BRIDGEPORT – The Colville Tribes’ Fish and Wildlife program released 178 lampreys at the mouth of the Okanogan River and Coyote Falls on the Similkameen River in a joint effort with the Yakama Nation and Douglas County and Grand County PUDs.
The lamprey were trapped and tagged at the Priest Rapids Dam prior to their release. The tags will be used to help monitor the movement in the Columbia River and tributaries above Wells Dam.
In total, 128 were released in the Okanogan River and 50 were released in the Similkameen River.
Over the last several years, only a single lamprey was counted passing over Wells Dam, but this year, 57 have been detected to date.
“As a result, [the release] was an opportunity to assist in improving the abundance of adult lamprey above Wells Dam, assess migration characteristics and re-establish lamprey in the Okanogan Basin, and improve lamprey pheromone signature in the areas above Wells Dam in an attempt to improve passage past Wells Dam,” reads a notice to the public from CTFW.
The release further notes Pacific lampreys are an anadromous parasitic fish from the Pacific Coast of North America and Asia. Adult lampreys spawn in rivers and then die. The young larvae spend several years in the rivers, where they live burrowed in fine sediment, filter feeding on microorganisms. They undergo metamorphosis and migrate to the ocean where they rear to adulthood before returning to freshwater to spawn.
Pacific lamprey abundance above Wells Dam has seen a precipitous decline in the last decade and has been highly variable in the Columbia River Basin and is thought to be influenced by many of the same factors affecting Pacific salmon. Additionally, adult Pacific lamprey migrations are negatively affected by dams; however, substantial effort is being invested to study and improve passage at the mainstem Columbia River Dams.