Heterotrophic utilization of extracellular products of phytoplankton in a tropical estuary

Bacterial uptake of algal exudates has been estimated in a tropicalestuary, Dona Paula, where the seasonal fluctuations in hydrographicand nutrient parameters as well as dissolved organic matterconcentrations and phytoplankton species composition are dominatedby the monsoon regime. A close coupling existed between algaland bacterial trophic levels. Algal exudation products wererapidly assimilated with short turnover times. An average 80%of the excreted material was removed by heterotrophic bacteriaand there was a significant correlation between algal extracellularproduction and net bacterial uptake of algal exudates.