The Scottish salmon industry has warned that the new restrictions, which they view as applying a freshwater standard to a marine context, could undermine effective sea lice control.
Scottish salmon farmers have raised concerns over new restrictions on the use of the in-feed sea lice treatment, Slice (emamectin benzoate), warning that the move could severely impede their ability to manage lice infestations.
The Scottish Government has directed the Scottish Environment Protection Agency (SEPA) to implement a revised environmental quality standard (EQS) for the treatment, according to The Source, the newsletter of Scottish Sea Farms.
The changes, which reduce the permissible levels of Slice, were prompted by environmental concerns about the treatment’s potential impact on crustaceans in freshwater ecosystems. The revised standard has been applied to new or increased consents since March 2023 and will extend to all salmon farms within the next 48 months.
The salmon sector, however, has questioned the scientific basis for these restrictions. Anne Anderson, Head of Sustainability and Development at Scottish Sea Farms, criticized the new EQS as overly cautious, given that Slice is used in marine, not freshwater, environments.
“The standard was set to protect a freshwater species, yet Slice is administered in a marine setting,” Anderson said. She added that the sector’s annual usage of emamectin benzoate has averaged 42kg, impacting only a small area of the seabed and posing minimal risk.
The Scottish Government has acknowledged that the new standard is likely to reduce the number of Slice treatments that can be administered during a farming cycle, which has raised concerns among veterinarians.
Ronnie Soutar, Head of Veterinary Services at Scottish Sea Farms, highlighted the critical role Slice plays in managing juvenile sea lice and seasonal influxes from wild fish. “Slice has been an essential part of our lice control programme for 25 years,” said Soutar. “Losing it from our toolbox will have serious consequences for fish survival.”
Environmental groups argue that the four-year phase-in period for the new EQS is too long, but the salmon industry has warned that the restrictions, which they view as applying a freshwater standard to a marine context, could undermine effective sea lice control.
The Scottish Government has indicated it will continue to monitor the situation and may review the EQS based on ongoing scientific evaluations.
