱ assessȱ sedimentȱ qualityȱ fourȱ yearsȱ afterȱ theȱ oilȱ spillȱ ofȱ theȱ tankerȱ Prestigeȱ (2002).ȱ ȱ Sublethalȱ bioassaysȱ withȱ crabsȱ andȱ clamsȱ wereȱ carriedȱ outȱ underȱ laboratoryȱ andȱ fieldȱ conditionsȱ andȱ includedȱ theȱ determinationȱ of:ȱ Ethoxyresorufinȱ OȬdeethylaseȱ (EROD)ȱ activityȱ toȱ assessȱ theȱ phaseȱ Iȱ detoxificationȱ system;ȱ glutathioneȬSȬtransferaseȱ (GST)ȱasȱaȱphaseȱIIȱdetoxificationȱenzymeȱbutȱalsoȱimplicatedȱinȱoxidativeȱstressȱ events;ȱglutathioneȱperoxidaseȱ(GPX),ȱglutathioneȱreductaseȱ(GR)ȱandȱtheȱferricȱ reducingȱ abilityȱ ofȱ plasmaȱ (FRAP)ȱ assayȱ wereȱ analyzedȱ toȱ determineȱ theȱ tissuesȇȱ antioxidantȱ activity.ȱ Theȱ integrationȱ ofȱ biomarkersȱ withȱ sedimentsȱ contamination,ȱ acuteȱ toxicityȱ andȱ benthicȱ alterationȱ parametersȱ provideȱ anȱ “earlyȱwarning”ȱtoolȱwhichȱnotȱonlyȱindicatesȱtheȱenvironmentalȱqualityȱofȱanȱ area,ȱ itȱ alsoȱ constitutesȱ anȱ advisoryȱ toolȱ forȱ ȱ potentialȱ ecologicalȱ risks.ȱ Theȱ presentȱ studyȱ demonstratesȱ thatȱ theȱ useȱ ofȱ theȱ setȱ ofȱ biomarkersȱ asȱ partȱ ofȱ aȱ WOEȱ approachȱ designedȱ toȱ assessȱ contaminatedȱ sedimentsȱ contributesȱ addedȱ ȱEnvironmentȱToxicologyȱandȱChemistryȱ(enviado) - 307 - valueȱtoȱtheȱclassicalȱLOEsȱandȱallowsȱcharacterizingȱtheȱenvironmentalȱstatusȱ ofȱtheȱstudiedȱareaȱinȱaȱmoreȱpreciseȱandȱaccurateȱway.ȱ Keywords:ȱȱPAHs,ȱcontamination,ȱtoxicity,ȱsublethal,ȱWOE.ȱ 1.ȱIntroductionȱ Chemicalȱ analysisȱ normallyȱ isȱ theȱ mainȱ toolȱ inȱ sedimentȱ qualityȱ assessmentȱ evenȱ thoughȱ chemicalȱ concentrationsȱ aloneȱ areȱ inadequateȱ forȱ predictionȱofȱbiologicalȱconsequences.ȱTheȱbiologicalȱeffectsȱcanȱbeȱestablishedȱ basedȱonȱlaboratoryȱtestsȱthatȱdetermineȱtoxicȱresponses,ȱasȱwellȱasȱfieldȱdataȱonȱ theȱ communitiesȱ livingȱ inȱ theȱ sedimentsȱ allowȱ toȱ establishȱ whetherȱ thereȱ isȱ observableȱ pollutionȬinducedȱ degradationȱ effectȱ inȱ theȱ biotaȱ [1].ȱ Weightȱ ofȱ evidenceȱ (WOE)ȱ investigationsȱ determinesȱ possibleȱ ecologicalȱ impactsȱ fromȱ chemicalsȱorȱotherȱstressorsȱbasedȱonȱmultipleȱlinesȱofȱevidenceȱ(LOEs)ȱ[2]ȱandȱ haveȱ beenȱ widelyȱ usedȱ inȱ recentȱ yearsȱ toȱ assessȱ sedimentȱ qualityȱ aroundȱ theȱ worldȱ[3,4]ȱincludingȱdifferentȱareasȱinȱtheȱIberianȱPeninsulaȱ[5,6,7,8,9].ȱȱ Sinceȱ theȱ sinkingȱ ofȱ theȱ tankerȱ Prestigeȱ (2002),ȱ whichȱ spiltȱ aboutȱ 63,000ȱ tonnesȱ ofȱ heavyȱ fuelȱ oilȱ (aȱ mixtureȱ ofȱ saturatedȱ hydrocarbons,ȱ aromaticȱ hydrocarbons,ȱresins,ȱandȱasphaltenes,ȱwithȱmostȱofȱtheȱPAHsȱbeingȱofȱmediumȱ toȱ highȱ molecularȱ weight)ȱ andȱ mainlyȱ affectedȱ theȱ Galicianȱ Coast,ȱ severalȱ investigationsȱ haveȱ focusedȱ onȱ determiningȱ theȱ biologicalȱ effectsȱ andȱ environmentalȱ statusȱ afterȱ thisȱ dramaticȱ episodeȱ byȱ followingȱ singleȱ linesȱ ofȱ evidence,ȱ suchȱ asȱ chemicalȱ analysesȱ [10,11,12],ȱ toxicityȱ [13,14,15,16]ȱ orȱ benthicȱ alterationȱ [17,18].ȱ Recently,ȱ authorsȱ presentedȱ aȱ reportȱ [9]ȱ whereȱ aȱ classicalȱ WOEȱ approachȱ basedȱ onȱ threeȱ linesȱ ofȱ evidenceȱ (physicochemicalȱ characterizationȱ ofȱ theȱ sediments,ȱ determinationȱ ofȱ acuteȱ toxicityȱ andȱ benthicȱ alteration)ȱ wasȱ carriedȱ outȱ inȱ theȱ Galicianȱ Coast;ȱ theȱ sedimentȱ qualityȱ ofȱ theȱ areaȱ wasȱ monitoredȱ duringȱ theȱ timeȱ andȱ aȱ generalȱ recoveryȱ ofȱ theȱ - 308 - environmentalȱ healthȱ wasȱ observed.ȱ Howeverȱ thereȱ wereȱ signsȱ thatȱ otherȱ sourcesȱ ofȱ contaminantsȱ apartȱ fromȱ theȱ Prestigeȱ oilȱ spillȱ couldȱ beȱ producingȱ someȱ environmentalȱ stressȱ toȱ theȱ exposedȱ organisms.ȱ Theȱ aimȱ ofȱ theȱ presentȱ studyȱisȱtoȱuseȱaȱnewȱlineȱofȱevidenceȱ(LOE)ȱwithȱtheȱweightȱofȱevidenceȱ(WOE)ȱ approachȱ toȱ improveȱ theȱ sedimentȱ qualityȱ assessmentȱ conductedȱ byȱ previousȱ studiesȱ inȱ theȱ Galicianȱ Coast.ȱ Theȱ linesȱ ofȱ evidenceȱ selectedȱ constituteȱ anȱ improvementȱofȱtheȱclassicalȱWOEȱincludingȱlaboratoryȱandȱfieldȱstudiesȱbasedȱ onȱ biomarkersȱ determinations.ȱ Biomarkersȱ canȱ actȱ asȱ anȱ importantȱ earlyȱ warningȱ systemȱ byȱ tellingȱ whetherȱ environmentalȱ pollutantsȱ areȱ presentȱ atȱ sufficientlyȱ highȱ concentrationsȱ toȱ causeȱ anȱ effectȱ [19].ȱ Chemicalsȱ suchȱ asȱ theȱ PolyciclicȱAromaticȱHydrocarbonsȱ(PAHs)ȱhaveȱveryȱshortȱbiologicalȱhalfȬlivesȱ inȱmostȱspeciesȱbutȱmayȱneverthelessȱhaveȱlongȬtermȱeffectsȱ[19].ȱInȱthisȱsense,ȱ someȱcompoundsȱmightȱnotȱproduceȱacuteȱtoxicȱeffectsȱbutȱsublethalȱeffectsȱcanȱ beȱexpected.ȱTheȱmainȱaimsȱofȱthisȱresearchȱare:ȱ(a)ȱtoȱproveȱtheȱfeasibilityȱandȱ viabilityȱ ofȱ incorporatingȱ newȱ linesȱ ofȱ evidenceȱ toȱ theȱ classicalȱ methodologyȱ employedȱinȱtheȱWOEȱandȱitsȱapplicationȱtoȱassessȱtheȱenvironmentalȱqualityȱofȱ oilȱ contaminatedȱ sedimentsȱ ,ȱ (b)ȱ toȱ monitorȱ theȱ sedimentȱ qualityȱ 4ȱ yearsȱ afterȱ theȱ impactȱ ofȱ anȱ accidentalȱ oilȱ spillȱ byȱ usingȱ aȱ newlyȱ WOEȱ approach,ȱ (c)ȱ toȱ determineȱtheȱextentȱofȱtheȱimpactȱfromȱtheȱspillȱaddressingȱtheȱcontamination,ȱ pollutionȱ andȱ noȱ effectsȱ inȱ theȱ stationsȱselected,ȱincludingȱtheȱidentificationȱofȱ theȱcontaminantsȱresponsibleȱforȱtheȱdamage.ȱȱȱȱ 2.ȱMaterialȱandȱmethodsȱ 2.1.ȱApproachȱ TheȱstudyȱwasȱperformedȱonȱtwoȱareasȱofȱtheȱGalicianȱCoastȱ(NWȱSpain)ȱ importantlyȱaffectedȱbyȱtheȱPrestigeȱoilȱspillȱinȱ2002ȱ(Figureȱ1):ȱCiesȱIslandȱ(A,ȱB,ȱ C)ȱ inȱ theȱ Atlanticȱ Islandȱ Nationalȱ Parkȱ andȱ theȱ Bayȱ ofȱ CormeȬLaxeȱ (D,ȱ E,ȱ F).ȱ - 309 - Ciesȱ Island,ȱ locatedȱ inȱ theȱ Atlanticȱ Islandȱ Nationalȱ Parkȱ actedȱ asȱ aȱ naturalȱ barrierȱprotectingȱtheȱriasȱfromȱtheȱentranceȱofȱtheȱfuel.ȱTheȱBayȱofȱCormeȬLaxeȱ isȱ alsoȱ consideredȱ aȱ placeȱ withȱ highȱ ecologicalȱ relevanceȱ withȱ aȱ lowȱ anthropogenicȱ andȱ industrialȱ influenceȱ withȱ fishingȱ andȱ farmingȱ beingȱ theȱ mainȱeconomicȱactivities.ȱ ȱ ȱ ȱ ƒE ƒF Ría de ƒD Corme-Laxe ȱ ȱ Spain ȱ ȱ •C •A •B ȱ ȱ N Cíes Islands E W S ȱ Figureȱ 1.ȱ Mapȱ ofȱ theȱ coastalȱ areaȱ ofȱ Galiciaȱ (NWȱ Spain)ȱ showingȱ theȱ samplingȱ sitesȱ inȱ theȱ Atlanticȱ Islandȱ Nationalȱ Parkȱ (A,ȱ B,ȱ C)ȱ andȱ theȱ areaȱ ofȱ CormeȬLaxeȱ(D,ȱEȱandȱF).ȱ Theȱ4ȱlinesȱofȱevidenceȱemployedȱinȱtheȱWOEȱapproachȱincluded:ȱȱ (a)ȱ sedimentȱ contamination:ȱ physicochemicalȱ characterizationȱ ofȱ sedimentsȱ byȱ analyzingȱ PAHsȱ (acenaphtalene,ȱ acenaphtylene,ȱ anthracene,ȱ benzo(a)anthracene,ȱ perylene,ȱ benzo(a)pyrene,ȱ benzo(k)fluoranthene,ȱ benzo(b)fluoranthene,ȱ chrysene,ȱ dibenzo(a,h)ȱ benzo(g,h,i)ȱ anthracene,ȱ fenanthrene,ȱfluoranthene,ȱfluorene,ȱindeneȱ(1,2,3,cdȱ)pyrene,ȱnaphthalene,ȱandȱ - 310 - pyrene)ȱ usingȱ GCȬMSȱ withȱ selectedȱ ionȱ monitoringȱ andȱ traceȱ metalsȱ (Zn,ȱ Pb,ȱ Cu,ȱNiȱandȱHg)ȱwithȱanodicȱvoltamperimetryȱ[16];ȱȱ (b)ȱ acuteȱ toxicityȱ andȱ bioaccumulation:ȱ ȱ byȱ performingȱ sedimentȱ bioassaysȱsuchȱasȱtheȱcommercialȱassayȱMicrotox®ȱ[20],ȱtheȱamphipodȱmortalityȱ testȱ withȱ Corophiumȱ volutatorȱ [20],ȱ theȱ ȱ polychaetaȱ mortalityȱ assayȱ [21]ȱ andȱ bioaccumulationȱexperimentȱwithȱArenicolaȱmarinaȱ[22];ȱȱ (c)ȱ‘inȱsituȱalteration’:ȱBenthicȱalterationȱwasȱselectedȱandȱdeterminedȱbyȱ measuringȱ parametersȱ inȱ situȱ basedȱ inȱ taxonomicȱ identificationsȱ andȱ communityȱdescriptiveȱstatisticsȱ(abundanceȬbiomassȱanalysis,ȱspeciesȱrichness,ȱ diversity,ȱdominanceȱandȱproportionsȱofȱtheȱmajorȱtaxonomicȱgroups)ȱ[5];ȱȱ (d)ȱ laboratoryȱ andȱ fieldȱ studiesȱ basedȱ onȱ biomarkersȱ byȱ usingȱ twoȱ invertebrateȱ species,ȱ theȱ crabȱ Carcinusȱ maenasȱ andȱ theȱ clamȱ Ruditapesȱ philippinarum,ȱ andȱ aȱ setȱ ofȱ biomarkersȱ [23,24]:ȱ mixedȱ functionȱ oxygenaseȱ activity,ȱ whichȱ isȱ theȱ firstȱ modeȱ ofȱ detoxificationȱ inȱ manyȱ organicȱ pollutants,ȱ wasȱ measuredȱ usingȱ theȱ adaptedȱ ERODȱ assay;ȱ theȱ phaseȱ IIȱ metabolizingȱ enzymeȱGlutathioneȬSȬtransferaseȱ(GST)ȱactivityȱwasȱdeterminedȱbyȱmonitoringȱ theȱ rateȱ ofȱ conjugationȱ ofȱ glutathioneȱ (GSH)ȱ toȱ 1ȬchloroȬ2,4Ȭdinitrobenzeneȱ (CDNB)ȱ atȱ 340ȱ nm;ȱ theȱ oxidationȱ ofȱ 1ȱ mMȱ NADPHȱ byȱ Glutathioneȱ Reductaseȱ activityȱ(GR)ȱinȱtheȱpresenceȱofȱ10ȱmMȱoxidizedȱglutathioneȱwasȱalsoȱmonitoredȱ atȱ340ȱnm;ȱtheȱantioxidantȱGlutathioneȱPeroxidaseȱactivityȱ(GPX)ȱwasȱanalyzedȱ byȱ determiningȱ theȱ oxidationȱ ofȱ NADPHȱ withȱ theȱ presenceȱ ofȱ 1.25ȱ mMȱ hydrogenȱperoxide;ȱtheȱFRAPȱassay,ȱferricȱreducingȱabilityȱofȱplasma,ȱallowsȱaȱ measureȱ ofȱ theȱ antioxidantȱ capacity;ȱ allȱ theȱ biomarkersȱ responsesȱ wereȱ normalizedȱwithȱtheȱtotalȱproteinȱcontent.ȱ 2.2.ȱDataȱintegrationȱȱ - 311 - Theȱ dataȱ obtainedȱ fromȱ theȱ differentȱ LOEsȱ wereȱ integratedȱ throughȱ aȱ multivariateȱ analysisȱ approachȱ basedȱ onȱ linkingȱ allȱ theȱ variablesȱ obtainedȱ [7]ȱ andȱ aȱ pieȱ chartȱ representationȱ ofȱ comparisonsȱ betweenȱ sitesȱ ofȱ multivariateȱ factorsȱ [7,9].ȱ Theȱ multivariateȱ analysisȱ wasȱ performedȱ usingȱ principalȱ componentȱanalysisȱ(PCA)ȱasȱtheȱextractionȱprocedure,ȱwhichȱisȱaȱmultivariateȱ statisticalȱtechniqueȱtoȱexploreȱvariableȱdistributionsȱ[25].ȱTheȱoriginalȱdataȱsetȱ usedȱ inȱ theȱ analysisȱ includedȱ theȱ variablesȱ obtainedȱ fromȱ theȱ 4ȬLOEsȱ andȱ itsȱ objectiveȱ wasȱ toȱ deriveȱ aȱ reducedȱ numberȱ ofȱ newȱ variablesȱ asȱ linearȱ combinationsȱ ofȱ theȱ originalȱ variables.ȱ Thisȱ providesȱ aȱ descriptionȱ ofȱ theȱ structureȱ ofȱ theȱ dataȱ withȱ theȱ minimumȱ lossȱ ofȱ information.ȱ Forȱ theȱ representationȱ ofȱ theȱ pieȱ charts,ȱ theȱ newȱ factorsȱ obtainedȱ fromȱ theȱ PCAȱ wereȱ submittedȱ toȱ ANOVAȱ andȱ Tukeyȱ testsȱ whichȱ identifiedȱ significantȱ differencesȱ inȱ sensitivityȱ amongȱ stationsȱ andȱ controlsȱ forȱ eachȱ factorȱ [9];ȱ everyȱ studyȱ siteȱ hasȱ aȱ pieȱ chartȱ dividedȱ intoȱ theȱ obtainedȱ factorsȱ whichȱ useȱ differentȱ coloursȱ dependingȱonȱtheȱlevelȱofȱsignificantȱdifferencesȱinȱrelationȱwithȱtheȱreference.ȱ 3.ȱResultsȱandȱdiscussionȱ Tableȱ 1ȱ showsȱ theȱ summarizedȱ resultsȱ ofȱ theȱ differentȱ parametersȱ analyzed.ȱ Inȱ general,ȱ theȱ concentrationȱ ofȱ chemicalsȱ variesȱ amongȱ theȱ stationsȱ fromȱtheȱAINPȱ(A,ȱBȱandȱC)ȱandȱthoseȱfromȱCormeȬLaxeȱ(D,ȱE,ȱandȱF)ȱalthoughȱ noȱgeneralȱpatternȱwasȱobserved,ȱexceptȱforȱHgȱwhichȱwasȱhigherȱinȱallȱCormeȬ Laxeȱ sites.ȱ Stationȱ Aȱ andȱ Fȱ presentedȱ theȱ highestȱ contentsȱ inȱ metals.