Marine Primary Production Flashcards
What is the basic process involved in marine primary production
Fixation of carbon from inorganic sources, (e.g C02) dissolved in water column or from the atmosphere
Name 6 marine primary producers
Phytoplankton, macroalgae, Seagrass, Mangrove, Saltmarsh, Coral reefs
Two reasons why marine primary production is so important
Start of the food webs supporting nearly all life on earth. Marine production is of vital importance for socio-economic and environmental reasons.
Also primary production controls the earths atmosphere and has implications to global warming.
Name in order from least to highest the marine ecosystems/processes in terms of rates of primary production, g C m-2 y-1
Arctic Ocean, Antartic Ocean, Temperate seas, Temperate seas (coastal), Coastal Upwellings, Seagrass and Kelp, Coral Reefs
What governs the relative proprotions of marine inorganic carbons, carbon dioxide, (CO2), carbonic acid, (H2CO3), bicarbonate ions, (HCO-3), and carbonate ions, (CO3^2-).
Acidity, (pH), salinity and temperature
What is RUBISCO
An enzyme of very high molecular weight and in planktonic algae amounts to 50% of the protein of the cell - most abundant protein on this planet and a key part of the Calvin Cycle.
What is the Calvin Cycle
It is a process central to making of biomass following photosynthetic capture of light.
What is unusual about RUBISCO’s function as an Oxygenase and why it this important for plants
Ribulose-1, 5-Bisphosphate + O2 –> 3-phosphoglycerate + phosphoglycolate. This reaction known as photorespiration results eventually in the loss of carbon and the formation of C02
In terms of the Calvin Cycle, what does a high CO2/O2 ratio at the RUBISCO enzyme cause
Carboxylase function –> CO2 fixation and O2 production
In terms of the Calvin Cycle, what does a low CO2/O2 ratio at the RUBISCO enzyme cause
Oxygenase function –> CO2 production and O2 utilisation
What two processes are coupled in photosynthesis and what do they involve
- Conversion of light energy into chemical energy. 2. Conversion of inorganic carbon to organic carbon.
They involve The Electron Transport Chain and The Calvin Cycle
What limits marine primary productivity
Light quanity and quality, stratification and mixing depth - thermal density of water - nutrient limitations, salinity and temperature
What is the main limiting nutrient in marine systems
Nitrogen
What causes algal blooms and what aid their formation
Eutrophication of watersystems aided by anthropogenic nutrient additions
Why in the antarctic ocean is there a low algals biomass despote high nutrient concentrations
Iron limitation
