After a few bad years, salmon have returned to spawn in the Torne River to a greater extent. But it is anything but peace and joy, as in an unusually high number of cases they have been attacked by fungus. The fungal spores are always present in the water and it is not obvious that the fish will get sick from them.
It often takes something more for it to become sick, that it is impaired for some reason or has suffered mechanical damage. We do not know what the underlying cause is now, says Hampus Hällbom, veterinarian at SVA.
The fungus appears as white patches on the salmon. Those that are severely affected are sometimes described as “zombie salmon.” The fungus is not dangerous to humans and anyone who eats an infected salmon will not get sick.
But you shouldn't eat a salmon that has died by itself or looks very sick, says Hampus Hällbom.
Similar fungal attacks have occurred in previous years, but according to Hällbom there has been a sharp increase in the last 10–15 years.
Anyone who sees a sick or dead salmon is urged to report it to SVA, preferably with a picture of the fish. This will assist in the attempts to get a better picture of the spread of the fungus and what may be behind the Torne River salmon being affected so severely.
SVA is also curious about the extent to which salmon in other parts of the country are affected.
It is reasonable that we see more attacks in the Torne River now that there are more salmon, but that does not explain everything, says Hällbom.
What do you think?