Presentation Abstract

Historically, salmon hatcheries were designed to increase fishery production and to recover depleted native populations. As demands of human protein consumption increase and wild populations continue to decline due to anthropogenic impacts like climate change and habitat loss, hatcheries and stocking programs will be called on to provide food security and to supplement threatened populations. Since 1950 over 3.7 billion Chinook salmon have been released into the Salish Sea and its tributaries in Washington State and southern British Columbia. However, relatively little research has been conducted that considers the impact of hatchery subsidies on estuarine and nearshore marine ecosystems in this region. Here, we assessed spatiotemporal patterns of several traits in hatchery-origin Chinook salmon in the Salish Sea over the last 65 years. We found that the average size at release of hatchery Chinook has increased significantly in Puget Sound, but not the Strait of Georgia. Further, it appears the average release date from hatcheries in the Puget Sound and Strait of Georgia have both converged within a common two week window. This could suggest diminished strength of the portfolio effect of hatchery subsidies on the Chinook salmon population complex in the Salish Sea. In this talk, I’ll discuss the implications these changes in hatchery practices could have for conservation of wild salmon populations, predators of salmon, and fishery production in the northeastern Pacific.

Session Title

The Salish Sea Marine Survival Project: Bottom-up and Top-down Processes

Keywords

aquaculture, Chinook salmon, hatcheries, portfolio effects, predation, size-selective, subsidies

Conference Track

SSE11: Species and Food Webs

Conference Name

Salish Sea Ecosystem Conference (Seattle, WA : 2018)

Document Type

Event

SSEC Identifier

SSE11-530

Start Date

6-4-2018 9:30 AM

End Date

6-4-2018 9:45 AM

Type of Presentation

Oral

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

Geographic Coverage

Salish Sea (B.C. and Wash.)

Rights

This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.

Type

text

Language

English

Format

application/pdf

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Apr 6th, 9:30 AM Apr 6th, 9:45 AM

Changes in hatchery subsidies of Chinook salmon in the Salish Sea: implications for predators, fisheries, and conservation

Historically, salmon hatcheries were designed to increase fishery production and to recover depleted native populations. As demands of human protein consumption increase and wild populations continue to decline due to anthropogenic impacts like climate change and habitat loss, hatcheries and stocking programs will be called on to provide food security and to supplement threatened populations. Since 1950 over 3.7 billion Chinook salmon have been released into the Salish Sea and its tributaries in Washington State and southern British Columbia. However, relatively little research has been conducted that considers the impact of hatchery subsidies on estuarine and nearshore marine ecosystems in this region. Here, we assessed spatiotemporal patterns of several traits in hatchery-origin Chinook salmon in the Salish Sea over the last 65 years. We found that the average size at release of hatchery Chinook has increased significantly in Puget Sound, but not the Strait of Georgia. Further, it appears the average release date from hatcheries in the Puget Sound and Strait of Georgia have both converged within a common two week window. This could suggest diminished strength of the portfolio effect of hatchery subsidies on the Chinook salmon population complex in the Salish Sea. In this talk, I’ll discuss the implications these changes in hatchery practices could have for conservation of wild salmon populations, predators of salmon, and fishery production in the northeastern Pacific.