As WeAreAquaculture reported earlier this month, unusually high sea temperatures in Northern Norway this summer have led to "explosive growth" of sea lice, placing a severe strain on fish farming operations.
The 4-5 degree Celsius rise in water temperatures has led to what Geir Ove Ystmark, CEO of Norwegian seafood trade body Sjømat Norge, describes as an "extraordinary situation" with potentially long-lasting consequences for the industry.
"Temperatures this summer are 4-5 degrees above normal. It has created an extraordinary situation that we are very concerned about," said Ystmark in a news release.
Sea lice, also called salmon lice, which thrive in warmer waters, have proliferated in the higher-than-usual sea temperatures, posing significant challenges for many fish farmers. In particular, Northern Norway’s typically cooler waters had historically kept lice pressure low, but this year’s spike has left the region's aquaculture facilities scrambling to manage the outbreak.
The Norwegian Institute of Marine Research has recorded water temperatures of 16.85 degrees Celsius at its Eggum station in Lofoten, far above the usual 12-13 degrees for this time of year. This marine heatwave has created optimal conditions for lice growth, intensifying pressure on fish farming operations.
The consequences for the industry are significant. In Norwegian aquaculture, regulations require that salmon farms maintain an average of no more than 0.5 adult female lice per fish to prevent the spread of parasites to wild salmon populations. But now, many facilities are far above that limit, forcing them to quickly implement lice removal measures to avoid penalties or even shutdowns.
The surge in lice numbers has also placed a strain on the industry’s lice treatment capacity. With so many farms needing lice removal at the same time, resources are stretched thin, Ystmark notes.
"The aquaculture industry uses well boats and service vessels to carry out lice removal. When so many companies need de-licing at the same time, it creates capacity challenges in Northern Norway," Ystmark explained.
Due to its typically cooler waters, Northern Norway has not historically needed the level of treatment infrastructure now required, and the current crisis is testing the limits.
"We are concerned that temperature changes are coming faster than we have predicted. It is generally cause for concern, also for the aquaculture industry, which is now experiencing higher lice pressure," Ystmark added.
If lice numbers continue to rise, farms may face reduced fish health, lower yields, and even temporary closures, significantly impacting production and profitability.
Additionally, handling fish during the treatment process can compromise fish welfare, leading to further complications. Fish farms must now balance the need for rapid lice removal with the potential stress and harm to their stocks, all while managing rising operational costs.
"The situation we are now experiencing may become a new normal that we must prepare for," Ystmark warned.
For ongoing updates on the sea lice situation, see lusedata.no.