Ecologist Megan Adams didn’t know she was in love with salmon until she spent a little time getting to know them. As an Alberta native she was only peripherally aware of their status on Canada’s west coast; but while studying the health of juvenile salmon on the undeveloped Broughton Archipelago near Vancouver Island, something changed. “It was a kind of awakening,” she says of the experience. “I was blown away by how complicated and beautiful the migration paths of juvenile salmon are.”
Now, as a Hakai-Raincoast scholar and PhD Candidate at the University of Victoria, Adams has been pulling at the thread of salmon migration. She has published her findings in a study that reveals just how interconnected salmon are with the wildlife that surround them — bears specifically. “I was so inspired by salmon, I wanted to kind of move up the food web to a consumer. And the bear is the real conduit between the ocean and the sea,” says Adams.
Experts have long been aware of the relationship between salmon and bears but this study is unique because it shows just how closely connected bears are to salmon. Adams and her colleagues analyzed samples from 1,400 bears across 690,000 km2 of their habitat in BC to find out where salmon-eating bears live, and the percentage of their diet that comes from salmon.
They collected the hair samples by stringing up barbed wire in forests across BC around the time of the bears’ annual molt. “If you grab the hair right before that happens, it’s got the whole chemical signature of their diet in the previous year. So we can estimate from the hair, the percentage of salmon in their diet,” explains Adams.
It turns out it’s not just coastal bears that are getting their fill of salmon. The study found bears eating a salmon-rich diet more than 1,000 kilometres inland, some close to the Alberta border. Adam’s team mapped out these “salmon hot spots” to show what species of bears eat the most salmon, where — and to clearly lay out how this predator-prey relationship unfolds across the province.
The researchers found that male grizzly bears are the top salmon eaters in BC, while male bears of both species eat more salmon than females. “There’s a nuance involved,” explains Adams, and by visualizing where bears are eating the most salmon, the hope is to help conservationists better understand which regions need more attention. “[The map] lets us say that bears are using salmon a lot in those places, so do our management practices need to reflect that?”
Collaboration is also taking place between local Indigenous communities and the researchers. Data collection occurs on unceded traditional Indigenous lands, so the researchers have learned to work with First Nations communities on shared objectives. Adams says they were able to learn about how bears and salmon systems interact in a way that wouldn’t have been possible without local knowledge.
She works with the Wuikinuxv First Nation near Rivers Inlet, specifically. “They shared space with bears on a salmon river for thousands of years. So Bears are very personal to them,” she says.
Now that they have an extensive map of where bears and salmon interact, the research team is planning on figuring out exactly how much fish bears need on average to stay healthy. This in turn will help Indigenous communities decide when to put their nets in the water, and also, how much salmon needs to be protected from commercial harvest.
“This is an extremely amazing and generous animal that travels so far, comes back home consistently to the same place, same time every year and provides amazing food sources for the people and animals that live along the rivers that they bond to,” says Adams.
You can read the study here.