ȱ Mainly,ȱ acuteȱtoxicityȱandȱPAHsȱbioaccumulationȱwasȱhigherȱinȱorganismsȱexposedȱtoȱ sedimentsȱ fromȱ theȱ Bayȱ ofȱ CormeȬLaxeȱ whereasȱ biomarkersȱ responsesȱ whereȱ alsoȱ higherȱ inȱ theȱ areaȱ ofȱ CormeȬLaxe,ȱ bothȱ underȱ fieldȱ andȱ laboratoryȱ deployments.ȱ Itȱ wasȱ notȱ observedȱ aȱ generalȱ patternȱ inȱ benthicȱ parametersȱ betweenȱtheȱsamplingȱsites.ȱ - 312 - ȱ ȱ ȱ Tableȱ 1.ȱ Summarizedȱ resultsȱ ofȱ chemicalȱ analysisȱ (mgKgȬ1ȱ forȱ metals,ȱ ΐgKgȬ1ȱ forȱ PAHs)ȱ theȱ acuteȱ toxicityȱ testsȱ (Corophiumȱ andȱ Arenicola:ȱ %ȱ mortality;ȱ Microtox:ȱ IC50;ȱ bioaccumulationȱ ofȱ PAHs:ȱ ΐgKgȬ1),ȱ biomarkerȱ responsesȱ underȱ fieldȱ andȱ laboratoryȱ conditionsȱ (glutathioneȱ peroxidaseȱ activityȱ GPX:ȱ nmol/min/mgȱ prot,ȱ glutathioneȱ transferaseȱ GSTȱ activityȱ nmol/min/mgȱprot,ȱglutathioneȱreductaseȱGRȱactivityȱnmol/min/mgȱprot,ȱferricȱ reducingȱ abilityȱ ofȱ plasmaȱ FRAPȱ activityȱ ΐM/mg/minȱ andȱ ERODȱ activityȱ pmol/mg/min)ȱandȱtheȱalterationȱparametersȱforȱsedimentsȱfromȱtheȱAINPȱ(A,ȱ B,ȱC)ȱandȱCormeȬLaxeȱ(D,ȱE,ȱF).ȱn.d.:ȱnotȱdetected;ȱn.a.:ȱnotȱavailable.ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ - 313 - Benthicȱalterationsȱȱ Biomarkersȱ(field)ȱ Biomarkersȱ(laboratory)ȱ Toxicityȱtestsȱ Chemicalȱ analysesȱ ȱȱ ȱȱ Znȱȱ Pbȱ Cuȱ Niȱ Hgȱ PAHȱ Corophiumȱ Arenicolaȱ Microtoxȱ Bioaccumulationȱ PAHȱ GPXȬcrabȬlabȱ GPXȬclamȬlabȱ GRȬcrabȬlabȱ GRȬclamȬlabȱ GSTȬcrabȬlabȱ GSTȬclamȬlabȱ ERODȬcrabȬlabȱ ERODȬclamȬlabȱ FRAPȬcrabȬlabȱ FRAPȬclamȬlabȱ GPXȬcrabȬfieldȱ GPXȬclamȬfieldȱ GRȬcrabȬfieldȱ GRȬclamȬfieldȱ GSTȬcrabȬfieldȱ GSTȬclamȬfieldȱ ERODȬcrabȬfieldȱ ERODȬclamȬfieldȱ FRAPȬcrabȬfieldȱ FRAPȬclamȬfieldȱ Numberȱofȱspeciesȱ specificȱrichnessȱ Diversityȱ Dominanceȱ %ȱMolluscaȱ %ȱPolychaeteȱ %ȱCrustaceaȱ Aȱ 377ȱ 1.5ȱ 5.2ȱ 13.3ȱ 0.7ȱ 108ȱ 23ȱ 28ȱ 5631ȱ Bȱ 91ȱ 0.9ȱ 1.4ȱ 2.4ȱ 0.8ȱ 67ȱ 20ȱ 28ȱ 9422ȱ Cȱ 164ȱ 0.85ȱ 1.4ȱ 4.5ȱ 0.6ȱ n.d.ȱ 17ȱ 22ȱ 1801ȱ Dȱ 25ȱ 3.7ȱ 0.7ȱ 1.7ȱ 2ȱ 38ȱ 10ȱ 39ȱ 3977ȱ Eȱ 19.9ȱ 7.3ȱ 0.43ȱ 1.5ȱ 2.1ȱ 52ȱ 17ȱ 17ȱ 21041ȱ Fȱ 271ȱ 5.9ȱ 4.2ȱ 5.7ȱ 3.4ȱ 323ȱ 20ȱ 17ȱ 4398ȱ 2927ȱ 11.6ȱ 2.1ȱ 1.1ȱ 2.1ȱ 140ȱ 1293ȱ 0.1ȱ 0.3ȱ 3.9ȱ 10.6ȱ 17.8ȱ 10.5ȱ 0.7ȱ 2.9ȱ 1098ȱ 2061ȱ 0.1ȱ 0.2ȱ 2.7ȱ 10.4ȱ 28.5ȱ 5.1ȱ 15.3ȱ 0.50ȱ 15.3ȱ 20.0ȱ 37.0ȱ 2573ȱ 9.7ȱ 2.9ȱ 0.7ȱ 1.6ȱ 218ȱ 839ȱ 0.1ȱ 0.3ȱ 2.1ȱ 7.8ȱ 23.1ȱ 3.6ȱ 1.4ȱ 1.3ȱ 1564ȱ 372ȱ 3.0ȱ 0.1ȱ n.a.ȱ 3.1ȱ 33.9ȱ 5ȱ 28.4ȱ 0.10ȱ 28.4ȱ 21.5ȱ 41.0ȱ 2666ȱ 8.2ȱ 4.5ȱ 0.9ȱ 2.3ȱ 407ȱ 1624ȱ 0.1ȱ 0.4ȱ 2.6ȱ 4.0ȱ 15.9ȱ 4.0ȱ 1.4ȱ 3.8ȱ 690ȱ 1199ȱ 0.0ȱ 0.1ȱ n.a.ȱ 2.6ȱ 42.4ȱ 4.3ȱ 39.1ȱ 0.06ȱ 39.1ȱ 21.7ȱ 39.1ȱ 2616ȱ 19.3ȱ 6.1ȱ 0.9ȱ 3.4ȱ 430ȱ 1199ȱ 0.0ȱ 0.4ȱ 2.9ȱ 13.7ȱ 41.4ȱ 25.5ȱ 9.9ȱ 9.7ȱ 1489ȱ 3366ȱ 8.5ȱ 0.6ȱ 2.4ȱ 23.6ȱ 28.6ȱ 3ȱ 30ȱ 0.15ȱ 30.0ȱ 20.0ȱ 50.0ȱ 3912ȱ 19.5ȱ 3.1ȱ 0.6ȱ 11.7ȱ 684ȱ 910ȱ 0.1ȱ 0.4ȱ 2.9ȱ 12.1ȱ 193.1ȱ 3.2ȱ 9.5ȱ 14.7ȱ 7523ȱ 131ȱ 0.4ȱ 0.1ȱ n.a.ȱ 2.0ȱ 32.1ȱ 3ȱ 40.1ȱ 0.19ȱ 32.4ȱ 20.4ȱ 47.2ȱ 3285ȱ 15.9ȱ 4.2ȱ 1.5ȱ 4.0ȱ 1071ȱ 848ȱ 0.1ȱ 0.2ȱ 1.6ȱ 6.4ȱ 125.7ȱ 7.0ȱ 23.4ȱ 8.0ȱ 6073ȱ 1558ȱ 0.5ȱ 0.1ȱ n.a.ȱ 6.6ȱ 48.2ȱ 2.9ȱ 15.4ȱ 0.20ȱ 15.4ȱ 23.1ȱ 61.5ȱ - 314 - Theȱ multivariateȱ analysisȱ wasȱ usedȱ inȱ theȱ originalȱ dataȱ setȱ byȱ usingȱ replicatesȱ(notȱaverages)ȱinȱorderȱtoȱlinkȱtheȱresultsȱobtainedȱfromȱtheȱdifferentȱ linesȱ ofȱ evidenceȱ investigated.ȱ Theȱ factorȱ analysisȱ revealsȱ thatȱ theȱ originalȱ variablesȱ canȱ beȱ groupedȱ intoȱ threeȱ newȱ factorsȱ whichȱ explainȱ aȱ 79ȱ %ȱ ofȱ theȱ totalȱ varianceȱ (Tableȱ 2).ȱ Theȱ multivariateȱ analysisȱ isȱ aȱ toolȱ thatȱ allowsȱ usȱ toȱ interpretȱ aȱ largeȱ groupȱ ofȱ differentȱ variablesȱ byȱ groupingȱ themȱ usingȱ correlations;ȱ inȱ additionȱ itȱ indicatesȱ theȱ importanceȱ ofȱ eachȱ factorȱ inȱ everyȱ singleȱstudyȱsite.ȱ Tableȱ 2.ȱ Sortedȱ rotatedȱ factorȱ loadingsȱ ofȱ 36ȱ variablesȱ forȱ theȱ threeȱ principalȱ factorsȱ resultingȱ fromȱ theȱ multivariateȱ analysisȱ ofȱ theȱ singleȱ resultsȱ obtainedȱ fromȱ theȱ chemicalȱ analysis,ȱ theȱ acuteȱ toxicityȱ tests,ȱ theȱ suiteȱ ofȱ biomarkersȱandȱtheȱalterationȱparametersȱforȱtheȱstudyȱofȱtheȱsedimentsȱqualityȱ inȱ theȱ Galicianȱ Coast.ȱ Chemicals:ȱ loadingsȱ areȱ relatedȱ toȱ theȱ concentrationȱ ofȱ contaminantsȱinȱsediments;ȱAcuteȱeffects:ȱloadingsȱexplainȱtheȱtoxicityȱdetectedȱ byȱ theȱ acuteȱ assaysȱ andȱ theȱ bioaccumulationȱ ofȱ PAHsȱ inȱ Arenicola.ȱ Sublethalȱ effects:ȱ loadingsȱ areȱ relatedȱ toȱ theȱ inductionȱ ofȱ biomarkers.ȱ Benthicȱ alteration:ȱ loadingsȱ areȱ relatedȱ toȱ alterationȱ ofȱ theȱ biotaȱ (decreaseȱ ofȱ numberȱ ofȱ species,ȱ specificȱ richness,ȱ diversity,ȱ diminuitionȱ inȱ theȱ percentageȱ ofȱ molluscsȱ andȱ crustaceaȱ andȱ increaseȱ onȱ theȱ polychaeteȱ population.ȱ Theȱ groupȱ ofȱ variablesȱ selectedȱ forȱ theȱ interpretationȱ presentedȱ aȱ loadingȱ 0.40ȱ orȱ higherȱ forȱ aȱ goodȱ associationȱbetweenȱanȱoriginalȱvariableȱandȱaȱfactor.ȱ ȱ ȱ ȱ ȱ - 315 - ȱ ȱȱ ȱȱ Benthicȱalterationȱ Sublethalȱeffectsȱ(laboratoryȱ&ȱfield)ȱ Acuteȱ effectsȱ Chemicalsȱ ȱ ȱ Znȱȱ Pbȱȱ Cuȱȱ Niȱȱ Hgȱ PAHȱȱ Corophiumȱ Arenicolaȱȱ Microtoxȱ Bioaccumulationȱ GPXȬcrabȬlabȱ GPXȬclamȬlabȱ GRȬcrabȬlabȱ GRȬclamȬlabȱ GSTȬcrabȬlabȱ GSTȬclamȬlabȱ ERODȬcrabȬlabȱ ERODȬclamȬlabȱ FRAPȬcrabȬlabȱ FRAPȬclamȬlabȱ GPXȬcrabȬfieldȱ GPXȬclamȬfieldȱ GRȬcrabȬfieldȱ GRȬclamȬfieldȱ GSTȬcrabȬfieldȱ GSTȬclamȬfieldȱ ERODȬcrabȬfieldȱ ERODȬclamȬfieldȱ FRAPȬcrabȬfieldȱ FRAPȬclamȬfieldȱ Numberȱofȱspeciesȱ specificȱrichnessȱ Diversityȱ %ȱMoluscaȱ %ȱPolychaetaȱ %ȱCrustaceaȱ Factorȱ1ȱ 35.2ȱ Factorȱ2ȱ 24.5ȱ Factorȱ3ȱ 19.2ȱ ņȱ 0.95ȱ ņȱ ņȱ 0.95ȱ 0.59ȱ ņȱ Ȭ0.41ȱ ņȱ 0.73ȱ 0.48ȱ ņȱ 0.41ȱ 0.65ȱ 0.85ȱ Ȭ0.53ȱ 0.62ȱ ņȱ Ȭ0.46ȱ ņȱ 0.88ȱ ņȱ 0.91ȱ 0.77ȱ 0.89ȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ 0.91ȱ ņȱ ņȱ 0.62ȱ Ȭ0.96ȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ 0.90ȱ ņȱ 0.93ȱ 0.76ȱ ņȱ 0.76ȱ 0.75ȱ ņȱ ņȱ ņȱ ņȱ ņȱ 0.78ȱ 0.49ȱ ņȱ ņȱ ņȱ Ȭ0.89ȱ ņȱ ņȱ ņȱ - 316 - Ȭ0.52ȱ 0.87ȱ ņȱ ņȱ Ȭ0.77ȱ 0.53ȱ ņȱ ņȱ ņȱ ņȱ Ȭ0.78ȱ ņȱ ņȱ 0.64ȱ ņȱ 0.99ȱ ņȱ ņȱ ņȱ 0.75ȱ 0.88ȱ 0.98ȱ 0.76ȱ 0.99ȱ 0.56ȱ ņȱ ņȱ ņȱ Ȭ0.68ȱ ņȱ ņȱ ņȱ Ȭ0.46ȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ 0.97ȱ 0.96ȱ ņȱ ņȱ Factorȱ#1ȱ Theȱ mainȱ factor,ȱ Factorȱ 1,ȱ accountsȱ forȱ aȱ 35.2ȱ %ȱ ofȱ theȱ varianceȱ andȱ showsȱ theȱ relationshipȱ betweenȱ differentȱ variablesȱ relatedȱ withȱ chemicals,ȱ sublethalȱresponses,ȱbioaccumulationȱandȱbenthicȱalteration.ȱTheȱconcentrationȱ ofȱPAHs,ȱPbȱandȱHgȱinȱsedimentȱisȱrelatedȱtoȱtheȱbioaccumulationȱofȱPAHsȱinȱ Arenicolaȱ marinaȱ exposedȱ underȱ laboratoryȱ conditions,ȱ butȱ oppositeȱ toȱ theirȱ mortalityȱinȱtheȱacuteȱassays.ȱAȱsetȱofȱantioxidantȱandȱdetoxificationȱbiomarkersȱ includingȱ GPX,ȱ GR,ȱ GST,ȱ ERODȱ andȱ FRAPȱ activitiesȱ analyzedȱ inȱ crabsȱ underȱ laboratoryȱconditionsȱareȱcorrelatedȱinȱtheȱFactorȱ#1,ȱinȱadditionȱtoȱGRȱandȱGSTȱ activityȱinȱtheȱdigestiveȱglandȱofȱclams.ȱERODȱandȱFRAPȱinȱtheȱfieldȱexposuresȱ wereȱ notȱ correlatedȱ toȱ otherȱ variables.ȱ Theȱ aforementionedȱ contaminantsȱ andȱ theȱtoxicityȱvariablesȱareȱslightlyȱconnectedȱtoȱtheȱbenthicȱalterationȱexplainedȱ byȱ alterationȱ ofȱ theȱ specificȱ richnessȱ andȱ anȱ increaseȱ ofȱ theȱ polychaeteȱ population,ȱ whileȱ aȱ positiveȱ developmentȱ ofȱ crustaceansȱ wasȱ detected.ȱ Theȱ combinationȱ ofȱ thisȱ largeȱ groupȱ ofȱ variablesȱ inȱ Factorȱ #1ȱ isȱ interpretedȱ asȱ aȱ contaminationȱ byȱ PAHsȱ mixedȱ withȱ theȱ metalsȱ Hgȱ andȱ Pbȱ whichȱ areȱ notȱ producingȱ lethalȱ effects,ȱ althoughȱ PAHsȱ bioaccumulationȱ andȱ subȬlethalȱ responsesȱ inȱ organismsȱ areȱ generatedȱ resultingȱ inȱ aȱ slightȱ alterationȱ ofȱ theȱ inȱ situȱ benthicȱ community.ȱ Environmentalȱ alterationsȱ dueȱ toȱ theseȱ contaminantsȱ haveȱbeenȱreportedȱbyȱotherȱauthorsȱ[26].ȱThisȱfactorȱhasȱaȱpositiveȱeffectȱinȱtheȱ stationsȱ Eȱ (1.0)ȱ andȱ Fȱ (1.4)ȱ locatedȱ inȱ CormeȬLaxeȱ (Figureȱ 2).ȱ Theȱ hydrodynamicsȱ ofȱ theȱ Bayȱ ofȱ CormeȬLaxeȱ suggestȱ anȱ accumulationȱ ofȱ contaminantsȱincludingȱfuelȱoilȱfromȱtheȱPrestigeȱ[27,ȱ28]ȱwhatȱcouldȱexplainȱtheȱ sedimentȱcontaminationȱandȱeffectsȱofȱtheȱstudyȱsites.ȱPreviousȱstudiesȱdidȱnotȱ detectȱ theȱ presenceȱ ofȱ Pbȱ andȱ Hgȱ concentrationsȱ inȱ emulsifiedȱ samplesȱ ofȱ theȱ Prestigeȱfuelȱ(withȱ54–59%ȱwater)ȱ[29]ȱalthoughȱtheȱPbȱoriginȱinȱtheȱpollutingȱoilȱ wasȱcorroboratedȱbyȱotherȱauthorsȱ[30].ȱTakingȱthisȱfactorȱintoȱaccountȱseemsȱtoȱ - 317 - describeȱtheȱpollutionȱcausedȱbyȱtheȱremainingȱcontaminantsȱfromȱtheȱfuelȱspillȱ byȱtheȱtankerȱPrestige,ȱasȱwasȱshownȱinȱtheȱpreviousȱstudyȱ[22].ȱ 3 2 1 0 -1 -2 A B Factor 1 C Factor 2 D E F Factor 3 ȱ Figureȱ 2.ȱ Estimatedȱ factorȱ scoresȱ forȱ theȱ threeȱ factorsȱ inȱ eachȱ ofȱ theȱ 6cases.ȱTheȱfactorȱscoreȱquantifyȱtheȱprevalenceȱofȱeachȱfactorȱforȱeveryȱstationȱ andȱisȱusedȱtoȱestablishȱtheȱdefinitionȱofȱeachȱfactor.ȱ Despiteȱ toxicityȱ testsȱ didȱ notȱ demonstrateȱ theȱ acuteȱ effectsȱ ofȱ theseȱ contaminantsȱ(PAHs,ȱPbȱandȱHg),ȱtheȱbioaccumulationȱofȱPAHsȱexperiencedȱbyȱ A.ȱ marinaȱ inȱ theȱ conductedȱ bioassaysȱ demonstrateȱ theȱ bioavailabilityȱ ofȱ theseȱ substances.ȱ Theȱ inductionȱ ofȱ differentȱ biomarkersȱ inȱ theȱ hepathopancreasȱ ofȱ crabsȱandȱinȱtheȱdigestiveȱglandȱofȱclamsȱhaveȱbeenȱrelatedȱtoȱtheȱpresenceȱofȱ theseȱcontaminantsȱwhatȱsuggestsȱthatȱtheȱdeployedȱorganismsȱsufferedȱstressȱ dueȱtoȱtheȱpresenceȱofȱthisȱsubstancesȱinȱtheȱsediments;ȱtheȱcorrelationȱobservedȱ amongȱ theȱ biomarkersȱ andȱ theȱ differentȱ variablesȱ definedȱ byȱ Factorȱ #1ȱ isȱ strongerȱ forȱ thoseȱ enzymeȱ activitiesȱ measuredȱ inȱ organismsȱ exposedȱ underȱ laboratoryȱ conditionsȱ whatȱ implyȱ thatȱ fieldȱ deploymentsȱ resultȱ inȱ lessȱ sensitivity.ȱ Mostȱ likely,ȱ theȱ effectsȱ ofȱ theȱ contaminantsȱ withinȱ sedimentȱ areȱ reducedȱ becauseȱ ofȱ theȱ flushingȱ actionȱ ofȱ theȱ openȱ waterȱ environment.ȱ Inȱ - 318 - addition,ȱ theȱ crabȱ Carcinusȱ maenasȱ hasȱ shownȱ toȱ beȱ moreȱ perceptiveȱ thanȱ theȱ clamȱ Ruditappesȱ philippinarumȱ toȱ assessȱ thisȱ kindȱ ofȱ pollution,ȱ althoughȱ inȱ general,ȱaȱgoodȱcorrelationȱwasȱdetectedȱamongȱtheȱbiomarkersȱinducedȱinȱbothȱ invertebrateȱ species.ȱ Onȱ theȱ otherȱ handȱ someȱ ofȱ theȱ variablesȱ relatedȱ toȱ theȱ benthicȱ alterationȱ presentȱ inȱ Factorȱ #1ȱ corroborateȱ theȱ effectsȱ observedȱ inȱ theȱ sublethalȱexperiments.