The 20th anniversary of the discovery of zebra mussels in the Great Lakes was marked last week with regret and a warning by U.S. and Canadian conservationists.Click on Title link to view entire article. Thanks to Jane Dauffenbach, Aquarius Systems, for the submission.
The tiny mussels are an invasive species that wreak havoc on aquatic ecosystems.
"It's time to stop thinking of them as a Great Lakes crisis," said Jennifer Nalbone of Great Lakes United on a conference call. "The invasion struck suddenly, spread quickly and now it's a national crisis."
In Wisconsin, the zebra mussel has invaded the Mississippi River and roughly 75 inland bodies of water, said Philip Moy, a fisheries and invasive species specialist with the University of Wisconsin-Madison Sea Grant Institute.
"But we have 15,000 water bodies in the state and the mussels are only in one half of one percent of our state waters," he said.
The invasion of quagga mussels in Lake Michigan is even more serious - beds of zebra mussels in the lake have been colonized and overgrown by quaggas. Dense quagga populations, close to 40,000 per square meter, have been observed by scientists at the University of Wisconsin-Milwaukee's Great Lakes WATER Institute.
Zebra mussels are fingernail-sized mollusks that look like little striped clams. They attach themselves to hard surfaces such as the shells of native mussels, boats, water pipes, dock pilings and submerged rocks. They grow in clusters in algae-rich shallow water. In winter, they are dormant and do not feed.
Quagga mussels can live on lake bottoms where the water is deep and cold, as well as in warm and shallow waters. Quaggas are never dormant and feed continuously.
Wednesday, March 26, 2008
This is NOT really an anniversary one wants to celebrate, but the invasive species, zebra mussels, were first discovered in the Great Lakes twenty years ago, according to an article in the Milwaukee Journal Sentinal.