CODY, Wyo. (AP) — Wildlife officials have been catching and killing as many walleye salmon as they can for the past three weeks at a Wyoming reservoir.

The Cody Enterprise reports Wyoming Game and Fish Department officials are killing off the invasive fish at Buffalo Bill Reservoir to keep the species from overwhelming and killing the smaller cutthroat trout.

Game and Fish officials say the process will go on indefinitely because the walleye cannot be eradicated.

Walleye were illegally introduced to the reservoir by an unknown party in 2002 and they grow larger and devour the cutthroat. As a policy, the agency has stated it has the responsibility to protect and restore the native cutthroat in this region.

The department wants to maximize its removal of walleye at a key spawning time