ȱ Factorȱ#2ȱ Theȱsecondȱfactor,ȱ Factorȱ #2ȱ(24.5ȱ%ȱofȱtheȱvariance)ȱ connectsȱtheȱ setȱofȱ biomarkersȱmeasuredȱunderȱfieldȱconditionsȱ(ERODȱandȱFRAPȱactivityȱinȱcrabsȱ andȱclams,ȱandȱGPXȱandȱGSTȱinȱclams),ȱtheȱmortalityȱofȱArenicolaȱinȱtheȱacuteȱ experiment,ȱnoȱtoxicityȱforȱamphipods,ȱtheȱalterationȱinȱtheȱnumberȱofȱspeciesȱ andȱ theȱ decreaseȱ ofȱ theȱ polychaeteȱ population.ȱ Positiveȱ andȱ negativeȱ correlationsȱ forȱ aȱ fewȱ biomarkersȱ wereȱ alsoȱ detectedȱ underȱ laboratoryȱ conditions,ȱ andȱ noȱ accordanceȱ withȱ theȱ amphipodȱ toxicityȱ testȱ wasȱ observed.ȱ Theȱ relationshipsȱ betweenȱ theȱ biologicalȱ responsesȱ identifiedȱ inȱ Factorȱ #2ȱ areȱ notȱ correlatedȱ withȱ anyȱ ofȱ theȱ chemicalsȱ analyzedȱ whatȱ suggestȱ thatȱ aȱ contaminantȱorȱgroupȱofȱcompoundsȱboundȱorȱnotȱtoȱtheȱsedimentȱwhichȱwereȱ notȱanalyzedȱareȱtheȱcauseȱofȱtheȱbiologicalȱeffects.ȱTakingȱintoȱaccountȱthatȱtheȱ acuteȱ toxicityȱ observedȱ byȱ theȱ Arenicolaȱ andȱ theȱ restȱ ofȱ theȱ bioassaysȱ wasȱ relativelyȱ lowȱ (lessȱ thanȱ 30%ȱ mortalityȱ inȱ mostȱ ofȱ theȱ cases)ȱ [22],ȱ aȱ sourceȱ ofȱ contaminantȱnotȱrelatedȱtoȱsedimentȱisȱtheȱmostȱprobableȱcauseȱofȱtheseȱeffects.ȱ StationȱAȱ(0.1)ȱlocatedȱonȱCiesȱIslandȱandȱmainlyȱtheȱsiteȱDȱ(2.0)ȱinȱtheȱbayȱofȱ CormeȬLaxeȱ presentȱ positiveȱ loadingȱ ofȱ Factorȱ #2ȱ (Figureȱ 2).ȱ Theȱ goodȱ correlationȱ experiencedȱ byȱ theȱ biomarkersȱ measuredȱ inȱ bothȱ crabsȱ andȱ clamsȱ underȱ fieldȱ conditionsȱ suggestȱ thatȱ theseȱ locationsȱ sufferȱ theȱ stressȱ ofȱ nonȬ measuredȱ variable/sȱ whichȱ inȱ theȱ caseȱ ofȱ siteȱ Dȱ couldȱ beȱ relatedȱ toȱ theȱ proximityȱofȱaquacultureȱinfrastructuresȱforȱmusselȱgrowth.ȱOtherȱauthorsȱ[31],ȱ - 319 - haveȱ describedȱ theȱ negativeȱ impactsȱ ofȱ theseȱ raftsȱ forȱ musselȱ aquaculture,ȱ including:ȱ theȱ dischargeȱ ofȱ aȱ largeȱ volumeȱ ofȱ bioȬdepositsȱ containingȱ highȱ concentrationsȱ ofȱ nutrients;ȱ theȱ releaseȱ ofȱ drugsȱ andȱ pesticidesȱ intoȱ theȱ environment;ȱanȱincreaseȱinȱsedimentationȱandȱaccumulationȱofȱorganicȱmatter;ȱ anȱincreaseȱinȱtheȱconcentrationȱofȱnutrientsȱinȱsedimentsȱandȱwatersȱ(mainlyȱNȱ andȱ P).ȱ Negativeȱ effectsȱ onȱ wildȱ populationsȱ ofȱ animalsȱ haveȱ alsoȱ beenȱ reflected,ȱrangingȱfromȱgeneticȱinteractionȱandȱdiseaseȱtransmission,ȱtoȱchangesȱ inȱtheȱcompositionȱofȱtheȱstructureȱofȱbenthicȱfaunaȱdueȱtoȱaȱchangeȱfromȱoxicȱ toȱanoxicȱconditionsȱ[31].ȱ Factorȱ#3ȱ Theȱ thirdȱ factor,ȱ Factorȱ #3ȱ accountsȱ forȱ aȱ 19.2ȱ %ȱ ofȱ theȱ varianceȱ andȱ showsȱ theȱ sedimentsȱ contaminationȱ byȱ theȱ metalsȱ Zn,ȱ Cuȱ andȱ Ni,ȱ andȱ theȱ PAHs;ȱ thisȱ contaminantsȱ areȱ relatedȱ toȱ acuteȱ toxicityȱ determinedȱ byȱ theȱ amphipodsȱassay,ȱwhichȱisȱnotȱsignificantȱ(theȱtoxicityȱdetectedȱwasȱnotȱenoughȱ toȱ considerȱ sedimentȱ samplesȱ asȱ toxicȱ accordingȱ toȱ thisȱ acuteȱ assay:ȱ samplesȱ whereȱ theȱ mortalityȱ rateȱ ofȱ theȱ amphipodsȱ isȱ 20%ȱ higherȱ thanȱ theȱ mortalityȱ recordedȱ inȱ theȱ referenceȱ andȱ showȱ significantlyȱ differentȱ (*pȱ <ȱ 0.05)ȱ resultsȱ comparedȱ toȱ thoseȱ obtainedȱ inȱ theȱ referenceȱ areȱ consideredȱ asȱ toxic)ȱ [22]ȱ andȱ antioxidantȱ responsesȱ underȱ laboratoryȱ assaysȱ withȱ crabsȱ andȱ clamsȱ (GR);ȱ theȱ effectsȱ onȱ theȱ benthicȱ communityȱ areȱ shownȱ asȱ anȱ alterationȱ ofȱ theȱ diversityȱ andȱ percentageȱ ofȱ molluscs.ȱ Theseȱ correlationsȱ suggestȱ theȱ presenceȱ ofȱ someȱ stressȱinȱtheȱenvironmentȱdueȱtoȱaȱsourceȱorȱsourcesȱofȱmetalsȱ(Zn,ȱCuȱandȱNi)ȱ andȱorganicȱcompoundsȱ(PAHs)ȱdifferentȱtoȱtheȱsourceȱexplainedȱbyȱFactorȱ#1.ȱ Inȱthisȱcase,ȱFactorȱ#3ȱpresentsȱaȱpositiveȱeffectȱinȱsitesȱAȱ(1.2)ȱinȱtheȱAINPȱandȱFȱ (1.3)ȱinȱtheȱBayȱofȱCormeȬLaxeȱ(Figureȱ2).ȱPreviousȱstudiesȱinȱtheȱareaȱofȱCormeȬ LaxeȱhaveȱdetectedȱsevereȱcontaminationȱbyȱCuȱinȱtheȱsedimentsȱ[28],ȱhoweverȱ aȱ fuelȱ oilȱ originȱ wasȱ unlikelyȱ andȱ aȱ majorȱ sourceȱ ofȱ Cuȱ relatedȱ toȱ antifoulingȱ - 320 - paintsȱ fromȱ theȱ hullsȱ ofȱ fishingȱ vesselsȱ wasȱ suggestedȱ [32].ȱ Althoughȱ contaminationȱ byȱ Cuȱ andȱ Znȱ wasȱ observedȱ inȱ theȱ uppermostȱ layerȱ inȱ theȱ Prestigeȱ shipwreckȱ areaȱ ofȱ theȱ Northeastȱ Atlanticȱ Oceanȱ [33,ȱ 34],ȱ thisȱ contaminationȱ shouldȱ notȱbeȱrelatedȱtoȱ theȱshipwreck,ȱbecauseȱlevelsȱofȱCuȱinȱ theȱ fuelȱ oilȱ carriedȱ byȱ theȱ Prestigeȱ wereȱ relativelyȱ lowȱ (3.39ȱ mgȱ kgȬ1)ȱ andȱ previousȱstudiesȱhaveȱshownȱthatȱinputsȱfromȱterrestrialȱsourcesȱofȱmetalsȱareȱ probablyȱ higherȱ thanȱ inputsȱ fromȱ theȱ spilledȱ fuelȱ oilȱ [35,ȱ 36].ȱ Someȱ ofȱ theȱ studiedȱ variablesȱ demonstrateȱ theȱ stressȱ ofȱ theseȱ contaminantsȱ andȱ theȱ effectsȱ onȱ theȱ benthicȱ community;ȱ however,ȱ theȱ resultsȱ mostlyȱ pointȱ toȱ chronicȱ contaminationȱ withȱ lowȱ bioavailability,ȱandȱpotentialȱ butȱlargelyȱunconfirmedȱ biologicalȱrisk.ȱInȱthisȱsenseȱpreviousȱstudiesȱ[37]ȱconsideredȱthatȱdespiteȱaȱhighȱ percentageȱ ofȱ theȱ totalȱ contentȱ ofȱ traceȱ metalsȱ inȱ sedimentsȱ fromȱ theȱ Galicianȱ coastȱpresentedȱaȱreactivityȱandȱbioavailabilityȱwereȱveryȱlow,ȱtheȱhighȱdegreeȱ ofȱpyritizationȱfoundȱforȱsomeȱofȱtheȱmostȱtoxicȱtraceȱmetalsȱmayȱfavourȱtheirȱ releaseȱ byȱ oxidationȱ ofȱ theȱ sulphidesȱ thatȱ theyȱ form,ȱ thusȱ makingȱ themȱ bioavailableȱtoȱbenthicȱfauna.ȱ Significantȱdifferencesȱamongȱstationsȱ Fromȱ theȱ resultsȱ obtained,ȱ theȱ authorsȱ consideredȱ stationȱ C,ȱ whichȱ presentedȱanȱabsenceȱofȱPAHsȱcontaminationȱandȱtheȱlowestȱbiologicalȱeffects,ȱ asȱaȱsuitableȱsiteȱtoȱuseȱasȱreferenceȱstation.ȱTakingȱthisȱintoȱaccount,ȱtheȱfactorȱ loadingsȱ obtainedȱ inȱ theȱ MAAȱ wereȱ submittedȱ toȱ ANOVAȱ andȱ Tukeyȱ testȱ inȱ orderȱ toȱ determineȱ theȱ significantȱ differencesȱ betweenȱ theȱ stationsȱ andȱ theȱ referenceȱsiteȱforȱeachȱofȱtheȱthreeȱdisplayedȱfactorsȱtoȱidentifyȱtheȱcauseȱwhichȱ isȱproducingȱ(orȱnot)ȱpollutionȱinȱeveryȱsingleȱstudyȱsiteȱ(Figureȱ3).ȱ - 321 - A Factor 3 B Factor 1 Factor 3 Factor 1 Factor 2 Factor 2 D Factor 3 Factor 1 Factor 2 E Factor 3 F Factor 1 Factor 3 Factor 2 Factor 1 Factor 2 ȱ Figureȱ 3.ȱ Pieȱ chartsȱ whichȱ representȱ theȱ significantȱ differencesȱ ofȱ theȱ factorsȱscoreȱinȱeveryȱstudyȱsiteȱrelatedȱtoȱtheȱreferenceȱsiteȱCȱ(dotted:ȱpȱ<ȱ0.01;ȱ slightlyȱdotted:ȱpȱ<ȱ0.05;ȱnotȱdotted:ȱnoȱsignificantȱdifferences,ȱp>0.05).ȱȱȱ ȱ ȱ ȱ - 322 - Noneȱ ofȱ theȱ sedimentsȱ fromȱ Ciesȱ Islandȱ inȱ theȱ AINPȱ presentedȱ significantȱ differencesȱ inȱ Factorȱ #1ȱ whichȱ meansȱ thatȱ theȱ effectsȱ ofȱ theȱ Prestigeȱ oilȱspillȱareȱnotȱstillȱoccurringȱinȱtheȱarea.ȱHowever,ȱsiteȱAȱpresentsȱsignificantȱ differencesȱ(pȱ<ȱ0.01)ȱwithȱtheȱselectedȱreferenceȱstationȱ(C)ȱrelatedȱtoȱFactorȱ#ȱ2ȱ andȱ#ȱ3ȱwhichȱsuggestsȱtheȱpotentialȱriskȱandȱtheȱenvironmentalȱstressȱcausedȱ byȱnonȬmeasuredȱsubstancesȱcomingȱfromȱotherȱsourcesȱapartȱfromȱtheȱtankerȱ Prestige.ȱ Siteȱ Bȱ presentsȱ significantȱ differencesȱ (pȱ <ȱ 0.05)ȱ withȱ theȱ referenceȱ stationȱ accordingȱ toȱ Factorȱ #3,ȱ whatȱ meansȱ thatȱ theȱ presenceȱ ofȱ someȱ contaminantsȱ inȱ theȱ areaȱ areȱ consideredȱ aȱ potentialȱ risk,ȱ althoughȱ inȱ general,ȱ theȱ sedimentsȱ presentȱ aȱ relativelyȱ goodȱ environmentalȱ quality.ȱ Onȱ theȱ otherȱ hand,ȱsedimentsȱfromȱCormeȬLaxeȱD,ȱEȱandȱFȱshowȱsignificantȱdifferencesȱ(pȱ<ȱ 0.01)ȱ withȱ theȱ referenceȱ stationȱ forȱ Factorȱ #1ȱ meaningȱ theȱ remainingȱ contaminantsȱ fromȱ theȱ Prestigeȱ oilȱ spillȱ areȱ stillȱ producingȱ subȬlethalȱ effectsȱ toȱ theȱbiotaȱofȱtheȱbay.ȱInȱaddition,ȱtheȱsignificantȱdifferencesȱ(pȱ<ȱ0.01)ȱshownȱforȱ Factorȱ#2ȱinȱDȱfocusȱtoȱotherȱunknownȱsourcesȱofȱcontaminantsȱresponsibleȱofȱ biologicalȱ stressȱ inȱ theȱ studyȱ site,ȱ whereasȱ inȱ theȱ caseȱ ofȱ siteȱ Fȱ aȱ mixtureȱ ofȱ metalsȱandȱPAHsȱfromȱdifferentȱsourcesȱcouldȱbeȱconsideredȱaȱpotentialȱriskȱinȱ theȱareaȱasȱitȱisȱshownȱinȱFactorȱ#3ȱ(pȱ<ȱ0.01).ȱ Itȱ isȱ wellȱ knownȱ thatȱ biomarkersȱ haveȱ beenȱ shownȱ toȱ beȱ usefulȱ “earlyȱ warning”ȱ toolsȱ inȱ characterizingȱ theȱ healthȱ statusȱ ofȱ animalsȱ fromȱ impactedȱ areasȱ [38,ȱ 39],ȱ suchȱ asȱ oilȱ affectedȱ placesȱ [40],ȱ whereȱ complexȱ mixturesȱ ofȱ pollutantsȱ areȱ usuallyȱ present.ȱ Inȱ theȱ presentȱ studyȱ itȱ hasȱ beenȱ showȱ howȱ theȱ useȱ ofȱ theȱ setȱ ofȱ biomarkersȱ asȱ partȱ ofȱ aȱ WOEȱ approachȱ designedȱ toȱ assessȱ contaminatedȱsedimentsȱcontributesȱaddedȱvalueȱtoȱtheȱclassicalȱLOEsȱoriginalȱ ideaȱ andȱ allowsȱ forȱ theȱ characterizationȱ ofȱ theȱ environmentalȱ statusȱ ofȱ theȱ studiedȱareaȱinȱaȱmoreȱpreciselyȱandȱaccuratelyȱway.ȱInȱadditionȱtheȱinclusionȱ ofȱ chronicȱ bioassaysȱ withȱ twoȱ invertebrateȱ speciesȱ notȱ onlyȱ underȱ laboratoryȱ - 323 - conditionsȱbutȱalsoȱinȱfieldȱdeploymentsȱfavourȱtoȱelucidateȱdifferentȱsourcesȱofȱ contaminantsȱapartȱfromȱtheȱsedimentsȱpermittingȱaȱmoreȱrealisticȱapproachȱtoȱ theȱoriginalȱsituationȱofȱtheȱecosystem,ȱandȱtheȱpotentialȱecologicalȱrisks.ȱȱ 4.ȱConclusionsȱ Thereȱisȱevidenceȱthatȱ4ȱyearsȱafterȱtheȱimpactȱofȱtheȱPrestigeȱoilȱspillȱtheȱ fuelȱ isȱ notȱ producingȱ acuteȱ toxicȱ effectsȱ onȱ theȱ environmentȱ [9]ȱ butȱ subȬlethalȱ responsesȱ haveȱ beenȱ detectedȱ inȱ theȱ areaȱ ofȱ CormeȬLaxe,ȱ relatedȱ toȱ PAHs,ȱ Pbȱ andȱ Hg;ȱ noȱ effectsȱ ofȱ thisȱ spillȱ wereȱ observedȱ inȱ theȱ studyȱ sitesȱ locatedȱ inȱ theȱ AINPȱ althoughȱ aȱ contaminationȱ byȱ metals,ȱ speciallyȱ Zn,ȱ Cuȱ andȱ Niȱ wasȱ observedȱinȱsomeȱsitesȱonȱCíesȱIsland.ȱTheȱcoastalȱanthropogenicȱinfluenceȱhasȱ madeȱ evidentȱ inȱ bothȱ areasȱ dueȱ toȱ anȱ inputȱ ofȱ aȱ mixtureȱ ofȱ pollutantsȱ thatȱ shouldȱ beȱ consideredȱ aȱ potentialȱ risk.ȱ Inȱ theȱ caseȱ ofȱ CormeȬLaxe,ȱ aȱ possibleȱ impactȱofȱtheȱmusselȱraftsȱwasȱdetected.ȱȱ Theȱ useȱ ofȱ biomarkersȱ hasȱ demonstratedȱ havingȱ higherȱ sensitivityȱ thanȱ acuteȱ toxicityȱ approachesȱ asȱ partȱ ofȱ aȱ moreȱ completeȱ andȱ integratedȱ studyȱ basedȱ onȱ aȱ weightȬofȬevidenceȱ approachȱ [9].ȱ Theȱ presentȱ studyȱ hasȱ demonstratedȱ theȱ feasibilityȱ ofȱ incorporatingȱ aȱ fourthȱ lineȱ ofȱ evidenceȱ toȱ theȱ classicalȱ methodologyȱ employedȱ inȱ theȱ Sedimentȱ Qualityȱ Triadȱ andȱ theȱ aȱ suitabilityȱ ofȱ biomarkersȱ asȱ aȱ toolȱ toȱ assessȱ metallicȱ andȱ petrogenicȱ contaminatedȱ sedimentsȱ asȱ wellȱ asȱ unknownȱ mixturesȱ ofȱ compounds,ȱ byȱ carryingȱ outȱ bioassaysȱ underȱ fieldȱ andȱ laboratoryȱ conditionsȱ whichȱ helpȱ toȱ distinguishȱ possibleȱ sourcesȱ ofȱ pollutantsȱ inȱ theȱ environmentȱ andȱ providesȱ informationȱaboutȱecologicalȱrisks.