Lecturer Material can be downloaded here

03/12/12
Plankton
PLANKTON
Phytoplankton
Kategori Kehidupan Laut:
1. Benthos: bottom dwellers; sponges, crabs
2. Nekton: perenang kuat- whales, fish, squid
3. Plankton: hewan/tumbuhan yang hanyut
di air. Memiliki sedikit kontrol untuk
pergerakannya.
termasuk: diatoms, dinoflagellates, larvae,
jellyfish, bacteria.
•
•
•
•
Phyto= plant
Plankton= drifting organisms
Critical base of the marine food chain
Responsible for the biological carbon pump
-biologically-mediated pumping of carbon
from the surface to the ocean interior
• Produce ~50% of atmosphere’s free oxygen
• Most are single-celled
1
03/12/12
What Exactly are Plankton?
Faktor yang mempengaruhi?
1. Waves
2. Tides
3. Currents
Plants and animals that live in the water and
Plants
Animals
cannot
swim against major currents.
Size:
Plankton diklasifikasikan
berdasarkan:
Size
Habitat
• Picoplankton (.2-2 µm) bacterioplankton
• Nanoplankton (2 - 20 µm) protozoans
• Microplankton (20-200 µm) diatoms, eggs,
larvae
• Macroplankton (200-2,000 µm) some eggs,
juvenile fish
• Megaplankton (> 2,000 µm) includes
jellyfish, ctenophores, Mola mola
Taxonomy
2
03/12/12
Habitat:
• Holoplankton- Seluruh siklus hidupnya sebagai
plankton Ex. Jellyfish, diatoms, copepods
• Meroplankton- Sebagian dari siklus hidupnya
sebagai plankton Ex. fish and crab larvae, eggs
snail
lobster
Siklus hidup squid
• Squid dalam
siklusnya pernah
sebagai benthic,
planktonic, and
nektonic
• Squid digulongkan
sebagai
meroplankton
(opposite =
holoplankton)
fish
Habitat:
Zooplankton
Taxonomy
Phytoplankton
• Pleuston- organisme yang secara pasif mengapung
di permukaan laut
Ex. Physalia, Velella
• Neuston – organisme yang hidup beberapa mm
dari permukaan air
Ex. bacteria, protozoa, larvae; light intensity too high
for phytoplankton
From The World Book (TM) Multimedia
Encyclopedia (c) 1999 World Book,
Inc., 525 W. Monroe, Chicago, IL
60661. All rights reserved.
Maira & Rod Borland, Bruce Coleman,
Inc.
Neuston net
3
03/12/12
Importance of Phytoplankton
Why Are Plankton So Important?
Phytoplankton dasar dari rantai makanan.
Small fish
Mackerel
Penurunan populasi fitoplankton disebabkan oleh
zooplankton.
Tuna
Seasonal Cycle: the North Atlantic Bloom
Nitrate
Chlorophyll
Zooplankton
J Jan F Feb MMar A Apr MMay J Jun J
Jul
A Aug S Sep O Oct N Nov DDec
Winter: strong winds, deep mixing, high nutrients but phytoplankton can’t use
them because mixing exposes them to low and variable light conditions
Spring: water column stabilizes, favorable light conditions, bloom, nutrient uptake
Summer: Continued water column stability, moderate productivity but biomass
remains relatively low and stable due to equilibrium with zooplankton consumption
Fall: Possible secondary bloom as winds increase and mix nutrients into surface, but
before mixing becomes too deep
4
03/12/12
Some important types of phytoplankton
Phytoplankton- dibatasi di zona
euphotic dimana cahaya cukup
tersedia untuk fotosintesis.
Blooms:
• High nutrients
• Upwelling
• Seasonal conditions
Some important types of zooplankton
• Crustaceans: Copepods
Krill
Cladocera
Mysids
Ostracods
• Jellies
Cniderian (True jellies, Man-of-wars,
By-the-wind-sailors)
• Ctenophores (comb jellies)
• Urochordates (salps and larvacea)
• Worms (Arrow worms, polychaetes)
• Pteropods (planktonic snails)
•
•
•
•
•
•
Diatoms: temperate and polar waters, silica case or shell
Dinoflagellates: tropical and subtropical waters.... also
summer in temperate
Coccolithophores: tropical, calcium carbonate shells or
"tests"
Silicoflagellates: silica internal skeleton... found world
wide, particularly in Antarctic
Cyanobacteria (blue-green algae): not true algae, often in
brackish nearshore waters and warm water gyres
Green Algae: not common except in lagoons and estuaries
Importance of krill
in Antarctic food
web
5
03/12/12
Fish larvae
Chaetognath
Copepod
Crab larvae
jellies
Queen Trigger fish Egg
to Juv.
