Friday, May 24, 2019

Corps OKs plan for keeping Asian carp out of Great Lakes; it's more expensive than first draft and might not be effective

Milwaukee Journal Sentinel maps show drainage near Chicago, including the Little Calumet River, where an adult Asian carp was found in June 2017, and Lake Calumet, where environmental DNA of two Asian carp species was found recently.
The Army Corps of Engineers will ask Congress for $778 million for its latest plan to keep Asian carp out of the Great Lakes. "The strategy calls for installing devices such as noisemakers, air bubbles and an electric barrier to deter the fish," The Associated Press reports. "Scientists say if Asian carp become established in the Great Lakes, they could out-compete native fish."

The devices would be installed at the Brandon Road Lock and Dam on the Des Plaines River near Joliet, Illinois, AP reports: "It's considered a chokepoint where Asian carp and other invasive species could be prevented from migrating into Lake Michigan." The Corps already has an electric barrier farther upstream, past the northernmost set of locks on the canals connecting to Lake Michigan.

Silver carp (top) and bighead carp, species whose DNA was
found. (Asian Carp Regional Coordinating Committee photo)
The plan is much more expensive than a $275 million draft plan that the Corps announced last year, and it might not be effective. Brandon Road is 140 miles south of Lake Michigan, but the fish may already be on their way to getting established between the dam and the lake. "Researchers with the U.S. Fish and Wildlife Service have found environmental DNA of two species of carp in a lake that's just a few miles from Lake Michigan," Tracy Samilton reports for Michigan Radio.

"Environmental DNA comes from things like fish scales. It's an indicator that the fish could be present," Samilton reports. "The eDNA that was recently found came from samples from Lake Calumet." In June 2017, an adult carp was found in the Little Calumet River, in the same area.

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