1. Plankton

2. Phytoplankton Can’t move against currents (float or weakly move)
• >40% of global primary productivity

3. Phytoplankton Classification
From two kingdoms
Monera (bacteria)
Protista (algae)
3 divisions (Phyla)
Cyanobacteria
Chrysophyta
Dinophyta

4. Cyanobacteria •Prokaryotic (No nucleus, few organelles)
•Photosynthetic bacteria
•Prokaryotic (No nucleus, few organelles)
•Reproduce by cell fission
•Nitrogen fixation: convert Nitrogen gas
(N2) to nitrates or ammonia

5. Chrysophyta Most with hardened cell walls or
internal skeletons: silica or calcium carbonate (CaCO3)
•Some have flagella for motility

6. Coccolithophores – type of Chrysophyta
Calcium CaCO3 plates
•large numbers at surface
•Prefer still, nutrient-poor H2O
•Reflect sunlight: lower heat & UV light – counter global warming

7. Diatom – type of Chrysophyta
Most abundant phytoplankton
• Major oceanic primary producer
• Cell walls (frustule) of silica (glass-like)
• Live alone or in chains

8. Dinophyta Dinoflagellates •Most photosynthetic, few heterotrophic
•Unicellular, 2 flagella: adjust vertically in
water column (light, nutrients)
•Rapid asexual cell division

9. Dinoflagellates Abundant in warm surface H2O (tropics)
•Some symbiotic (zooxanthellae)
–Live in coral, clams, urchins, anemones
•Zooxan. give carbohydrates & receive nutrients & shelter

10. Dinoflagellates are Bioluminescent
Organisms produce light by a chemical reaction

11. Why Do Dinos. Produce Light?
Camouflage!
•When it senses a predator (motion in H2O)
•Which attracts larger predators that
consumes the would-be Dino predator

12. Red Tides (Dinoflagellate Bloom)
Mass development of dinoflagellates discolor water
•Often caused by excess nutrients
•Enter ocean from land (runoff)
•Fertilizer, sewage

13. Red Tide Impacts:
Toxic to marine life: accumulates in clams, mussels, scallops, fish, mammals
•Death to some species, Human poisoning after consumption (30 min.)
•Symptoms:
•Paralytic: paralysis, asthma, heart attack (rare)
•Neurotoxic: tingling, paralysis,
memory loss
•Diarrhetic: cramps, vomiting, diarrhea

15. Special Planktonic Adaptations
Unique shapes –increase surface areas
•Gas filled-vesicles
Oils
Hard shells