With a bumper crop of fish streaming up the Columbia and Snake rivers this year, the Idaho Department of Fish and Game has begun to trap and move steelhead from the Snake River to the Boise River to provide extra opportunities there for anglers.
A total of 333 steelhead that are in excess of hatchery needs were released Nov. 10 in the Boise River, the first of at least three planned stocking efforts. Another 330 steelhead will be stocked in the Boise River on Thursday, with a third stocking effort tentatively planned for the week of Thanksgiving. The fish are being released between the Glenwood Bridge and Barber Park.
A higher than normal proportion of the steelhead return this year has spent two years in the ocean, rather than one. The result is a 9-pound average per fish, which is much greater than last year’s average.
“I think it’s a remnant of last year’s huge return,” the IDFG’s Pete Hassemer said of a record record return that was dominated by “1-ocean” fish. This year their broodmates, which lingered in the Pacific Ocean for an extra year, have returned in force. The fish likely benefited from favorable ocean conditions when they left freshwater as juveniles in 2008.
Because fish released will be older and larger, the transport truck may not be able to haul quite as many per load as in recent years, but the larger fish should add to the excitement generated by the fishery.
The fish are so-called “A-run” hatchery steelhead that are returning to the Oxbow Hatchery fish trap below Hells Canyon Dam on the Snake River. The hatchery, operated by the IDFG, is owned and funded by Idaho Power Company. Many of the returning steelhead will be collected as broodstock for the steelhead hatchery program at Oxbow Hatchery as part of Idaho Power's mitigation.
"We're hopeful that this year's hatchery steelhead run will easily allow Oxbow Hatchery personnel to fill their broodstock needs," IDFG anadromous fish coordinator Sam Sharr said. "Any additional hatchery fish collected at the fish trap will be divided among Idaho Fish and Game, the treaty tribes and the Oregon Department of Fish and Wildlife."
Steelhead once were able to make it upriver as far as Boise and the Boise River but their path has long since been blocked by a complex of three Idaho Power hydro projects on the Snake River in Hells Canyon along the Idaho-Oregon border. Fish passage was not provided at the three projects. Hells Canyon is the lowermost of the three dams.
In recent years, improved steelhead returns have allowed fishery officials trap fish that are in excess of the hatchery’s broodstock needs and drop some of them into the Boise.
“It’s probably been the past dozen years that we’ve been able to do it almost every year,” said the IDFG’s Ed Mitchel.
“It’s been a very, very good year,” he said the most recent return. The steelhead count from July 1 through Nov. 14 this year at Lower Granite Dam was 192,246, which is well above the five-year average count through that date, 177,088. That average includes last year’s record counts – 308,691 through Nov. 14 and 312,430 by season’s end. Lower Granite on the lower Snake River is the eighth and final federal hydro project that the steelhead pass on Columbia and Snake on their way to streams and hatcheries in Idaho, Oregon and Washington.
Idaho's steelhead, which are rainbow trout that migrate to the ocean, are often classified into two groups, A-run and B-run, based on their size and ocean life history.
Idaho's A-run steelhead are usually found in the Snake and Salmon rivers. They return from the ocean earlier in the year (usually June through August) and they most often return after spending one year in the ocean. Because they return early in the year and because they usually come back after only one year in the ocean, they typically weigh between 4 and 6 pounds and are generally 23 to 26 inches in length, according to the IDFG.
The B-run steelhead most often return to the Clearwater River, but some return to tributaries in the Salmon River in Idaho. These fish usually spend two years in the ocean, and start their migration to Idaho later in the summer or fall of the year (usually late August or September). Because of the extra year and the extra summer of growing in the ocean, they return as much bigger fish.
Average B-run steelhead weigh between 10 and 13 pounds and are 31 to 34 inches long. Steelhead grow very large when they spend a third year in the ocean before they return to Idaho to spawn. These steelhead are usually larger than 37 inches and often weigh more than 20 pounds. The Idaho state record steelhead was 30 pounds and was caught in the Clearwater River in 1973.
Besides a fishing license, anglers hoping to tangle with one of the hatchery steelhead need a $12.75 steelhead permit, good for 20 fish. Though required in other steelhead waters, barbless hooks are not required for Boise River steelhead angling.
All steelhead stocked in the Boise River will lack an adipose fin -- the small fin normally found immediately behind the dorsal fin. Boise River anglers catching a rainbow trout longer than 20 inches that lacks an adipose fin should consider the fish a steelhead.
Any steelhead caught by an angler not holding a steelhead permit must immediately be returned to the water. Steelhead limits on the Boise River are three fish per day, nine in possession and 20 for the fall season.
For more information regarding the Boise River steelhead release, contact the Fish and Game Nampa office at 208-465-8465 or check the department's Web site at http://fishandgame.idaho.gov/cms/fish/steelhead/.