OROVILLE — Colville tribal fishermen set up nets in the Similkameen River near Oroville last week, catching some 70 summer Chinook salmon in two days of fishing.

Their fishing method — a beach seine net similar to the purse seine nets they’re using from a boat on the Columbia River near Brewster — is part of the tribe’s larger effort to selectively fish for hatchery salmon while leaving naturally-spawned salmon in the river to return to their spawning grounds.

Scientists reviewing how the Confederated Tribes of the Colville Reservation are managing adult salmon told them they need to remove more hatchery fish from the system, said Joe Peone, the tribe’s fish and wildlife director.

He said in order for the new Chief Joseph Hatchery to be successful, the tribe has to show it can remove a large percentage of the hatchery fish that return to the area, in order to keep the naturally spawning fish populations strong. The net fishing for hatchery salmon in the Similkameen River will likely be a temporary solution, to help the tribe achieve a better ratio of hatchery-to-natural origin salmon on the spawning ground, he said.

Eventually, the tribe hopes to remove many of these hatchery-born fish at a weir that was placed across the Okanogan River this summer.

But that weir is now temporary and in its testing phase, so no fish are being removed as biologists study its impact on the fish that approach it and pass through.

Peone said he hopes in the next four or five years, the tribe will have permission to use the weir to remove hatchery-born fish.

But until then, the Colvilles will use a combination of purse seine net fishing in the Columbia and beach seine net fishing in the Similkameen River to pull the hatchery fish from the system.

Fishing on the Similkameen River — which extends from its confluence with the Okanogan River upstream to Kline Site on state Department of Fish and Wildlife property — will continue through the early part of this month, he said.

The state agency issued a permit allowing them to remove the hatchery fish, he said.

Peone added that many of the summer Chinook have already been captured from their commercial fishing boat, the Dream Catcher, which operates on the Columbia River. An estimated 800 to 900 naturally spawning summer Chinook were released during that process to continue their journey to the Similkameen, he said.

K.C. Mehaffey: 997-2512

mehaffey@wenatcheeworld.com