ȱȱȱ ȱ - 324 - 5.ȱAcknowledgementsȱ Theȱ workȱ describedȱ wasȱ partlyȱ supportedȱ byȱ theȱ projectsȱ VEM2003Ȭ 20563/INTER,ȱ andȱ CTM2005Ȭ07282ȬC03Ȭ01/TECNOȱ financedȱ byȱ theȱ Spanishȱ Educationȱ andȱ Scienceȱ Ministryȱ andȱ byȱ CISȱ fundedȱ byȱ theȱ Ministryȱ ofȱ Environment.ȱ Carmenȱ MoralesȬCasellesȱ thanksȱ theȱ Ministryȱ ofȱ Educationȱ andȱ Scienceȱforȱfundingȱherȱresearchȱfellowshipȱ(FPU).ȱAuthorsȱwouldȱlikeȱtoȱthankȱ theȱmembersȱofȱtheȱCISȱforȱtheirȱsupportȱandȱhelpȱinȱtheȱchemicalȱanalysisȱandȱ theȱ benthicȱ communityȱ information;ȱ specialȱ thanksȱ areȱ givenȱ toȱ Lauraȱ Martín,ȱ Nuriaȱ Fernández,ȱ Augustoȱ César,ȱ Pabloȱ Vidalȱ andȱ Antonioȱ Moreno.ȱ Authorsȱ appreciateȱ theȱ helpȱ ofȱ theȱ reviewersȱ andȱ theȱ supportȱ ofȱ CSLMȱ inȱ theȱ Englishȱ revision.ȱ 6.ȱReferencesȱȱȱȱ [1]ȱ Chapmanȱ PM,ȱ Powerȱ EA,ȱ Dexterȱ RN,ȱ Andersenȱ HB.ȱ 1991.ȱ Evaluationȱ ofȱ effectsȱ associatedȱwithȱanȱoilȱplatform,ȱusingȱtheȱsedimentȱqualityȱtriad.ȱEnvironȱToxicolȱ Chemȱ10:ȱ407–424ȱ [2]ȱ Chapman,ȱ P.M.ȱ 2007.ȱ Determiningȱ whenȱ contaminationȱ isȱ pollutionȱ –ȱ Weightȱ ofȱ evidenceȱdeterminationsȱforȱsedimentsȱandȱeffluents.ȱEnvionȱIntȱ33:ȱ492Ȭ501ȱ [3]ȱ Chapmanȱ PM.ȱ 2000.ȱ Theȱ Sedimentȱ Qualityȱ Triad:ȱ 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Theȱapplicationȱofȱaȱweightȱofȱevidenceȱapproachȱtoȱcompareȱtheȱ qualityȱofȱcoastalȱsedimentsȱaffectedȱbyȱacuteȱ(Prestigeȱ2002)ȱandȱ chronicȱ(BayȱofȱAlgeciras)ȱoilȱspillsȱ CarmenȱMoralesȬCaselles1,2,*,ȱInmaculadaȱRiba1,2,ȱCarmenȱSarasquete1,ȱT.ȱÁngelȱ DelValls1,2ȱ 1 ȱUnidadȱAsociadaȱdeȱCalidadȱAmbientalȱyȱPatologíaȱ(CSICȱ&ȱUCA)ȱinstitutoȱdeȱ CienciasȱMarinasȱdeȱAndalucíaȱ(ICMANȬCSIC),ȱAvda.ȱRepúblicaȱSaharauiȱs/n,ȱPuertoȱ Realȱ11510,ȱCádiz,ȱSpainȱ UNESCOȱUNITWIN/WiCop,ȱFacultadȱdeȱCienciasȱdelȱMarȱyȱAmbientales,ȱ 2ȱ UniversidadȱdeȱCádiz,ȱPolígonoȱRíoȱSanȱPedroȱs/n,ȱPuertoȱRealȱ11510,ȱCádiz,ȱSpain.ȱ Abstractȱ Toȱ evaluateȱ sedimentȱ qualityȱ inȱ differentȱ areasȱ affectedȱ byȱ oilȱ spillsȱ aȱ weightȱ ofȱ evidenceȱ approachȱ wasȱ employedȱ byȱ includingȱ aȱ completeȱ setȱ ofȱ parametersȱ asȱ partȱ ofȱ 4ȱ differentȱ linesȱ ofȱ evidence:ȱ sedimentȱ contamination,ȱ biologicalȱ effectsȱ andȱ bioaccumulationȱ underȱ laboratoryȱ conditions,ȱ toxicityȱ inȱ fieldȱ conditionsȱ andȱ benthicȱ alteration.ȱ Theȱ methodologyȱ wasȱ appliedȱ toȱ sedimentsȱfromȱtheȱBayȱofȱAlgecirasȱ(SȱSpain)ȱchronicallyȱimpactedȱbyȱdifferentȱ oilȱ spills,ȱ andȱ theȱ Galicianȱ Coastȱ (NWȱ Spain)ȱ acutelyȱ impactedȱ byȱ anȱ oilȱ spillȱ (Prestigeȱ 2002).ȱ Resultsȱ obtainedȱ haveȱ elucidatedȱ theȱ sourcesȱ andȱ fatesȱ ofȱ pollutantsȱ andȱ theȱ typeȱ ofȱ riskȱ involvedȱ forȱ theȱ ecosystem.ȱ Itȱ hasȱ beenȱ demonstratedȱ thatȱ theȱ impactȱ associatedȱ withȱ chronicȱ eventȱ ofȱ contaminationȱ byȱoilȱspillsȱareȱsignificantlyȱmoreȱdangerousȱandȱpollutedȱthanȱthoseȱrelatedȱtoȱ acuteȱeffects.ȱInȱtheȱacuteȱeventsȱitȱhasȱbeenȱshownȱthatȱtheȱoriginalȱpollutionȱisȱ recoveredȱ yearsȱ latersȱ whereasȱ theȱ pollutionȱ stillȱ inȱ thoseȱ chronicȱ affectedȱ environments.ȱȱ Keywords:ȱsedimentȱcontamination,ȱsedimentȱtoxicity,ȱSedimentȱQualityȱTriad,ȱ bioaccumulation,ȱsublethal,ȱbenthicȱalteration.ȱ ȱEnvironmentalȱPollutionȱ(aceptadoȱconȱrevisiones) - 331 - Capsule:ȱChronicȱinputsȱdueȱtoȱtheȱcontinuousȱentranceȱofȱcontaminantsȱresultȱ muchȱ moreȱ harmfulȱ inȱ coastalȱ ecosystemsȱ thanȱ majorȱ butȱ preciseȱ environmentalȱ impactsȱ 1.ȱIntroductionȱ Nowadays,ȱhumanȱactivitiesȱinȱcoastalȱareasȱinvolveȱaȱhighȱpressureȱandȱ aȱ sourceȱ ofȱ differentȱ contaminantsȱ toȱ theȱ naturalȱ environmentȱ thatȱ becomesȱ evidentȱinȱtheȱdecreasedȱqualityȱofȱcoastalȱsediments.ȱSedimentsȱactȱasȱaȱtrapȱofȱ contaminantsȱ andȱ mayȱ becomeȱ sufficientlyȱ pollutedȱ toȱ disruptȱ naturalȱ biologicalȱ communitiesȱ (Adamsȱ etȱ al.ȱ 1992;ȱ Tolunȱ etȱ al.ȱ 2001).ȱ Substancesȱ introducedȱintoȱtheȱenvironmentȱmayȱbeȱmoreȱorȱlessȱbioavailableȱtoȱorganismsȱ dependingȱ onȱ theirȱ chemicalȱ form,ȱ modifyingȱ factorsȱ inȱ theȱ environment,ȱ theȱ environmentalȱ compartmentȱ theyȱ occupy,ȱ andȱ theȱ reactionsȱ (behaviouralȱ andȱ physiological)ȱ ofȱ exposedȱ biotaȱ (Chapmanȱ etȱ al.,ȱ 2003;ȱ Chapman,ȱ 2007).ȱ Theȱ biologicalȱ effectsȱ canȱ beȱ establishedȱ basedȱ onȱ laboratoryȱ testsȱ thatȱ determineȱ toxicȱresponses,ȱbesides,ȱfieldȱdataȱonȱtheȱcommunitiesȱlivingȱinȱtheȱsedimentsȱ allowȱ toȱ establishȱ whetherȱ thereȱ isȱ observableȱ pollutionȬinducedȱ degradationȱ effectȱinȱtheȱbiotaȱ(Chapmanȱetȱal.,ȱ1991).ȱ Integratedȱ studiesȱ useȱ differentȱ linesȱ ofȱ evidenceȱ (LOEs)ȱ whichȱ addressȱ differentȱquestionsȱaboutȱtheȱpresenceȱofȱcontaminants,ȱtheirȱbioavailabilityȱandȱ theirȱadverseȱbiologicalȱeffectsȱ(Ribaȱetȱal.,ȱ2004)ȱinȱaȱweightȱofȱevidenceȱ(WOE)ȱ framework.ȱInȱtheȱpresentȱstudyȱaȱWOEȱfollowingȱ4ȬLOEsȱhasȱbeenȱappliedȱtoȱ compareȱtheȱsedimentȱqualityȱofȱtwoȱareasȱofȱtheȱSpanishȱCoastȱaffectedȱbyȱoilȱ spills.ȱ Theȱ Bayȱ ofȱ Algecirasȱ (Sȱ Spain)ȱ hasȱ sufferedȱ aȱ chronicȱ impactȱ lastingȱ severalȱ decades,ȱ causedȱ byȱ theȱ inputȱ ofȱ oilȱ andȱ otherȱ contaminantsȱ fromȱ theȱ variousȱindustriesȱlocatedȱinȱtheȱareaȱandȱfromȱaccidentalȱspillsȱandȱdeliberateȱ dischargesȱ fromȱ commercialȱ shippingȱ activitiesȱ (MoralesȬCasellesȱ etȱ al.,ȱ 2007),ȱ - 332 - whereasȱtheȱGalicianȱCoastȱwasȱimpactedȱbyȱtheȱsinkingȱofȱtheȱtankerȱPrestigeȱ (2002),ȱ whichȱ spiltȱ aboutȱ 63,000ȱ tonnesȱ ofȱ heavyȱ fuelȱ oilȱ (MariñoȬBalsaȱ etȱ al.,ȱ 2003;ȱBlancoȱetȱal.,ȱ2006;ȱFernándezȱetȱal.,ȱ2006).ȱInȱadditionȱaȱthirdȱareaȱlocatedȱ inȱ theȱ Bayȱ ofȱ Cádizȱ (SWȱ Spain)ȱ andȱ widelyȱ characterizedȱ byȱ differentȱ ecotoxicologicalȱstudiesȱwasȱselectedȱasȱtheȱreferenceȱsiteȱ(DelȱVallsȱetȱal.,ȱ1998,ȱ Ribaȱetȱal.,ȱ2004,ȱMartínȬDíazȱetȱal.,ȱ2005;ȱMoralesȬCasellesȱetȱal.,ȱ2007).ȱȱ Theȱ aimȱ ofȱ thisȱ studyȱ are:ȱ (a)ȱ toȱ determineȱ theȱ feasibilityȱ ofȱ usingȱ theȱ selectedȱ parametersȱ asȱ partȱ ofȱ 4ȱ LOEsȱ toȱ assessȱ sedimentsȱ contaminatedȱ byȱ differentȱtypesȱofȱoilȱspills;ȱ(b)ȱtoȱestablishȱtheȱenvironmentalȱdegradationȱinȱtheȱ studiedȱ areas;ȱ andȱ (c)ȱ toȱ elucidateȱ whatȱ isȱ moreȱ harmfulȱ toȱ theȱ environment:ȱ acuteȱorȱchronicȱimpactsȱassociatedȱwithȱoilȱspills.ȱȱ 2.ȱMethodologyȱ 2.1.ȱApproachȱ Fig.ȱ 1ȱ showsȱ theȱ 6ȱ sedimentȱ samplingȱ stationsȱ locatedȱ inȱ theȱ areaȱ ofȱ Galiciaȱ (NWȱ Spain),ȱ threeȱ stationsȱ inȱ theȱ Atlanticȱ Islandsȱ Nationalȱ Parkȱ (A,ȱ Bȱ andȱC)ȱandȱthreeȱstationsȱinȱtheȱ BayȱofȱCormeȬLaxeȱ(D,ȱE,ȱF).ȱBothȱareasȱwereȱ importantlyȱ affectedȱ byȱ theȱ Prestigeȱ oilȱ spillȱ andȱ areȱ consideredȱ ofȱ highȱ ecologicalȱ importance.ȱ Inȱ theȱ Gulfȱ ofȱ Cádizȱ (Sȱ Spain)ȱ threeȱ stationsȱ wereȱ selectedȱ inȱ theȱ areaȱ ofȱ theȱ Bayȱ ofȱ Algecirasȱ (GR3’,ȱ GR4,ȱ P1)ȱ whichȱ isȱ highlyȱ industrializedȱ placeȱ whereȱ itȱ takeȱ placeȱ aȱ largeȱ numberȱ ofȱ petrochemicalȱ activitiesȱthatȱcompriseȱseveralȱaccidentalȱoilȱspills;ȱbesides,ȱaȱreferenceȱsiteȱwasȱ chosenȱinȱaȱcleanȱareaȱinȱtheȱBayȱofȱCádizȱ(CA)ȱ(Ribaȱetȱal.,ȱ2003).ȱȱ ȱ ȱ ȱ - 333 - ȱ ȱ Atlantic Islands National Park ȱ •C ƒF ƒE ƒD ȱ •A •B Corme-Laxe ȱ ȱ Spain ȱ ȱ Bay of Cádiz •GR3 •GR4 •P1 ȱ ȱ •CA Bay of Algeciras N E W S ȱ Figureȱ1.ȱMapȱofȱtheȱcoastalȱareaȱofȱGalicia,ȱtheȱBayȱofȱAlgecirasȱandȱtheȱ BayȱofȱCádizȱshowingȱtheȱgeneralȱareasȱsampledȱandȱlocationsȱofȱtheȱsamplingȱ stations.ȱ A,ȱ Bȱ andȱ Cȱ areȱ theȱ stationsȱ locatedȱ inȱ theȱ Ciesȱ Islandȱ inȱ theȱ Atlanticȱ IslandsȱNationalȱParkȱ(GalicianȱCoast);ȱD,ȱEȱandȱFȱareȱtheȱsitesȱfromȱtheȱBayȱofȱ CormeȬLaxeȱ (Galicianȱ Coast);ȱ GR3,ȱ GR4ȱ andȱ P1ȱ areȱ locatedȱ inȱ theȱ Bayȱ ofȱ AlgecirasȱwhereasȱtheȱreferenceȱstationȱCAȱisȱplacedȱinȱtheȱBayȱofȱCádiz.ȱ ȱ ȱ ȱ - 334 - 2.1.ȱTheȱWOEȱcomponentsȱ Aȱ weightȬofȬevidenceȱ approachȱ (WOE)ȱ wasȱ conductedȱ inȱ theȱ sitesȱ selectedȱthatȱincludesȱ4ȱlinesȱofȱevidenceȱ(LOEs)ȱincorporatingȱtheȱnextȱanalysisȱ (Figureȱ2):ȱȱ ȱ Contamination - PAHs - metals ȱ ȱ Effects in laboratory ȱ Benthic alteration - abundance-biomass analysis, species richness, diversity, dominance, % polychaete, ȱ % crustacean, % molluscs SEDIMENT QUALITY ȱ - Acute: Microtox® (bioluminiscence), Arenicola marina (biaccumulation and mortality), Corophium volutator (mortality). - Chronic: Carcinus maenas and Ruditapes philippinarum (biomarkers: GR, GST, GPX, EROD, FRAP) In situ effects - Carcinus maenas and Ruditapes philipinarum (biomarkers: GR, GST, GPX, EROD, FRAP) ȱ Figureȱ 2.ȱ Summarizedȱ descriptionȱ ofȱ theȱ 4ȱ linesȱ ofȱ evidenceȱ selectedȱ inȱ theȱ weighȱ ofȱ evidenceȱ approachȱ usingȱ theȱ schematicȱ representationȱ modificationȱofȱtheȱclassicalȱtriad.ȱ (a)ȱ sedimentȱ contamination:ȱ includesȱ theȱ concentrationȱ ofȱ totalȱ PAHsȱ (acenaphtalene,ȱ acenaphtylene,ȱ benzo(a)pyrene,ȱ benzo(k)fluoranthene,ȱ anthracene,ȱ benzo(b)fluoranthene,ȱ chrysene,ȱ dibenzo(a,h)ȱ - 335 - benzo(a)anthracene,ȱ benzo(g,h,i)ȱ perylene,ȱ anthracene,ȱ fenanthrene,ȱ fluoranthene,ȱfluorene,ȱindeneȱ(1,2,3,cdȱ)pyrene,ȱnaphthalene,ȱandȱpyrene)ȱandȱ traceȱ metalsȱ (Zn,ȱ Pb,ȱ Cu,ȱ Ni,ȱ Coȱ andȱ V).ȱ Sedimentȱ characterizationȱ byȱ organicȱ carbonȱ andȱ percentageȱ ofȱ finesȱ isȱ alsoȱ includedȱ inȱ thisȱ sectionȱ (methodologiesȱ describedȱinȱMoralesȬCasellesȱetȱal.,ȱ2006);ȱȱ (b)ȱsedimentȱtoxicityȱunderȱlaboratoryȱconditions:ȱincludingȱtheȱbacteriaȱ assayȱ Microtox®ȱ (MoralesȬCasellesȱ etȱ al.,ȱ 2007),ȱ theȱ amphipodȱ mortalityȱ testȱ withȱ Corophiumȱ volutatorȱ (MoralesȬCasellesȱ etȱ al.,ȱ 2007)ȱ andȱ theȱ ȱ polychaetaȱ mortalityȱ andȱ bioaccumulationȱ assayȱ (CasadoȬMartínezȱ etȱ al.,ȱ inȱ press)ȱ withȱ Arenicolaȱmarina;ȱsublethalȱassaysȱwereȱalsoȱconductedȱbasedȱonȱbiomarkersȱbyȱ usingȱtwoȱinvertebrateȱspecies,ȱtheȱcrabȱCarcinusȱmaenasȱandȱtheȱclamȱRuditappesȱ philippinarum,ȱ andȱ aȱ suiteȱ ofȱ biomarkersȱ measuredȱ afterȱ 28ȱ daysȱ ofȱ exposure:ȱ Ethoxyresorufinȱ OȬdeethylaseȱ (EROD),ȱ phaseȱ Iȱ detoxificationȱ enzymeȱ implicatedȱ inȱ monooxygenationȱ reactionsȱ ofȱ dioxinsȱ andȱ PAHs;ȱglutathioneȬSȬ transferaseȱ (GST)ȱ phaseȱ IIȱ detoxificationȱ enzymeȱ butȱ alsoȱ implicatedȱ inȱ oxidativeȱstressȱevents;ȱglutathioneȱperoxidaseȱ(GPX)ȱandȱglutathioneȱreductaseȱ (GR),ȱantioxidantȱenzymesȱ(MartínȬDíazȱetȱal.,ȱ2007);ȱFerricȱreducingȱabilityȱofȱ plasmaȱ (FRAP)ȱ assayȱ asȱ aȱ measureȱ ofȱ antioxidantȱ capacityȱ (Benzieȱ andȱ Strain,ȱ 1996);ȱandȱtheȱvitellogeninȱvariationȱinȱcrabsȱ(MartínȬDíaz,ȱ2004).