NOAA Technical Memorandum NMFS-F/NWC-187 Status and Future of Spring Chinook Salmon in the Columbia River Basin—Conservation and Enhancement Donn L. Park, Convenor August 1990 U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Marine Fisheries Service

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Park, Donn L. 1990. Status and Future of Spring Chinook Salmon in the Columbia River Basin—Conservation and Enhancement. U.S. Dep. Commer., NOAA Tech. Memo. NMFS F/NWC-187. 130 p.

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Introduction by Donn L. Park

Session I: Stock Structure and Population Dynamics

1. Sustainable harvest rates for spring chinook salmon in the upper Columbia River Basin by Reginald R. Reisenbichler

2. Stock structure and gene conservation in Columbia River spring chinook salmon by Robin S. Waples

3. Effect of mainstern survival rates on spring chinook salmon production by Willis E. McConnaha

4. An assessment of adult losses, production rates, and escapements for wild spring and summer chinook salmon in the Snake River by T. C. Bjornn

Session II: Stock Status and Carrying Capacity

1. Status of Snake River Idaho spring chinook salmon stocks by Dexter R. Pitman

2. Status of chmook salmon stocks in the Mid-Columbia by James W. Mullan

3. Estimating spring chinook parr and smolt abundance in wild and natural production areas by C. E. Petrosky

4. Effects of hatchery broodstock weirs on natural production by John G. Williams

5. Conversion of weighted usable area to potential fish production in the Yakima River Basin by J. M. Stempel

Session III: Hatchery Management Strategies and Supplementation

1. Adult recoveries from releases of subyearling and yearling spring chinook salmon by W. A. Zaugg, J. E. Bodle, and J. E. Manning

2. Zero-age smolt studies, Mid-Columbia River 1987-89 by Don E. Weitkamp and Robert D. Sullivan

3. Evaluation of outmigration performance and smolt-to-adult survival of subyearling spring chinook salmon smolts by Richard W. Carmichael and Rhine T. Messmer

4. A review of rearing density experiments: Can hatchery effectiveness be improved? by J. L. Banks

5. Inbreeding depression, local adaptation, and outhreeding depression in salmon stocks: Some implications for hatchery management by John M. Emlen

6. Biological manipulation of migratory behavior: The use of advanced photoperiod to accelerate smoltification in yearling chinook salmon by Albert Giorgi

Session IV: Habitat Enhancement

1. Expectations for spring chinook salmon population responses to habitat enhancement projects in northeastern Oregon by Richard W. Carmichael

2. Evaluation of riparian habitat rehabilitation by William S. Platts

by Donn L. Park

The National Marine Fisheries Service (NMFS) sponsored the Spring Chinook Salmon Workshop because we believe urgent changes in priorities am required if a meaningful resurgence of the Columbia River Bm&s once plentiful spring chinook salmon (Oncorhynchus tshawytscha) stocks are to be realized. Others share our concern for spring chmook salmon. About a week prior to the workshop we received a letter from the Idaho Chapter of the American Fisheries Society calling for additional protection of spring chinook salmon in light of potential endangered species listing. The letter states in part: "The protection of species native to the Columbia River system is a fundamental obligation we all share. Species preservation does not 'compete' with other uses of the river; it automatically takes precedence over them as a reserved right." The letter further states: 'The Chapter regards the potential for extinction of wild chinook salmon with considerable dismay and is actively monitoring the status of this species within the Snake River watershed. We have notified the Regional Director, NMFS, and other State and Federal agencies (including the Bonneville Power Administration) and Indian tribes in the region that we will formally seek listing of these stocks pursuant to the Endangered Species Act if a material improvement in their status is not realized by 1992." Because of perceived mutual concerns throughout the Basin for spring chmook salmon we chose the theme Status and Future of Spring Chinook Salmon in the Columbia River Basin-Cowervation and Enhancement.

The upriver stocks of spring chmook salmon have been in a general decline since 1970. Outmigrations from the Snake River alone produced approximately 100,000 adults annually as recently as 1975. These runs provided so abundance of naturally spawning fish and a harvestable surplus was used by commercial, tribal, and sport fishing interests. Notable depletion of spring chinook salmon have been cataclysmic in some years. The adult runs in 1979, 1980, and 1984 were approximately 9,000 fish counted each year at Ice Harbor Dam. Recently, the runs rebounded to more than 30,000 fish, only to collapse again in 1989. The fluctuating but low numbers of spring chinook salmon returning to Columbia Basin stream prompted the Columbia Basin Fish and Wildlife Authority to call for a status report on the stocks. The ensuing report prepared by the Columbia River fisheries agencies and tribes did not offer substantive alternatives for improving the runs. It did, however, attempt to explain why the run has been depressed and fluctuating.

Time may be running out for restoration of the valuable population of spring chinook salmon. We hope that the workshop can be a starting point for a revitalized restoration process.

The proceedings of the workshop include an abstract of each speaker's presentation as well as a condensation of the questions and answers that followed each presentation.

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