Lyons Ferry Hatchery Evaluation: Summer Steelhead and Trout Report 1998, 1999 and 2000 Run Years

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Published: October 2002

Pages: 130

Publication number: FPA02-09

Author(s): Joseph Bumgarner, Mark Schuck, Steve Martin, Jerry Dedloff and Lance Ross

Abstract

As part of the Lower Snake River Compensation Plan (LSRCP) mitigation program, Lyons Ferry Complex (LFC) released summer steelhead into area rivers, and rainbow trout were stocked into local lakes and rivers during the springs of 1999, 2000 and 2001. Additionally, fry and fingerling rainbow trout were reared and provided to Idaho.

During 1999-2001, groups of juvenile steelhead were freeze branded, coded-wire tagged (CWT), Visual Elastomer (VI) tagged, adipose and ventral fin clipped and released into the Tucannon, Walla Walla, Touchet, Snake, and Grande Ronde rivers. Not all release locations were given marked groups during the three release years. In addition, Passive Integrated Transponder (PIT) tags were inserted into many of the hatchery origin study groups to monitor their migration timing and success through the Snake and Columbia River dams. Natural origin steelhead from the Tucannon River were also tagged at the Tucannon River smolt trap. Detection rates and migration timing varied among the groups but appear to be directly related to bypass efficiency at each collector facility.

Residualism of hatchery released steelhead in the Tucannon River was monitored through hook and line methods in 1999. Residualism rates were similar to previous estimates. During 2000, intensive creel surveys were conducted on the Touchet River to assess impacts on natural origin steelhead. Impacts to natural steelhead from the trout fishery appear to be minimized by angler preference for larger sized fish.

Natural origin steelhead have been captured at the Tucannon River smolt trap during all three run years. Age, length, and total estimated number of smolts varied slightly between years, which was likely due to environmental conditions and number of spawning adults. Peak outmigration was similar among the years.

Adult trapping was accomplished at numerous remote traps and hatchery facilities during the study period. Adult collections occurred at Lyons Ferry Hatchery and Cottonwood trap for the collection of standard hatchery broodstocks (Lyons Ferry and Wallowa stocks). In addition, endemic broodstock programs were investigated and initiated on the Touchet and Tucannon rivers. These programs may eventually replace the Lyons Ferry Stock in each of the rivers. Efforts to date have been successful, with improved stock performance (survival) in the hatchery for both stocks. Test trapping was also conducted on small tributaries of the Grande Ronde to assess the potential for endemic broodstock development to replace the Wallowa stock. Results from these traps were not encouraging, as numbers of natural fish were too low to develop programs. Many hatchery fish were captured, indicating that the stocks were likely a mixture of hatchery and natural fish.

Freeze-brand data from adult steelhead captured at Lower Granite Dam was provided by National Marine Fisheries Service. The data that was compiled provided insight to the potential rates of straying of Lyons Ferry stock steelhead into the upper Snake River Basin. Also, freezebrand data on the Wallowa Stock fish released from the Grande Ronde River at Cottonwood AP, provided an estimate of adult returns to the project area, which have generally been more reliable than coded-wire tag estimates.

Creel surveys were conducted in all three run years, though data is only complete for the 1998/1999 and 1999/2000 run years. Each year we surveyed about 6,000 steelhead anglers. Overall catch rates varied slightly between the years. Estimates of angler effort, total harvest and tagged fish harvested were summarized. We also cooperated with Oregon Department of Fish and Wildlife (ODFW) to conduct creel surveys on the Lower Grande Ronde River in Washington. Grande Ronde creel data (total catch, effort hours, etc.) were summarized by ODFW and provided to WDFW for inclusion into this report.

Based on harvest estimates and returns to traps, we estimated total adult returns for the 1995 to 1999 run years of steelhead from the LFC. Run years have varied slightly, but most years have greatly exceeded the LSCRP goals of 4,655 adult steelhead. Returns over the 5-year period have varied between 114%-297% of the LSRCP steelhead mitigation goal established for Washington.

Spawning ground surveys were conducted in the Tucannon River, portions of the Touchet River, and portions of the Asotin Creek basin for 1999, 2000, and 2001. River flows varied between years and made surveys difficult in 2000. Estimated number of redds and spawners were derived for each year.

Electrofishing surveys on the Tucannon and Touchet rivers, and Asotin Creek were conducted during July and August each year. Areas sampled and site lengths were increased in 2000. Estimates provided are for the same river reaches as in previous years. The numbers of naturally produced steelhead in LSRCP rivers were similar to previous years and appear to be generally stable.

In summary, the Lyons Ferry summer steelhead program is meeting it’s original mitigation goals by supplying above adequate returns for harvest within the Lower Snake River area. However, impact to listed salmonid species and other non-target taxa are probably not within acceptable levels. Further evaluation and monitoring must occur to fully assess these impacts. In the interim, new production goals for the Lyons Ferry and Wallowa Stock program need to be established to reduce impacts.