Great Lakes Environmental Directory Great Lakes Great Lakes environment Great Lakes grants exotic species water pollution water export drilling environment Great Lakes pollution Superior Michigan Huron Erie Ontario ecology Great Lakes issues wetlands Great Lakes wetlands Great Lakes Great Lakes environment Great Lakes watershed water quality exotic species Great Lakes grants water pollution water export oil gas drilling environment environmental Great Lakes pollution Lake Superior Lake Michigan Lake Huron Lake Erie Lake Ontario Great Lakes ecology Great Lakes issues Great Lakes wetlands Great Lakes Resources Great Lakes activist Great Lakes environmental organizations Great Lakes Aquatic Habitat air pollution alien species threatened rare endangered species ecological Great Lakes information Success Stories Great Lakes Directory Home/News Great Lakes Calendar Great Lakes jobs/volunteering Search Great Lakes Organizations Take Action! Contact Us Resources/Links Great Lakes Issues Great Lakes News Article About Us Networking Services

Great Lakes Article:

Biologists discover Lake Erie silver trove

 

02/08/2002

ohio news

Bill Sloat Plain Dealer Reporter

 

With the glee of treasure hunters searching for sunken casks, U.S. and Canadian fishery biologists exploring the Great Lakes say they've spotted a different type of trove sparkling in the waters of Lake Erie.

 

Some even quip they've found "the Pisces of ate."

 

What's got them buzzing is an all-but-extinct native fish called the silver chub, which is reappearing in Ohio in abundant numbers. It's an unexpected resurrection for a ghost fish.

 

The return of the silver chubs after their virtual absence of almost a half-century is good news on two fronts for the lake.

 

The chubs are extremely sensitive to pollution, so their presence indicates that Erie is continuing to get cleaner. Moreover, these little fish, which aren't eaten by humans, seem to have an unquenchable hunger for zebra mussels, the exotic pests that have infested U.S. waterways.

 

Only one other species of North American fish - the sheepshead - has successfully integrated zebra mussels into its diet. So far, eating mussels have been detrimental to all the rest, scientists say.

 

For example, Lake Michigan white fish are in steep decline. Even when their stomachs are filled with shells, their health fails because they can't get any nutrition, said Tom Nalepa, a research biologist with the Great

Lakes Environmental Research Laboratory in Ann Arbor, Mich.

 

"Nature sometimes works in mysterious ways," said Nicholas E. Mandrak, a research scientist with the Canadian Department of Fisheries and Oceans. "A nuisance moves into the neighborhood and the chubs discover they have a taste for it, and now they're coming back in huge numbers."

 

Mandrak, formerly on the faculty at Youngstown State University, said silver chubs originally evolved to eat small clams and native mussels.

 

They were all but gone from Lake Erie by 1953, killed off by the industrial waste and other toxic substances dumped into the lake up through the 1970s. The pollution caused excessive growth of algae. When the algae died and decayed, they used up all the oxygen near the lake bottom, making it difficult for the chubs to survive.

 

However, Mandrak doubts that the chubs will ever to be able to eliminate the zebra mussels. "It's not the solution. There will never be enough" chubs, he said. "But if they can make a dent, that would be pretty incredible."

 

The zebra mussel hitch-hiked from Europe on freighters that unloaded ballast water in the Great Lakes in the late 1980s. Since then, they have invaded every major waterway east of the Mississippi River. Sewer lines and water intakes are blocked by the mussels, which also kill off native mussels.

 

The zebra mussels eat algae, filter plankton and gobble up other micro food sources for fish. They encrust rock ledges, reefs, shipwrecks and docks - and grow virtually unchecked.

 

Although the food chain has suffered, the mussels still have helped clear up lakes and streams, experts say.

 

Silver chubs also are a good source of food for other lake fish.

 

Jeff Tyson, an Ohio Department of Natural Resources wildlife expert, said the chubs are bottom feeders with flesh "that's fatty, oily and packed with energy." Among fish in the lake, he said, the chub probably are preferred by pike and muskies.

 

"The silver chubs aren't exactly overrunning the lake, but they are coming back strong," he said.

This information is posted for nonprofit educational purposes, in accordance with U.S. Code Title 17, Chapter 1,Sec. 107 copyright laws.
For more information go to: http://www.law.cornell.edu/uscode/17/107.shtml. If you wish to use copyrighted material from this site for
purposes of your own that go beyond "fair use," you must obtain permission from the copyright owner.


Great Lakes environmental information

Return to Great Lakes Directory Home/ Site Map