FISHERIES -- A temporary picket-style salmon weir recently has been installed on the Okanogan River about 15 miles upstream from its confluence with the Columbia River near Brewster, the Colville Tribe reports.
The structure spans the Okanogan river, but leaves room along the west bank for small waterdraft to pass around the weir.
The weir was installed a mile downstream from Malott Bridge during three weeks of construction by Chief Joseph Hatchery staff to test methods for sampling chinook salmon heading upstream to spawn. The river can flow through the weir but the picket slots form a barrier to upstream-bound adult salmon and angles them into a trap.
“This summer we will watch for any negative effects the structure may cause,” said Keith Wolf, the hatchery's lead scientist. “We will be able to count fish, and get good estimates on the salmon returning to the Okanogan River. After closely monitoring the site for the next several weeks, we will see how salmon react to the weir and we’ll make any necessary modifications we need to for the permanent structure.”
The weir allows the staff to manage summer-fall chinook, sorting out fish of hatchery origin while releasing wild fish to continue their spawning migration.
Joe Peone, Colville Confederated Tribes (CCT) Fish and Wildlife director, explained in a media release:
“This project plays an important role in adult management of summer Chinook that are destined for the spawning grounds in the Similkameen River and the U.S. portion of the Okanogan River. It allows managers to manage natural-origin (NOR) summer Chinook to be the primary spawners (70%) and allows us to control the number of hatchery-origin spawners (HOR) about (30%) on the breading grounds.
In return, the CCT will be able to harvest the HOR summer Chinook and distribute to the CCT members,” he said. “At the same time, we want to make sure our Okanogan weir does not hinder any salmon stocks from migrating up the river. This is why we are doing a two-year feasibility study to monitor adult behavior as they approach the weir.”
The Okanogan River test weir was funded by Grant County Public Utility District and will be operating until the end of September.
Peone said the hatchery staff will operate the weir and communicate with resource agencies regarding the project findings.
