Algae threat moving closer to Norway

This potentially damaging development for fish farmers is not yet a direct threat, but the danger is getting closer.

HUI, the Norwegian Institute of Marine Research, said the concentration of the algae Pseudochattonella in the south is still so low that it does not yet pose a threat to fish. The weather over the next few days should determine how the situation will develop.

Institute researcher Lars-Johan Naustvoll has asked fish farmers to let him know if they notice changes of behaviour or if there is an increase in mortality.

In recent days, the concentration has increased outside Arendal, as measured by water samples. In addition, satellite images indicate that the bloom now extends all the way down to areas outside Grimstad and  Lillesand.

The Institute says: “If there are no changes in relation to the weather forecast, the algae will probably be transported out into the Skagerrak and thus away from the coast over the next few days.

“Since there is uncertainty around these model results, more model runs will be made both today and tomorrow to capture any changes.”

The Institute says it is monitoring the situation and will publish new information as it becomes available.

Small and larger blooms of various algae are natural, but some algae can be toxic to fish if the bloom is severe enough. The last time there was a fatal bloom of Pseudochattonella was in 1998.