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| Significant fish predation on zebra mussels Dreissena polymorpha in Lake Champlain, U.S.A.
M. C. Watzin†*, K. Joppe-Mercure†, J. Rowder†, B. Lancaster† L. Bronson†
† Rubenstein Ecosystem Science Laboratory, Rubenstein School of Environment and Natural Resources, University of Vermont, 3 College Street, Burlington, VT 05401, U.S.A.
Correspondence to *Tel.: +1 802 859 3086; fax: +1 802 859 3089; email: [email protected]
Copyright Journal compilation © 2008 The Fisheries Society of the British Isles
KEYWORDS
diet composition • freshwater drum • non-native species • pumpkinseed
ABSTRACT
The objectives of this study were to: (1) determine which fishes were consistently eating zebra mussels Dreissena polymorpha in Lake Champlain and document their feeding behaviour and (2) quantify the diet composition of the fish predators that were found to consume zebra mussels. From 2002 to 2005, freshwater drum Aplodinotus grunniens, pumpkinseed Lepomis gibbosus, yellow perch Perca flavescens and rock bass Ambloplites rupestris all consumed zebra mussels at varying frequencies and amounts. Aplodinotusgrunniens and L. gibbosus chewed clumps of zebra mussels, expelling shells, whereas P. flavescens and A. rupestris swallowed small individuals whole. Lepomis gibbosus consumed zebra mussels at the highest frequency (65–89% of prey consumed) and zebra mussels comprised a large part of this fish's diet (up to 40% by dry mass). Zebra mussels were also an important component of the diet of A. grunniens (up to 59% of the diet by dry mass, 40–63% frequency of consumption). The percentage of the diet comprising zebra mussels in P. flavescens and A. rupestris varied significantly from year to year but never exceeded 10%. Because A. grunniens and L. gibbosus crushed zebra mussels, the nutritional return from consuming zebra mussels would be similar to other prey; for P. flavescens and A. rupestris zebra mussels were only partially digested and the nutritional return would probably be low. As predation on zebra mussels is widespread and significant, it is possible that fish predators could contribute to regulating the population of zebra mussels in Lake Champlain.
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Member
Posts: 1314
Location: Menasha, WI | Good find Larry. I know from fileting Winnebago perch this summer that they're feeding on zebra mussels. I hope they don't figure out how to crush them like the sheephead otherwise they'll be too fat and happy to bite my hook  |
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Member
Posts: 2445
Location: Fremont, Wisconsin | Yea Viking, it has stopped the sheephead from biting, LOL |
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Member
Posts: 1314
Location: Menasha, WI | Good point but I think the sheephead are kind of like my youngest kid, they'll eat anything whereas the perch are more like my oldest, they're a bit more finicky. |
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Member
Posts: 2445
Location: Fremont, Wisconsin | If your oldest is anything like mine, they may not be so picky, but looking for an easy meal, and, when they start eating the free stuff, they will eat till full rest 5 mins and start again. Sheeps seem to be alot like that. Maybe the greedy perch will like them zeebee's and grow huge. Then they will take our easy meals over crushing the zeebee's for a treat. |
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