Fighting against Zebra Muscles

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Fish Feast on Zebra Mussels

By Will Mikell Article published August 27, 2001

Researchers in natural resources have found evidence of a natural predator that eats zebra mussels, the most aggressive of the exotic nuisance species that have invaded Lake Champlain, the Great Lakes and other inland waterways. The discovery was made on Lake Champlain by a team LED by Mary Watzin, director of the Rubenstein Ecosystem Science Laboratory and associate professor in of natural resources.

Watzin’s crew, using a sophisticated underwater, remote-controlled vehicle, witnessed sheepshead fish using their powerful jaws to crush the mollusks. Most revealing was the sighting of a massive pile of crushed zebra mussel shells.

The researchers also saw yellow perch dining on the zebra mussels, but unlike the sheepshead, the perch were seen eating the mussels whole. The observations are prompting Watzin to look at other impacts of zebra mussels.

"We need to know what eating zebra mussels means to the overall nutrition of these fish," she said. Watzin previously has documented a slow growth rate in yellow perch in Lake Champlain. The increasing abundance of zebra mussels might exacerbate that problem, causing yellow perch to grow even slower, she said. That’s not good news if you’re an angler.

Further research is also underway to determine if both fish (sheepshead and yellow perch) are eating enough zebra mussels to serve as some kind of population control against the pesky mollusks.