Battle Plans for Asian Carp

Asian carp are the new poster fish in the campaign against invasive species. For years, foreign invaders like the zebra mussel, the round goby, and now the carp have been threatening the ecosystem of the Great Lakes. Like their fellow species of concern, the carp have no natural predators to keep their numbers in check. Ecologists report that they are now closing in on Lake Michigan from the Mississippi and Illinois rivers. This has authorities in the U.S. and Canada stepping up efforts to control them. The Great Lakes Radio Consortium’s Diantha Parker reports:

Transcript

Asian carp are the new poster fish in the campaign against invasive species. For years, foreign invaders like the zebra mussel, the round goby, and now the carp have been threatening the ecosystem of the Great Lakes. Like their fellow species of concern, the carp have no natural predators to keep their numbers in check. Ecologists report that they are now closing in on Lake Michigan from the Mississippi and Illinois rivers. This has authorities in the U.S. and Canada stepping up efforts to control them. The Great Lakes Radio Consortium’s Diantha Parker reports:


The Asian carp now in the spotlight are the silver and bighead varieties, and they share traits that worry environmentalists.


For one thing, they’re large…sometimes reaching up to a hundred pounds in less than three years. They escaped from fish farms in Mississippi about twenty years ago, and have been making their way up the Mississippi River ever since.


The carp voraciously consume the same microscopic organisms that native fish depend on.


They’ll out-eat anything in their midst. That means game fish won’t have as much to eat, and their populations will suffer.


And the carp are invasive in other ways, too. At a recent news conference a few yards from Lake Michigan, journalists and curious passersby inspected three enormous dead carp laid out on a folding table…glistening in the sun next to Pam Theil, a project leader at the U.S. Fish and Wildlife Service.


“It sounds sensational, but they can jump out of the water into your boat. A gentleman who works for the Illinois Natural History Survey has gotten hit four times, the last time he had to file for workman’s compensation with a neck injury. A commercial fisherman on the Caskaskia River got his nose broken. And there are reports of people on the Caskaskia, who are going out fishing, or just recreation in their boat…they’re taking cookie sheets with them to act as a shield, so that they don’t get hit.”


The newest weapon in the Great Lakes Fight against the carp is an electronic barrier.
It was built in April by the Army Corps of Engineers and the International Joint Commission, an organization that oversees the use of waterways between the U.S. and Canada.


The electronic barrier sits in the Chicago Sanitary and Ship Canal about 30 miles downstream from the city. The Canal is a manmade link between Lake Michigan and the Chicago River. This particular spot was chosen for the barrier because it’s a revolving door between the Great Lakes and the Mississippi River basin.


The barrier itself consists of about one hundred and sixty wires, spaced a few feet apart, that lie crosswise along the bottom of the canal. The wires emit electrical impulses to deter all fish that approach them.


“There is a charge that is applied to those cables.”


Dennis Schornack is U.S. chairman of the International Joint Commission.


“Not a real strong charge, not one that would be harmful to people, if they fell into the
canal, but strong enough for fish to sense it, and when they sense this charge in the water they turn, and turn back down the river.”


Right now, the electronic barrier is only in an 18 month test phase. The authorities involved say after that time is up, funding from Congress will be needed to keep it in operation.


Some people wonder why we can’t just catch these invasive carp and eat them. But while the carp are a popular food source in Asia, they’ve been slow to catch on here, says Pam Theil.


“I think that there is a mentality that we’d rather be eating walleye or something than carp.”


But a chicken processing plant in southern Illinois has looked into processing the carp…they’ve taste tested it as a product similar to tuna, but are still deciding whether it’s marketable.


For the Great Lakes Radio Consortium, I’m Diantha Parker.