SREL Reprint #1768
Development of the zooplankton assemblage in a new cooling reservoir
Barbara E. Taylor, Adrienne E. DeBiase, and Diane L. Mahoney
Savannah River Ecology Laboratory, Drawer E, Aiken, South Carolina 29802, USA
Abstract: We document changes in the developing zooplankton assemblage of a new cooling reservoir in the southeastern United States. Our 3-year study began nine months after the reservoir filled. The reservoir received thermal effluent from a nuclear reactor during cooler months of the first two years of the study. The effluent increased water temperatures by 10-15°C and sharply reduced zooplankton populations, mainly rotifers, at the upper end of the reservoir. At the lower end, the thermal effluent increased temperatures by 3-5°C, but had little detectable effect on the zooplankton. Crustacean zooplankton initially dominated the assemblage at the lower end of the reservoir. A year before reactor operation ceased entirely, their abundances began to decline as populations of threadfin shad (Dorosoma petenense) and other pelagic planktivorous fish increased. We infer that fish predation caused the decline of the crustaceans. Fish predation may indirectly have allowed the rotifer populations to increase by suppressing invertebrate predation or by reducing competition from crustacean grazers for algal food resources.
SREL Reprint #1768
Taylor, B. E., A. E. DeBiase, and D. L. Mahoney. 1993. Development of the zooplankton assemblage in a new cooling reservoir. Archiv fuer Hydrobiologie 128: 129-148.
This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).