Adult salmon
Photo: Audun Richardsen
Salmon grow much faster in the sea than in the river. Towards the end of the first winter in the sea, we call salmon adults. Salmon can stay in the sea from one to five years. Then they return to the river where they were born.
The ocean is vast, and we still have many questions about how salmon live there. But thanks to talented researchers, we have recently gained a lot of new knowledge about salmon in the sea. Among other things, researchers have attached special tags to salmon. These tags tell us where the salmon swim, what temperatures they are in, and how deep they swim and dive. We now know that salmon stay closer to the surface in summer, fall and spring than in winter. We also know that they can dive deep. Dives as deep as 900 meters have been recorded.
While in the ocean, salmon migrate further than previously thought, all the way to Greenland and Svalbard. Salmon like cold water, especially where cold water from the Arctic Ocean meets warmer water from the Atlantic Ocean. There is plenty of food there. For long periods, salmon swim around in water colder than 5 degrees Celsius.
We know that the migration route varies from salmon to salmon, and that salmon from different parts of the country go to different areas of the sea. With as many wild salmon populations as we have in Norway, there is still a lot we don't know. It is therefore important to have new knowledge about salmon in the sea so that we can take the best possible care of them. Because now, fewer salmon survive their stay in the sea than before.
The journey home
It varies how long salmon stay in the sea before they swim back to their river to spawn. Some go home after just one year, while others stay in the sea for up to five years before returning home.
What do salmon eat in the sea?
There are many different types of food in the sea, including insects, crustaceans, octopuses and various types of small fish such as spotted seatrout, herring, capelin and sandeel.
Why does salmon meat turn red?
When salmon are in the sea, their flesh turns red. It becomes colored when the salmon eat crustaceans that contain a dye. This dye is similar to that found in carrots.
Tobis is good food for the smallest salmon in the sea. Photo: Magdalene Langset, NINA
Before the salmon migrates to the sea, the flesh is colorless. In the sea it turns red. Photo: Tone Løvold