Limitation of primary production by heterotrophic assimilation and transformation of inorganic nutrients

Abstract

The planktonic environment is usually characterized by non-steady state conditions with events of phytoplankton blooms and sedimentation. Inorganic nutrients are stripped from the water column by sedimentation and end up in the sediments where they may be permanently deposited, or nitrogen may be liberated as nitrogen gas by denitrification. A major part of the denitrification activity is a coupled process of nitrification and denitrification which is dependent on a good supply of oxygen to the sediment. Urea may constitute a major part of the total outflux of dissolved N compounds from the sediment.