CAN WIND-INDUCED RESUSPENSION OF MEROPLANKTON AFFECT PHYTOPLANKTON DYNAMICS

Data from Lake Apopka, Florida, are presented to illustrate the import ance of wind-induced resuspension of sediments in a shallow, subtropic al, hypereutrophic lake. Wind-induced resuspension of meroplankton, pr imarily planktonic diatoms that settle to the benthic environment, acc ounts for a large component of the temporal variation in phytoplankton biomass. Chlorophyll concentrations >100 mu g/L are highly correlated with wind speed, and the regression of wind speed on chlorophyll acco unts for 53% of the temporal variability in chlorophyll. Resting cells of diatoms are also resuspended with the meroplanktonic community. In duction of resting cells that are physiologically dormant occurs in da rkness; but within a few hours after exposure to the water-column ligh t and nutrient environment, resting cells become physiologically activ e. Other types of resting propagules in addition to diatom resting cel ls also may be resuspended from sediments and affect phytoplankton dyn amics. Data from Lake Apopka and other systems are used to develop par adigms about time and depth scales for resuspension of meroplankton an d resting propagules in lakes and in the sea.