Lyons Ferry Hatchery Evaluation Fall Chinook Salmon Annual Report: 2003 and 2004

This report summarizes activities by the Washington Department of Fish and Wildlife's (WDFW) Lower Snake River Hatchery Fall Chinook Evaluation Program from 16 April 2003 to 15 April 2005. This work was completed by WDFW’s Snake River Lab (SRL) staff with Federal fiscal year 2003 and 2004 funds provided through the U.S. Fish and Wildlife Service (USFWS), under the Lower Snake River Compensation Plan (LSRCP).

Congress authorized the LSRCP in 1976. As a result of that plan, Lyons Ferry Hatchery (LFH) was constructed and has been in operation since 1984 (Figure 1). One objective of the hatchery was to compensate for an annual loss of 18,300 adult (non-juvenile)¹, Snake River stock, fall Chinook salmon (U.S. Army Corps of Engineers 1975). An evaluation program was initiated in 1984 to monitor the success of LFH in meeting the LSRCP compensation goals and to identify any production adjustments required to accomplish those goals. This mitigation program was modified in the early 1990s by agreement of the United States v. Oregon parties to supplement natural fall Chinook production above LGR (14,363 fall Chinook were expected to persist through natural production), an action consistent with the U.S. Endangered Species Act and Washington’s Wild Salmonid Policy.

The WDFW has two general goals in its fall Chinook evaluation program:

(1) monitor hatchery practices at LFH to ensure quality smolt releases, high downstream migrant survival, and sufficient adult fish contribution to fisheries, with escapement, to meet the LSRCP compensation goals; and

(2) gather genetic information to help maintain the integrity of the Snake River Basin fall Chinook salmon stock (WDF 1994). Our efforts have contributed to evaluating the status of Snake River fall Chinook by monitoring population abundance, distribution, genetics, and life history (sex and age information of returns) as well as by removing strays at Lower Granite Dam (LGR) on the Snake River to minimize the effects of out-of-basin strays on the population (NMFS 1993). Specific annual program objectives can be obtained from the Snake River Lab Project office.

¹ The LSRCP Special Report has language referring to adult recoveries. That language was intended to differentiate adults from juveniles in the document (Dan Herrig personal communication). The LSCRP mitigation goal was based upon 97,500 fall Chinook counted at McNary Dam in 1958. At that time adult and jack counts were combined to give a total count. Therefore the mitigation goal consists of jacks and adults, not just adults. Since minijacks (fish < 30 cm total length) are not counted at the dams, they were excluded from the calculations which determined the mitigation goal.