Slides 2 - Primary Production in the Sea

• Large group • Unicellular • 50% are photosynthetic • 2 flagella • Chromalveolata • some are bioluminescent

• Unicellular • Mixotroph • Excavata

• Large group • unicellular • marine and in fresh water • benthic and planktonic • silica casing • no flagella

• some are marine, most are in fresh water • mostly unicellular, some colonial • contain pigment: fucoxanthin

• Multicellular • Only marine • form large thalli

• small group • mixotrophic • unicellular • mostly in tropical seas

• multicellular • no flagella • marine

• fresh water and marine • unicellular and multicellular • most related to land plants

• the only embryophytes that have re-invaded the sea

• trees that grow in saline costal habitats in the tropics and subtropics

• photosynthetic bacteria • aka “blue green algae”

• some organisms have endosymbiotic algae

6CO2 + 6H2O + Energy –> C6H12O6 + 6O2

• decreases exponentially with depth • depends on clouds & aerosols • depends on angle of the sun • depends on clarity of the water • spectral composition diminishes with depth

• the light-induced damage and loss of photosynthetic activity that occurs when the energy absorbed by photosynthetic organisms exceeds the capacity of the photosynthetic apparatus to process it

the depth at which net photosynthesis is zero (gross photosynthesis = respiration)

the upper part of the ocean that is homogenized by wave and wind action to a certain depth.

depth where total water column photosynthesis = total water column respiration

When mixed layer depth > critical depth, there is no net phytoplankton growth

the response of photosynthetic cells to changing irradiance by altering the concentration and composition of pigments in the cell

• N, (proteins) P, (membranes) • Si, S, K, Na, Ca

• Fe, (chlorophyll) • Cu, Mg, Zn

low nutrient content

intermediate nutrient content