Collection and Assessment of Emigrating Snake River Steelhead (Oncorhynchus mykiss) Kelts at Lower Granite Dam
Steelhead, the anadromous form of rainbow trout, are capable of repeat spawning (iteroparity). Current iteroparity rates of wild steelhead in the Snake River system are depressed due to the operation of hydroelectric dams and other anthropogenic factors. Methods are being developed to capture post spawn fish (kelts), recondition fish in a captive environment and release rematuring fish into rivers to spawn naturally. This strategy, known as kelt reconditioning, is being deployed to assist in the recovery of ESA-listed Snake River steelhead populations. The first step in kelt reconditioning is to capture enough kelts capable of survival to meet recovery goals. During 2012-2014, emigrating kelts were collected at Lower Granite Dam, the farthest upriver dam with fish passage. Downstream migrating kelts diverted through a juvenile bypass system were sampled daily from April through June. Collection date, fish size, condition, sex, hatchery or wild origin as indicated by an adipose fin clip, and the presence of injuries were recorded, a tissue sample was taken for genetic analysis, fish were marked with a PIT tag, and fish were either selected for reconditioning or released back into the river. Collection is ongoing, and current results will be reported.
Graham, N., S. Everett, L. Jenkins, A. Pierce, and D. Hatch. 2014. Collection and assessment of emigrating Snake River steelhead (Oncorhynchus mykiss) kelts at Lower Granite Dam. American Fisheries Society Annual Conference, Quebec City, Canada, August 17-21, 2017.