Studies of Adult and Larval Zebra Mussel Populations in Conesus Lake, NY

Abstract

The goal of this study was to assess the status of the zebra mussel population (Family Dreissinidae, species Dreissena polymorpha) in Conesus Lake by sampling benthic adults and planktonic larvae during the summer reproductive season. Another invasive dreissinid bivalve, the quagga mussel, D. bugensis, has firmly established itself in some of the larger Finger Lakes, including Seneca and Canandaigua Lake. Therefore a second goal of this study was to determine if quagga mussels had invaded Conesus Lake. In this report we provide data on population numbers and size distribution of adult zebra mussels and describe temporal patterns of larval density and cohort development. Water quality data for are also provided for a deep-water station where larvae were sampled. Our observations indicate that, while populations of adult mussels have declined by about 20% since the year 2000, adult densities and the supply of larvae are still moderately high and the species seems to be well established in Conesus Lake.