Possible mechanisms of small-scale regional variability of juvenile coho salmon growth in the Strait of Georgia
Presentation Abstract
Growth during early marine residence is correlated to survival to adulthood, thus the growth of juvenile coho in the Strait of Georgia is important for overall survival. The physiologic growth potential of a given individual is correlated to temperature and food quality and quantity. In the summers of 2012, 2013, 2014, and 2015 juvenile coho salmon were collected within diverse regions within the Strait of Georgia to compare regional growth rates and potential influences on differences in growth such as diet contents and water temperature. Sampling ranged from the Gulf Islands in the south to the Discovery Islands in the north. Growth was assessed via plasma concentration of insulin-like growth factor-1, or IGF-1. IGF-1 is correlated to instantaneous (within 3-7 days) growth in juvenile fishes. There was significant variation in growth between the northern Strait of Georgia and southern Strait of Georgia in 2012 and 2014 (p0.05). Non-significant negative relationships were observed between IGF-1 concentration and crab larvae (megalops and zoea) and hyperiid amphipod. Additionally, there was no significant correlation between regional water column temperature at 5 meters and regional IGF-1 among years or regions within a year. These results provide a direct field based correlation between positive growth and increased larval fish consumption (most importantly young-of-the-year herring). Further emphasizing higher caloric quality diet contents as an important component in early marine growth of juvenile coho salmon.
Session Title
Posters: Species & Food Webs
Conference Track
SSE18: Posters
Conference Name
Salish Sea Ecosystem Conference (2018 : Seattle, Wash.)
Document Type
Event
SSEC Identifier
SSE18-118
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)
Coho salmon--Georgia, Strait of (B.C. and Wash.)--Growth; Coho salmon--Food--Georgia, Strait of (B.C. and Wash.); Water temperature--Georgia, Strait of (B.C. and Wash.)
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
Possible mechanisms of small-scale regional variability of juvenile coho salmon growth in the Strait of Georgia
Growth during early marine residence is correlated to survival to adulthood, thus the growth of juvenile coho in the Strait of Georgia is important for overall survival. The physiologic growth potential of a given individual is correlated to temperature and food quality and quantity. In the summers of 2012, 2013, 2014, and 2015 juvenile coho salmon were collected within diverse regions within the Strait of Georgia to compare regional growth rates and potential influences on differences in growth such as diet contents and water temperature. Sampling ranged from the Gulf Islands in the south to the Discovery Islands in the north. Growth was assessed via plasma concentration of insulin-like growth factor-1, or IGF-1. IGF-1 is correlated to instantaneous (within 3-7 days) growth in juvenile fishes. There was significant variation in growth between the northern Strait of Georgia and southern Strait of Georgia in 2012 and 2014 (p0.05). Non-significant negative relationships were observed between IGF-1 concentration and crab larvae (megalops and zoea) and hyperiid amphipod. Additionally, there was no significant correlation between regional water column temperature at 5 meters and regional IGF-1 among years or regions within a year. These results provide a direct field based correlation between positive growth and increased larval fish consumption (most importantly young-of-the-year herring). Further emphasizing higher caloric quality diet contents as an important component in early marine growth of juvenile coho salmon.
