Salmon: A Keystone Species

Salmon: A Keystone Species

Wild Salmon Center’s keystone species logo, created by Ed Hepp, is based on a study by the Washington Department of Natural Resources. The report found that at least 137 wildlife species in the Pacific Northwest alone – from caddisflies to orcas – are predators or scavengers of salmon at some stage in their life cycle. This study underscores the importance of wild salmon as a keystone species to food webs and watershed health as they transport vital nutrients and protein from the ocean to be deposited in upstream spawning grounds after they die.

Who loves salmon? Click on the salmon-hungry species hidden below to learn more.

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Grizzly Bear As salmon migrate from oceans to the upper reaches of rivers to spawn on gravel beds, they sometimes reach areas where they are forced to leap waterfalls. Grizzlies often gather at the base of the falls to catch and feed on the fish. Grizzly Bear Orca Adult salmon are a significant portion of the diet of killer whales, also known as orcas. In the Pacific Northwest, declines in wild salmon stocks have led to seasonal shortages of salmon prey for orcas. In the late 1990s, there were close to 100 orcas in the Puget Sound region; today, there are fewer than 75. Killer Whale (Orca) River Otter River otters prey on salmon runs as they migrate from the ocean and swim to the upper reaches of rivers to spawn on gravel beds. After spawning, all Pacific salmon and most Atlantic salmon die, and their life cycle starts over again. Northern River Otter Pacific Giant Salamander The Pacific giant salamander depends on clean water habitats for the survival of its young, and for food sources such as fish hatchlings. They are particularly sensitive to changes in water quality and are considered an indicator species for declining waterway health due to logging and other human activities. Pacific Giant Salamander Caddis Fly This fly is very useful when fishing for steelhead, a form of the coastal rainbow trout. Steelhead migrate to the ocean, similar to salmon species, and return to freshwater tributaries to spawn. Caddis Fly Mountain Lion Mountain lions are an "umbrella species" because their survival requires preserving large amounts of habitat. They require 13 times the area of a black bear to thrive. By preserving enough wilderness to support a stable mountain lion population, countless other species of plants and animals that share this habitat benefit. Mountain Lion Gray Wolf Wolves mostly eat large hoofed animals such as moose, deer, and cattle. However, the diet of coastal wolves in Alaska is about 20 percent salmon. Wolves in British Columbia and nearby islands source anywhere from 25-75 percent of their diet from marine environments. Gray Wolf
Forest The death of the salmon has important consequences; their carcasses, rich in nitrogen, sulfur, carbon and phosphorus, are transferred from the ocean to wildlife and woodlands adjacent to rivers. This affects not only the next generation of salmon, but every species living in the riparian zones that salmon reach. Forest
Blakistons Owl The salmon-eating Blakiston's fish owl, the world's largest, prefers a diet of overwintering juvenile salmon and spring frogs. This owl requires big trees with nesting cavities in close proximity to salmon-rich waters that don't freeze over in winter. Blakiston's Fish Owl
Western Pond Turtle Estuaries and their associated wetlands provide vital nursery areas for western pond turtles and also salmon prior to their ocean departure. These wetlands help buffer the estuary from silt and pollutants, and also provide important feeding and hiding areas for turtles and other aquatic species. Western Pond Turtle
Sea Lion Steller sea lions are skilled and opportunistic predators. They continually enter the Columbia River estuary and feed on migrating salmon as far upstream as Bonneville Dam. Protected under the Marine Mammal Protection Act, Steller sea lions are a concern for agencies charged with managing fish populations. Northern (Steller) Sea Lion

People For centuries, Indigenous communities have fed themselves and built their cultures around the abundance of salmon. With healthy salmon runs, our oceans and coastal river systems flourish and provide healthy food and clean drinking water to our communities. People

Condor The California condor prefers to feast on large mammal carcasses, but it also enjoys a variety of aquatic mammals such as whales, California sea lions, and salmon. California Condor

Merganser This merganser lives near ponds, estuaries, wetlands, and rivers. It feeds on aquatic insects that are supported by nutrients left by salmon carcasses during spawning migration. Hooded Merganser

Raccoon While raccoons’ diets in spring and early summer consists mostly of insects, worms, and small animals, they prefer prey that is easier to catch such as fish, amphibians, salmon, and bird eggs.
Raccoon

Garter Snake This highly aquatic snake eats small fish and fish eggs, salamanders, tadpoles, frogs, and toads that live in rivers, streams, lakes, and ponds supported by salmon-enriched nutrients. Pacific Coast Aquatic Garter Snake
Squirrel Douglas's Squirrel
Douglas's squirrels are dependent for habitat on old-growth or mature second-growth forests along the Pacific Coast. The bodies of salmon transfer rich nitrogen, sulfur, carbon, and phosphorus nutrients from the ocean to these forest ecosystems.
Great Blue Heron Salmon carcasses leave rich nitrogen, sulfur, carbon, and phosphorus in the riparian woodlands adjacent to rivers. Those nutrients wash downstream into estuaries where they accumulate and support estuarine breeding birds like the great blue herons. Great Blue Heron
Deer Black-tailed deer occupy coastal woodlands in the Pacific Northwest. They thrive on forest edges rich in underbrush and grassland. The bodies of salmon transfer rich nitrogen, sulfur, carbon and phosphorus nutrients from the ocean to these forest ecosystems. Black-tailed Deer

Cliff Swallow The American cliff swallow, like salmon species, feeds on flying insects such as flies, bees, lacewings, mayflies, butterflies, moths, grasshoppers, and damselflies. The cliff swallow's nesting colonies are close to fields, ponds, and ecosystems that host these insect populations. Cliff Swallow
Humpback Whale The humpback whale is an energetic hunter, taking krill and small schooling fish such as juvenile salmon by bubble net feeding, where a group of whales swim in a shrinking circle blowing bubbles. The bubbles encircle the prey, and the whales swim upward through the "net," mouths agape, swallowing thousands of fish in one gulp. Humpback Whale

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Can you find these species? Use this handy list to find some of the animals hidden in the illustration above.  Click away for fun facts about how they benefit from wild salmon and check out our Salmon School page for more fun facts and games.

  • Black-tailed deer
  • Blakiston’s fish owl
  • Caddis fly
  • California condor
  • Cliff swallow
  • Douglas’ squirrel
  • Forest
  • Gray wolf
  • Great blue heron
  • Grizzly bear
  • Hooded merganser
  • Humpback whale
  • Northern steller sea lion
  • Northern river otter
  • Orca
  • Pacific coast aquatic garter snake
  • Pacific giant salamander
  • People
  • Raccoon
  • Western pond turtle

Photo credits: Blakiston’s fish owl: Jonathan Slaght; grizzly bear: Dave McCoy; northern river otter: Sergey Gorschov; people: Ben Knight; remaining images: Alamy

Want your own Ed Hepp work of art? Donate $30 or more and get your very own Wild Salmon Center custom tote bag featuring our keystone species mosaic. 

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