Metabolic Potential of Deep-Sea Animals: Regional and Global Scales

The vertical transport of organic carbon in zooplankton and micronekton is significant but is not recorded in studies that rely on measurements of particles caught in sediment traps. The energy metabolism of pelagic vertical migrators results in the production of CO2 in deep water, but CO2 production is currently estimated from the differences in particle fluxes at different depths. We review the factors that affect metabolic rates and the use of enzyme assays to estimate metabolic rates and conclude that a combination of these methods would enable one to estimate the in situ metabolic rates of all major pelagic zooplankton and micronekton groups. These data could, if used with appropriate biomass estimates, enable calculation of the contribution of these animals’ respiration to global carbon flux and be a first step in evaluating their total role in the global carbon cycle.