Norwegian authorities warn of "worrying rise" in sea lice

High sea temperatures along the Norwegian coast this summer are setting the stage for a surge in sea lice numbers going into autumn, Norwegian authories have warned.

According to data from the Institute of Marine Research, sea lice infection levels are higher than in previous years. The Norwegian Food Safety Authority (Mattilsynet) has also registered a sudden escalation of reported lice infestations received via field reports.

Bård Skjelstad, director of the aquaculture supervision division at Mattilsynet, said "We also see a rapidly escalating breach of permitted lice limits in some areas.”

However, the authority warns, farmers still need to prioritise fish welfare in tackling the surge in sea lice numbers. “To solve the challenges, farmers must follow and respect the decisions of authorised animal health personnel regarding lice treatments," Skjelstad said.

Issuing its warning, Mattilsynet acknowledged that efforts have been made by some operators to increase preparedness, following difficulties in northern Norway during a similar increase in sea lice in August last year.

However, according to the authority, treatment capacity remains stretched in several locations, and animal health staff are facing difficult decisions about when and how to treat fish.

Skjelstad emphasised that animal health personnel have the final say on whether lice treatments can be carried out. Skjelstad said that some professionals have reported pressure from farmers to carry out delousing procedures that could compromise welfare standards.

“We take this very seriously,” he said. “We expect farming companies to act professionally and respect the professional decisions of animal health personnel in order to safeguard fish welfare – even if it entails financial loss."

The authority confirmed it is in dialogue with professional organisations regarding these concerns.

Representatives of veterinarians and other fish health professionals have previously warned that such professionals, many of whom work as external consultants for fish farming companies, face pressure from their clients over decisions on treatment of sea lice infestations. In a Tekna survey carried out last year, one in four respondents said they were worried about contradicting their client's views regarding de-licing.

Tekna said their survey also showed that "a significant proportion feel that they have limited influence on decisions, and that their professional advice is not always taken into account."

Mattilsynet announced it will continue joint operations with the Norwegian Coast Guard this autumn to carry out unannounced inspections of delousing treatments.

The authority also confirmed it will carry out follow-up inspections after serious incidents, together with checks on emergency slaughter from processing vessels.