ILLIA, Wash. — The Nez Perce Tribe and Columbia River Inter-Tribal Fish Commission released 37 wild steelhead into the Snake River below Lower Granite Dam near here in mid-November.
The female fish are expected to increase the number of spawning female wild B-run steelhead by about 10 percent this year and represent a unique effort to boost wild steelhead numbers in the Snake River Basin.
The fish, known as kelts, spawned in their natal streams last year and were captured at the dam as they attempted to slip downstream, reach the ocean and regain their strength, all in an effort to return once again to the streams where they hatched.
Steelhead are unique among anadromous fish — fish that migrate from the sea to reproduce — in that they don’t necessarily die after spawning.
A percentage of female steelhead have the ability to repeat spawn. It’s more common in coastal streams but rare this far up in the basin, more than 400 miles from the Pacific Ocean. In order to do it, the fish must repeat the downstream journey they made as juveniles, negotiate their way past eight dams and reach salt water with enough energy left over to forage and grow strong enough to surge upstream again to spawn, after once again passing eight dams.
Doug Hatch, senior fisheries scientist with the Columbia River Inter-Tribal Fish Commission at Portland, said less than half a percent of Snake River steelhead are able to do it on their own. To help boost wild fish populations, the fish that attempt to do so are intercepted at Lower Granite Dam and then taken to Dworshak National Fish Hatchery where they are held for one to two years and reconditioned. Some of the fish are ready to spawn after just one year, while others skip a year.
“They are really valuable fish,” Hatch said. “They have about a third more eggs than the fish that are coming back (for the first time.) These repeat spawners are larger and have more eggs than first-time spawners, so they are super valuable.”
Hatch said they have, on average, about 5,000 eggs, and one large female, a skip spawner, had an estimated 12,000 eggs. The fish are even more prized this year. This fall’s steelhead run is shaping up to be one of the worst on record. The preseason forecast called for only about 700 wild B-run steelhead to return this fall, with about half of those fish being female.
Wild Snake River steelhead are listed as threatened under the Endangered Species Act. The kelt program is listed as one of the emergency responses that could be implemented when fish numbers are alarmingly low. The National Marine Fisheries Service said this week that steelhead numbers have declined steeply since a robust return recorded in 2014. The decline is prompting a review by federal officials to determine if additional steps should be taken to help the species.
Becky Johnson, production director of the tribe’s Department of Fisheries Resources Management, said federal officials have committed to boosting the kelt program by constructing a new facility at the Nez Perce Tribal Hatchery at Cherrylane. The facility is expected to be complete in about two years.