Atlantic Salmon
Salmo salar
Quick answer
The Atlantic salmon is a powerful migratory fish that hatches in freshwater rivers, matures in the ocean, and then swims back upstream to the river where it was born to spawn. This epic journey can cover hundreds of kilometers against strong currents and waterfalls. Atlantic salmon are an important food fish and a keystone species in the rivers and seas of the North Atlantic.
Atlantic Salmon facts at a glance
| Scientific name | Salmo salar |
|---|---|
| Diet | Carnivore |
| Habitat | North Atlantic rivers and ocean |
| Lifespan | 4–8 years |
| Weight | 3–15 kg (7–33 lb) |
| Top speed | Around 40 km/h (25 mph) in bursts |
| Conservation status | Least Concern (IUCN) |
| Kingdom | Animalia |
|---|---|
| Phylum | Chordata |
| Class | Actinopterygii |
| Order | Salmoniformes |
| Family | Salmonidae |
| Genus | Salmo |
Where it lives
Rivers and coastal waters of the North Atlantic, from northeastern North America to Europe.
Migration and life cycle
Atlantic salmon are anadromous, meaning they live in both fresh and salt water at different life stages. Young salmon hatch in cool, gravelly rivers, then migrate to the sea to grow for one to several years. Guided by smell and the Earth's magnetic field, adults return to their birth river to spawn, often leaping waterfalls along the way.
Diet and feeding
At sea, salmon are active predators that feed on small fish, squid, and crustaceans, building the rich, oily flesh they are known for. Once they enter freshwater to spawn, they largely stop feeding and rely on stored energy. This fasting leaves them weakened after the demanding upstream journey.
Habitat and range
Atlantic salmon are native to the rivers and coastal waters of the North Atlantic, from northeastern North America to Europe. They need clean, cool, well-oxygenated rivers to spawn successfully. Unlike Pacific salmon, some Atlantic salmon survive spawning and return to the sea to breed again.
Conservation and fishing
Atlantic salmon are a major food and sport fish, and most sold for food is now farmed. Wild populations have declined in many rivers due to dams, pollution, overfishing, and warming waters, and some local stocks are seriously depleted even though the species overall is listed as Least Concern. Restoring free-flowing, clean rivers is central to their recovery.
Frequently asked questions about the Atlantic Salmon
Why do salmon swim upstream?
Salmon swim upstream to return to the freshwater rivers where they hatched in order to spawn. The clean, gravelly riverbeds give their eggs the cool, oxygen-rich conditions they need to develop.
How do salmon find their home river?
Salmon navigate using the Earth's magnetic field to reach the right coastline, then rely on their keen sense of smell to recognize the unique scent of the river where they were born.
What do salmon eat?
At sea, salmon are carnivores that eat small fish, squid, and crustaceans. Once they enter freshwater to spawn, they mostly stop eating and live off energy stored in their bodies.
How big do Atlantic salmon get?
Atlantic salmon typically weigh 3 to 15 kg (7 to 33 lb) and reach around 70 to 90 cm long, though exceptional fish can grow larger after several years at sea.
Is most salmon wild or farmed?
Most Atlantic salmon sold as food today is farmed. Wild populations have declined in many rivers, so fish farming supplies the large majority of the salmon people eat.