ȱ (c)ȱ Fieldȱ bioassaysȱ wereȱ carriedȱ outȱ toȱ determineȱ theȱ “inȱ situ”ȱ effects.ȱ Theseȱ toxicityȱ testsȱ wereȱ performedȱ usingȱ fieldȱ deploymentsȱ inȱ cagesȱ ofȱ theȱ crabȱ Carcinusȱ maenasȱ andȱ theȱ clamȱ Ruditappesȱ philippinarum.ȱ Theȱ sameȱ suiteȱ ofȱ biomarkersȱ describedȱ aboveȱ andȱ usedȱ underȱ laboratoryȱ conditionsȱ wasȱ employedȱtoȱdetermineȱsublethalȱeffectsȱinȱtheȱorganismsȱexposedȱduringȱaȱ28Ȭ dȱperiodȱ(MartínȬDíazȱetȱal.,ȱ2007).ȱ (e)ȱ‘inȱsituȱalteration’:ȱBenthicȱalterationȱwasȱselectedȱandȱdeterminedȱbyȱ measuringȱ parametersȱ inȱ situȱ basedȱ inȱ taxonomicȱ identificationsȱ andȱ - 336 - communityȱdescriptiveȱstatisticsȱ(abundanceȬbiomassȱanalysis,ȱspeciesȱrichness,ȱ diversity,ȱdominanceȱandȱproportionsȱofȱtheȱmajorȱtaxonomicȱgroups).ȱ 2.2.ȱDataȱintegrationȱȱ Theȱ integrationȱ ofȱ theȱ dataȱ obtainedȱ fromȱ theȱ 4ȬLOEsȱ wasȱ performedȱ throughȱ aȱ multivariateȱ analysisȱ approachȱ basedȱ onȱ linkingȱ allȱ theȱ variablesȱ obtainedȱ whichȱ determinesȱ theȱ environmentalȱ degradationȱ ofȱ theȱ studiedȱ ecosystemsȱ (Ribaȱ etȱ al.,ȱ 2004)ȱ andȱ (b)ȱ aȱ representationȱ usingȱ pieȱ chartsȱ byȱ anȱ ANOVAȱapproachȱandȱbyȱmeansȱofȱtheȱdeterminationȱofȱdifferentȱfactorsȱ(Ribaȱ etȱ al.,ȱ 2004;ȱ MoralesȬCaselles,ȱ accepted).ȱ Theȱ multivariateȱ analysisȱ wasȱ performedȱ usingȱ principalȱ componentsȱ analysisȱ (PCA)ȱ inȱ orderȱ toȱ deriveȱ aȱ reducedȱnumberȱofȱnewȱvariablesȱ(factors)ȱasȱlinearȱcombinationsȱofȱtheȱoriginalȱ variables.ȱ Thisȱ providesȱ aȱ descriptionȱ ofȱ theȱ structureȱ ofȱ theȱ dataȱ withȱ theȱ minimumȱ lossȱ ofȱ informationȱ (Ribaȱ etȱ al.,ȱ 2003).ȱ Pieȱ chartsȱ wereȱ obtainedȱ byȱ conductingȱanȱANOVAȱandȱTukeyȱtestsȱwhichȱidentifiedȱsignificantȱdifferencesȱ (pȱ <ȱ 0.05;ȱ pȱ <ȱ 0.01)ȱ inȱ sensitivityȱ amongȱ stationsȱ andȱ theȱ referenceȱ stationȱ forȱ eachȱ ofȱ theȱ factorȱ scoresȱ obtainedȱ fromȱ theȱ PCAȱ (MoralesȬCasellesȱ etȱ al.,ȱ accepted).ȱ 3.ȱResultsȱ Tableȱ 1ȱ showsȱ theȱ summarizedȱ resultsȱ ofȱ theȱ differentȱ parametersȱ analyzedȱ inȱ theȱ study.ȱ ȱ Inȱ general,ȱ noȱ organicȱ contaminationȱ wasȱ observedȱ inȱ theȱreferenceȱsiteȱwhereasȱtheȱhighestȱlevelsȱofȱPAHsȱwereȱdetectedȱinȱstationsȱ fromȱ theȱ Bayȱ ofȱ Algeciras.ȱ Theȱ concentrationȱ ofȱ metalsȱ inȱ sedimentsȱ variesȱ amongȱ theȱ sitesȱ andȱ theȱ organicȱ carbonȱ andȱ finesȱ contentsȱ areȱ higherȱ inȱ sedimentsȱ collectedȱ onȱ Algeciras.ȱ Itȱ wasȱ notȱ observedȱ aȱ generalȱ patternȱ inȱ biologicalȱ parametersȱ betweenȱ theȱ samplingȱ sitesȱ exceptȱ forȱ siteȱ GR3ȱ whichȱ - 337 - presentedȱ theȱ highestȱ mortalityȱ inȱ theȱ acuteȱ bioassaysȱ andȱ alsoȱ aȱ remarkableȱ benthicȱ alteration.ȱ Toȱ elucidateȱ theȱ matrixȱ ofȱ dataȱ theȱ PCAȱ wasȱ performedȱ toȱ linkȱ theȱ variablesȱ includedȱ inȱ theȱ 4ȱ LOEsȱ (contamination,ȱ effectsȱ underȱ laboratoryȱ conditions,ȱ inȱ situȱ effectsȱ andȱ benthicȱ alteration)ȱ appliedȱ toȱ determineȱtheȱsedimentȱ qualityȱ ofȱtheȱtwoȱareasȱaffectedȱbyȱoilȱspillsȱweȱhaveȱ obtainedȱfiveȱnewȱfactorsȱthatȱaccountȱforȱallȱtheȱvariablesȱandȱhaveȱaȱdifferentȱ influenceȱforȱeachȱsamplingȱsiteȱ(tableȱ2).ȱTheseȱfactorsȱexplainȱanȱ82.7ȱ%ȱofȱtheȱ varianceȱ inȱ theȱ originalȱ dataȱ set,ȱ andȱ negativeȱ loadingȱ areȱ consideredȱ asȱ importantȱasȱpositiveȱvalues.ȱTheȱpredominantȱfactor,ȱFactorȱ#1,ȱaccountsȱforȱaȱ 34.5ȱ%ȱofȱtheȱvarianceȱandȱshowsȱtheȱrelationshipȱbetweenȱtheȱconcentrationȱofȱ Pb,ȱNiȱandȱPAHsȱinȱsediment,ȱtheȱpercentageȱofȱorganicȱcarbonȱandȱfines,ȱtheȱ lethalȱ toxicityȱ determinedȱ byȱ theȱ amphipodȱ bioassay,ȱ theȱ bioaccumulationȱ ofȱ PAHsȱ inȱ A.ȱ marina,ȱ theȱ inductionȱ ofȱ GPXȱ (crabs),ȱ ERODȱ (crabsȱ andȱ clams),ȱ vitellogeninȱ variationȱ (crab)ȱ andȱ FRAPȱ (clam)ȱ activityȱ underȱ laboratoryȱ conditionsȱ andȱ theȱ inductionȱ ofȱ ERODȱ activityȱ (clams)ȱ afterȱ fieldȱ exposures;ȱ besidesȱ allȱ theȱ variablesȱ relatedȱ withȱ benthicȱ alterationȱ (abundance,ȱ speciesȱ richness,ȱ diversity,ȱ dominanceȱ andȱ proportionsȱ ofȱ molluscs,ȱ polychaeteȱ andȱ crustacean)ȱ areȱ gatheredȱ inȱ Factorȱ #1.ȱ Takingȱ thisȱ intoȱ accountȱ thisȱ factorȱ representsȱenvironmentalȱdegradationȱbyȱPAHs,ȱPbȱandȱNi.ȱ Factorȱ#2ȱ(18.0ȱ%)ȱcombines,ȱwithȱnegativeȱloading,ȱtheȱpresenceȱofȱHgȱinȱ theȱsedimentsȱwithȱaȱsetȱofȱbiomarkersȱ(GPXȱandȱGSTȱactivityȱinȱcrabȱandȱGRȱ inductionȱinȱclamsȱunderȱlaboratoryȱandȱfieldȱconditions,ȱGPX,ȱGRȱandȱGSTȱinȱ crabsȱ afterȱ fieldȱ exposures,ȱ GRȱ andȱ FRAPȱ activityȱ inȱ clamsȱ underȱ laboratoryȱ conditionsȱ andȱ inverseȱ relationȱ withȱ GSTȱ inȱ clamȱ inȱ laboratoryȱ studiesȱ andȱ FRAPȱinȱcrabsȱunderȱfieldȱdeployments)ȱandȱtheȱvariablesȱofȱbenthicȱalterationȱ describedȱbyȱ speciesȱ richnessȱ andȱ percentageȱ ofȱ crustacean.ȱ Thisȱ factorȱ canȱ beȱ explainedȱasȱpollutionȱproducedȱbyȱtheȱpresenceȱofȱHgȱinȱtheȱsediments.ȱ - 338 - Tableȱ 1.ȱ Summarizedȱ resultsȱ ofȱ physicochemicalȱ analysisȱ (mgKgȬ1ȱ forȱ metals,ȱ ΐgKgȬ1ȱ forȱ PAHs,ȱ percentageȱ ofȱ organicȱ carbonȱ –o.c.Ȭȱ andȱ finesȱ inȱ sediment)ȱ theȱ acuteȱ toxicityȱ testsȱ (Corophiumȱ andȱ Arenicola:ȱ %ȱ mortality;ȱ Microtox:ȱIC50;ȱbioaccumulationȱofȱPAHs:ȱΐgKgȬ1),ȱbiomarkerȱresponsesȱunderȱ fieldȱ andȱ laboratoryȱ conditionsȱ (glutathioneȱ peroxidaseȱ activityȱ GPX:ȱ nmol/min/mgȱ prot,ȱ glutathioneȱ transferaseȱ GSTȱ activityȱ nmol/min/mgȱ prot,ȱ glutathioneȱreductaseȱGRȱactivityȱnmol/min/mgȱprot,ȱferricȱreducingȱabilityȱofȱ plasmaȱ FRAPȱ activityȱ ΐM/mg/min,ȱ ERODȱ activityȱ pmol/mg/minȱ andȱ vitellogeninȱ variationȱ ngȱ100mLȬ1)ȱ andȱtheȱalterationȱ parametersȱforȱsedimentsȱ fromȱtheȱGalicianȱCoastȱȬAINPȱ(A,ȱB,ȱC)ȱandȱCormeȬLaxeȱ(D,ȱE,ȱF)ȬȱandȱtheȱGulfȱ ofȱCádizȱ–BayȱofȱAlgecirasȱ(GR3,ȱGR4,ȱP1)ȱandȱtheȱBayȱofȱCádizȱ–CAȬ.ȱn.d.:ȱnotȱ detected;ȱn.a.:ȱnotȱavailable.ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ - 339 - ȱȱ Biomarkersȱ(laboratory)ȱ Toxicityȱtestsȱ Physicochemicalȱanalysesȱ ȱȱ Aȱ Biomarkersȱ(field)ȱ Cȱ Dȱ Eȱ Fȱ GR3ȱ GR4ȱ P1ȱ CAȱ Znȱȱ 377ȱ 91ȱ 164ȱ 25ȱ 19.9ȱ 271ȱ 138ȱ 35.3ȱ 56.7ȱ 21.3ȱ Pbȱ 1.5ȱ 0.9ȱ 0.85ȱ 3.7ȱ 7.3ȱ 5.9ȱ 21.6ȱ 6.21ȱ 12.3ȱ 2.28ȱ Cuȱ 5.2ȱ 1.4ȱ 1.4ȱ 0.7ȱ 0.43ȱ 4.2ȱ 5.01ȱ 3.67ȱ 75.2ȱ 6.98ȱ Niȱ 13.3ȱ 2.4ȱ 4.5ȱ 1.7ȱ 1.5ȱ 5.7ȱ 74.7ȱ 13.1ȱ 13.3ȱ 0.06ȱ Hgȱ 0.7ȱ 0.8ȱ 0.6ȱ 2ȱ 2.1ȱ 3.4ȱ 1.04ȱ 0.25ȱ 0.65ȱ n.d.ȱ PAHȱ 108ȱ 67ȱ n.d.ȱ 38ȱ 52ȱ 323ȱ 2961ȱ 802ȱ 641ȱ n.d.ȱ O.C.ȱ 0.28ȱ 0.26ȱ 0.30ȱ 0.31ȱ 0.37ȱ 0.65ȱ 2.15ȱ 3.19ȱ 3.86ȱ 1.07ȱ Finesȱ 4.32ȱ 2.81ȱ 2.76ȱ 3.79ȱ 5.50ȱ 5.95ȱ 69.35ȱ 59.33ȱ 35.44ȱ 2.5ȱ Corophiumȱ 23ȱ 20ȱ 17ȱ 10ȱ 17ȱ 20ȱ 100ȱ 75ȱ 20ȱ 0ȱ Arenicolaȱ 28ȱ 28ȱ 22ȱ 39ȱ 17ȱ 17ȱ 30ȱ 17ȱ 46ȱ 0ȱ Microtoxȱ 5631ȱ 9422ȱ 1801ȱ 3977ȱ 21041ȱ 4398ȱ 235ȱ 249ȱ 1642ȱ 6013ȱ BioaccumulationȱPAHȱ 2927ȱ 2573ȱ 2666ȱ 2616ȱ 3912ȱ 3285ȱ GPXȬcrabȬlabȱ 11.6ȱ 9.7ȱ 8.2ȱ 19.3ȱ 19.5ȱ 15.9ȱ 18.8ȱ 9.1ȱ 12.4ȱ 6.3ȱ GPXȬclamȬlabȱ 2.1ȱ 2.9ȱ 4.5ȱ 6.1ȱ 3.1ȱ 4.2ȱ 3.8ȱ 2.7ȱ 2.5ȱ 5.1ȱ 5158.9ȱ 4809.1ȱ 4097.0ȱ 2421.0ȱ GRȬcrabȬlabȱ 1.1ȱ 0.7ȱ 0.9ȱ 0.9ȱ 0.6ȱ 1.5ȱ 1.1ȱ 0.5ȱ 1.0ȱ 0.9ȱ GRȬclamȬlabȱ 2.1ȱ 1.6ȱ 2.3ȱ 3.4ȱ 11.7ȱ 4.0ȱ 2.8ȱ 1.4ȱ 1.5ȱ 2.7ȱ GSTȬcrabȬlabȱ 140ȱ 218ȱ 407ȱ 430ȱ 684ȱ 1071ȱ 294.6ȱ 203.2ȱ 377.7ȱ 611.2ȱ GSTȬclamȬlabȱ 1634.5ȱ 1117.7ȱ 1542.1ȱ 1293ȱ 839ȱ 1624ȱ 1199ȱ 910ȱ 848ȱ 901.1ȱ ERODȬcrabȬlabȱ 0.1ȱ 0.1ȱ 0.1ȱ 0.0ȱ 0.1ȱ 0.1ȱ 0.3ȱ 0.3ȱ 0.0ȱ 0.0ȱ ERODȬclamȬlabȱ 0.3ȱ 0.3ȱ 0.4ȱ 0.4ȱ 0.4ȱ 0.2ȱ 1.2ȱ 0.7ȱ 0.8ȱ 0.1ȱ FRAPȬcrabȬlabȱ 3.9ȱ 2.1ȱ 2.6ȱ 2.9ȱ 2.9ȱ 1.6ȱ 2.1ȱ n.a.ȱ 6.1ȱ 1.7ȱ FRAPȬclamȬlabȱ 10.6ȱ 7.8ȱ 4.0ȱ 13.7ȱ 12.1ȱ 6.4ȱ 15.4ȱ 3.6ȱ 8.7ȱ 9.5ȱ VITȬcrabȬlabȱ Benthicȱalterationsȱ Bȱ 0.0936ȱ 0.0380ȱ 0.0879ȱ 0.1130ȱ 0.0889ȱ 0.1440ȱ 0.3074ȱ 0.2332ȱ 0.4301ȱ 0.0755ȱ GPXȬcrabȬfieldȱ 17.8ȱ 23.1ȱ 15.9ȱ 41.4ȱ 193.1ȱ 125.7ȱ 4.8ȱ 6.5ȱ 4.0ȱ GPXȬclamȬfieldȱ 10.5ȱ 3.6ȱ 4.0ȱ 25.5ȱ 3.2ȱ 7.0ȱ 2.9ȱ 2.8ȱ 3.6ȱ 5.1ȱ GRȬcrabȬfieldȱ 0.7ȱ 1.4ȱ 1.4ȱ 9.9ȱ 9.5ȱ 23.4ȱ 0.8ȱ 1.5ȱ 0.5ȱ 0.9ȱ 6.3ȱ GRȬclamȬfieldȱ 2.9ȱ 1.3ȱ 3.8ȱ 9.7ȱ 14.7ȱ 8.0ȱ 1.9ȱ 1.1ȱ 0.8ȱ 2.7ȱ GSTȬcrabȬfieldȱ 1098ȱ 1564ȱ 690ȱ 1489ȱ 7523ȱ 6073ȱ 443.4ȱ 1352.7ȱ 592.7ȱ 611.2ȱ GSTȬclamȬfieldȱ 2061ȱ 372ȱ 1199ȱ 3366ȱ 131ȱ 1558ȱ 997.8ȱ 1031.6ȱ 876.5ȱ 1542.1ȱ ERODȬcrabȬfieldȱ 0.1ȱ 3.0ȱ 0.0ȱ 8.5ȱ 0.4ȱ 0.5ȱ 0.0ȱ 0.0ȱ 0.0ȱ 0.0ȱ ERODȬclamȬfieldȱ 0.2ȱ 0.1ȱ 0.1ȱ 0.6ȱ 0.1ȱ 0.1ȱ 0.3ȱ 0.3ȱ 0.3ȱ 0.1ȱ FRAPȬcrabȬfieldȱ 2.7ȱ n.a.ȱ n.a.ȱ 2.4ȱ n.a.ȱ n.a.ȱ 1.9ȱ 3.5ȱ 4.2ȱ 1.7ȱ FRAPȬclamȬfieldȱ 10.4ȱ 3.1ȱ 2.6ȱ 23.6ȱ 2.0ȱ 6.6ȱ 2.4ȱ 7.7ȱ 4.1ȱ 9.5ȱ VITȬcrabȬfieldȱ 0.0049ȱ 0.0099 0.0879 0.0047 0.0426 0.0098 0.0189ȱ 0.1652ȱ 0.0303 speciesȱNºȱ 28.5ȱ 42.4ȱ 28.6ȱ 32.1ȱ 48.2ȱ 0.67ȱ 4.67ȱ 4.67ȱ 14ȱ 33.9ȱ 0.0721 specificȱrichnessȱ 5.1ȱ 5ȱ 4.3ȱ 3ȱ 3ȱ 2.9ȱ 0ȱ 1.21ȱ 1.25ȱ 2.57ȱ Diversityȱ 15.3ȱ 28.4ȱ 39.1ȱ 30ȱ 40.1ȱ 15.4ȱ 0ȱ 1.29ȱ 1.24ȱ 1.64ȱ Dominanceȱ 0.50ȱ 0.10ȱ 0.06ȱ 0.15ȱ 0.19ȱ 0.20ȱ 0ȱ 0.72ȱ 0.68ȱ 0.66ȱ %ȱMolluscaȱ 15.3ȱ 28.4ȱ 39.1ȱ 30.0ȱ 40.1ȱ 15.4ȱ 0.0ȱ 34.4ȱ 25.4ȱ 78.5ȱ %ȱPolychaeteȱ 20.0ȱ 21.5ȱ 21.7ȱ 20.0ȱ 22.2ȱ 23.1ȱ 100.0ȱ 45.3ȱ 64.4ȱ 12.7ȱ %ȱCrustaceaȱ 37.0ȱ 41.0ȱ 39.1ȱ 50.0ȱ 51.4ȱ 61.5ȱ 0.0ȱ 20.3ȱ 10.2ȱ 8.8ȱ ȱ - 340 - Tableȱ 2.ȱ Sortedȱ rotatedȱ factorȱ loadingsȱ forȱ theȱ fiveȱ principalȱ factorsȱ obtainedȱafterȱ applyingȱ theȱ principalȱcomponentsȱanalysisȱtoȱtheȱ originalȱdataȱ setȱofȱ41ȱparametersȱincludedȱinȱtheȱweightȱofȱevidenceȱapproach.ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ - 341 - ȱȱ Znȱȱ Pbȱȱ Cuȱȱ Niȱȱ Hgȱ PAHȱȱ O.C.