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 (2018 : Seattle, Wash.)
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
Genre/Form
conference proceedings; presentations (communicative events)
Contributing Repository
Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.
Subjects – Topical (LCSH)
Salmon stock management--Salish Sea (B.C. and Wash.); Fish habitat improvement--Salish Sea (B.C. and Wash.); Fishes--Development--Salish Sea (B.C. and Wash.); Fishes--Mortality--Salish Sea (B.C. and Wash.)
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
Included in
Fresh Water Studies Commons, Marine Biology Commons, Natural Resources and Conservation Commons, Terrestrial and Aquatic Ecology Commons
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.
