We investigated sinking velocity (ws
) of suspended particulate matter (SPM) in the German Bight. By inferring ws
indirectly from an extensive turbidity data set and hydrodynamic model results, we found enhanced ws
in a coastal transition zone. Combined with known residual circulation patterns, this led to a new conceptual understanding of the retention of fine minerals and nutrients in shallow coastal areas. The retention is likely modulated by algal excretions enhancing flocculation of SPM.