Coho Salmon Production in the Clearwater River VII

The project is complete. We reared Coho salmon from brood year 2007 (BY 07). In the fall of 2007, a total of 561 adult Coho salmon were collected from hatchery ladders in the Snake River sub-basin. In total, 236 females were spawned yielding approximately 355,500 eyed eggs. On 12/28/07, an additional 100,000 eyed eggs were transferred from Eagle Creek NFH to Dworshak NFH. Of these, 30,000 Eagle Creek stock eggs were transferred to the Potlatch Corporation for fry releases (Orofino Creek) in the spring of 2008. On 1/15/08, a brief power outage caused a rapid decrease of ~ 10 degrees F in the water supplied to the BY 07 Coho eggs/alevins. As a result mortality and coagulated yolk sacs significantly increased in the BY 07 Coho. The increase of dead eggs/alevins also resulted in an increase of fungus and intensified early rearing mortality in the BY 07 Coho at Dworshak NFH. On 3/27/08 and 3/28/08, 334,000 Coho fry were ponded from Dworshaks nursery to outside rearing raceways. The BY 07 Coho will rear in these raceways until March 2009 at which point they will be transported to Kooskia NFH. In early July, 40,561 Eagle Creek stock and 80,777 Clearwater stock Coho pre-smolts were coded wire-tagged by Mike Tuell, the Marking Coordinator for the Nez Perce Tribe Fisheries Research Department. A different tag code was applied to each stock to help assess smolt to adult survival between the two stocks. As of 11/30/08 we have (234,100) Clearwater stock and (51,680) Eagle Creek stock Coho pre-smolts on station at Dworshak NFH. These Coho are scheduled for release in the spring of 2009 from Kooskia NFH following a 4-6 week acclimation period. Staff at Eagle Creek NFH is currently rearing enough BY 07 Coho salmon to meet the U.S. Fish and Wildlife Services rearing obligation of 550,000 smolts. As of 11/30/08 Eagle Creek has 556,827 smolts reserved for the Nez Perce Tribe Coho Project. These fish are reared at Eagle Creek NFH to the smolt stage and transported to Idaho for release into Lapwai Creek and Clear Creek in March 2009.
We trapped and reared Coho salmon from brood year 2008 (BY 08). In the fall of 2008, 4,770 returning Coho salmon were counted across Lower Granite Dam. This is the highest return of Coho to the Snake River sub-basin since restoration efforts were initiated by the Nez Perce Tribe. Although this is speculation, this is likely the highest Coho return since the species was exterminated by the Lewiston Dam in 1927. Adult traps/weirs were not operated on Lapwai Creek or the Potlatch River for adult Coho collection in the fall of 2008. Brood stock was collected from hatchery ladders/traps in the Snake River and Clearwater sub basins. Trapping began at Dworshak NFH on 10/1/08; fish were also collected and transported from Lyons Ferry Fish Hatchery, Kooskia NFH, and Nez Perce Tribal Hatchery. A total of 765 adult and 722 jack Coho salmon were captured in 2008 (~37% of the returning population). Of the four trap sites, Kooskia NFH provided over 75% of the brood stock needed for spawning (Table 1 of final report). In total, 461 females were spawned in 2008 which yielded approximately 1.5 million green eggs (Table 2). Of the 1.5 million eggs, 800,000 are tentatively scheduled for transfer to Eagle Creek NFH, 30,000 to the Potlatch Corporation, and less than 1,000 to research and outreach programs. All remaining eggs will be incubated and reared at Dworshak NFH until March 2010.

Other Project products included: We developed monthly summary, semi-annual and annual progress reports. We participated and assisted with developing Annual Operating Plans with cooperating hatcheries. We updated the Regional Mark Information System (RMIS) database with Coded Wire Tag data, and the Passive Integrated Transponder Tag Information System (PTAGIS) with Passive Integrated Transponder tag data. Trap and release end-of-season summary reports and monthly production reports are produced and distributed.

Restore adult returns in the Clearwater River to support natural production as well as tribal and non-tribal harvest. We believe a population of 5,000 to 15,000 adults can meet the production and harvest goals; the long-term goal is 14,000 as identified in Wy-Kan-Ush-Mi-Wa-Kish-Wit (CRITFC 1996). In addition, this project will expand the range of Coho in the Columbia River Basin and into the Snake River tributaries. Natural production of Coho salmon has been documented in the Tucannon River (tributary to the Snake River) as a result of the Clearwater River releases.