Trophic distress of juvenile salmon in Johnstone/Queen Charlotte Strait?
Presentation Abstract
Johnstone Strait and Queen Charlotte Strait are situated between the northern end of Vancouver Island and the British Columbia mainland, connecting the Strait of Georgia to Queen Charlotte Sound. For juvenile salmon, this area provides a migratory corridor between initial marine rearing areas in the Strait of Georgia to Queen Charlotte Sound and the Gulf of Alaska. Tidal mixing homogenizes the water column in the narrow passages of this region, creating both an unstable water column with relatively low primary productivity and dissipation of any zooplankton or juvenile fish patches. McKinnell et al. (in review) have suggested that this region represents a trophic challenge for juvenile salmon, as food is scarce and fish must transit this region to reach more favorable marine feeding grounds. They term this challenge the “Trophic gauntlet hypothesis”. We will present plasma insulin-like growth factor 1 (IGF1) data for juvenile salmon (coho, sockeye, chum, Chinook and pink) collected opportunistically in Queen Charlotte Sound, Queen Charlotte Strait, Johnstone Strait or the Strait of Georgia between 2009 - 2013. IGF1 is a hormone that is an index of the relative growth of fish. The trophic gauntlet hypothesis will be exposed to these data as we report on growth of juvenile salmon in Strait of Georgia, before they enter Johnstone Strait; in Johnstone Strait, the putative zone of deprivation; and then from Queen Charlotte Sound, after fish have presumably reached richer feeding grounds. Results from this challenge of the trophic gauntlet hypothesis may result in more directed studies of the marine ecology of juvenile salmon as they migrate through this region.
Session Title
Session S-08D: Salmon Recovery: Implementation and Progress I
Conference Track
Species and Food Webs
Conference Name
Salish Sea Ecosystem Conference (2014 : Seattle, Wash.)
Document Type
Event
Start Date
1-5-2014 5:00 PM
End Date
1-5-2014 6:30 PM
Location
Room 6C
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--British Columbia--Johnstone Strait--Growth; Salmon--British Columbia--Queen Charlotte Strait--Growth
Geographic Coverage
Salish Sea (B.C. and Wash.); Johnstone Strait (B.C.); Queen Charlotte Strait (B.C.)
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
Trophic distress of juvenile salmon in Johnstone/Queen Charlotte Strait?
Room 6C
Johnstone Strait and Queen Charlotte Strait are situated between the northern end of Vancouver Island and the British Columbia mainland, connecting the Strait of Georgia to Queen Charlotte Sound. For juvenile salmon, this area provides a migratory corridor between initial marine rearing areas in the Strait of Georgia to Queen Charlotte Sound and the Gulf of Alaska. Tidal mixing homogenizes the water column in the narrow passages of this region, creating both an unstable water column with relatively low primary productivity and dissipation of any zooplankton or juvenile fish patches. McKinnell et al. (in review) have suggested that this region represents a trophic challenge for juvenile salmon, as food is scarce and fish must transit this region to reach more favorable marine feeding grounds. They term this challenge the “Trophic gauntlet hypothesis”. We will present plasma insulin-like growth factor 1 (IGF1) data for juvenile salmon (coho, sockeye, chum, Chinook and pink) collected opportunistically in Queen Charlotte Sound, Queen Charlotte Strait, Johnstone Strait or the Strait of Georgia between 2009 - 2013. IGF1 is a hormone that is an index of the relative growth of fish. The trophic gauntlet hypothesis will be exposed to these data as we report on growth of juvenile salmon in Strait of Georgia, before they enter Johnstone Strait; in Johnstone Strait, the putative zone of deprivation; and then from Queen Charlotte Sound, after fish have presumably reached richer feeding grounds. Results from this challenge of the trophic gauntlet hypothesis may result in more directed studies of the marine ecology of juvenile salmon as they migrate through this region.
