Matching the growth of juvenile salmon to plankton dynamics in the Salish Sea

Presentation Abstract

Several studies have suggested that early ocean growth rate of juvenile salmon relates to subsequent adult returns. A corollary is the abundance and nutritive quality of prey available will dictate growth rates and thus also relate to adult returns. The Salish Sea Marine Salmon Survival Project was organized to help understand why “Chinook, coho, and steelhead have experienced tenfold declines in survival during the marine phase of their lifecycle, and their total abundance remains well below what it was 30 years ago.” The first key hypothesis of the Salish Sea Marine Survival Project is: “Bottom-up processes that drive juvenile Chinook, coho and forage fish prey availability have changed and his is limiting salmon growth and survival.” Coincidently the Pacific Salmon Commission Southern Fund supported a study of growth for juvenile salmon in the Strait of Georgia, using measures of the hormone IGF1. IGF1 levels have been shown to be well correlated with feeding and growth in juvenile salmon. Samples were obtained on the DFO June juvenile salmon survey 2012 - 2015. The study revealed both spatial and inter-annual differences in growth for all species assessed (coho, chinook, chum and pink salmon). As part of the Salish Sea Marine Survival Project, zooplankton abundances and species composition are being monitored in the Salish Sea. In this study, we compare the spatial and temporal patterns of the zooplankton in the Salish Sea with the patterns of IGF1 for several species of juvenile Pacific salmon. We ask whether ‘hotspots’ for plankton are concurrent with ‘hotspots’ for juvenile salmon growth, and whether there is a correlation between the occurrence of the ‘right’ kind of plankton and salmon growth. This analysis could identify locations in the Salish Sea which are important for growth and survival of salmon, and therefore important locations for enhanced management or protection.

Session Title

Posters: Species & Food Webs

Conference Track

SSE18: Posters

Conference Name

Salish Sea Ecosystem Conference (2018 : Seattle, Wash.)

Document Type

Event

SSEC Identifier

SSE18-116

Start Date

5-4-2018 11:30 AM

End Date

5-4-2018 1:30 PM

Type of Presentation

Poster

Genre/Form

conference proceedings; presentations (communicative events); posters

Contributing Repository

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

Subjects – Topical (LCSH)

Chinook salmon--Washington (State)--Georgia, Strait of (B.C. and Wash.); Chinook salmon--Food--Georgia, Strait of (B.C. and Wash.); Zooplankton--Georgia, Strait of (B.C. and Wash.); Smolting

Geographic Coverage

Salish Sea (B.C. and Wash.); Georgia, Strait of (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 5th, 11:30 AM Apr 5th, 1:30 PM

Matching the growth of juvenile salmon to plankton dynamics in the Salish Sea

Several studies have suggested that early ocean growth rate of juvenile salmon relates to subsequent adult returns. A corollary is the abundance and nutritive quality of prey available will dictate growth rates and thus also relate to adult returns. The Salish Sea Marine Salmon Survival Project was organized to help understand why “Chinook, coho, and steelhead have experienced tenfold declines in survival during the marine phase of their lifecycle, and their total abundance remains well below what it was 30 years ago.” The first key hypothesis of the Salish Sea Marine Survival Project is: “Bottom-up processes that drive juvenile Chinook, coho and forage fish prey availability have changed and his is limiting salmon growth and survival.” Coincidently the Pacific Salmon Commission Southern Fund supported a study of growth for juvenile salmon in the Strait of Georgia, using measures of the hormone IGF1. IGF1 levels have been shown to be well correlated with feeding and growth in juvenile salmon. Samples were obtained on the DFO June juvenile salmon survey 2012 - 2015. The study revealed both spatial and inter-annual differences in growth for all species assessed (coho, chinook, chum and pink salmon). As part of the Salish Sea Marine Survival Project, zooplankton abundances and species composition are being monitored in the Salish Sea. In this study, we compare the spatial and temporal patterns of the zooplankton in the Salish Sea with the patterns of IGF1 for several species of juvenile Pacific salmon. We ask whether ‘hotspots’ for plankton are concurrent with ‘hotspots’ for juvenile salmon growth, and whether there is a correlation between the occurrence of the ‘right’ kind of plankton and salmon growth. This analysis could identify locations in the Salish Sea which are important for growth and survival of salmon, and therefore important locations for enhanced management or protection.