Rapid River Fish Hatchery
Thursday, July 31, 2014
The Rapid River Hatchery is located in Idaho County seven miles southwest of Riggins, Idaho. The Hatchery is three miles west of Idaho State Highway 95 on Rapid River Road.
Tours are available for individuals or groups. Visiting hours are 8 a.m. to 4 p.m. every day.
Rapid River originates in Adams County and flows through an undeveloped canyon before reaching the hatchery. The drainage is protected as part of the Wild and Scenic Rivers Act. It is not subjected to perturbations, such as logging or road building. Rapid River generally provides adequate water for rearing salmon. The steep nature of the drainage makes it a highly variable river. Spring runoff and flash floods can be violent and carry tons of silt into the hatchery. Water temperature also varies considerably. The minimum in January can be 33° F and the maximum in August can exceed 60° F.
Fish-rearing facilities at the hatchery consist of: 52 double vertical stack egg incubators, 12 outdoor concrete raceways, and six earthen rearing ponds with concrete side walls. Holding facilities for adult salmon broodstock consist of one concrete holding pond and one earthen holding pond These holding ponds provide space for up to 4,000 adult salmon prior to spawning.
The facilities include a fish trap located on Rapid River approximately 1.5 miles downstream from the hatchery. It is designed to trap and hold adult fish migrating upstream. The trap consists of a permanent concrete velocity barrier, a seven-step fish ladder, and a two-stage trap. Adult salmon can be transferred from the trap by means of an Alaska Steep Pass Ladder to a 500-gallon bucket that is lifted by an overhead hoist to a 1,000-gallon tank truck for transport to the hatchery. The trap facility allows unimpeded migration of anadromous and resident fish around the velocity barrier when trapping operations are not in progress.
The hatchery was constructed in 1964 by the Idaho Power Company. It is operated by the Idaho Department of Fish and Game. All funding for this project is provided by Idaho Power as part of its operating license for Brownlee, Oxbow, and Hells Canyon dams on the Snake River. The Federal Energy Regulatory Commission requires Idaho Power to operate this facility to conserve fish runs that were impacted by the construction of the three dam complex. These dams were built without fish passage facilities with the idea that salmon and steelhead would be trapped and trucked around the dams. When this program failed, Idaho Power provided funds to build Rapid River Hatchery and transplant part of the salmon run here to the undamed Salmon River. In addition to this hatchery, Idaho Power also provides funding for Niagara Springs, Oxbow, and Pahsimeroi hatcheries as part of their steelhead and salmon conservation programs.
The hatchery was constructed in 1964 by the Idaho Power Company (IPC). It is operated by the Idaho Department of Fish and Game. All funding for this project is provided by Idaho Power as part of its operating license for Brownlee, Oxbow, and Hells Canyon dams on the Snake River. The Federal Energy Regulatory Commission requires IPC to operate this facility to conserve fish runs that were impacted by the construction of the three-dam complex. These dams were built without fish passage facilities with a plan to trap and transport salmon and steelhead around the dams. When that program failed, Idaho Power provided funds to build Rapid River Hatchery and transplant part of the salmon run here to the undammed Salmon River. In addition to Rapid River Hatchery, IPC provides funding for Niagara Springs, Oxbow, and Pahsimeroi hatcheries as part of their steelhead and salmon mitigation programs.
The mitigation goal for Rapid River Hatchery is to release three million spring chinook smolts annually. The majority of these fish are released directly into Rapid River. In addition, an agreement between the western states and tribes provides between one hundred thousand and a million fish to be transported to the Snake River and released below Hells Canyon Dam and between fifty and three hundred thousand to be released into the Little Salmon River. The IPC has also constructed a facility below Hells Canyon Dam for trapping adult steelhead and chinook salmon from the Snake River. Spring Chinook salmon from the Hells Canyon Trap are transported to Rapid River Hatchery for spawning and rearing.
Adult Chinook salmon arrive at the Rapid River Trap from May to September. All smolts released from the hatchery have an adipose fin clip for identification. Returning adult fish that do not bear this fin clip are designated as summer Chinook salmon. These summer Chinook salmon are released back into Rapid River to maintain a naturally reproducing population upstream from the hatchery. The hatchery broodstock and wild fish are segregated populations.
When adult fish enter the trap they are removed daily, checked for tags, and measured. Each fish receives an injection of antibiotic to prevent disease. The USDA prohibits their consumption after this treatment.
After processing at the trap, fish for broodstock are transferred to holding ponds at the hatchery to await spawning. Spring Chinook salmon trapped in excess of broodstock needs are released back into fisheries or provided to humanitarian agencies for consumption. The broodstock fish begin to mature by mid-August and the females are sorted for ripeness and spawned. Each female produces 3,500 to 5,000 eggs. After spawning, the eggs from each female are placed into buckets and fertilized with the sperm from a male. The fertilized eggs are taken to the incubation building where they are disinfected with iodine and placed in vertical egg incubators. River water flows through the incubators during the entire incubation cycle. The total number of eggs collected each year depends upon the number of returning females. This hatchery requires a return of 2,400 adults to produce enough eggs to meet release goals. It takes about six weeks for the eyes of the embryonic fish to appear within the eggs. This is called eye-up. Eggs can be handled after eye-up to allow removal of unviable eggs or segregation. The eggs will remain in the incubators until they hatch and develop enough to swim about and search of food. For the earliest spawn this occurs in December and will continue through March for the latter egg takes. The total time needed for the eggs to hatch and for the fry to swim-up depends on water temperature.
Newly emerged fry are fed dry food in the raceways until they are about 2 inches in length. In June, they are each marked with an adipose fin clip to identify their hatchery origin. Coded-wire and PIT tags are imbedded in a percentage to provide information that is more detailed. After marking, the fingerlings are moved to the large rearing ponds. Each pond section can hold about half a million fish. Feeding continues through the summer and fall until water temperatures drop below 35 F°. As water temperature begins to increase in late winter, feeding resumes until the fish are released during March and April. At the time of release, a physiological change occurs (smolting) and the fish begin to show different behavior indicating their readiness to migrate the 600 miles to the Pacific Ocean.
From 1964 to the present, adult spring Chinook salmon returns to Rapid River Hatchery have varied from less than 200 to more than 17,000. Nature continues to be an important ingredient to successful migration and return. Man made barriers pose a challenge to fish. Migration conditions as well as oceanic variables combine to influence the subsequent return of adult salmon to Idaho. Rapid River Hatchery has been rated one of the most successful in the Pacific Northwest. With the addition of fish produced at other facilities, improvement in migration conditions along the lower Snake and Columbia Rivers, the salmon will again provide anglers in Idaho the chance to fish for these magnificent creatures.