Short Description

The Washington Department of Fish and Wildlife (WDFW) in cooperation with the U. S. Fish and Wildlife Service (USFWS) is conducting a research project entitled "Evaluating relative reproductive success of natural- and hatchery-origin Snake River fall Chinook spawners upstream of Lower Granite Dam."  This Statement of Work is for the USFWS component of the study.  All WDFW activities, tasks and budget for the study are not included here, but can be found in their SOW under contract 20951.

Background

Wild Snake River fall Chinook salmon were listed for protection under the Endangered Species Act in 1992 by the National Marine Fisheries Service (NMFS 1992).  Wild fall Chinook spawn upstream of Lower Granite Dam in the Snake River and the lower portions of its tributaries including the Imnaha, Salmon, Grande Ronde, and Clearwater rivers (Connor et al. 2003).  A genetic profile constructed by sampling wild fall Chinook salmon subyearlings in the Snake River during 1991?1995 showed distinctive patterns in allelic diversity and differentiation from Columbia River fall Chinook salmon as well as similarity with fall Chinook salmon produced at Lyons Ferry Hatchery (LFH; Marshall et al. 2000).  Based on a review by Bugert et al. (1995), the empirical results of Marshall et al. (2000), and other information; LFH was selected by NMFS staff in the 1999 Biological Opinion on Artificial Propagation in the Columbia River Basin as the source for juveniles to be released upstream of Lower Granite Dam to supplement production in the wild.  

Fall Chinook salmon juveniles of LFH origin have been released upstream of Lower Granite Dam into the Snake and Clearwater rivers since 1996 and 1997, respectively.  Trends in redd counts during 1993?2003 showed a marked increase in fall Chinook salmon spawning during 1998?1993 that corresponded to the return of F1 generation hatchery adults (Garcia et al. in review).  Although the release of LFH fish for supplementation likely contributed to this increase, information does not exist to confirm this speculation or to determine if the F1 generation hatchery spawners are producing viable F2 generation "natural" spawners.  Determining reproductive success of natural spawners was identified as a priority by NMFS staff in the 2000 Biological Opinion for operation of the Columbia River hydrosystem.

The goal of our study is to determine if LFH fall Chinook salmon released for supplementation are contributing to recovery of the Snake River population.  If this is the case, we expect the genetic profile of wild-origin fall Chinook in future years to become very similar to that of LFH broodstock.  A time-series of genetic data for Snake River fall Chinook is required to monitoring for changes in genetic profile.  One of our strategies for collecting this time-series data is to trap spawners at Lower Granite Dam and collect genetic samples.  For this strategy to be most effective, it is necessary for the sampled fish to pass upstream and spawn.  In 2004, however, fishery managers agreed that wild fall Chinook salmon should trapped at Lower Granite Dam and used in LFH broodstocks to reduce genetic divergence from the wild spawning population.  Thus, the fish we sampled were not passed upstream of the dam to spawn.  This practice introduced a level of uncertainty into our study because we had to assume that sampled fish accurately represent those that did pass upstream and spawn.  The present statement of work was drafted by staff of the USFWS to collect data in 2005 to evaluate this assumption as well as determine the feasibility of increasing the sample size of wild fall Chinook salmon spawners for analyses in 2005 and future years.

Objectives

Objective 1:  Sample wild adults returning to spawn in 2005
Objective 2:  Produce summary report to WDFW for incorporation into annual report
Objective 3:  Produce quarterly progress reports for BPA COTR
Objective 4:  Manage and administer contracting and budget process  

References

Bugert, R. M., C. W. Hopley, C. A. Busack, and G. W. Mendel.  1995.   Maintenance of stock integrity in Snake River fall chinook salmon.  American Fisheries Society Symposium 15:267-276.

Connor, W. P., C. E. Piston, and A. P. Garcia.   2003.  Temperature during incubation as one
factor affecting the distribution of Snake River fall Chinook salmon spawning areas.  Transactions of the American Fisheries Society 132:1236-1243.

Garcia, A. P., W. P. Connor, P. A. Groves, and B. D. Arnsberg.   In review.   Trends in fall Chinook salmon Redd counts in the Snake River basin, 1993-2003.  Submitted to North American Journal of Fisheries Management.

Marshall, A. R., H. L. Blankenship, and W. P. Connor.  2000.  Genetic Characterization of Naturally Spawned Snake River Fall-Run Chinook Salmon.  Transactions of the American Fisheries Society 129:680-698.

NMFS (National Marine Fisheries Service).  1992.  Endangered and Threatened Species: Threatened status for Snake River spring/summer chinook salmon, threatened status for Snake River fall chinook salmon.  Final rule.  U.S. Federal Register, 57:78 (22 April 1992): 14653B14663.