U.S. conservation federation latest to call for action to keep Asian carp out of Great Lakes

The National Wildlife Federation is the latest group to call for closing the locks that connect the Mississippi River system with Lake Michigan in an effort to prevent Asian carp from reaching the Great Lakes. At the national conservation group's annual meeting in Houston on Friday, members unanimously passed a resolution calling for the river to be separated from the lakes. It's a step that has been vigorously opposed by the shipping industry, the tourism industry in Chicago and Illinois lawmakers.

"The National Wildlife Federation realizes this is a hugely important issue, not just for the Great Lakes but for all U.S. waters," said Jordan Lubetkin of the federation's Great Lakes office. "Invasive species are a problem that has to be tackled aggressively and immediately."

Asian carp are considered a major threat to the ecosystem of the Great Lakes, as well as the tourism and fishing industries. After being brought to the Unites States in the 1970s, the invasive fish have been making their way north through the Mississippi River system.

They can grow to 4 and 5 feet, weigh as much as 100 pounds and eat 40 percent of their body weight daily. If they reach Lake Michigan in large numbers, conservation groups fear they will quickly crowd out native fish species and spread throughout the Great Lakes.

In January, researchers announced Asian carp DNA had been found in Lake Michigan at Calumet Bay and a half-mile up the Calumet River. A DNA sample can include fish tissue, scales or feces, but does not necessarily mean the fish are there.

Elected officials in the region, led by Michigan Attorney General Mike Cox, have tried legal maneuvers to force closure of the locks and canal system that connect the Mississippi River system. Last month, the U.S. Supreme Court declined to grant Cox's request for an injunction forcing the closure of the navigational locks.

Later this month, justices are expected to consider reopening a 1922 decision that cleared the way for Illinois to divert water from Lake Michigan south through the Chicago Sanitary and Ship Canal. That canal is considered one possible way for the carp to reach the lake.