Phytoplankton sinking rate dynamics in the southern Benguela upwelling system

Abstract

Sinking rates of phytoplankton assemblages with diverse and variabletaxonomic composition, growing under a variety of environmental conditions,were measured in St. Helena Bay (South Africa) using the homogenoussample method SETCOL. Sinking rates were found to be influenced bythe duration of the settling experiments. Chlorophyll a sinking ratesranged from 0 to 0.91 m/d but were poorly correlated to phytoplanktoncarbon sinking rates which ranged from 0 to 0.78 m/d. Sinking ratesof phytoplankton populations were significantly correlated not toany of the environmental parameters measured but to taxonomic propertiesof the assemblages