Phytoplankton Flashcards
Dinoflagellates
Single celled eukaryotes Reproduce asexually - fission Cells reinforced by armoured carbohydrate cellulose plates Not all photosynthetic 2 flagella - allow cell to spin Can cause toxic blooms
Bioluminescent species
Zooxanthellae symbionts
Diatoms
Single celled eukaryotes Cells encased in silica dioxide No way to move Reproduce through cell division Size reduces through generations - until back to sexual reproduction and formation of auxospores
Coccolithophores
Single celled eukaryote protists Shell of calcareous plates Photosynthetic Fossil remains are a good indication of historic productivity, temperature and salinity Prefer deep warm water
Photosynthetic output?
Seas primary production - 20x10^9 tonnes of carbon per year - 50% of the worlds carbon fixing
Dependent on light level and nutrient availability
Seasonal plankton production
Phytoplankton uses all nutrients and decline
Predator prey relationship between phytoplankton and zooplankton
Storms in September - upwelling - nutrients bought to the surface
Smaller peak due to less sunlight
Biomass produced is lower in the tropics than the Atlantic
Light penetration?
Blue is most penetrating
Red is the least penetrating
What is the compensation depth?
The depth where photosynthesis rates = the respiratory rate of a single phytoplankton cell
What is the critical depth?
Total respiration = total photosynthesis
What is photoinhibitation?
Too much sunlight prohibiting photosynthesis
What is marine snow?
Rich organic material
Travels down to the sea floor
Transported by currents
Eaten by bacteria etc
What is the importance of phytoplankton to humans?
Provides energy for marine ecosystems
Distribution and timing drives major fisheries
Buffer against climate change
Nanophytoplankton
Single celled eukaryote protists
So small they weren’t captured in traditional plankton nets
Probably account for 70% of phytoplankton biomass in the sea
