Researching Salmon: Understanding habitat to support Chinook recovery
The Salmon: Chinook Salmon (Oncorhynchus tshawytscha)
Chinook salmon, also known as King, Spring, and Tyee Salmon grow to be the largest salmon species on the Pacific coast. The
current record for a fully mature Chinook Salmon is 126lbs, while the average
weight of a mature Chinook is anywhere from 10-50lbs.
Chinook salmon at different life stages
Also known for their diverse life span, Chinook salmon spend the first part of their life (0-2 years) in fresh water estuary areas, before heading to sea. They reach sexual maturity anywhere from 2-7years old, and return to spawn in the river system from which they came.
Given the large size of these salmon, they require deeper water for spawning. Major river systems in British Columbia, like those found the Squamish River Watershed offers ideal spawning habitat for Chinook. Protected estuaries, like the Squamish River Estuary provides young Chinook smolts with shelter and food to grow.
Once at sea these fish feed on smaller fish, and serve as a tasty treat to higher tropic level organisms like the killer whale.
Killer whale eats Chinook Salmon
(Photo credit Karl Solomon)
At sexual maturity the male Chinooks teeth enlarge, and their nose develops into a hook which aids in their competition to fertilize eggs laid in gravel beds. The males also develop a distinct red belly, which signals to their female counterparts that they are ready to spawn.
The Howe Sound once supported a Chinook salmon fishery, that was shut down in 1968 because stocks were in major decline. Local hatcheries have focused their efforts on rebuilding Chinook populations in recent years, but the species still struggles.
Given the diverse life cycle of this King salmon, successful restoration of stocks faces a lot of unknowns. To help answer some of these unknowns, the SRWS in partnership with Department of Fisheries and Oceans, and the Pacific Salmon Foundation is leading a 2 year monitoring study examining the out migration of juvenile Chinook in the Howe Sound.
The Study: The Howe Sound Juvenile Chinook Out-migration Study (2011-2015)
The Juvenile Chinook Out-migration Study is a part of the Squamish Salmon Recovery Plan and has been led by the SRWS, in partnership with the Department of Fisheries and Oceans and the Pacific Salmon Foundation. This study seeks to... "better understand the spatial and temporal distribution of juvenile Chinook in Howe Sound and the Squamish Estuary to identify key habitats or community assemblages preferred by these fish." - Kendra Morgan.
The study commenced in the spring of 2011 to study how juvenile Chinook are moving through Howe Sound. This was expanded upon in 2012 to include a total of 28 sample sites throughout Howe Sound. In 2013 and again in 2015 the study concentrated on the Squamish Estuary in an attempt to better understand how juvenile Chinook are making use of the estuary tidal channels.
Howe Sound beach seine sample sites
Based on the studies interim results, it appears that juvenile Chinook prefer the northern and southern ends of the Howe Sound. DNA samples are being processed to determine if these juveniles have emerged from the Squamish River system, or if juvenile Chinook from other coastal river systems are using the Howe Sound as protected habitat before heading to sea. To learn more about this study please contact us at firstname.lastname@example.org.