Drug resistant sea lice have ‘grave implications’ for salmon: Report
Sea lice are “out of control” at salmon farms on the West Coast of B.C. this year because they have become drug resistant, says a new report by two environmental groups.
The groups, Living Oceans and Raincoast Research, also claim that industry regulators have failed to protect wild juvenile salmon and other fish from the parasites.
The report, “Lousy Choices,” released Tuesday, says sea lice at fish farms on Clayoquot Sound have evolved a resistance to SLICE, an emamectin benzoate drug, approved for use to eradicate the parasite in Canada. The researchers say some resistance to the drug has also been observed at fish farms in the Broughton area.
This has “grave implications” for both the salmon farming industry and wild salmon, the report says.
This year, sea lice are responsible for “considerable losses” to wild salmon in Clayoquot Sound and at least one salmon farming company, Cermaq, the report said.
Earlier this spring, independent researchers in Clayoquot Sound discovered juvenile wild salmon were heavily infested with sea lice. This after Cermaq Canada was found to have sea lice above management levels at its Clayoquot Sound farms. The company was forced to close one of its fish farms, Fortune Channel, this summer after a high number of lice were found at the site.
The report says that 96 per cent of wild juvenile salmon in the area were infected with an average of eight lice a fish, according to the researchers. Some were found with as many as 50 lice, the report notes, which concerns researchers, who say it only takes one to three lice to kill the young fish.
The report claims Fisheries and Oceans Canada knew as early as 2014 that resistance was developing in sea lice, but didn’t take measures to ensure the protection of wild juvenile salmon from the parasite.
Measures could have included alternative treatments for sea lice ready for deployment when SLICE failed, the report says.
Fisheries has yet to respond to a request for comment.
“Eighteen years after this issue was brought to DFO’s attention there is still no protection for wild salmon,” said Alexandra Morton, one of the report’s authors with Raincoast Research and an outspoken critic of salmon farming.
Karen Wristen, executive director of Living Oceans Society, said at a meeting in Tofino this summer that Cermaq reported resistance in the sea lice on their farms.
She said now they’re trying to set up another meeting with Fisheries to discuss the sea lice drug resistance.
“The last meeting we had (with the department) they were still denying that they are resistant to the drug,” said Wristen.
In June, the environmental groups were outraged when the B.C. NDP government refused to cancel 20 fish-farm tenures in the Broughton Archipelago that were up for renewal.