On a sunny Friday afternoon in late June we head out on the North Arm of the Fraser River, riding the river downstream to our North Arm Jetty breach project. It is hard to imagine that it’s nearly July after the cold spring that we have had, but our field crew has already been monitoring fish in the estuary for over three months and the largest waves of juvenile salmon have passed.
However, while the juvenile pink and chum salmon have left the system for the year, we continue our monitoring as our main target, juvenile Chinook salmon, are still using the estuary. After three months, we have our sampling method pretty well figured out, and we arrive just as the tide has risen high enough to create a nice amount of flow moving from the river through the breach and out onto Sturgeon Bank, important habitat for juvenile salmon that the breach gives juvenile salmon access to.
This work is part of our Fraser River Connectivity Project, our five-year restoration project to create openings in several of the man-made barriers in the Fraser Estuary that prevent the natural migration of juvenile salmon.
We set our net quickly, our 20 meter beach seine tied taught only captures about half of the flow moving through our 30 meter wide breach, the flow steadily increasing as the tide rises. After a quick 15 minute set we pull the net, drifting sideways with the flow before we are able to pull the net ashore beside the breach and out of the flow.
Success! We see that we have captured 4 juvenile Chinook salmon, as well as dozens of three-spine stickleback…not bad for just 15 minutes. We measure each of the juvenile Chinook and I take a small clip from the caudal fin of each one for future genetic analysis before releasing them; this will allow us to determine the population origin and give us an idea of who is using our breaches.
We do another quick 15 minute set and capture another Chinook, but as the tide and the flow continue to rise, we are losing our sampling window. Although it likely means many more fish are passing through, it is not possible to hold our net in the strong flow and any fish captured would end up worse for the wear, so we wrap things up for the day and head back to the harbour.
So far, the North Arm Jetty breach has proven to be a great success, with high rates of juvenile chum and pink salmon observed early in the season, and consistent passage of juvenile Chinook, which has continued late into the season. We have also continued to monitor our three Steveston Jetty breaches which have shown similar high rates of juvenile salmon passage this spring. We will continue our monitoring through August and hope to catch a few more Chinook before the season wraps up, while also preparing for the next round of construction in early winter 2023.
Through our continued efforts to restore connectivity in the Fraser Estuary, we strive to improve conditions for juvenile salmon survival and population recovery.
We are so excited to share our annual report – Tracking Raincoast Into 2023 – with you! Tracking gives you highlights from the year, our science, flagship projects, as well as a peek at what’s in store for the coming year.
Dive into Tracking and learn more about our work safeguarding coastal carnivores in the Southern Great Bear Rainforest tenure. We are currently raising funds to stop commercial trophy hunting in more than a quarter of the Great Bear Rainforest in British Columbia. Now is a good time to sign up and stay connected to our community of researchers and change-makers.