ȱ Finesȱ Corophiumȱ Arenicolaȱȱ Microtoxȱ BioaccumulationȱPAHsȱ GPXȬcrabȬlabȱ GPXȬclamȬlabȱ GRȬcrabȬlabȱ GRȬclamȬlabȱ GSTȬcrabȬlabȱ GSTȬclamȬlabȱ ERODȬcrabȬlabȱ ERODȬclamȬlabȱ FRAPȬcrabȬlabȱ FRAPȬclamȬlabȱ VTGȬcrabȬlabȱ GPXȬcrabȬfieldȱ GPXȬclamȬfieldȱ GRȬcrabȬfieldȱ GRȬclamȬfieldȱ GSTȬcrabȬfieldȱ GSTȬclamȬfieldȱ ERODȬcrabȬfieldȱ ERODȬclamȬfieldȱ FRAPȬcrabȬfieldȱ FRAPȬclamȬfieldȱ VTGȬcrabȬfieldȱ speciesȱNºȱ specificȱrichnessȱ Diversityȱ Dominanceȱ %ȱMolluscȱ %ȱPolychaetaȱ %ȱCrustaceaȱ Factor 1 34.5ȱ Factor 2 18.0ȱ Factor 3 14.0ȱ Factor 4 9.0ȱ Factor 5 7.1ȱ ņȱ ņȱ ņȱ ņȱ 0.78ȱ 0.90ȱ ņȱ 0.95ȱ ņȱ 0.98ȱ 0.45ȱ 0.86ȱ 0.92ȱ ņȱ ņȱ 0.83ȱ 0.47ȱ ņȱ ņȱ ņȱ ņȱ ņȱ 0.85ȱ 0.88ȱ ņȱ 0.45ȱ 0.55ȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ 0.30ȱ ņȱ ņȱ ņȱ 0.96ȱ 0.52ȱ 0.93ȱ 0.93ȱ 0.55ȱ 0.89ȱ ņȱ ņȱ ņȱ Ȭ0.81ȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ Ȭ0.46ȱ ņȱ ņȱ Ȭ0.87ȱ Ȭ0.72ȱ 0.50ȱ ņȱ ņȱ ņȱ ņȱ ņȱ Ȭ0.96ȱ ņȱ Ȭ0.76ȱ Ȭ0.88ȱ Ȭ0.94ȱ ņȱ ņȱ ņȱ 0.47ȱ ņȱ ņȱ ņȱ 0.42ȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ Ȭ0.35ȱ ņȱ ņȱ 0.68ȱ Ȭ0.57ȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ Ȭ0.45ȱ ņȱ ņȱ Ȭ0.94ȱ ņȱ ņȱ ņȱ Ȭ0.73ȱ Ȭ0.89ȱ Ȭ0.86ȱ ņȱ Ȭ0.93ȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ 0.35ȱ 0.93ȱ ņȱ ņȱ ņȱ 0.67ȱ ņȱ ņȱ 0.70ȱ Ȭ0.30ȱ ņȱ ņȱ Ȭ0.31ȱ ņȱ ņȱ ņȱ ņȱ ņȱ 0.38ȱ 0.77ȱ ņȱ 0.77ȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ 0.34ȱ 0.65ȱ ņȱ ņȱ ņȱ 0.36ȱ ņȱ ņȱ ņȱ 0.38ȱ ņȱ ņȱ ņȱ 0.43ȱ ņȱ Ȭ0.38ȱ ņȱ ņȱ 0.43ȱ Ȭ0.47ȱ ņȱ ņȱ ņȱ 0.64ȱ ņȱ ņȱ Ȭ0.49ȱ ņȱ ņȱ 0.39ȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ ņȱ Ȭ0.80ȱ ņȱ Ȭ0.54ȱ ņȱ ņȱ 0.70ȱ ņȱ 0.53ȱ 0.60ȱ ņȱ ņȱ Ȭ0.35ȱ - 342 - ȱ Theȱ thirdȱ factor,ȱ Factorȱ #3,ȱ accountsȱ forȱ aȱ 14.0ȱ %ȱ ofȱ theȱ varianceȱ andȱ links,ȱ withȱ negativeȱ loading,ȱ theȱ toxicityȱ detectedȱ byȱ theȱ Arenicolaȱ assay,ȱ withȱ theȱ inductionȱ ofȱ someȱ biomarkersȱ mainlyȱ underȱ fieldȱ conditionsȱ (GPXȱ andȱ FRAPȱ inȱ clamȱ inȱ fieldȱ andȱ laboratoryȱ exposures;ȱ GSTȱ inductionȱ inȱ clamȱ andȱ ERODȱactivityȱinȱclamȱandȱcrabsȱunderȱfieldȱconditions;ȱoppositeȱlinkȱwithȱGPXȱ activityȱ inȱ crabsȱ fromȱ theȱ laboratoryȱ experiments).ȱ Thisȱ factorȱ isȱ relatedȱ toȱ anȱ unknownȱstressorȱwhichȱisȱproducingȱaȱgeneralȱstressȱtoȱtheȱexposedȱorganismsȱ butȱ notȱ aȱ benthicȱ alterationȱ neitherȱ aȱ pollutionȱ norȱ degradationȱ inȱ theȱ benthicȱ environment.ȱ Factorȱ #4ȱ (9.0ȱ %)ȱ isȱ aȱ combinationȱ ofȱ theȱ concentrationȱ ofȱ Pbȱ andȱ Cuȱ inȱ theȱ sediments,ȱ withȱ theȱ percentageȱ ofȱ organicȱ carbon,ȱ toxicityȱ inȱ theȱ Arenicolaȱ toxicityȱtest,ȱinȱsituȱalterationȱofȱtheȱpolychaeteȱpopulationȱandȱtheȱvariationȱofȱ someȱbiomarkersȱ(ERODȱinȱclamsȱandȱFRAPȱinȱcrabsȱunderȱlaboratoryȱanȱfieldȱ conditions,ȱ Vitellogeninȱ variationȱ inȱ crabsȱ andȱ GPXȱ activityȱ inȱ clamsȱ underȱ laboratoryȱ conditions).ȱ Inȱ general,ȱ Factorȱ #4ȱ canȱ beȱ relatedȱ toȱ aȱ contaminationȱ byȱCuȱandȱPbȱthatȱcanȱbeȱconsideredȱaȱpotentialȱriskȱtoȱtheȱenvironmentȱbutȱnotȱ associatedȱwithȱpollution.ȱ Factorȱ #5ȱ representsȱ aȱ 7.1ȱ %ȱ ofȱ theȱ varianceȱ andȱ groupsȱ theȱ metalsȱ Znȱ andȱHgȱboundȱtoȱsedimentȱwithȱtoxicȱresponsesȱinȱtheȱArenicolaȱtoxicityȱtest,ȱtheȱ antioxidantȱ activityȱ determinedȱ byȱ theȱ inductionȱ ofȱ GRȱ andȱ FRAPȱ inȱ crabsȱ inȱ laboratoryȱ exposuresȱ andȱ theȱ alterationȱ ofȱ theȱ molluscȱ population.ȱ Otherȱ variablesȱ presentȱ oppositesȱ behaviourȱ suchȱ asȱ theȱ GSTȱ inȱ clamsȱ andȱ vitellogeninȱ variationȱ inȱ crabs,ȱ specificȱ richnessȱ andȱ theȱ percentageȱ ofȱ crustacean.ȱ Inȱ thisȱ sense,ȱ thisȱ factorȱ couldȱ beȱ explainedȱ asȱ aȱ contaminationȱ byȱ Znȱ andȱ Hgȱ whichȱ isȱ producingȱ someȱ stressȱ inȱ theȱ environmentȱ butȱ notȱ pollution.ȱ Inȱorderȱtoȱestablishȱtheȱmeaningȱofȱeachȱfactorȱinȱtheȱareaȱofȱstudy,ȱtheȱ factorȱscoresȱhaveȱbeenȱrepresentedȱforȱeveryȱsingleȱstationȱ(Figureȱ3).ȱFactorȱ#1ȱȱ - 343 - ȱ 3 2 GR3 Factor 1 Factor 2 1 2 A CA B C GR3 GR4 P1 0 1 D GR4 -1 F 0 D -1 CA A B E P1 F -2 E C -3 2 P1 3 Factor 4 Factor 3 1 B CA E C F A GR3 GR4 P1 2 0 1 -1 D E GR4 0 -2 A -1 -3 D B CA C F GR3 -2 -4 2 Factor 5 A 1 F B GR3 C P1 D 0 E -1 CA -2 GR4 Figureȱ 3.ȱ Estimatedȱ factorȱ scoresȱ forȱ theȱ threeȱ factorsȱ inȱ eachȱ ofȱ theȱ 10ȱ cases.ȱTheȱfactorȱscoresȱquantifyȱtheȱprevalenceȱofȱeachȱfactorȱforȱeveryȱstation.ȱ relatedȱ toȱ theȱ environmentalȱ degradationȱ byȱ PAHs,ȱ Pbȱ andȱ Niȱ presentsȱ aȱ positiveȱ loadingȱmainlyȱinȱ theȱstationȱGR3ȱ(2.7)ȱfollowedȱbyȱtheȱsiteȱGR4ȱ(0.6)ȱ fromȱ theȱ Bayȱ ofȱ Algeciras.ȱ Theȱ secondȱ factorȱ whichȱ explainsȱ withȱ negativeȱ loadingȱ theȱ stressȱ producedȱ byȱ theȱ presenceȱ ofȱ Hgȱ inȱ theȱ sedimentsȱ showsȱ prevalenceȱinȱtheȱstudyȱsitesȱlocatedȱinȱtheȱBayȱofȱCormeȬLaxeȱEȱ(Ȭ2.2)ȱ>ȱFȱ(Ȭ1.4)ȱ >ȱDȱ(Ȭ0.3).ȱTheȱunknownȱstressorȱdescribedȱbyȱFactorȱ#3ȱwithȱnegativeȱloadingȱ hasȱ onlyȱ prevalenceȱ inȱ theȱ stationȱ Dȱ (Ȭ2.8)ȱ fromȱ CormeȬLaxe.ȱ Inȱ theȱ caseȱ ofȱ Factorȱ #4ȱ relatedȱ toȱ aȱ contaminationȱ byȱ Cuȱ thatȱ whichȱ couldȱ beȱ consideredȱ aȱ - 344 - potentialȱrisk,ȱtheȱaffectedȱareȱslightlyȱstationsȱDȱ(0.2)ȱandȱEȱ(0.1)ȱlocatedȱinȱtheȱ areaȱofȱCormeȬLaxeȱandȱmainlyȱstationȱP1ȱ(2.8)ȱlocatedȱinȱtheȱBayȱofȱAlgeciras.ȱ Finally,ȱ theȱ prevalenceȱ ofȱ Factorȱ #5,ȱ whichȱ explainsȱ theȱ stressȱ causedȱ byȱ theȱ contaminationȱbyȱZnȱandȱHg,ȱisȱdetectedȱinȱtheȱstationsȱlocatedȱinȱtheȱAINPȱAȱ (1.3),ȱBȱ(0.6)ȱandȱCȱ(0.2),ȱtheȱsiteȱFȱ(1.1)ȱinȱCormeȬLaxeȱandȱGR3ȱ(0.6)ȱinȱtheȱBayȱ ofȱAlgeciras.ȱȱ Figureȱ 4ȱ showsȱ theȱ significantȱ differencesȱ betweenȱ theȱ stationsȱ andȱ theȱ referenceȱ siteȱ forȱ eachȱ ofȱ theȱ fiveȱ studiedȱ factors.ȱ Significantȱ differencesȱ (pȱ <ȱ 0.01)ȱfromȱtheȱreferenceȱ(CA)ȱwereȱobservedȱforȱFactorȱ#1ȱandȱ#2ȱinȱtheȱstationsȱ fromȱCormeȱLaxeȱ(D,ȱE,ȱF)ȱandȱtheȱBayȱofȱAlgecirasȱ(GR3,ȱGR4ȱandȱP1).ȱFactorȱ #3ȱwasȱsignificantlyȱdifferentȱforȱB,ȱCȱ(pȱ<ȱ0.05)ȱinȱCies,ȱDȱ(pȱ<ȱ0.01),ȱEȱ(pȱ<ȱ0.01)ȱ inȱCormeȬLaxeȱandȱP1ȱ(pȱ<ȱ0.05)ȱinȱAlgeciras.ȱOnȱtheȱotherȱhandȱFactorsȱ#4ȱandȱ #5ȱ resultedȱ toȱ beȱ significantlyȱ differentȱ (pȱ <ȱ 0.01ȱ exceptȱ forȱ F#4ȱ inȱ Cȱ whichȱ presentedȱpȱ<ȱ0.05)ȱtoȱtheȱreferenceȱforȱallȱtheȱstudiedȱstationsȱexceptȱforȱFactorȱ #5ȱ inȱ P1ȱ whichȱ didȱ notȱ presentȱ theseȱ differences.ȱ Accordingȱ toȱ theȱ Clusterȱ analysisȱ (Figureȱ 5)ȱ theȱ stationsȱ wereȱ groupedȱ inȱ aȱ wayȱ similarlyȱ toȱ theirȱ realȱ locationȱinȱfield.ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ - 345 - ȱ ȱ A ȱF 5 B F1 F5 C F1 F5 F1 ȱ F4 F2 F4 F2 F4 F2 ȱ F3 F3 F3 D E F ȱ ȱ ȱ F5 F1 F5 F1 F5 F1 ȱ F4 F2 F4 F2 F4 F2 ȱ F3 F3 GR3 GR4 F3 ȱ F5 F1 F5 ȱ P1 F1 F5 F1 ȱ F4 F2 F4 F2 F4 F2 ȱ F3 F3 F3 ȱ Figureȱ 4.ȱ Pieȱ chartsȱ whichȱ representȱ theȱ significantȱ differencesȱ ofȱ theȱ factorsȱscoreȱinȱeveryȱstudyȱsiteȱrelatedȱtoȱtheȱreferenceȱsiteȱCAȱ(dotted:ȱpȱ<ȱ0.01;ȱ slightlyȱdotted:ȱpȱ<ȱ0.05;ȱnotȱdotted:ȱnoȱsignificantȱdifferences,ȱp>0.05).ȱȱȱ ȱ ȱ - 346 - Tree Diagram for 20 Cases Single Linkage Percent disagreement 1.0 Linkage D istance 0.8 0.6 0.4 0.2 0.0 GR3-2 GR4-2 P1-2 F-2 E-2 D-2 B-2 C-2 A-2 CA-2 GR3-1 GR4-1 P1-1 F-1 E-1 D-1 B-1 C-1 A-1 CA-1 ȱFigureȱ 5.ȱ Treeȱ diagramȱ classificationȱ ofȱ theȱ 10ȱ stationsȱ (inȱ duplicate)ȱ basedȱinȱClusterȱanalysisȱ(CA:ȱreferenceȱstation;ȱA,ȱBȱandȱC:ȱAINP;ȱD,ȱEȱandȱF:ȱ CormeȬLaxe;ȱGR3,ȱGR4ȱandȱP1:ȱBayȱofȱAlgeciras).ȱȱ 4.ȱDiscussionȱ Inȱtheȱpresentȱstudyȱtheȱintegrationȱofȱ4ȱLOEsȱasȱpartȱofȱaȱWOEȱapproachȱ toȱassessȱoilȱcontaminatedȱsedimentsȱisȱproposed.ȱTheȱdifferentȱlinesȱemployedȱ includeȱ aȱ setȱ ofȱ 41ȱ variablesȱ relatedȱ toȱ contamination,ȱ toxicityȱ andȱ bioaccumulationȱunderȱlaboratoryȱconditions,ȱsedimentȱtoxicityȱmeasureȱunderȱ fieldȱ conditionsȱ andȱ benthicȱ alterationȱ analyzingȱ theȱ macrobenthicȱ structureȱ parameters.ȱ Theȱ useȱ ofȱ sublethalȱ bioassaysȱ validatedȱ bothȱ inȱ laboratoryȱ andȱ fieldȱ exposuresȱ byȱ usingȱ biomarkersȱ contributesȱ toȱ aȱ betterȱ understandingȱ ofȱ theȱ toxicȱ processesȱ ofȱ theȱ contaminantsȱ andȱ suppliesȱ theȱ lackȱ ofȱ informationȱ oftenȱ shownȱ byȱ acuteȱ toxicityȱ testsȱ performedȱ alone.ȱ Theȱ applicationȱ ofȱ thisȱ methodologyȱ toȱ sedimentsȱ affectedȱ byȱ oilȱ spillsȱ inȱ differentȱ mannersȱ hasȱ allowedȱdeterminingȱtheȱenvironmentalȱqualityȱofȱtheȱimpactedȱareasȱasȱwellȱasȱ differentiatingȱtheȱmostȱprobableȱcausesȱofȱtheȱenvironmentalȱdegradation.ȱȱȱȱ - 347 - TheȱMultivariateȱanalysesȱhaveȱdemonstratedȱtheȱsuitableȱuseȱofȱtheȱsiteȱ CAȱasȱreferenceȱstation.ȱResultsȱhaveȱshownȱthatȱtheȱGalicianȱCoastȱwhichȱwasȱ affectedȱ byȱ theȱ oilȱ spillȱ fromȱ theȱ tankerȱ Prestigeȱ inȱ 2002ȱ doesȱ notȱ presentȱ anȱ environmentalȱdegradationȱdueȱtoȱhydrocarbonsȱwhenȱcomparingȱwithȱtheȱBayȱ ofȱ Algecirasȱ fourȱ yearsȱ afterȱ theȱ spill;ȱ howeverȱ significantȱ differencesȱ (P<0.01)ȱ wereȱdetectedȱ withȱ theȱ referenceȱstationȱregardingȱ toȱ sedimentsȱpollutionȱ dueȱ toȱfuelȱoilȱinȱtheȱBayȱofȱCormeȬLaxeȱ(MoralesȬCasellesȱetȱalȱsubmitted).ȱOnȱtheȱ otherȱ handȱ theȱ studyȱ sitesȱ locatedȱ inȱ theȱ Ciesȱ Islandȱ inȱ theȱ AINPȱ presentȱ absenceȱ ofȱ pollutionȱ dueȱ toȱ fuelȱ oilȱ stemȱ fromȱ theȱ tankerȱ Prestigeȱ althoughȱ anȱ environmentalȱ riskȱ causedȱ byȱ aȱ metallicȱ contaminationȱ ofȱ Cu,ȱ Znȱ andȱ Hgȱ isȱ presentȱ inȱ theȱ area.ȱ Previousȱ studiesȱ haveȱ demonstrateȱ sourcesȱ ofȱ metalsȱ comingȱ fromȱ anthropogenicȱ sourcesȱ locatedȱ inȱ theȱ areaȱ closedȱ toȱ theȱ AINPȱ (Carballeiraȱ etȱal.,ȱ 1997;ȱPérezȬLópezȱetȱal.,ȱ2003).ȱTheȱBayȱofȱCormeȬLaxeȱalsoȱ presentsȱ environmentalȱ stressȱ dueȱ toȱ Cu,ȱ Znȱ andȱ Hgȱ comingȱ fromȱ anthropogenicȱsourcesȱwhichȱcouldȱincludeȱdifferentȱkindȱofȱspillsȱcomingȱfromȱ landȱ andȱ theȱ maritimeȱ traffic.ȱ Evenȱ thoughȱ noȱ signalsȱ ofȱ alterationȱ ofȱ theȱ benthicȱcommunityȱhaveȱthenȱdetectedȱinȱtheȱarea,ȱaȱnonȱquantifiedȱstressorȱhasȱ beenȱ determinedȱ asȱ potentiallyȱ toxic.ȱ Theȱ stressȱ wasȱ mainlyȱ detectedȱ underȱ fieldȱ exposuresȱ whatȱ suggestsȱ thatȱ theȱ stressorȱ couldȱ cameȱ fromȱ theȱ water;ȱ aȱ possibleȱ causeȱ couldȱbeȱ relatedȱtoȱtheȱpresenceȱofȱ industrialȱculturedȱofȱ cagedȱ musselsȱspeciallyȱclosedȱtoȱstationȱDȱwhichȱimplyȱaȱsourceȱofȱorganicȱmatterȱtoȱ theȱ waterȱ columnȱ providingȱ stressȱ toȱ theȱ organismsȱ exposed.ȱ ȱ Onȱ theȱ otherȱ hand,ȱ theȱ resultsȱ observedȱ inȱ theȱ studyȱ sitesȱ fromȱ theȱ Bayȱ ofȱ Algecirasȱ haveȱ shownȱ anȱ importantȱ environmentalȱ degradationȱ inȱ theȱ Guadarranqueȱ Riverȱ dueȱ toȱ aȱ chronicȱ contaminationȱ byȱ aȱ mixtureȱ ofȱ contaminantsȱ thatȱ includeȱ mainlyȱ Pb,ȱ Niȱ andȱ PAHs,ȱ allȱ ofȱ themȱ representativeȱ ofȱ hydrocarbonȱ contaminationȱ inȱ theȱ ecosystemȱ andȱ previouslyȱ reportedȱ byȱ otherȱ studiesȱ (CSIC,ȱ2003;ȱCSIC,ȱ2005).ȱAcuteȱandȱsublethalȱtoxicologicalȱresponsesȱbesidesȱanȱ importantȱ alterationȱ onȱ theȱ biotaȱ wereȱ associatedȱ withȱ thisȱ kindȱ ofȱ pollution.ȱ Theȱ presenceȱ ofȱ petrochemicalȱ industries,ȱ theȱ highȱ maritimeȱ trafficȱ andȱ theȱ - 348 - bunkeringȱ activitiesȱ areȱ theȱ mainȱ factorsȱ whichȱ involveȱ aȱ threatȱ toȱ theȱ marineȱ ecosystemȱofȱtheȱBayȱofȱAlgecirasȱinȱadditionȱtoȱtheȱhumanȱriskȱrepresentedȱbyȱ theȱcollectionȱofȱgoodsȱforȱconsumeȱinȱtheȱzone.