Malaysia_IOC-Westpac 2016 new

CurrentstatusofimplementationforOA
studiesinMalaysia
Locationoftheproposedstudysite
N
Tarutao
NationalPark
Pulau Gaya
PulauBidong
PulauPayar
SOUTHCHINASEA
Sumatra
400km
STUDY
SITE
PulauPayarMarinePark
N
STRAITOFMALACCA
P.Lembu
P.Kaca
MarinePark
Centre
P.Payar
1km
Pulau Bidong (UMTMarineResearchStation)
N
SOUTHCHINASEA
UMTMarine
Research
Station
1km
Investigatingthediurnalvariationofthe
seawaterpHandalkalinityinshallowwater
coralreefofPulau Payar (StraitofMalacca),
Pulau Bidong andPulau Gaya(SouthChina
Sea)astheproposedsitesoftheocean
acidificationstudy.
DiurnalvariabilityofpHandtotalalkalinity
3dayperiodofobservationatashallow
water coralreefarea
HydrolabDS5Xrecorded
readingevery15minute
(pH,Temperature,Salinity,
DissolvedOxygen,DO)
In-situ measurement&
watersamplecollection
Aragonitesaturationweredetermined
usingtheCO2SYSprogram(Lewisand
Wallace,1998)throughinsituAT,pH,
salinity,temperaturedata.
Every3hours,water
samplewerecollected
andmeasuredforthe
TotalAlkalinity(AT)
Methodsthatwereusedtodetermine
theseawatercarbonateparameter
Parameters
Unit
MeasurementMethods
Temperature
°C
HydrolabDS5X
Salinity
ppt
HydrolabDS5X
HydrolabDS5X
pH
DissolvedOxygen(DO)
mg/L
HydrolabDS5X
TotalAlkalinity
µmol/kg
PotentiometricTitration(Dicksonetal.2007)
AragoniteSaturation
ΩAragonite
CO2SYSprogram(LewisandWallace,1998)
DiurnalvariationinseawaterpHatthe
studyarea
day
night
day
night
day
night
Payar(SOM)
Bidong(SCS)
Gaya(SCS)
• pH trend fluctuates daily following the diurnal pattern which is regulated by
the biological activity such as photosynthesis and respiration
SeawaterpHatPulauPayar,PulauBidongand
PulauGaya
• Decreasing surface
seawater pH trend
from the Strait of
Malacca to the South
China Sea
morebasic
lessbasic
Diurnalvariationoftotalalkalinity
day
night
day
night
day
night
Gaya(SCS)
Bidong(SCS)
Payar(SOM)
•
•
•
Total alkalinity (AT) did not show any diurnal trend through out this study.
However, the largest difference of AT was recorded at Payar with the value of 28.92 μmol/kg.
Changes in AT are attributed to calcification or carbonate dissolution (Murillo et al., 2014)
Relationshipbetweentotalalkalinity
andsalinity
•
Precipitation and
evaporation mainly controls
the AT variability of surface
ocean
(Brewer et al., 1986; Millero et al., 1998a)
•
Concentrations of the key
chemical species (i.e., HCO3CO32-) that contribute to AT
proportionally increase with
increasing salinity (Lee et al.,
2006)
CO2 ParameterVariation
pH
ρCO2 (µatm)
•
pH ranged 7.21 to 7.81°C
•
ρCO2 ranged 710 to 3151 µatm
•
Lower pH observed at the southern
region
•
Higher ρCO2 observed at the southern
region
CO2 ParameterVariation
Aragonite Saturation (ΩAra)
(ReefsatRiskRevisited 2011)
Saturation States in the Pacific
Hoegh-Guldberg et al. 2007: Ωarag = 3.3
•
Aragonite saturation ranged 0.57 to 2.26
•
Low saturation state observed at the
southern region
•
At extremely marginal state
Shamberger et al. 2011
Saturation state in our region
(Shambergeretal.2011)
Carbonateenvironmentcomparison
•
Pulau Bidong and Pulau Gaya
– Higher AT were recorded at these sites, 2161.78 μmol kg-1 and
2160.45 μmol kg-1 respectively.
– The pH at both sites are lower than Payar as denoted by the higher
H+ concentration in the seawater.
– Aragonite saturation in the seawater at both sites were recorded at
adequate (3.41) and marginal (2.99) level respectively.
•
Pulau Payar
– Lower AT (2140.77 μmol kg-1) means the capacity of the seawater
buffer system to neutralize acidic pollution is reduced.
– At present, the seawater carbonate system is maintained because of
the pH value (pH 8.14).
– Only a small amount of acidic pollution is needed to disrupt the
carbonate system equilibrium.
– Optimal aragonite saturation state in Payar contributes to the high
coral calcification rate in the area.
Currentstatusofimplementationfor
OAstudiesinMalaysia
• AllrequiredCAUs,BMUsandARMshavebeen
manufacturedbutasyetnotdeployed
• diurnalvariationsurveyofselectedstationhas
beencompletedfortemperature,salinity,pHDO,
aragonitesaturationandtotalalkalinity
• Coralcoveranddiversitystudiesareplannedfor
2016-2017).Bioticsurvey(georeferenced,cover,
diversity)iscurrentlybeinganalysed.
•
•
•
•
Localorganizingcommittee
IOC/WESTPAC
Mr.WenxiZhu
PhuketMarineBiologicalStation