Can Wind-Induced Resuspension of Meroplankton Affect Phytoplankton Dynamics?

Data from Lake Apopka, Florida, are presented to illustrate the importance of wind-induced resuspension of sediments in a shallow, subtropical, hypereutrophic lake. Wind-induced resuspension of meroplankton, primarily planktonic diatoms that settle to the benthic environment, accounts for a large component of the temporal variation in phytoplankton biomass. Chlorophyll concentrations >100 μg/L are highly correlated with wind speed, and the regression of wind speed on chlorophyll accounts for 53% of the temporal variability in chlorophyll. Resting cells of diatoms are also resuspended with the meroplanktonic community. Induction of resting cells that are physiologically dormant occurs in darkness; but within a few hours after exposure to the water-column light and nutrient environment, resting cells become physiologically active. Other types of resting propagules in addition to diatom resting cells also may be resuspended from sediments and affect phytoplankton dynamics. Data from Lake Apopka and other systems are used to develop paradigms about time and depth scales for resuspension of meroplankton and resting propagules in lakes and in the sea.