Microbial aggregation and degradation of phytoplankton-derived detritus in seawater. I. Microbial succession

Abstract

We have examined the microbial processes associated with degrading detritus from 3 phytoplankters in natural seawater. We describe a remarkably similar and well-defined pattern of microbial succession involving heterotrophic bacteria and bacterivorous protozoa occurring in all 3 cases. It appears that detritus aggregation, degradation and disaggregation are continuous processes occurring in the water column. The similarity in microbial processing of all detritus may be the reason why most particulate matter in the sea appears similar. A 'detritosphere' concept is proposed, under which the detritus-microbe environment may be considered in its natural context. We see the fate of detritus in the water column as aggregation-disaggregation sequences in time and space.