See Figure 10-16. El Nino results is less upwelling of nutrients and the surface nutrients then become depleted. What is the consequence of this fact for fish biomass. Oceanic food chains are longer. Since there is a large loss in biomass at each transfer between trophic levels, the fish biomass in oceanic areas is low.
Respiration is the oxydation of organic matter to release energy.
They separate Oxygen from SO 4 and use it in the respiration reaction.