The spring chinook fishing season on the lower Salmon and Little Salmon rivers is closed because there aren’t enough adult hatchery fish returning to meet spawning goals.
Idaho Department of Fish and Game officials closed fishing this week on the two rivers, putting an early end to an otherwise disappointing season. Fishing was closed on the Clearwater River and its tributaries last month.
Using genetic data from returned fish to predict the run, biologists learned that about 9,100 fish, much fewer than average, were bound for the Rapid River Hatchery near Riggins.
The Rapid River Fish Hatchery is the largest collecting, spawning and rearing facility of spring Chinook salmon in Idaho.
Modeling data showed that about 3,654 chinook would likely show up at the hatchery, which requires 2,353 adult chinook for brood stock, or spawning fish, according to Fish and Game. That would leave approximately 1,300 fish, or about 650 each tribal and sport anglers.
Joe DuPont, regional fisheries manager at Lewiston who monitors the fishery, said sport anglers had already harvested 622 hatchery chinook from the two rivers, which theoretically leaves only 29 fish.
“Using the best data we have, we think the right thing to do is shut this entire fishery down so we can meet brood needs,” DuPont said. “Hopefully, the adults we collect for this year’s brood stock will make a difference in future fisheries.”
Last year’s forecast for the Snake River, which the fish use to enter the Salmon system, called for a return of 107,400, but just 67,595 chinook showed up.
This year’s forecast was predicted at 8,200 wild spring chinook and just fewer than 40,000 hatchery fish, but the numbers didn’t pan out.
Fish spend nearly two years at the Riggins hatchery growing to a length of 4-6 inches before being released into Rapid River to begin their 600-mile journey to the ocean, which can take two months.
One to three years later, they travel back up the Columbia River and into the Snake River to return as adults to Idaho, usually between May and September. Spawning begins around mid-August and is completed by the end of September. Records going back to 1964 show adult spring salmon returns have varied from less than 200 to more than 17,000.
Reduced survival among chinook destined for Idaho waters has been blamed on poor ocean conditions, according to Fish and Game.