Algal bloom raises risk for salmon farms along Skagerrak coast.
A rapid increase in the potentially harmful algae Pseudochattonella along Norway’s Skagerrak coast is raising concerns about possible impacts on aquaculture operations, according to Havforskningsinstituttet in a story first reported by NRK.
The algae has been detected from the Oslofjord to Arendal and has recently spread further south to Farsund. Researchers reported a sharp rise in concentrations in recent days, describing the increase as significant.
“This is a species that can cause fish mortality in aquaculture facilities,” said researcher Lars-Johan Naustvoll at Havforskningsinstituttet’s Flødevigen research station.
The species is not new to the region but is currently concentrated closer to the coastline and within fjord systems, increasing the risk of exposure for sea-based salmon farms.
Havforskningsinstituttet said modelling indicates the bloom will remain close to shore and move southwest in the coming days, with the potential to reach areas further along the coast, including parts of Rogaland.
If algae enters farming sites at sufficient concentrations, it can lead to fish mortality, welfare issues and economic losses for producers.
The institute has issued alerts to industry and authorities and is monitoring the situation. Farmers in affected production areas have been advised to report abnormal fish behaviour or increased mortality.
Harmful algal blooms have previously caused significant losses in Norwegian aquaculture. Past events along the Skagerrak coast have resulted in large-scale fish mortality.