Juvenile Chinook Outmigration in Howe Sound
Presentation Abstract
Chinook salmon populations returning to the Squamish River have been declining in recent years along with many other salmon populations in North America (DFO Science 1999). Howe Sound supported a major commercial fishery for chum, pink and Chinook salmon until declining returns resulted in the closure of the fishery in 1968. Since that time there have been significant efforts to limit exploitation and increase escapement through hatchery programs, especially for Squamish River Chinook. Despite these efforts this population is still struggling (Levings and Riddell 1992) for unknown reasons though poor marine survival could be a major contributing factor (DFO Science 1999, Wada and Sander 2005). Natural populations of salmon have differing life histories with variable timing of juvenile migration. This may result in greater survival rates due to less pressure on limited food and space resources (Beamish et al 2003) and a decreased likelihood that chance oceanic events will wipe out an entire brood year (Bottom et al 2005). Results from this study can be used to guide the establishment of hatchery release times that limit potential competition between wild and hatchery juveniles while also increasing our limited knowledge how hatchery programs effect wild salmon (Bottom et al 2005). Howe Sound is a necessary travel corridor for salmon returning to the Squamish River and its tributaries and may also play an important role for juvenile salmon during their outmigration and transition to the marine environment. Most studies of salmon distribution and survival are limited to freshwater life stages and consequently relatively little is known about survival and behaviour in marine waters (Beamish et al 2003). In addition, no broad scale juvenile fish sampling has occurred in Howe Sound since 1998 when a sampling methodology was established (Grout et al1998), through there have been many changes to the local environment. The primary objectives of this study are to better understand the spatial and temporal distribution of juvenile Chinook in Howe Sound and to identify key habitats or community assemblages preferred by these fish.
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--Howe Sound
Geographic Coverage
Salish Sea (B.C. and Wash.); Howe Sound (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
Juvenile Chinook Outmigration in Howe Sound
Room 6C
Chinook salmon populations returning to the Squamish River have been declining in recent years along with many other salmon populations in North America (DFO Science 1999). Howe Sound supported a major commercial fishery for chum, pink and Chinook salmon until declining returns resulted in the closure of the fishery in 1968. Since that time there have been significant efforts to limit exploitation and increase escapement through hatchery programs, especially for Squamish River Chinook. Despite these efforts this population is still struggling (Levings and Riddell 1992) for unknown reasons though poor marine survival could be a major contributing factor (DFO Science 1999, Wada and Sander 2005). Natural populations of salmon have differing life histories with variable timing of juvenile migration. This may result in greater survival rates due to less pressure on limited food and space resources (Beamish et al 2003) and a decreased likelihood that chance oceanic events will wipe out an entire brood year (Bottom et al 2005). Results from this study can be used to guide the establishment of hatchery release times that limit potential competition between wild and hatchery juveniles while also increasing our limited knowledge how hatchery programs effect wild salmon (Bottom et al 2005). Howe Sound is a necessary travel corridor for salmon returning to the Squamish River and its tributaries and may also play an important role for juvenile salmon during their outmigration and transition to the marine environment. Most studies of salmon distribution and survival are limited to freshwater life stages and consequently relatively little is known about survival and behaviour in marine waters (Beamish et al 2003). In addition, no broad scale juvenile fish sampling has occurred in Howe Sound since 1998 when a sampling methodology was established (Grout et al1998), through there have been many changes to the local environment. The primary objectives of this study are to better understand the spatial and temporal distribution of juvenile Chinook in Howe Sound and to identify key habitats or community assemblages preferred by these fish.
