Officials at Yellowstone National Park have turned to an unlikely ally in their battle to protect the native cutthroat trout - the angler.

Park Superintendent Mike Finley opened Yellowstone Lake to fishing on June 1, two weeks earlier than usual, in hopes that eager anglers will catch the lake trout that prey on the cutthroat."We hope the angler catch will assist us in removing as many lake trout as possible, as soon as possible," Finley said. The park itself is also working to deplete alien lake trout.

The early opening date will also mean more cutthroat trout are hooked, and many will die, but that fishery is catch-and-release until July 25 when a limited number can be taken.

Anglers can keep lake trout, and officials said the overall effect of the early opening will save about 10,000 cutthroat. They said each time angler catches a lake trout, he saves 50 cutthroat.

Cutthroat trout are an important source of food for grizzly bears and other wildlife. Larger lake trout, native to the Great Lakes, can eat up to 6,000 cutthroat in their lifetime, Finley said.