Marine Snow
tunicate
Jelly-like house
Oikopleura
Marine snow
6
03/12/12
Marine Snow
Marine Snow
A major component of marine
snow is fecal pellets
Base of Florida Escarpment covered
with marine snow. Octocorals attach to
steep sides and under ledges to avoid
burial.
Vertical Zonation of Zooplankton
Nutritional modes of zooplankton:
• Herbivores: feed primarily on
phytoplankton
• Carnivores: feed primarily on other
zooplankton (animals)
• Detrivores: feed primarily on dead
organic matter (detritus)
• Omnivores: feed on mixed diet of
plants and animals and detritus
•
Epipelagic: upper 200-300 m water column; high diversity, mostly small and
transparent organisms; many herbivores
•
Mesopelagic = 300 – 1000 m; larger than epipelagic relatives; large forms of
gelatinous zooplankton (jellyfish, appendicularians) due to lack of wave action;
some larger species (krill) partly herbivorous with nightly migration into
epipelagic regimes; many species with black or red color and big eyes (why?);
•
Oxygen Minimum Zone: 400 – 800 m depth, accumulation of fecal material due
to density gradient, attract high bacterial growth, which in turn attracts many
bacterial and larger grazers; strong respiration reduces O 2 content from 4-6 mg
l-1 to < 2 mg l-1
•
Bathypelagic: 1000 – 3000 m depth, many dark red colored, smaller eyes
•
Abyssopelagic: > 3000 m depth, low diversity and low abundance
•
Demersal or epibenthic: live near or temporarily on the seafloor; mostly
crustaceans (shrimp and mysids) and fish
7
03/12/12
Diurnal Vertical Migration
Diurnal vertical migration
Organisms within
the deep
scattering layer
undertake a
daily migration
to hide in deep,
darker waters
during daytime
Each species has its own preferred day and night depth range, which may
vary with lifecycle.
1. Nocturnal Migration
• single daily ascent near sunset
2. Twilight migration (crepuscular period)
• two ascents and two descents
3. Reverse migration
• rise during day and descend at night
Advantages for Diurnal vertical
migration
1. An antipredator strategy; less visual to
predators
Zooplankton migrate to the surface at night
and below during the day to the
mesopelagic zone. Copepods avoid
euphasiids which avoid chaetognaths.
Advantages for DVM
•
•
•
•
Energy conservation
Encounter new feeding areas
Get genetic mixing of populations
Hastens transfer of organic
material produced in the euphotic
zone to the deep sea
8
03/12/12
Plankton Patchiness
• Zooplankton not distributed uniformly
or randomly
• Aggregated into patches of variable
size
• Difficult to detect with plankton nets
- Nets “average” the catch over the
length of the tow
• May explain enormous variability in
catches from net tows at close
distances apart
Causes of Patchiness
• Aggregations around phytoplankton
- If phytoplankton occurs in patches,
grazers will be drawn to food
- Similar process that led to
phytoplankton patches will form
zooplankton patches
• Grazing “holes”
• Physical process
- Langmuir Cells
- Internal waves
9
03/12/12
Langmuir Cells
Accumulation of Plankton
in Langmuir Cells
• Buoyant particles and upwardswimming zooplankton will
accumulate over downwelling
zones
Langmuir Cells
Internal Waves
• Underwater
waves
propagated
along the
thermocline
• Generated by
overflow over
rough
topography
• Much greater
amplitude than
surface waves
10
03/12/12
Satellite image of internal wave
Deep sea scattering layer:
Composite echogram of hydroacoustic data showing a
distinct krill scattering layer.
Black line represents surface tracking of a blue whale
feeding
patchiness
Plankton Tow
“Red Tides,” or
Harmful Algal Blooms
Aiea High School students aboard the Honu Kai
11
03/12/12
“Red Tides” are actually Harmful Algal
Blooms, or simply Algal Blooms.
Algal Blooms
•Algal blooms are not always
red, can also be green, brown,
orange, or even not pigmented
at all.
•“Red Tides” have little to no
relation to actual ocean tides.
•Many different species and
organisms can cause the
phenomenon, and there is no
single cause.
Image: http://drake.marin.k12.ca.us/stuwork/ROCKwater/PLANKTON/redtide.jpg
http://www.whoi.edu/cms/images/lstokey/2005/1/v43n2-anderson4en_5499.jpg
12
03/12/12
TUGAS
• BUAT KLASIFIKASI, MORFOLOGI, HABITAT, DAN
HAL HAL YANG TERKAIT
• NPM Ganjil Fitoplankton
• NPM Genap Zooplankton
• Masing-masing 5 spesies
• Lengkapi dengan gambar
• BUAT KLIPING TENTANG RED TIDE DAN HARMFUL
ALGA BLOOM
• DIKUMPULKAN MINGGU DEPAN
13