Pink salmon swimming up the Ahta River, B.C. (Jordan Manely photo)

Pink salmon swimming up the Ahta River, B.C. (Jordan Manely photo)

New report shows river-to-river status of Pacific salmon in the Broughton Archipelago

Population abundance is low, but in many cases capacity to rebound is strong, researchers observe

A new report analyzing salmon populations in the Broughton Archipelago has concluded that while most rivers have low to moderate abundance of salmon, many runs seem to be resilient enough to support a rebound in the population.

The report identified 94 distinct populations of Pacific salmon in the area of Vancouver Island’s northeast coast, down to the river they spawn in. Report authors from the Salmon Coast Field Station measured abundance and resilience for each population, producing a snapshot of salmon health unique to each river and inlet.

Take the Viner Sound Creek on Gilford Island as an example. Its chum population dipped severely in the ‘80s to the point where it appeared each spawning chum had less than one surviving offspring. The Viner Sound chum were not replacing themselves. But somewhere in the mid-’90s, something improved just enough to allow a slow, steady increase in population.

Their abundance is coded as amber in the stop-light score card — red, amber or green. — but their resilience is green because their capacity to rebound has been quite strong, said lead researcher Emma Atkinson.

Knowing what exactly caused the chum offspring to survive better is the million-dollar question in salmon research.

One guess for the Viner Sound chum is a small-scale hatchery that operated for a few years in the mid-90s.

“It’s possible that little seed of a boost might have helped. We don’t know that for sure. It’s also possible that something like ocean survival or juvenile survival improved just enough to get them out of that hole,” Atkinson said.

“That’s the really tricky thing with salmon in general. It’s really appealing to have one smoking gun, I am just as interested as anyone in that, but it’s this big pot of stressors that are all having their influence.”

The report, called ‘The Status of Pacific Salmon in the Broughton Archipelago, Northeast Vancouver Island, and Mainland Inlets,’ is really that: a status report. It doesn’t draw conclusions about what is to be done, but is meant as a resource.

The data isn’t perfect, Atkinson said, and needs to be supplemented with lived experience of people with intimate connections with the rivers and much older baselines. Historical records from DFO started to get organized around the 1950s, so that’s when this report begins. Ideally researchers would have had more history to compare to, but this at least provides one useful scorecard to refer to.

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Data collection has also plummeted over time, notably in the early 2000s. Atkinson attributes that to Fisheries and Oceans budget cuts. Where there used to be about 50 river systems being counted, in 2017 just 11 were observed. Assessments are getting more uncertain over time, Atkinson said.

The level of granularity this report provides has not been scientifically reported before, the researchers said, and it’s needed for people and organizations in the areas.

While anyone who has lived in the area for many years can attest anecdotally to the decline in returning salmon, specific evidence was lacking. Other reports tend to group data, for example all the pink salmon in the region, into one number. That works for province-level discussions, but is less helpful for people and organizations on the ground.

Researchers wanted to answer the oft-asked question of a salmon researcher, how are the salmon? Salmon biology and the myriad influences on their environment make it a complicated question to answer.

“One year of low returns to a river could be part of a normal biological cycle or it could be the first sign of a serious decline driven by external stressors. How do we differentiate between such disparate explanations?” the authors asked.

Salmon Coast is a non-profit located in Echo Bay on Gilford Island. It was founded in 2006 by Alexandra Morton, Sarah Haney and Alan Calderwood.

Do you have something to add to this story or something else we should report on? Email: zoe.ducklow@blackpress.ca


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