There it is. The email I’ve been waiting for! “Genetics results!!!!!” reads the subject line. My colleague Misty MacDuffee, Raincoast’s Wild Salmon Program Director, clearly shares my enthusiasm to finally see the fruit of our labour.
When you picture a research biologist’s day you probably imagine them on a boat or in a forest, immersed in nature with a notebook in hand. However, for much of the year we are tucked away in labs or at our desks, analyzing data or writing up our research findings. My research focuses on Fraser estuary juvenile salmon.
In 2016 Raincoast, with our partners at UVic’s Baum Lab, began surveying sites in the marsh, eelgrass and sand flat habitats of the Fraser estuary. Our goal is to expand the knowledge of how juvenile Chinook and other salmon use habitats in the Fraser estuary during the critical time before they enter the open ocean.
The Fraser supports BC’s largest Chinook runs, however the numbers that reach maturity have been dismal in recent years. Many researchers believe that poor survival during the early marine period is to blame. Therefore, we’re investigating juvenile Chinook outmigration timing, estuary residence and habitat preferences to determine how these characteristics influence trends in survival. This information will help determine important areas to protect and restore. This should also help juvenile Chinook grow to maturity, and ultimately find their way into the stomachs of Southern Resident killer whales.
Raincoast’s first year in 2016 was a great success. After scouting missions to choose our sites, we established our methods with guidance from colleagues and our fantastic captain, Steve Stark with the Tsawwassen First Nation. From March until October we repeatedly sampled 17 sites, catching over 33,000 fish from 39 different species, during 59 days on the water. We found that juvenile Chinook were primarily captured in marsh habitats, where they were consistently present from March until June.
Our genetics results reveal the origin of the juvenile Chinook we capture. In early spring most came from the Harrison River, but as the season continued, they were joined by Chinook from the Chilliwack and Thompson Rivers along with a few from some Middle and Upper Fraser populations. These populations, despite the distances between where they originate, all rely on critical estuary habitats before transitioning to life at sea.
We are now busy planning year two. My list of tasks grows: search for funding, apply for permits, repair nets, order equipment, and find new students and volunteers. All of this is necessary for a successful field season.
Since we found that juvenile Fraser Chinook prefer marsh habitat, we are expanding our study in marsh areas of the estuary. We are also adding a new method that will allow us to catch (and release) more juvenile salmon and replicate a study first conducted in 1979 to gain a historical comparison!
With memories of beautiful days out on the water in the back of my mind, it’s hard not to be excited for the upcoming field season. Now if we can just get everything ready in time…
David Scott
Raincoast Biologist and Lower Fraser Salmon Program Coordinator
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Topic: The Results are In! (Read 2967 times)