the film forum library tutorial contact

Where the Wild Chinook Are by Idaho Fish & Game EIN News, July 12, 2023

One of the most valuable samples collected at Lower Granite is a piece of fin tissue, about the size of an eraser head. With this fin tissue, we can evaluate the genetics and determine whether the fish was wild or not and where it most likely came from.

Upstream of Lower Granite Dam there are five unique genetic stocks of spring/summer Chinook: Hells Canyon, South Fork Salmon River, Middle Fork Salmon River, Chamberlain Creek, and Upper Salmon River.

The Hells Canyon stock is an aggregate genetic stock that includes naturally produced Chinook from the Clearwater, Little Salmon, Grande Ronde, Imnaha and lower Snake rivers. The first batch of 2023 fin tissue samples were analyzed earlier in June, and included every wild Chinook trapped and sampled through June 2nd.

Through this early portion of the wild spring/summer Chinook run at Lower Granite, 56% assigned to the Hells Canyon stock, 19% to the Middle Fork Salmon River stock, 17% to the upper Salmon River stock, 7% to the South Fork Salmon River stock, and 1% to the Chamberlain Creek stock.

This early sampling will be mostly represented by spring fish and fish arriving later in the season will be mostly summer fish, as such we expect the proportions of the Hells Canyon stock to decrease, and fish destined for areas in the Salmon River basin to increase.