New jellyfish fears in Norway

The jellyfish scourge which cost Norwegian salmon companies millions of krone last winter may be on the way back.

The Norwegian Institute of Marine Research, through its Jellysafe project, says there have been increased sightings of the “perlesnormanet” jellyfish – also known as string or barbed jellyfish – and estimated numbers are now running at the same level as last year.

So far, however, no salmon farmers have reported any losses from this growing and serious problem.

Jellyfish attacks adversely affected almost every major salmon company in Norway last year – and some in Scotland – leading to the premature deaths of millions of salmon.

Some colonies were up to 30 metres long, but when broken up they got into the cages, killing the fish.

Jellysafe said the number of weekly Apolemia uvaria observations continues to increase in a pattern similar to the autumn last year.

A cluster of Apolemia was observed in salmon farming area PO3 near Bergen.

The Institute has been carrying out research on how much of the damage and huge cost of last winter can be prevented. It says that the industry may be able to help. JellySafe is inviting  fish farmers to participate in a discussion forum to share experiences, get quick access to results, and help the project to continuously come up with solutions that will prevent  major damage in the cage.

The Institute also wants samples from along the coast, so it can see if there are genetic differences between the various groups and those from last year, and it has offered to send out sampling kits.