TRAVERSE CITY, Mich. — Charter boat operators in the Great Lakes say Congress might be giving up on a permanent solution to the threat of invasive Asian carp.

The government has spent millions of dollars to prevent bighead and silver carp from reaching the lakes from the Mississippi River watershed, where they compete with native fish species.

But some charter captains say more is needed. They want structures placed in Chicago-area waterways to separate the Mississippi and Great Lakes systems. That would require funding from Congress.

Denny Grinold of Fish N’ Grin Charter Service in Michigan says he fears lawmakers are getting “Asian carp fatigue” and are losing interest in a permanent fix.

Dave Spangler of the Lake Erie Charter Boat Association says a carp invasion would devastate the lake’s walleye and perch populations.