Cermaq Canada has applied to continue using a pesticide to treat sea lice on Atlantic salmon reared in its marine aquaculture sites in Clayoquot Sound, north of Tofino, as environmental groups express concern.
If the B.C. Ministry of Environment issues the permit, it would give the company the option to bath fish in a treatment of Interox Paramove 50 to remove sea lice and egg strings. The permit allows for the use of 903,240 litres over three years.
On Feb. 2, the ministry told Cermaq it must advertise their application within 45 days and describe how it will respond to any public and First Nation comments within 90 days of advertising. The ministry has yet to review the application and said there is no specific timeline for a decision.
Health Canada labels Interox Paramove 50 as toxic to humans and aquatic organisms. The Ministry of Environment says Cermaq’s proposal involves administering it by well-boat only and neutralizing the treatment bath with additional seawater before releasing it into the environment.
“The active ingredient in Interox Paramove 50 is hydrogen peroxide, which is considered a safe pesticide option for sea lice treatment as it breaks down very quickly and does not have lingering effects,” reads the Ministry of Environment’s statement, adding it is fully registered for use by Health Canada.
Cermaq Canada started using hydrogen peroxide to treat sea lice in 2018. The pest control product was touted as an alternative to SLICE, an antibiotic insecticide called emamectin benzoate that is put into the fish food and ingested.
The finfish aquaculture company says studies have shown higher concentrations of Paramove 50 may have a negative affect on sea lice but, under the method used, would be unlikely to have a significant impact on larval bivalves or crustaceans.
Clayoquot Action, Tofino’s environmental watchdog, disagrees.
“New science coming out of Norway is showing that peroxide is much more toxic to krill than we thought it was even three years ago,” said Dan Lewis, Clayoquot Action’s executive director. “And it spreads farther, and persists longer than was previously understood. I thought we learned long ago that dilution is not the solution to pollution.”
Department of Fisheries and Oceans (DFO) reported an unusually high number of whale mortalities in 2020. From the Pacific Coast of Mexico upwards to Alaska, approximately 150 gray whales have washed up dead, and Lewis wonders if there is a link.
Paul Cottrell, DFO’s B.C. marine mammals co-ordinator, acknowledges one theory for the die-off is related to food supply, but the Ministry of Environment maintains the pesticide process is safe, and there is no science linking it to fish farm pesticide.
Clayoquot Action’s concern persists.
“Cermaq’s timing couldn’t be worse”, said the group’s campaigns director Bonny Glambeck. “Grey whales are just returning from Mexico, and their diet is tiny crustaceans. There are rare herring spawning nearby, and tiny juvenile wild salmon are just now emerging from the rivers.”
— With files from Andrew Bailey