CHICAGO, Feb 23 (Reuters) - U.S. officials declared on Thursday that no Asian carp had reached the Great Lakes and promised to spend $51 million on new strategies aimed at keeping the invasive fish out, such as a water gun to drive them back and a sex pheromone to lure males to their deaths.
“This strategy builds on the unprecedented and effective plan we’ve been implementing since 2010 to keep Asian carp out of the Great Lakes while we develop long-term solutions,” said John Goss, who coordinates the effort led by the White House Council on Environmental Quality.
This year’s effort to keep the carp at bay stands in contrast to the position of several Great Lakes states and many environmental groups that demand a permanent ecological separation of the Great Lakes from the Mississippi River watershed, where the carp are found. About $51 million would be spent this year to keep the carp back, a council official said, while nearly $200 million has been spent altogether on the problem.
The objecting states and environmentalists argue the carp will make their way up through manmade waterways near Chicago and decimate the lakes’ $7 billion fishery.
Asian carp can weigh as much as 100 pounds (45 kg) and environmentalists fear their voracious appetites could threaten the food chain for other aquatic life.
Commercial shippers, tour boat operators and recreational boaters industries want to keep the waterways open, and argue separating the two watersheds could cause flooding problems.
A recent Great Lakes Commission study identified three multibillion-dollar alternatives to separate the two watersheds while maintaining ship traffic and preventing flooding. Goss said the findings will be looked at and will flow into the U.S. Army Corps of Engineers’ own study of the best ways to keep carp out of the Great Lakes.
Silver and bighead carp have been found within 55 miles of electric barriers erected in a connecting waterway near Chicago. Reproducing carp populations are 150 miles away from the barriers, said Charlie Wooley of the U.S. Fish and Wildlife Service.
The federal program includes electrofishing, netting, and water sampling to look for environmental DNA shed by the carp. So far, there have been no Asian carp spotted in the lakes since three were taken from Lake Erie a decade ago, Wooley said.
“This is probably the most heavily sampled body of water anywhere in the world,” Wooley said.
The U.S. Geological Survey was experimenting with a water gun that fires a high-energy pulse of water to drive fish away, which could be employed when the electric barriers are turned off for maintenance, said the agency’s Dr. Leon Carle.
Scientists also are working on extracting a sex pheromone from female carp that could be used to lure isolated males that manage to enter forbidden waters so they could be killed, Carle said.
Another technique under development is a selective poison encased in a “nano-particle” targeted at the carp’s digestive systems, Carle said.
Asian carp dominate broad sections of the Mississippi River, the lower Missouri River, the Ohio River and the Illinois River.