An effort to build a new, “local” coho salmon broodstock in central Idaho’s Clearwater River drainage reached an important milestone last week with the release of 550,000 hatchery reared juvenile fish that are the offspring of adults that returned to the basin in 2009.
It was the first time in the 17-year history of the Nez Perce Tribe’s coho restoration program that all of 550,000 of the juveniles coho reared annually at Eagle Creek Hatchery came from spawners that had returned to the Clearwater and its tributaries, according to Mike Bisbee, coho project leader for the tribe.
Clearwater coho had officially been declared extinct in 1986. But the NPT’s Clearwater Coho Restoration program has reintroduced the species and is building the flow of spawners into the basin, which is helping with the desired transition to upriver brood sources.
The program began in 1994 as a result of a U.S. V. Oregon agreement between the Nez Perce, Umatilla, Warm Springs and Yakama tribes, Idaho, Oregon and Washington, and the federal government. In the agreement, surplus coho eggs from lower Columbia River hatcheries were to be used to reintroduce the species in the Clearwater subbasin. The first releases of juvenile fish into the Clearwater and tributaries took place following year.
A lack of available space in the Clearwater basin at Dworshak National Fish Hatchery and Kooskia National Fish Hatchery limited the tribe’s ability to rear juveniles to about 300,000 coho per year. The national fish hatcheries are operated by the U.S. Fish and Wildlife Service.
So as part of the agreement, the Oregon Department of Fish and Wildlife’s Eagle Creek Hatchery was to be used to raise 550,000 smolts annually to be released in Idaho. Eagle Creek is located approximately 40 miles southeast of Portland.
The first results from the NPT program were witnessed in 1997 when 85 adult coho were counted at the lower Snake River’s Lower Granite Dam, the eighth and final hydro project the fish pass on their return to the Clearwater. The 1997 return followed a period from 1987-1996 when zero coho were counted at Lower Granite, according to data compiled by the Fish Passage Center.
Since 1997, the returns have been on the rise with some year-to-year variability. The count rose to a peak of 3,802 in 2004, before dropping off to 2,077 in 2005 and then 1,141 in 2006. The counts then climbed steadily each year to a new peak of 4,629 in 2009. That return provided the eggs to produce the juvenile fish released a week ago.
The 2010 returned slumped to 1,509, however, leaving the program short of the number of spawners needed to fill rearing space at Eagle Creek and the two hatcheries in Idaho.
“So far the only year we were able to do that” was 2009, Bisbee said.
Returning adult coho were trapped at weirs at Dworshak NFH on the North Fork of the Clearwater and Kooskia NHF, on Clear Creek, for spawning at the Kooskia facility. The juvenile fish produced were then reared for a year and a half, the bulk of them at Eagle Creek Hatchery.
The Nez Perce Tribe’s CCRP has largely been funded by the Pacific Coast Salmon Recovery Fund through NOAA Fisheries. Mitchell Act appropriations, also channeled through NOAA Fisheries, fund the Eagle Creek rearing operation. Coho produced by the Nez Perce Tribe contribute to Columbia Basin and coastal ocean fisheries.
The construction of Harpster Dam in 1910 eliminated coho salmon access to the South Fork Clearwater River, and in 1927, the Washington Water Power Diversion Dam was constructed just above the mouth of the Clearwater River. Fish passage facilities were not provided at the time of construction, and retrofitted ladders proved impassable for coho salmon, which were subsequently extirpated from the Clearwater River subbasin.
The Harpster Dam was removed in 1963, and the Washington Water Power Diversion Dam was removed in 1972. However, the North Fork Clearwater River remains inaccessible due to the construction of Dworshak Dam in 1972.
A coho restoration attempt was made by the Idaho Department of Fish and Game from 1962 to 1968 in the South Fork of the Clearwater River. But the effort largely failed due to ice formation, de-watering, flooding and siltation and other factors so the program was discontinued,
Meanwhile the tribe recently received a $201,661 federal grant that will allow them to modify an existing streamside facility to allow coho salmon smolts to be acclimated prior to release. The acclimation is expected to increase juvenile survival and adult returns, and improved the ability to collect broodstock and minimize impacts to non-target populations such as wild fall chinook and steelhead that are listed under the Endangered Species Act.
The proposed pond modifications would occur at the existing Nez Perce Tribal Hatchery facility known as the North Lapwai Valley acclimation site. The site is operated by the NPT with funding from Bonneville Power Administration, and is located approximately three-quarters of a mile upstream of the confluence of Lapwai Creek and the Clearwater River. It is currently used to acclimate fall chinook salmon subyearling smolts, which precludes the use of existing facilities for the acclimation of coho salmon.
The NLV satellite currently has two ponds with both a surface and groundwater supply system that can be mixed to control water temperature. The ponds are located in the higher elevation area of the site with discharge entering Lapwai Creek near the State Highway Route 95 bridge crossing.
The plan is to excavate a pond to acclimate up to 550,000 coho salmon down slope from the existing ponds. Bisbee said the goal is to have the coho pond ready for uses by the spring of 2012.