Salmon Farms Down, Salmon Returns Up

The main migration route for Fraser River and other South Coast salmon was largely cleared of salmon farms by 2020. A few still operate at the north end of Vancouver Island and there’s a problematic cluster of 3 at the entrance to the Broughton, but by and large, the route has been cleaned up. So what’s been the result for wild fish? 

Let’s be clear up front: it’s too soon to say whether or not the removal of salmon farms is responsible for what I’m about to tell you. Lots of factors influence salmon returns—ocean conditions, habitat conditions, climate and more. And since the impacts of salmon farms on wild salmon have not been fully studied, it isn’t even certain what number of threats vanished or decreased with farm removal. 

But the news is good! 

There are several ways of looking at recent years’ salmon returns. You can compare the actual numbers to what DFO predicted for that year or you can compare the returns to the number in the parent (brood year) generation. Or, you can compare returns to an average taken over a relevant period—say 3-4 generations of any particular species of salmon. We chose the latter approach for our new mapping project, because it provides a longer-term view of the trends in a salmon population. Our new interactive maps [link] show which rivers are seeing improvement and which are static or declining. 

The Fraser River has so many discrete populations that it’s worth taking a closer look at recent returns versus brood year returns. Alex Morton culled the numbers on Fraser sockeye and made the graph below. 

Scientists at DFO and elsewhere have been saying for a decade or more that early marine survival of salmon has been poor and they attribute declining populations to this.  

Clearly, early marine survival for these fish in 2024 was not a problem! Farms had been removed from the Discovery Islands and the Broughton in the year prior to their outmigration. This shows the potential for Fraser sockeye to rebuild, despite high water temperatures in the river, landslides and other habitat degradation. 

Scientists may never agree on the relationship between farm removal and salmon returns, but the First Nations of the Broughton see it pretty clearly. They identified the impacts to their fish from the farms and systematically closed them. The results for pink salmon in local rivers have been astounding---mind you, returns were good in many other places as well, so clearly there were some favourable ocean conditions at work, too. But you’ll never convince former Chief Don Svanvik that there’s no link between farm removal and increased returns, when the pinks are coming back orders of magnitude stronger. 

Compelling science now links both farm-bred disease agents and sea lice with poor salmon returns and/or poor body condition in the outmigrating smolts. It’s time for a Transition Plan that fulfills the longstanding Liberal government promise to remove open-net pens from BC waters. We await the Plan, said to be completed and itself awaiting a budget allocation. We expect it to finally realize the potential to restore the wild salmon economy and the wild salmon ecosystem for the benefit of all.