Grizzly and black bears do a lot of the heavy lifting when it comes to connecting marine and terrestrial ecosystems along the coast. As fish return each fall to spawn, bears catch salmon and eat them along the river banks or adjacent forests, leaving food and nutrient sources for hundreds of species of scavengers on the remaining salmon carcasses. We’re learning now that bears are also important seed dispersers for fruit-bearing shrubs in coastal rainforests, and that salmon-supported bear populations are able to distribute more seeds at greater distances the next spring.
Research throughout the coast shows that greater numbers of salmon contribute to denser bear populations because of the important fat and protein sources fish provide bears before winter sleep. This means that salmon carcasses deposited by bears in the fall may not only fertilize plants, but also support bears as dispersers of seeds from those plants the following spring!
Each spring, Raincoast’s Salmon Carnivore program monitors grizzly and black bears populations on the central coast. Our methods are non-invasive: we build small enclosures of a single-strand of barbed wire and bait the center with fish oil. The bears are drawn to the smell and approach the site, but are not rewarded with a fish feed. However, the tufts of hair they leave on the barbed wire open up a world of scientific possibilities for genetically identifying individual bears and analyzing the chemical signature of their diets.
We’re learning now that bears are also important seed dispersers for fruit-bearing shrubs in coastal rainforests, and that salmon-supported bear populations are able to distribute more seeds at greater distances the next spring. Tweet This!
Carbon and nitrogen in the hair can indicate the contribution of salmon to a bear’s overall diet from the previous year. We can tell this because bears shed their hair each spring, precisely why we are out in the field collecting data in those months each year.
From our fieldwork, we connect what we know about bears and their diets to data from coastal salmon populations in their home watersheds, asking, “Are bears getting enough salmon? How can we manage salmon populations and account for the needs of bears alongside human fishers?”.
The Wuikinuxv people in Rivers Inlet have shared a riverbank – a home and a fishery – with bears for thousands of years. Of primary concern to their coexistence with bears is ample salmon. The Wuikinuxv are one of five Nations who have collaborated in our Salmon Carnivore program. Through the guidance and direction of their Stewardship department, and with support from the Grizzly Bear Foundation, we are assessing how the Nation’s salmon harvest management plans can account for the needs of local fisherpeople and grizzly bears who share the local sockeye fishery.
I am inspired by the vision the Wuikinuxv Nation holds for fisheries allocations to support coexistence with wildlife. I am passionate about this work because it is important that bears not only get enough fish so they can sustain healthy populations, but also continue to confer the benefits of salmon fertilization into coastal rainforest ecosystems.
For the coast, its salmon, its bears and its people.
In 2018-2019 the Grizzly Bear Foundation was a key supporter of Megan’s research. Raincoast’s Director of Science, Professor Chris Darimont is a member of the Grizzly Bear Foundation’s Research Advisory Committee.