Tracking the Sockeye Salmon Run

Salmon power Bristol Bay’s remarkable productivity, returning vast quantities of marine nutrients to freshwater and terrestrial systems by feeding marine mammals, birds, and brown bears as they complete their migrations home. These nutrients flow throughout the entire landscape, fortifying plants that, in turn, feed everything from microbes to moose.

Vector map of Alaska

Togiak (Togiak River)


Dillingham Nushagak River


Nondalton (Six Lake Mile)


Igiugig (Kvichak River leading into Iliamna Lake)


Naknek (Naknek River)


Egegik (Egegik River)


Nelson Lagoon


Cold Bay


Juvenile outgoing migration


Adult return migration

Sockeye salmon life cycle

Sockeye Salmon Life Cycle

From stream to lake to sea and back again, sockeye move hundreds, if not thousands, of miles during their four-to-six year lifetime, and help sustain multiple human and wild ways of life.

Counter-clockwise from the top
  • Eggs in gravel
  • Alevin within gravel
  • Fry move to ponds
  • Smolts adapt to salt water
  • Young adults
  • Adult salmon
  • Return migration
  • Spawning

Bay Wildlife The watershed provides habitat for more than 29 fish species, 190 bird species, and 40 land mammal species.

Bald eagle illustration

Bald Eagle

Bald eagles are opportunistic, gorging on salmon, waterfowl, and even carrion— sustenance the bay’s clean water and abundant wildlife provide in spades.

Steller's Elder illustration

Steller's Elder

Bristol Bay’s eelgrass lagoons teem with small fish and saltwater invertebrates that fuel eiders through the winter and help them bulk up for breeding season.

Moose illustration


Moose traverse the watershed’s tundra and forest in search of the woody browse and wetland plants that grow lush in salmon-enriched soil.

Brown bear illustration

Brown Bear

Fattened by a salmon-rich diet, coastal brown bears can grow to epic proportions. Bears in Bristol Bay have been known to reach 1,500 pounds.

Rainbow trout illustration

Rainbow Trout

These hungry freshwater predators grow enormous on salmon eggs, alevin, and fry, making the bay a top destination for anglers from around the world.

Freshwater seal illustration

Freshwater Seal

Lake Iliamna is the year-round home to a small breeding colony of harbor seals. Worldwide, there are only a handful of seal populations adapted to dwelling in lakes.

Pacific walrus illustration

Pacific Walrus

These pinnipeds dive deep to feed at the bottom of the Chukchi and Bering seas. In spring and summer, thousands of males rest on four rocky beaches in Bristol Bay.

North Pacific Right Whale illustration

North Pacific Right Whale

The copepod- and krill-rich waters at the mouth of Bristol Bay are designated as critical habitat for this rarest of all large whale species.

Beluga whale illustration

Beluga Whale

Belugas in bay waters feast on vast schools of outbound salmon smolts and returning adults. Echolocation helps them find prey, even in murky river mouths.

All illustrations by Gaby D'Alessandro

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