ȱOtherȱcontaminantsȱsuchȱasȱCu,ȱ Znȱ andȱ Hgȱ areȱ producingȱ stressȱ toȱ theȱ biotaȱ inȱ stationsȱ P1ȱ andȱ GR3;ȱ onȱ theȱ contrary,ȱ theȱ siteȱ GR4,ȱ whichȱ isȱ locatedȱ inȱ theȱ mouthȱ ofȱ theȱ river,ȱ doesȱ notȱ presentȱthisȱenvironmentalȱpressureȱbyȱmetalsȱwhatȱsuggestsȱthatȱtheȱpollutionȱ byȱ theseȱ contaminantsȱ mightȱ comeȱ fromȱ directȱ spillsȱ toȱ theȱ riversȱ fromȱ theȱ industriesȱlocatedȱinȱtheȱarea.ȱDespiteȱtheȱtideȱregimeȱofȱtheȱareaȱwhichȱimpliesȱ anȱimportantȱwaterȱrenewal,ȱtheȱdegradationȱofȱtheȱecosystemȱinȱtheȱmouthȱofȱ theȱ Riverȱ Palmonesȱ andȱ Guadarranqueȱ isȱ aȱ fact.ȱ Takingȱ thisȱ intoȱ account,ȱ itȱ isȱ possibleȱ toȱ haveȱ otherȱ typesȱ ofȱ contaminantsȱ inȱ theȱ areaȱ whichȱ mayȱ beȱ contributingȱ toȱ theȱ environmentalȱ impactȱ andȱ notȱ measuredȱ inȱ thisȱ studyȱ (Antón,ȱ2007).ȱTheȱclusterȱanalysisȱhaveȱconfirmedȱtheȱdisparityȱofȱtheȱstationsȱ fromȱtheȱBayȱofȱAlgecirasȱ>ȱCormeȬLaxeȱ>ȱAINPȱ>ȱreferenceȱstation.ȱȱ Regardingȱ toȱ theȱ obtainedȱ results,ȱ theȱ recoveryȱ ofȱ theȱ Galicianȱ coastȱ affectedȱbyȱtheȱPrestigeȱoilȱspillȱisȱsignificantlyȱnotableȱ(MoralesȬCasellesȱetȱal.,ȱ accepted;ȱ MoralesȬCasellesȱ etȱ al.,ȱ submitted)ȱ althoughȱ otherȱ sourcesȱ ofȱ contaminantsȱshouldȱ beȱ takenȱ intoȱconsiderationȱdueȱtoȱtheȱpotentialȱriskȱthatȱ involve.ȱOnȱtheȱotherȱhand,ȱtheȱchronicȱpollutionȱinȱtheȱBayȱofȱAlgecirasȱwhichȱ isȱ notȱ onlyȱ composedȱ byȱ hydrocarbonsȱ spillsȱ butȱ withȱ theȱ existanceȱ ofȱ aȱ complexȱ mixtureȱ ofȱ contaminantsȱ inputs,ȱ isȱ producingȱ aȱ considerableȱ additionallyȱdamageȱ toȱ theȱecosystem.ȱInȱthisȱsense,ȱchronicȱinputsȱdueȱtoȱtheȱ continuousȱ entranceȱ ofȱ contaminantsȱ resultȱ muchȱ moreȱ harmfulȱ inȱ coastalȱ ecosystemsȱ thanȱ majorȱ butȱ preciseȱ environmentalȱ impacts,ȱ asȱ confirmedȱ inȱ previousȱstudiesȱ(Ribaȱetȱal.,ȱ2004).ȱ 5.ȱConclusionsȱ Inȱ theȱ presentȱ studyȱ authorsȱ haveȱ successfullyȱ integratedȱ 4ȱ LOEsȱ inȱ aȱ WOEȱapproachȱtoȱassessȱsedimentsȱaffectedȱbyȱoilȱspillsȱandȱdifferentȱsourcesȱofȱ - 349 - contaminants.ȱTheȱuseȱofȱphysicochemicalȱcharacterization,ȱbiologicalȱresponsesȱ underȱlaboratoryȱandȱfieldȱconditionsȱandȱinȱsituȱalterationȱofȱtheȱbiotaȱasȱpartȱ ofȱaȱWOEȱapproachȱisȱconsideredȱaȱsuitableȱtoolȱtoȱcarryȱoutȱsedimentȱqualityȱ studies.ȱ Thisȱ methodologyȱ basedȱ onȱ theȱ evaluationȱ ofȱ aȱ completeȱ setȱ ofȱ parametersȱ underȱ anȱ integratedȱ frameworkȱ goesȱ furtherȱ thanȱ theȱ classicalȱ studiesȱ byȱ studyingȱ theȱ realȱ statusȱ ofȱ theȱ environmentȱ andȱ includingȱ earlyȱ warningȱ signalsȱ ofȱ risk.ȱ Theȱ combinationȱ ofȱ fieldȱ andȱ laboratoryȱ analysisȱ supposesȱanȱaddedȱvalueȱtoȱtheȱassessmentȱwhereasȱtheȱcompleteȱmethodologyȱ employedȱhasȱelucidatedȱaboutȱtheȱcontaminantsȱsourcesȱandȱfates,ȱinȱadditionȱ toȱtheirȱimplicationȱasȱanȱenvironmentalȱrisk.ȱ Theȱ existenceȱ ofȱ aȱ wideȱ groupȱ ofȱ sourcesȱ inȱ theȱ Bayȱ ofȱ Algecirasȱ includingȱ urbanȱ andȱ industrialȱ activitiesȱ inȱ additionȱ toȱ theȱ maritimeȱ trafficȱ whichȱ involveȱ accidentalȱ spillsȱ makesȱ difficultȱ toȱ elucidateȱ theȱ mainȱ causeȱ ofȱ theȱ environmentalȱ healthȱ decrease.ȱ Resultsȱ obtainedȱ indicateȱ thatȱ theȱ highȱ environmentalȱ degradationȱ presentȱ inȱ theȱ Bayȱ ofȱ Algecirasȱ isȱ mainlyȱ dueȱ toȱ continuousȱoilȱspills.ȱOnȱtheȱotherȱhand,ȱfourȱyearsȱafterȱtheȱPrestigeȱoilȱspill,ȱaȱ generalȱ recoveryȱ ofȱ theȱ sedimentsȱ affectedȱ inȱ Atlanticȱ Islandsȱ Nationalȱ Parkȱ (AINP)ȱandȱanȱimprovementȱinȱtheȱenvironmentalȱqualityȱinȱtheȱBayȱofȱCormeȬ Laxeȱ wasȱ observed.ȱ Otherȱ inputsȱ ofȱ contaminantsȱ notȱ relatedȱ withȱ oilȱ spillsȱ wereȱalsoȱdetectedȱinȱtheseȱareas;ȱatȱtheȱmomentȱtheseȱsourcesȱofȱstressȱareȱnotȱ producingȱdamageȱtoȱtheȱbiotaȱalthoughȱtheyȱconstituteȱanȱenvironmentalȱriskȱ thatȱshouldȱnotȱbeȱignored.ȱȱȱ Toȱ sumȱ up,ȱ theȱ environmentȱ capacityȱ ofȱ recovermentȱ afterȱ aȱ majorȱ oilȱ spillȱ episodeȱ suchȱ asȱ theȱ Prestigeȱ hasȱ beenȱ demonstratedȱ whereasȱ littoralȱ sedimentsȱaffectedȱbyȱlowȱorȱmoderatedȱbutȱcontinuousȱoilȱspillsȱhaveȱresultedȱ toȱ beȱ moreȱ degradated.ȱ Thisȱ conclusionȱ shouldȱ leadȱ toȱ theȱ reflectionȱ onȱ ourȱ perceptionȱandȱmajorȱconcernsȱofȱtheȱenvironmentalȱpollution.ȱȱȱ ȱ - 350 - 6.ȱAcknowledgementsȱ Theȱ workȱ describedȱ wasȱ partlyȱ supportedȱ byȱ theȱ projectsȱ VEM2003Ȭ 20563/INTER,ȱ andȱ CTM2005Ȭ07282ȬC03Ȭ01/TECNOȱ financedȱ byȱ theȱ Spanishȱ Educationȱ andȱ Scienceȱ Ministryȱ andȱ byȱ CISȱ fundedȱ byȱ theȱ Ministryȱ ofȱ Environment.ȱ Carmenȱ MoralesȬCasellesȱ thanksȱ theȱ Ministryȱ ofȱ Educationȱ andȱ Scienceȱ forȱ fundingȱ herȱ researchȱ fellowshipȱ (FPU).ȱ Dr.ȱ Ribaȱ thanksȱ theȱ I3pȱ programȱ forȱ supportingȱ herȱ participationȱ inȱ thisȱ research.ȱ Authorsȱ wouldȱ likeȱ toȱ thankȱ theȱ membersȱ ofȱ theȱ CISȱ forȱ theirȱ supportȱ andȱ helpȱ inȱ theȱ chemicalȱ analysisȱ andȱ theȱ benthicȱ communityȱ information;ȱ specialȱ thanksȱ areȱ givenȱ toȱ Lauraȱ Martín,ȱ Nuriaȱ Fernández,ȱ 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MoralesȬCasellesȱ C,ȱ Ribaȱ I,ȱ Sarasqueteȱ C,ȱ DelVallsȱ TA.ȱ Usingȱ aȱ classicalȱ weightȬofȬ evidenceȱapproachȱforȱ4Ȭyearsȱmonitoringȱofȱtheȱimpactȱofȱanȱaccidentalȱoilȱspillȱ onȱsedimentȱquality.ȱEnvironȱIntȱ(accepted)ȱ MoralesȬCaselles,ȱC.,ȱJiménezȬTenorio,ȱN.,ȱGonzálezȱdeȱCanales,ȱM.ȱL.,ȱSarasquete,ȱC.,ȱ DelValls,ȱ T.ȱ A.ȱ 2006.ȱ Ecotoxicityȱ ofȱ sedimentsȱ contaminatedȱ byȱ theȱ oilȱ spillȱ associatedȱwithȱtheȱtankerȱ“Prestige”ȱusingȱjuvenilesȱofȱtheȱfishȱSparusȱaurata.ȱ Arch.ȱEnviron.ȱCon.ȱTox.ȱ51,ȱ652–660.ȱ MoralesȬCaselles,ȱ C.,ȱ Kalman,ȱ J.,ȱ Riba,ȱ I.,ȱ DelValls,ȱ T.A.ȱ 2007.Comparingȱ Sedimentȱ Qualityȱ Inȱ Spanishȱ Littoralȱ Areasȱ Affectedȱ Byȱ Acuteȱ (Prestige,ȱ 2002)ȱ Andȱ Chronicȱ(BayȱOfȱAlgeciras)ȱOilȱSpillsȱ.ȱEnviron.ȱPollut.ȱ146,ȱ233Ȭ240;ȱȱ PérezȬLópez,ȱM.,ȱNóvoa,ȱM.C.,ȱAlonso,ȱJ.,ȱGarcíaȬFernández,ȱM.A.,ȱMelgar,ȱM.J.ȱ2003.ȱ Nivelesȱdeȱplomoȱyȱcadmioȱenȱaguaȱmarinaȱyȱlapasȱ(PatellaȱvulgataȱL.)ȱdeȱlaȱRíaȱ deȱVigo.ȱRev.ȱToxicol.ȱ20,ȱ19Ȭ22ȱȱ Riba,ȱI.,ȱForja,ȱJ.M.,ȱGómezȬParra,ȱA.,ȱDelValls,ȱT.A.ȱ2004.ȱSedimentȱqualityȱinȱlittoralȱ regionsȱofȱtheȱGulfȱofȱCádiz:ȱaȱtriadȱapproachȱtoȱaddressȱtheȱinfluenceȱofȱminingȱ activities.ȱEnviron.ȱPollut.ȱ132,ȱ341Ȭ353ȱȱ - 353 - Riba,ȱI.;ȱZitko,ȱV.;ȱForja,ȱJ.M.;ȱDelValls,ȱT.A.ȱ2003.ȱDerivingȱsedimentȱqualityȱguidelinesȱ inȱ theȱ Guadalquivirȱ estuaryȱ associatedȱ withȱ theȱ Aznalcóllarȱ miningȱ spill,ȱ Aȱ comparisonȱofȱdifferentȱapproaches.ȱCienc.ȱMar.ȱ29ȱȱ Tolun,ȱ L.G.,ȱ Okay,ȱ O.S.,ȱ Gaines,ȱ A.F.,ȱ Tolay,ȱ M.,ȱ TfrkÅi,ȱ H.,ȱ Kiratli,ȱ N.ȱ 2001.ȱ Theȱ pollutionȱ statusȱ andȱ theȱ toxicityȱ ofȱ surfaceȱ sedimentsȱ inȱ Izmitȱ Bayȱ (Marmaraȱ Sea),ȱTurkey.ȱEnviron.ȱInt.ȱ26,163–168ȱ - 354 - ȱ Capítuloȱ6.ȱ Conclusionesȱ 1)ȱ Seȱ hanȱ determinadoȱ lasȱ concentracionesȱ deȱ metalesȱ yȱ contaminantesȱ orgánicosȱenȱdiferentesȱsedimentosȱdeȱlaȱcostaȱGallegaȱlocalizadosȱenȱelȱParqueȱ Nacionalȱ deȱ lasȱ Islasȱ Atlánticasȱ (islasȱ deȱ Onsȱ yȱ Cies)ȱ yȱ enȱ laȱ Bahíaȱ deȱ CormeȬ Laxeȱ trasȱ elȱ vertidoȱ delȱ petroleroȱ Prestigeȱ yȱ seȱ hanȱ comparadoȱ conȱ nivelesȱ deȱ estosȱ contaminantesȱ enȱ zonasȱ delȱ Golfoȱ deȱ Cádiz.ȱ Laȱ presenciaȱ deȱ nivelesȱ elevadosȱ deȱ PAHsȱ enȱ sedimentosȱ juntoȱ conȱ losȱ nivelesȱ moderadosȱ deȱ metalesȱ enȱalgunasȱdeȱlasȱzonasȱestudiadasȱenȱGalicia,ȱponenȱdeȱevidenciaȱlaȱinfluenciaȱ delȱvertidoȱdeȱpetróleoȱenȱlaȱzona.ȱLosȱnivelesȱdeȱcontaminantesȱenȱlaȱzonaȱdeȱ laȱBahíaȱdeȱAlgecirasȱconfirmanȱsuȱcarácterȱdeȱzonaȱcontaminadaȱenȱvariosȱdeȱ losȱpuntosȱestudiados,ȱtantoȱporȱmetalesȱcomoȱporȱcontaminantesȱorgánicos.ȱLaȱ estaciónȱ seleccionadaȱ enȱ laȱ Bahíaȱ deȱ Cádizȱ haȱ resultadoȱ serȱ adecuadaȱ comoȱ referenciaȱ dadosȱ susȱ bajosȱ nivelesȱ deȱ contaminaciónȱ metálicaȱ yȱ laȱ ausenciaȱ deȱ PAHsȱyȱPCBs.ȱȱȱ 2)ȱ Seȱ haȱ identificadoȱ yȱ cuantificadoȱ elȱ efectoȱ adversoȱ deȱ losȱ contaminantesȱ presentesȱ enȱ elȱ fuelȱ procedenteȱ delȱ petroleroȱ Prestige,ȱ demostrandoȱ queȱ laȱ ȱ Ȭȱ355ȱȬȱ Capítuloȱ6 especieȱAmpeliscaȱbrevicornisȱesȱadecuadaȱparaȱrealizarȱensayosȱdeȱtoxicidadȱaȱlaȱ horaȱ deȱ determinarȱ laȱ toxicidadȱ agudaȱ enȱ sedimentosȱ afectadosȱ porȱ contaminaciónȱdeȱtipoȱorgánicoȱyȱmetálico.ȱ 3)ȱ Seȱ haȱ demostradoȱ laȱ ventajaȱ deȱ utilizarȱ elȱ poliquetoȱ Arenicolaȱ marinaȱ enȱ laȱ caracterizaciónȱdeȱzonasȱafectadasȱporȱvertidosȱdeȱpetróleo,ȱyȱqueȱaȱpesarȱdeȱserȱ unaȱ especieȱ menosȱ sensibleȱ queȱ otrasȱ A.ȱ marinaȱ puedeȱ estarȱ presenteȱ enȱ áreasȱ polucionadasȱ loȱ queȱ permiteȱ realizarȱ estudiosȱ deȱ bioacumulación.ȱ Losȱ PAHȱ procedentesȱdelȱfuelȱdelȱPrestigeȱqueȱmásȱseȱbioacumularonȱfueronȱfluoranteno,ȱ pirenoȱ benzo(fluorantenoȱ yȱ benzo(k)fluorantenoȱ mientrasȱ queȱ fenantrenoȱ yȱ antracenoȱ seȱ acumularonȱ inicialmenteȱ yȱ luegoȱ fueronȱ probablementeȱ metabolizados.ȱ 4)ȱ Aȱ partirȱ deȱ losȱ ensayosȱ deȱ toxicidadȱ seȱ haȱ detectadoȱ unaȱ respuestaȱ agudaȱ moderadaȬbajaȱdebidoȱprincipalmenteȱaȱlosȱPAHsȱoriginadosȱtrasȱelȱvertidoȱenȱ losȱ sedimentosȱ delȱ Parqueȱ Nacionalȱ deȱ lasȱ islasȱ Atlánticas;ȱ porȱ otraȱ parte,ȱ laȱ Bahíaȱ deȱ Algecirasȱ presentóȱ elevadaȱ toxicidadȱ agudaȱ mientrasȱ queȱ noȱ seȱ detectaronȱ efectosȱ adversosȱ enȱ losȱ organismosȱ expuestosȱ aȱ sedimentosȱ procedentesȱdeȱlaȱestaciónȱdeȱreferenciaȱlocalizadaȱenȱlaȱBahíaȱdeȱCádiz.ȱ 5)ȱ Losȱ resultadosȱ obtenidosȱ demuestranȱ queȱ existeȱ unaȱ disminuciónȱ deȱ laȱ toxicidadȱagudaȱenȱlosȱsedimentosȱafectadosȱporȱelȱvertidoȱdelȱpetroleroȱPrestigeȱ enȱ laȱ costaȱ deȱ Galicia;ȱ losȱ sedimentosȱdeȱCormeȬLaxeȱyȱelȱParqueȱNacionalȱdeȱ lasȱ Islasȱ Atlánticasȱ noȱ presentaronȱ toxicidadȱ agudaȱ cuatroȱ añosȱ despuésȱ delȱ vertidoȱ aunqueȱ laȱ presenciaȱ deȱ algunosȱ metalesȱ yȱ PAHsȱ enȱ losȱ sedimentosȱ esȱ consideradaȱ comoȱ unȱ riesgoȱ potencialȱ paraȱ laȱ calidadȱ deȱ losȱ mismos.ȱ Laȱ bioacumulaciónȱdeȱPAHsȱenȱpoliquetosȱexpuestosȱaȱsedimentosȱdeȱCormeȬLaxeȱ indicaȱlaȱposibilidadȱdeȱqueȱseȱdenȱefectosȱsubletalesȱenȱlosȱorganismos.