It’s not just bears, whales and humans that love Pacific Salmon. The impact of these resilient but vulnerable creatures is in the soil we walk on, the air we breathe, the cities we live in – and all up and down the food chain.
Research points to over 130 species that rely on Pacific Salmon for survival-which also means they face a wide array of predators at every stage of their life and journey.
Being the keystone species of an ecosystem isn’t easy! Even as eggs and infants, salmon are preyed on by sea and aquatic birds, as well as by some river snakes and salamanders.
Baby salmon that survive long enough to develop into fry become an even more important food source, to a much larger and diverse group of predators. Herons, ravens, osprey, and crows all rely heavily on young salmon. As fry, salmon also become increasingly appealing to mammals such as mink, otters, and raccoons.
After transitioning from fry into adults, they become even more valuable prey – which is when predators typically associated with salmon come into play. Eagles, grizzly bears, sea lions, seals, otters and killer whales all depend on salmon as a significant part of their diet; and of course adult salmon serve as a food source for humans too.
British Columbia’s Pacific salmon are also critical to the diet of some of the world’s most endangered whales. Southern Resident Killer Whales, which are unique to the Pacific Northwest, feed almost exclusively on salmon. As of March 2021, there are only 75 left in the world.
Salmon keep on giving even after they die. Those that escape the wide range of predators and return home to spawn continue to benefit the ecosystem.
Dozens of species rely on salmon carcasses. Grizzly bears, black bears, coyotes, eagles, vultures, squirrels, hawks, sparrows, skunks, foxes, wolves, and turtles all depend on salmon carcasses for vital nutrients.
Salmon also help to improve water quality. As they decompose, the nitrogen and phosphorous in their bones seep into the surrounding waters, which helps develop plankton and other important marine life.
Salmon carcasses also help support forest health. The water supplemented by their remains improves the health of soil along shorelines and the trees that live along them.
But it’s not just the soil and trees surrounding shorelines that benefit from dead salmon.
As predators such as bears and wolves drag their carcasses away from the shoreline, nutrients from their skeletons work their way into the forest floor, enriching soil along the way. These remains act as a sort of natural fertilizer, improving living conditions for various trees and plants throughout the forest.
In fact, some studies estimate that decomposing salmon can actually increase soil quality and plant growth by up to 20%.
It turns out that some of the natural environment that helps to protect migrating salmon helps to protect cities too. One of the best examples is the seagrass that lives along shorelines, which serve not only as an important salmon habitat, but also as a physical stabilizer, helping to reduce erosion and the flooding of coastal regions.
Seagrasses also play a role in combatting climate change, the importance of which is becoming increasingly apparent. That’s another story…coming soon!