Graham, D.M., W.G. Sprules, and S.J. Nepzy, 1992. Effects of Zebra Mussels on the Diets and Growth of Juvenile Yellow (Perca flavescens) and White Perch (Morone americana) in Lake Erie, University of Toronto.

Reprinted with Permission from Journal of Shellfish Research (1992) 11(1): 226-227

Effects of Zebra Mussels on the Diets and Growth of Juvenile Yellow (Perca flavescens) and White Perch (Morone americana) in Lake Erie

Abstract
Since their appearance in 1987 in western Lake Erie, zebra mussels (Dreissena polymorpha) have depleted algal resources and likely altered the zooplankton community. Since young fish rely on certain species and sizes of zooplankton, it is hypothesized that these changes in community structure will have a negative effect on their condition and growth. Results indicate a reduction in growth rate for young-of-the-year yellow perch (Perca flavescens). Weight increased by a factor of 1.04 per day for YOY yellow perch in 1988, when zebra mussel densities were low, and only by a factor of 1.013 per day in 1990 when zebra mussel densities were high. No difference in growth rate were evident for YOY white perch Morone americana The diet of 1990 yellow perch may explain this apparent reduction in growth. Early in the season they consumed mostly Daphnia but as the summer continued Daphnia were no longer consumed and diet diversified as the fish consumed a greater number of taxa. White perch have a broader diet and are therefore less likely to be adversely affected by the reduction of a single prey taxon.

Contact: W. Gary Sprules, University of Toronto, Department of Zoology, 3359 Mississauga Road, Mississauga, ON L4T 1L9, CANADA
Key Words: Zebra_mussel, Environmental_impacts, White_perch
Product Type: Research, Impact
User Type: General