Atlantic Salmon

The Atlantic salmon (Salmo salar) is an anadromous fish that is born in freshwater, migrates to the North Atlantic to feed and grow, and returns to its home river to spawn. Many wild populations have declined, and the species is also the foundation of the global salmon farming industry.

🧬 Field Guide Specimen: Open Atlantic Salmon in the CRV Science Field Guide to log the specimen, see its place among the Vertebrates lineages in the Cladogram Explorer, and test your recall in the Red List conservation game.

Young salmon imprint on the chemical signature of their river before they leave, and adults use this smell to pick the right stream after oceanic travel guided by magnetic and other cues. Unlike Pacific salmon, many Atlantic salmon survive spawning and return to the sea.

Dams block migration routes, pollution and warming rivers stress the fish, and changes in ocean conditions have reduced marine survival. Escapes from farms, sea lice and disease may affect wild stocks. Some populations, such as the Gulf of Maine group, are listed as endangered in the United States.

Salmon farming produces more than a million tonnes of fish a year in Norway, Chile and elsewhere, and raises questions about feed, pollution and parasites.

• Climate change — warming rivers and migration
• Eutrophication — effects of aquaculture waste