A deadly algae bloom that has killed nearly eight million Atlantic salmon being farmed in northern Norway appears to be dispersing, according to the Norwegian Directorate of Fisheries.
The bloom, first reported in mid-May, has killed 3.8 million farmed salmon in the Nordland area, the equivalent of 6,400 metric tons, and four million salmon in Troms, or 6,820 metric tons, according to Norway’s Fiskeridirektoratet. Affected companies include Ballangen Sjøfarm, Ellingsen Seafood, Mortenlaks, and Nordlaks in Nordland and South Rollerfish, Northern Lights Salmon, Kleiva Fish Farm, Gratanglaks, Nordlaks, and Salaks in Troms.
“It may seem that blooming is on the way down. Generally lower numbers of algae are recorded, the cells are smaller in size and there are observations suggesting that the bloom/species is less harmful,” the directorate wrote in a 2 June update. “As reported in recent days, there have been high concentrations of algae without causing fish to die. It may happen that the algae bloom up again in smaller areas.”
Many salmon-farming companies in northern Norway have transferred their fish to locations less likely to be affected by the algae bloom. Cermaq, Nordlaks, Ellingsen Seafood, and Nordnorsk Stamfisk have moved fish and broodstock out of Nordland, while Lerøy had issued a notice that it was considering moving fish out of Troms, but delayed its decision as local water conditions improved.
Nordlaks, which had moved 350,000 three-kilogram fish away from its farms near the bloom area – an operation that took around 18 hours in six separate wellboat loads – suffered a related problem when it discovered an escape at its Brottøy farm site in Hadsel municipality. The escape was likely the result of damage done to the farm’s netting during its transfer operations over the weekend.
“This is a very regrettable event and the last thing we wanted right now. We believe the damage has occurred during the work on the site on Sunday,” Nordlaks Communications Manager Lars Fredrik Martinussen said in a press release. “Throughout the evacuation, safety for crew, fish and environment was our top priority. We are very sorry that there has now been an escapes after this operation.”
Nordlaks said it was not sure how many salmon escaped before the five-meter gash in the netting was discovered on Sunday.
In a 1 June update, the Norwegian Directorate of Fisheries gave a hopeful forecast the worst effects of the algae bloom may be past.
"If the positive development continues, the industry must be prepared from Monday to channel water samples through its fixed suppliers of analysis services," the directorate said, meaning that the government will be returning to a less active monitoring role if the bloom continues to subside.
The directorate reported only small numbers of salmon mortalities over the weekend. However, the total impact of the bloom will be significant; Some financial analysts have estimated losses from the algae bloom could top 40,000 metric tons.
Photo courtesy of Ivar Johnsen/Nordlaks
