Despite the challenges of COVID-19, our research and restoration efforts in the Fraser River Estuary continued through 2020. Now in year five, this work is helping us understand how the estuary supports millions of juvenile salmon in its different habitats each spring and summer. Informed by their movements, we began habitat restoration in 2019 to reconnect access to the marsh on Sturgeon Bank, between the North and South Arms of the Lower Fraser, by creating linear breaches in the long rock jetties that direct the flow of the river through the estuary.
In 2019, we captured 454 juvenile salmon (300 chum, 152 Chinook, and 2 sockeye) between March and May, just after we opened the first breaches. In 2020, our catches at the breach locations increased substantially with 1,480 total salmon (297 Chinook, 174 sockeye, 420 pink, 20 coho, 569 chum). We even had days when we captured all five species of salmon in one set. We captured both ocean-type and stream-type Chinook, and had large bursts of young pink and sockeye. We recorded ocean type Chinook at breach locations every month from March through August. We had big hopes, but these results exceeded even our expectations.
Our monitoring setup is simple. When the tide is at the right level, we set our net across the channels that are forming behind our breach locations. We have a net (pictured) with two wings that funnel fish into a trap box and then into a bag where they can be retrieved safely.
The strong current, especially at high tides, directs water from the river through the breaches and carves channels onto Sturgeon bank. The breaches will continue to result in channel formation over time, creating further opportunities for salmon to access marsh habitat with each successive tidal cycle, slowly eroding a natural pathway that has been blocked for over 100 years. In 2021, we will work with our partners to begin addressing some of the other major barriers in the estuary, like the North Arm jetty, doing everything we can to restore the Fraser Estuary and rebuild wild salmon populations.