Experiments on resuspension of natural microphytobenthos populations

Laboratory experiments on resuspension of benthic diatoms were performed in 1988 on intact cores of sediment obtained from 2 transects in the Ems Estuary (Dutch Wadden Sea, NW Europe). In the experiments, which were performed in a small carousel system, the percentage of resuspended diatoms increased concomitantly with angular velocity of the agitating paddles. Maximum microphytobenthos resuspension in terms of cell numbers was up to 45% of the total population present in the 0.5-cm top layer, and up to 11% in terms of chlorophyll a. Maximum sediment resuspension was 6%. The results show that the presence of a diatom film (numerous cells on the sediment surface) increases sediment stability, thereby suppressing resuspension of sediment and diatoms.