FISHING -- The special fishery for triploid rainbow trout below Chief Joseph Dam on the Columbia River will close Aug. 26 at midnight, five days earlier than initially announced.

State fishery managers decided to close the fishery to minimize the risk to wild steelhead moving into the area, said Jeff Korth, Washington Department of Fish and Wildlife regional fishery manager.

The special fishery, launched to remove triploid trout that escaped from a net-pen facility on Rufus Woods Reservoir in June, was originally scheduled to run through Aug. 31.

Triploid trout are “voracious” eaters and can pose a threat to juvenile steelhead, many of which listed for protection under the federal Endangered Species Act, Korth said.

“Just as we’d hoped, anglers caught hundreds of runaway triploids over the past few weeks,” Korth said. “But now, with increasing numbers of steelhead passing Wells Dam, we decided it was time to close the fishery.”

During the triploid fishery, anglers were required to release any steelhead they intercepted, said Korth, noting that creel checkers found no steelhead in the catch.

“Anglers demonstrated they could distinguish a steelhead from a triploid trout and were diligent about releasing the few steelhead encountered during the fishery,” he said.

The triploid fishery has been open since Aug. 1 on a 17-mile stretch of the Columbia River between the Highway 173 Bridge in Brewster to the Highway 17 Bridge in Bridgeport.