ȱ - 356 - Conclusionesȱ 6)ȱ Conȱ elȱ finȱ deȱ realizarȱ unȱ estudioȱ másȱ completoȱ deȱ laȱ toxicidadȱ deȱ losȱ sedimentosȱ afectadosȱ porȱ vertidosȱ deȱ petróleoȱ seȱ hanȱ diseñadoȱ unaȱ serieȱ deȱ bioensayosȱ conȱ invertebradosȱ yȱ vertebradosȱ marinosȱ queȱ medianteȱ exposicionesȱ subletalesȱ yȱ medidasȱ deȱ diferentesȱ biomarcadoresȱ hanȱ permitidoȱ diferenciarȱ “zonasȱ grises”ȱ enȱ laȱ clasificaciónȱ deȱ toxicidad.ȱ Losȱ resultadosȱ obtenidosȱmuestranȱunaȱclaraȱdiferenciaciónȱentreȱlosȱsedimentosȱrecogidosȱenȱ elȱ Parqueȱ Nacionalȱ deȱ lasȱ Islasȱ Atlánticas,ȱ laȱ Bahíaȱ deȱ CormeȬLaxe.ȱ Enȱ esteȱ sentido,ȱestosȱensayosȱyȱmedidasȱutilizadasȱenȱlosȱmismosȱhanȱdemostradoȱserȱ útilesȱparaȱlaȱclasificaciónȱdeȱlaȱcalidadȱdeȱlosȱsedimentosȱestudiados.ȱ 7)ȱ Seȱ hanȱ determinadoȱ losȱ efectosȱ adversosȱ deȱ losȱ contaminantesȱ enȱ losȱ sedimentosȱexponiendoȱduranteȱ60ȱdíasȱjuvenilesȱdelȱpezȱSparusȱaurataȱaȱéstosȱ medianteȱ laȱ aplicaciónȱ deȱ unȱ bioensayoȱ deȱ toxicidadȱ crónicaȱ yȱ analizandoȱ diferentesȱ biomarcadoresȱ deȱ exposiciónȱ aȱ metalesȱ (Metalotioneinas)ȱ yȱ aȱ contaminantesȱ orgánicosȱ (Actividadȱ EROD)ȱ yȱ biomarcadoresȱ deȱ efectoȱ (histopatologíaȱ enȱ dosȱ tejidos,ȱ branquiasȱ eȱhígado).ȱ Losȱ resultadosȱ despuésȱ deȱ losȱ 60ȱ díasȱ muestranȱ unaȱ correlaciónȱ conȱ losȱ datosȱ deȱ toxicidadȱ agudaȱ yȱ confirmanȱ laȱ presenciaȱ deȱ elevadasȱ concentracionesȱ deȱ PAHsȱ enȱ sedimentosȱ comoȱlaȱcausaȱdeȱlosȱefectosȱanalizadosȱtrasȱelȱvertidoȱenȱestacionesȱdelȱParqueȱ NacionalȱdeȱlasȱIslasȱAtlánticasȱ 8)ȱ Seȱ haȱ caracterizadoȱ laȱ relaciónȱ deȱ losȱ biomarcadoresȱ deȱ exposiciónȱ aȱ contaminantesȱorgánicosȱ(ActividadȱEROD)ȱyȱlaȱdeȱlosȱbiomarcadoresȱdeȱefectoȱ (histopatología)ȱ aȱ loȱ largoȱ delȱ tiempoȱ medianteȱ laȱ aplicaciónȱ deȱ unȱ modeloȱ cinético.ȱLaȱinducciónȱdeȱlaȱactividadȱERODȱaȱloȱlargoȱdelȱtiempoȱesȱmayorȱenȱ lasȱestacionesȱconȱmayorȱconcentraciónȱdeȱPAHs.ȱElȱmodeloȱprediceȱlaȱrelaciónȱ entreȱ laȱ inducciónȱ deȱ laȱ actividadȱ ERODȱ comoȱ elȱ primerȱ sistemaȱ deȱ defensaȱ enzimáticoȱfrenteȱaȱlaȱpresenciaȱdeȱéstosȱcontaminantesȱyȱademásȱdeterminaȱsuȱ eficienciaȱ frenteȱ aȱ laȱ apariciónȱ delȱ dañoȱ histopatológicoȱ provocandoȱ suȱ Ȭ 357ȱȬ Capítuloȱ6 inducciónȱ unȱ retrasoȱ enȱ laȱ apariciónȱ delȱ daño.ȱ Laȱ apariciónȱ deȱ estosȱ dañosȱ histológicosȱ esȱ másȱ severaȱ unaȱ vezȱ queȱ laȱ inducciónȱ deȱ actividadȱ ERODȱ seȱ estabilizaȱ oȱ disminuyeȱ enȱ lasȱ tresȱ estacionesȱ delȱ Parqueȱ deȱ lasȱ Islasȱ Atlánticasȱ utilizadasȱenȱesteȱestudio.ȱ 9)ȱ Seȱ haȱ demostradoȱ comoȱ losȱ biomarcadoresȱ medidosȱ enȱ laȱ almejaȱ Ruditapesȱ philippinarumȱ yȱ elȱ cangrejoȱ Carcinusȱ maenasȱ seȱ activanȱ enȱ funciónȱ delȱ tipoȱ yȱ elȱ nivelȱdeȱcontaminaciónȱenȱlosȱsedimentos,ȱpermitiendoȱestablecerȱdiferenciasȱenȱ funciónȱdelȱorigenȱyȱfuenteȱdeȱlosȱcontaminantes.ȱȱ 10)ȱ Trasȱ variosȱ añosȱ despuésȱ delȱ vertidoȱ delȱ petroleroȱ Prestigeȱ losȱ sedimentosȱ delȱParqueȱNacionalȱdeȱlasȱIslasȱAtlánticasȱpresentaronȱlosȱnivelesȱmásȱbajosȱdeȱ respuestaȱ subletal,ȱ mostrandoȱ unaȱ recuperaciónȱ deȱ laȱ zonaȱ trasȱ elȱ vertido;ȱ sinȱ embargo,ȱlaȱpresenciaȱdeȱalgunosȱmetalesȱligadosȱalȱsedimentoȱpodríanȱacarrearȱ ciertoȱ estrésȱ ambientalȱ enȱ elȱ parque.ȱ Losȱ organismosȱ expuestosȱ enȱ jaulasȱ ancladasȱenȱlaȱzonaȱdeȱCormeȬLaxeȱhanȱmostradoȱnivelesȱelevadosȱdeȱesteȱtipoȱ deȱ estrés,ȱ loȱ cualȱ noȱ seȱ observóȱ enȱ losȱ ensayosȱ deȱ laboratorioȱ loȱ queȱ revelaȱ elȱ impactoȱdeȱotrasȱfuentesȱdeȱcontaminaciónȱenȱlaȱzona.ȱEnȱelȱcasoȱdeȱlaȱBahíaȱdeȱ Algecirasȱ laȱ inducciónȱ deȱ losȱ biomarcadoresȱ fueȱ significativaȱ bajoȱ condicionesȱ deȱ laboratorioȱ mientrasȱ queȱ enȱ lasȱ exposicionesȱ enȱ campoȱ seȱ observóȱ unaȱ disminuciónȱdeȱlosȱmismos,ȱposiblementeȱrelacionadaȱconȱlaȱinfluenciaȱmarealȱ oȱ elȱ efectoȱ deȱ “lavado”ȱ deȱ laȱ contaminación,ȱ queȱ disminuiríaȱ laȱ biodisponibilidadȱdeȱlosȱcontaminantes.ȱEnȱelȱcasoȱdeȱlaȱvitelogeninaȱmedidaȱenȱ cangrejos,ȱ paraȱ todasȱ lasȱ estacionesȱ éstaȱ mostróȱ mayorȱ respuestaȱ bajoȱ condicionesȱ deȱ laboratorio,ȱ mientrasȱ queȱ lasȱ exposicionesȱ enȱ jaulasȱ resultaronȱ menosȱ sensiblesȱ aȱ laȱ toxicidadȱ deȱ losȱ sedimentos.ȱ Losȱ resultadosȱ obtenidosȱ ponenȱ deȱ manifiestoȱ laȱ importanciaȱ deȱ realizarȱ exposicionesȱ enȱ campoȱ complementariasȱaȱaquellosȱensayosȱdeȱlaboratorio.ȱȱ - 358 - Conclusionesȱ 11)ȱ Losȱ resultadosȱ deȱ biomarcadoresȱ obtenidosȱ enȱ losȱ diferentesȱ organismosȱ expuestosȱ aȱ sedimentoȱ deȱ laȱ Bahíaȱ deȱ Cádiz,ȱ confirmanȱ suȱ elecciónȱ comoȱ referenciaȱ enȱ estudiosȱ deȱ toxicidad,ȱ dadaȱ laȱ ausenciaȱ deȱ respuestasȱ biológicasȱ adversas.ȱ Yȱ confirmanȱ estaȱ zonaȱ comoȱ deȱ referenciaȱ paraȱ estudiosȱ queȱ impliquenȱ evaluacionesȱ deȱ toxicidadȱ medianteȱ ensayosȱ crónicosȱ yȱ utilizandoȱ medidasȱsubletalesȱcomoȱlosȱbiomarcadores.ȱ 12)ȱ Losȱ biomarcadoresȱ analizadosȱ enȱ cangrejosȱ yȱ almejasȱ seȱ indujeronȱ deȱ maneraȱ significativaȱ duranteȱ laȱ primeraȱ semanaȱ deȱ exposición.ȱ Seȱ hanȱ observadoȱrelacionesȱ entreȱ biomarcadoresȱdeȱ laȱ faseȱ Iȱ yȱ IIȱ deȱ detoxificaciónȱ loȱ queȱ sugiereȱ laȱ funcionalidadȱ delȱ esteȱ sistemaȱ enȱ ambasȱ especiesȱ deȱ invertebradosȱ marinos.ȱ ȱ Elȱ estudioȱ deȱ biomarcadoresȱ aȱ loȱ largoȱ delȱ tiempoȱ haȱ ayudadoȱaȱidentificarȱtantoȱlasȱfuentesȱcomoȱlaȱmaneraȱdeȱactuarȱyȱdetoxificarȱ losȱ contaminantes,ȱ asíȱ comoȱ deȱ identificarȱ respuestasȱ biológicasȱ frenteȱ aȱ contaminantesȱqueȱnoȱhanȱsidoȱanalizados.ȱȱȱ 13)ȱ Seȱ haȱ demostradoȱ comoȱ varíaȱ laȱ biologíaȱ delȱ poliquetoȱ Arenicolaȱ marinaȱ expuestoȱ aȱ diferentesȱ nivelesȱ deȱ contaminación.ȱ Seȱ hanȱ establecidoȱ correlacionesȱ entreȱ contaminantesȱ orgánicos,ȱ metalesȱ yȱ respuestasȱ biológicas,ȱ incluyendoȱ actividadȱ antioxidante,ȱ inmuneȱ yȱ químicoȬsensorialȱ siendoȱ elȱ biomarcadorȱ másȱ destacableȱ elȱ dañoȱ deȱ ADNȱ medidoȱ porȱ elȱ ensayoȱ Cometa.ȱ Porȱ vezȱ primeraȱ seȱ haȱ seleccionadoȱ yȱ aplicadoȱ unaȱ bateríaȱ deȱ biomarcadoresȱ conȱ elȱ poliquetoȱ A.ȱ marinaȱ yȱ losȱ resultadosȱ obtenidosȱ muestranȱ nuevasȱ herramientasȱparaȱsuȱaplicaciónȱenȱestudiosȱmedioambientales.ȱȱȱ 14)ȱ Seȱ haȱ demostradoȱ laȱ recuperaciónȱ deȱ laȱ faunaȱ bentónicaȱ añosȱ despuésȱ delȱ vertidoȱ delȱ Prestigeȱ enȱ laȱ zonaȱ deȱ Galicia.ȱ Seȱ haȱ demostradoȱ unaȱ importanteȱ alteraciónȱ biológicaȱ enȱ lasȱ estacionesȱ localizadasȱ enȱ laȱ bahíaȱ deȱ Algecirasȱ yȱ seȱ hanȱ relacionadoȱ conȱ alȱ concentraciónȱ deȱ PAHsȱ enȱ elȱ sedimento.ȱ Aȱ suȱ vez,ȱ lasȱ Ȭ 359ȱȬ Capítuloȱ6 comunidadesȱ bentónicasȱ deȱ CormeȬLaxeȱ yȱ Algeciras,ȱ puedenȱ verseȱ afectadasȱ porȱ laȱ presenciaȱ deȱ metalesȱ enȱ losȱ sedimentos.ȱ Laȱ estructuraȱ deȱ laȱ comunidadȱ bentónicaȱ enȱ laȱ zonaȱ deȱ Cádizȱ seȱ establecióȱ comoȱ normalȱ noȱ asociándoseȱ conȱ alteraciónȱsignificativa,ȱalȱmenosȱenȱlaȱestaciónȱelegidaȱcomoȱreferencia.ȱ 15)ȱ Seȱ haȱ llevadoȱ aȱ caboȱ unaȱ nuevaȱ mejoraȱ enȱ laȱ metodologíaȱ integradaȱ deȱ evaluaciónȱ deȱ laȱ calidadȱ deȱ losȱ sedimentosȱ dentroȱ delȱ marcoȱ delȱ “Weightȱ ofȱ Evidenceȱ approach”ȱ queȱhaȱpermitidoȱobtenerȱresultadosȱmásȱobjetivos.ȱSeȱhaȱ demostradoȱcomoȱtrasȱelȱvertidoȱlosȱPAHsȱfueronȱelȱprincipalȱcontaminanteȱdeȱ laȱ costaȱ gallega.ȱ Seȱ haȱ identificadoȱ laȱ existenciaȱ deȱ fuentesȱ deȱ metalesȱ enȱ elȱ Parqueȱ Nacionalȱ deȱ lasȱ Islasȱ Atlánticasȱ yȱ deȱ laȱ bahíaȱ deȱ CormeȬLaxeȱ queȱ aparentementeȱ noȱ estánȱ produciendoȱ efectosȱ biológicosȱ deȱ tipoȱ agudo.ȱ Laȱ poluciónȱhaȱdisminuidoȱenȱlosȱúltimosȱañosȱenȱambasȱzonasȱdeȱGalicia,ȱaunqueȱ aúnȱexisteȱciertoȱestrésȱambientalȱprincipalmenteȱenȱlasȱzonasȱestudiadasȱdeȱlaȱ bahíaȱdeȱCormeȬLaxe.ȱȱ 16)ȱSeȱhanȱdemostradoȱlasȱventajasȱdeȱincorporarȱlosȱbiomarcadoresȱcomoȱlíneaȱ deȱ evidenciaȱ dentroȱ deȱ unȱ estudioȱ integrado,ȱ éstosȱ hanȱ mostradoȱ unaȱ mayorȱ sensibilidadȱenȱlosȱresultadosȱaȱlaȱhoraȱdeȱcuantificarȱlaȱpoluciónȱeȱidentificarȱlaȱ misma;ȱ elȱ usoȱ deȱ losȱ biomarcadoresȱ obtenidosȱ enȱ exposicionesȱ deȱ campoȱ yȱ laboratorioȱdentroȱdelȱ“WeightȱofȱEvidenceȱapproach”ȱhaȱayudadoȱaȱrelacionarȱ lasȱfuentesȱdeȱcontaminaciónȱyȱlosȱefectosȱinclusoȱcuandoȱelȱcontaminanteȱnoȱhaȱ sidoȱ analizado.ȱ Aȱ pesarȱ queȱ variosȱ añosȱ despuésȱ delȱ vertidoȱ noȱ seȱ hanȱ detectadoȱ efectosȱ agudosȱ significativosȱ enȱ elȱ áreaȱ deȱ CormeȬLaxe,ȱ seȱ hanȱ observadoȱ respuestasȱ subletalesȱ relacionadasȱ conȱ lasȱ concentracionesȱ deȱ contaminantesȱcomoȱlosȱPAHs,ȱyȱlosȱmetalesȱPbȱyȱHg.ȱLaȱpresenciaȱdeȱciertosȱ metalesȱcomoȱZn,ȱCuȱyȱNiȱenȱlasȱislasȱCíesȱpodríanȱsuponerȱunȱriesgoȱaunqueȱ porȱelȱmomentoȱnoȱseȱhanȱdetectadoȱefectosȱbiológicosȱenȱlaȱzonaȱasociadosȱconȱ estosȱcontaminantes.ȱTrasȱlosȱresultadosȱobtenidosȱenȱlaȱBahíaȱdeȱCormeȬLaxe,ȱ - 360 - Conclusionesȱ seȱ sospechaȱ queȱ laȱ presenciaȱ deȱ lasȱ bateasȱ deȱ cultivoȱ deȱ mariscosȱ puedaȱ suponerȱunaȱfuenteȱdeȱestrésȱimportanteȱenȱlaȱzona.ȱ 17)ȱLaȱexistenciaȱdeȱdistintasȱfuentesȱdeȱcontaminaciónȱdaȱlugarȱaȱlaȱpresenciaȱ deȱunaȱmezclaȱcomplejaȱdeȱcontaminantesȱenȱlaȱBahíaȱdeȱAlgeciras,ȱincluyendoȱ vertidosȱ industriales,ȱ urbanosȱ yȱ derivadosȱ delȱ tráficoȱ marítimoȱ yȱ deȱ lasȱ actividadesȱdeȱbunkering.ȱTodoȱelloȱseȱreflejaȱenȱunaȱaltaȱdegradaciónȱambientalȱ debidaȱ aȱ laȱ entradaȱ continuadaȱ deȱ estosȱ vertidos.ȱ Porȱ otroȱ lado,ȱ cuatroȱ añosȱ despuésȱ delȱ vertidoȱ delȱ petroleroȱ Prestigeȱ seȱ observaȱ unaȱ recuperaciónȱ generalizadaȱ deȱ losȱ sedimentosȱ delȱ Parqueȱ Nacionalȱ deȱ lasȱ islasȱ Atlánticasȱ yȱ unaȱ mejoraȱ enȱ laȱ calidadȱ deȱ laȱ Bahíaȱ deȱ CormeȬLaxe.ȱ Elȱ métodoȱ integradoȱ haȱ demostradoȱ laȱ recuperaciónȱ delȱ sistemaȱ afectadoȱ enȱ laȱ costaȱ deȱ Galicia,ȱ laȱ poluciónȱ enȱ laȱ zonaȱ deȱ laȱ Bahíaȱ deȱ Algecirasȱ yȱ laȱ condiciónȱ deȱ zonaȱ deȱ referenciaȱenȱlaȱestaciónȱelegidaȱenȱlaȱBahíaȱdeȱCádiz.ȱȱ 18)ȱ Seȱ haȱ demostradoȱ laȱ capacidadȱ ambientalȱ deȱ recuperaciónȱ trasȱ unȱ granȱ vertidoȱ deȱ petróleoȱ comoȱ elȱ ocurridoȱ enȱ Galiciaȱ enȱ 2002ȱ mientrasȱ queȱ sedimentosȱ litoralesȱ queȱ seȱ venȱ afectadosȱ porȱ moderadasȱ dosisȱ deȱ vertidosȱ duranteȱunȱlargoȱperiodoȱdeȱtiempoȱyȱqueȱenȱprincipioȱnoȱdesatanȱtantaȱalarmaȱ socialȱ puedenȱ resultarȱ notablementeȱ másȱ degradadosȱ comoȱ esȱ elȱ casoȱ deȱ laȱ BahíaȱdeȱAlgeciras.ȱȱ ȱ ȱ Ȭ 361ȱȬ