B.C. anti-fish farm group claims sea lice are growing more resistant to drug
An anti-fish farm group says sea lice, which infect farmed salmon in B.C.’s waters, are growing more resistant to an anti-parasite drug — and nothing is being done to stop it.
A new report from Living Oceans and Raincoast Research says Fisheries and Oceans Canada (DFO) knew that sea lice are growing resistant to the drug called SLICE.
It is the treatment of choice for sea lice affecting farmed Atlantic Salmon and used to control the infestation of the parasite.
The DFO has been examining the issue for years, having ordered a study in 2014 to look into evidence that “recent treatment failures have been linked to resistance to SLICE within sea lice populations…treatment efficacy is variable among sites.”
However, Living Oceans claims that information was not shared with the Minister of Agriculture, and that the DFO remained silent while an advisory council was told there was no evidence drug resistance in B.C.
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“In the past year we saw juvenile wild salmon with as many as 50 lice on them,” Karen Wristen, executive director at Living Oceans Society, told Global News.
Examining the fish populations in Clayoquot Sound, the report found that 96 per cent of the wild juvenile salmon were infected with an average of more than eight lice per fish, which at those levels could prove lethal.
“During most years, more than 90 per cent of sites in B.C. are below the regulatory thresholds for sea lice during the wild salmon outmigration period. However, there were documented failures of SLICE treatment at Klemtu in 2013 and Esperanza Inlet in 2017 and now Clayoquot Sound in 2018,” the DFO said in a statement to Global News.
The statement added that the fish farm in Clayoquot Sound, Cermaq Canada, is now under review, and they are keeping a close eye on any possible SLICE resistance.
Living Oceans claims that if SLICE is no longer effective, salmon farmers will be forced to control the lice by dumping harmful chemicals into the ocean.
Wristen said fish farmers should have a variety of treatments available to them, otherwise the lice will become resistant to the drugs as seen in other areas of the world.
But others disagree, saying the research on SLICE’s ineffectiveness is not yet proven. As well, they say, SLICE is not the only method the aquaculture industry is using to control lice.
“Like any farming activity, we have pests we have to manage,” said Shawn Hall, spokesperson with the BC Salmon Farmers Association. “You know, if you’re farming on land — say you’re raising cows — you might have ticks to deal with. Well, sea lice are our pests that we have to manage.”
Hall says farms are already using several techniques including a new technology called a hydrolicer, which can delouse salmon using pressurized water.
“Well, sea lice are a real issue that needs to be managed, and so our focus is on managing that effectively to manage that risk,” Hall added.
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