Presentation Abstract

Bottom-up processes mechanistically link with top-down control of populations, and these interactions are mediated by environmental variability and human-induced changes in land and water use. Size-selective mortality can be a significant force regulating recruitment of salmon and may be imposed at different life stages and habitats for different species, stocks, or life history types. The first months of marine growth are commonly regarded as a critical period for growth and survival of salmon. For ESA-listed Puget Sound Chinook salmon, emergent bottom-up patterns include: 1) a critical growth period occurs when body mass increases 2-4 fold during the first month of feeding in epi-pelagic habitats within Puget Sound; 2) that growth is limited primarily by food supply, but can be exacerbated by warm temperatures in shoreline habitiats; 3) higher growth and survival correspond with higher contributions of key prey like larval crab. Piscivorous fishes exhibit size-selective predation on juvenile salmon in Puget Sound, and resident forms of Chinook salmon are capable of imposing significant mortality on subyearling Chinook in Puget Sound.

Session Title

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

Keywords

Infractructure, Visual conditions

Conference Track

SSE11: Species and Food Webs

Conference Name

Salish Sea Ecosystem Conference (Seattle, WA : 2018)

Document Type

Event

SSEC Identifier

SSE11-539

Start Date

6-4-2018 9:45 AM

End Date

6-4-2018 10:00 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, 9:45 AM Apr 6th, 10:00 AM

Bottom-up and top-down processes affecting marine survival of salmon in the Salish Sea

Bottom-up processes mechanistically link with top-down control of populations, and these interactions are mediated by environmental variability and human-induced changes in land and water use. Size-selective mortality can be a significant force regulating recruitment of salmon and may be imposed at different life stages and habitats for different species, stocks, or life history types. The first months of marine growth are commonly regarded as a critical period for growth and survival of salmon. For ESA-listed Puget Sound Chinook salmon, emergent bottom-up patterns include: 1) a critical growth period occurs when body mass increases 2-4 fold during the first month of feeding in epi-pelagic habitats within Puget Sound; 2) that growth is limited primarily by food supply, but can be exacerbated by warm temperatures in shoreline habitiats; 3) higher growth and survival correspond with higher contributions of key prey like larval crab. Piscivorous fishes exhibit size-selective predation on juvenile salmon in Puget Sound, and resident forms of Chinook salmon are capable of imposing significant mortality on subyearling Chinook in Puget Sound.