Tributary Non-native Trout Suppression and Eradication
On March 20, 2013, the City of Seattle was awarded a 42-year license
for Seattle City Light's 1,040-megawatt Boundary Hydroelectric Project (FERC No. 2144), located on the Pend Oreille River in Pend Oreille County, Washington. The license stipulates that City Light shall implement several fish and aquatic resource measures under Settlement Agreement License Article 9
. In consultation with Project stakeholders that comprise the Fish and Aquatics Work Group, City Light developed a Fish and Aquatics Management Plan
to guide measures that will be implemented over the Project license period.
The objective of the tributary aquatic habitat program is to establish self-sustaining, naturally
reproducing native stocks of fish and provide access to and improve habitat conditions in
tributaries draining to Boundary Reservoir. Westslope Cutthroat Trout, Bull Trout and Mountain Whitefish are native salmonids and the focal species of recovery efforts.
Non-native salmonid species are an important factor contributing to the decline of native fish populations in the Pend Oreille River and its tributaries. Most of the tributaries to the Pend Oreille River, including Boundary Reservoir, have been stocked with non-native trout species such as Eastern Brook Trout, Brown Trout, and Rainbow Trout. The presence of non-native trout, especially Eastern Brook Trout, has been identified as a serious threat to native salmonids due to competition for habitat and food resources, and predation. Biological treatments shall include suppression or eradication of non-native fish in tributary reaches and selected lakes draining to Boundary Reservoir.
Suppression is the mechanical removal of non-native fish species primarily by use of electrofishing crews; suppression is most often used in systems where migration of non-native fish from outside the treatment reach cannot be prevented. Eradication is the use of an approved piscicde (pesticide for fish) to treat streams isolated from other fish populations by a natural barrier. Streams scheduled for eradication treatments will be re-stocked with locally sourced native salmonids; the Native Salmonid Conservation Facility program (currently in design) will support reintroductions of native trout into streams targeted for non-native trout eradication treatments.
Treatment Activity Schedule