NOAA Technical Memorandum NMFS-NWFSC-32 Status Review of Chum Salmon from Washington, Oregon, and California Orlay W. Johnson, W. Stewart Grant, Robert G. Kope, Kathleen Neely, F. William Waknitz, and Robin S. Waples National Marine Fisheries Service Northwest Fisheries Science Center Conservation Biology Division 2725 Montlake Blvd. E. Seattle WA 98112-2097 (206) 860-3270 December, 1997 U.S. DEPARTMENT OF COMMERCE William Daley, Secretary National Oceanic and Atmospheric Administration D. James Baker, Administrator National Marine Fisheries Service Rolland A. Schmitten, Assistant Administrator for Fisheries

The Northwest Fisheries Science Center of the National Marine Fisheries Service, NOAA, uses the NOAA Technical Memorandum NMFS series to issue informal scientific and technical publications when complete formal review and editorial processing are not appropriate or feasible due to time constraints. Documents published in this series may be referenced in the scientific and technical literature.

The NMFS-NWFSC Technical Memorandum series of the Northwest Fisheries Science Center continues the NMFS-F/NWC series established in 1970 by the Northwest & Alaska Fisheries Science Center, which has since been split into the Northwest Fisheries Science Center and the Alaska Fisheries Science Center. The NMFS-AFSC Technical Memorandum series is now being used by the Alaska Fisheries Science Center.

Reference throughout this document to trade names does not imply endorsement by the National Marine Fisheries Service, NOAA.

This document should be cited as follows:

Johnson, O.W., W.S. Grant, R.G. Kope, K. Neely,
F.W. Waknitz, and R.S. Waples. 1997. Status review
of chum salmon from Washington, Oregon, and
California. U.S. Dept. Commer., NOAA Tech. Memo.
NMFS-NWFSC-32, 280 p.

This document is available to the public through:

National Technical Information Service
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5285 Port Royal Road
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1-800-553-8647
orders@ntis.fedworld.gov

The Biological Review Team for chum salmon consisted of the following members from the NWFSC: F. William Waknitz; Drs. Stewart Grant, Jeffrey Hard, Robert Iwamoto, Orlay Johnson, Robert Kope, Conrad Mahnken, Michael Schiewe, Robin Waples, and John G. Williams; and from the NMFS, Alaska Fisheries Science Center, Dr. John Helle.

Table of Contents

List of Figures

List of Tables

Executive Summary

Acknowledgments

Introduction

Scope and Intent of the Present Document

Key Questions in ESA Evaluations

The "Species" Question

Artificial propagation

The "Extinction Risk" question

Summary of Petitioners' Arguments to List Chum Salmon

PRO-Salmon Petition

Save Allison Springs" Citizens Committee Petition

Trout Unlimited Petition

Information Relating to the Species Question

Biology of Chum Salmon

Environmental Information

Physical Features

Physiography and geology

River hydrology

Coastal upwelling

Oceanic and climatic variability

Food production and zooplankton

Climate and salmon production: Alaska versus Northwest

Density dependence

Biological Features

Vegetation

Zoogeography

Ecoregions

Significance of environmental information for ESU determinations

Life-History and Ecological Information

Geographic distribution

Spawning migrations

Timing of spawning migrations

Asian run timing

North American run timing

Alaska run timing

British Columbia run timing

Washington run timing

Marine travel time to spawning grounds

Straying

Mark-release and recapture studies

Genetic studies on straying

Spawning behavior

Spawning ground and redd characteristics

Fecundity and egg size

Fecundity differences between run times

Incubation and time of emergence

Downstream movement

Estuarine life history

Smoltification

Timing of entry into estuary

Duration of estuarine residence

Migratory patterns within estuaries

Growth and feeding in estuaries

Habitat utilization

Interspecific interactions

Freshwater and estuarine survival

Juvenile offshore movement and residualism

Marine Life History

Marine migration patterns

Age and growth

Growth rate

Age at maturity

Significance of life history information for ESU determinations

Genetics of Chum Salmon

Regional differentiation

Asian populations

North American populations

Within-population genetic diversity

Summary of genetic information

Discussion and Conclusion of ESU Determinations

Puget Sound/Strait of Georgia ESU

Hood Canal summer-run ESU

Pacific Coast ESU

Columbia River ESU

Relationship to state conservation management units

Relationship to ESU boundaries for other anadromous Pacific salmonids

Artificial Propagation

NMFS Artificial Propagation Policy

Overview of Worldwide Artificial Propagation of Chum Salmon

Asia

Alaska

British Columbia

Washington and Oregon

Recent changes in hatchery management in Washington

Artificial Propagation by ESU in the Pacific Northwest

Puget Sound/Strait of Georgia ESU

Fall-run chum salmon

Summer-run chum salmon in southern Puget Sound

Winter-run chum salmon

Hood Canal summer-run chum salmon ESU

Pacific Coast ESU

Columbia River ESU

Assessment of Extinction Risk

Background

Absolute Numbers

Historical Abundance, Habitat, and Carrying Capacity

Historical changes in estuaries

Historical changes in freshwater habitat

Habitat factors identified in SASSI that may affect chum salmon

Trends in Abundance

Factors Causing Variability in Abundance

Oceanic and climatic changes

Genetic Integrity

Assessment of genetic influence of hatchery transfers

Other Risk Factors

Approach

Previous Assessments

Washington

Oregon

California

Data Evaluations

Data Types

Washington

Oregon

California

Run Size

Fishery landings

Computed statistics

Analysis of Biological Information by ESU

Puget Sound/Strait of Georgia ESU

Hood Canal Summer-Run ESU

Hatchery supplementation

Harvest reduction

Harvest in Canadian waters

Marine survival

Freshwater survival

Density dependence

Possible ecological effects of artificial propagation

Pacific Coast ESU

Columbia River ESU

Summary and Conclusions of Risk Analysis

Puget Sound/Strait of Georgia ESU

Hood Canal summer-run ESU

Pacific Coast ESU

Columbia River ESU

Citations

Glossary

Appendix (Part 1, Part 2, Part 3, Part 4)