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• Upwelling (coastal or otherwise) brings deep water to the surface (recall exercise on Tues.)• Deep water has high nutrient concentrations, so primary production increases. (What is primary production? Stay-tuned)•Primary production is traced by chlorophyll (green stuff in plants).
Upwelling, primary production, and iron fertilization: a short trip (with
detours) through the ocean ecosystem.
Model nitrate concentrations
Courtesy P.MacCready, UW
Primary Productivity: What is it?• Primary productivity is the synthesis of
organic molecules from inorganic substances.
We call organisms which perform primary productivity autotrophs (auto=self + trophe=nourishment.
• We’re all familiar with primary producers on land: they are the plants!
• Most oceanic primary production is accomplished by marine phytoplankton, also plants, but not stationary in one place.
• Phytoplankton photosynthesize to create organic molecules with 4 key ingredients:
• Sunlight
• Water
• CO2 (carbon dioxide)
• Nutrients (inorganic substances)
Primary Productivity: What is it?
Primary Productivity: What is it?
• All phytoplankton also use a pigment called chlorophyll to help trap sunlight
• Chlorophyll is useful for tracking area of primary production & phytoplankton – visible to satellites!
• The basic reaction is:
6CO2 + 6H20 + (sunlight & chlorophyll) --> C6H12O6 + 6O2
Dinoflagellates – both auto- & heterotrophes: Some dangerous (Gymnodinum, Gonyaulax- “red-tide”/PSP) and some pretty (Noctiluca - bioluminescent)
Primary Productivity: A multi-stage conversion process of energy and matter
• Primary production converts solar energy and inorganic nutrients into food for the entire ecosystem.
• It’s a critical part of the global carbon cycle.
Above is one version of a food web with trophic levels. Linked here is another graphical version (by Amity Femia)
An in-class group exercise• See hand-out•Go to SAL so all groups have a super-cool new computer.
http://seawifs.gsfc.nasa.gov/cgi/monthly_climatologies.pl?TYP=bios