Concept for estimation of secondary and tertiary biomass from primary production

Fixation of inorganic carbon to organic carbon in the ocean is driven purely by phytoplankton. Phytoplankton carbon fixation plays an important role in maintaining the quasi steady state level of atmospheric CO2. Relative contribution of marine primary productivity to global photosynthetic production is between 10 and 50%. Magnitude ranges from 20 to 55 Gt of C/ year (Ryther 1969, Smith et al., 1983, Walsh 1984 and Martin 1992). Ocean-atmospheric coupled climate models predict changes in the ocean circulation and hypothesize that changes in the ocean circulation will stimulate phytoplankton biomass production in the nutrient depleted areas in the open ocean (Roemmich & Wunch 1985). The effect on atmospheric CO2 is uncertain because the relationship between the enhanced primary production and air sea exchange of CO2 is not understood. The challenge is to study the magnitude and variability of Primary productivity, its time scales and changes in atmospheric forcing and upscale it into secondary and tertiary productivity