February

The migration of salmon, Audun Richardsen UiT

What do we know about wild salmon in the sea?

The wild salmon is probably one of the most studied fish. We now know a lot about the salmon's life in the river. It's fairly straightforward and easy to study them there. The ocean, on the other hand, is enormous, which is why we still have many questions about the salmon's migration to find food in the sea. In recent years, however, we have gained a lot of new knowledge about the ocean thanks to skilled scientists and modern research methods. For example, we are constantly receiving new information from salmon in the sea that are equipped with advanced tags. These tags can give us information about where the salmon go, what temperatures they stay in, and how deep they swim and dive.

Among other things, we now know that salmon stay closer to the surface in summer, fall and spring than in winter, and that they can dive really deep. Dives as deep as 900 meters have been recorded. The salmon also migrate further than we thought - all the way up to the Faroe Islands, Greenland and Svalbard. They 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, wild salmon can swim around in water colder than 5 degrees.

We now know that the migration route varies from salmon to salmon, and that salmon from different rivers graze in different areas of the sea. But with as many salmon stocks as we have in Norway, there is still a lot we don't know. It is therefore important to gain new knowledge about salmon in the sea so that we can take the best possible care of them. Over the past 20-25 years, fewer salmon have survived their stay in the sea than before.