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VANCOUVER – Fish farms are breeding grounds for a potentially lethal parasite that may have caused a massive die off of wild salmon in BC earlier this year, according to a scientific report released today.

“Both the Department of Fisheries and Oceans and the Province have trivialized the threat of farm-source sea lice. Wherever fish farms are found in the world, wild fish suffer from lice outbreaks,” says Dr. Craig Orr, Watershed Watch executive director. “BC certainly isn’t immune to this threat.”

The Watershed Watch report indicates that as few as five sea lice can debilitate a juvenile salmon, and 10 or more will kill it outright. Last summer, large but unknown numbers of wild juvenile pink salmon were infested with lethal loads of sea lice as they left coastal rivers and migrated past densely-packed fish farms in the Broughton Archipelago, northeast of Vancouver Island.

A recent Fisheries and Oceans report on the Broughton outbreak was deemed “more of a cover-up than science” by ex-DFO scientist, Otto Langer.

Watershed Watch commissioned fisheries biologist Dr. Diane Urban to research the interactions between fish farms, sea lice and wild salmon. “As I examined the research,” Dr. Urban says, “it became abundantly clear that lice from fish farms are a serious and immediate threat to wild salmon.”

The report found that sea lice outbreaks in wild fish stocks are most likely near fish farms, and notes that fisheries experts such as Ireland’s Dr. Paddy Gargan believe the salmon farm/sea lice threat “can be greater” than other biological and genetic threats associated with fish farms.

The report urges government to: research the farm/sea lice threat; set and monitor sea lice control measures at fish farms; publish monitoring results promptly; and review lice prevention and treatment strategies.

Watershed Watch’s findings and recommendations have already been praised by BC Aboriginal Fisheries Commission chair, Arnie Narcisse, who said “First Nations and all British Columbians deserve to know much more about the risks posed by fish farms, so that they can make intelligent choices about future employment.”

For further information contact: Dr. Craig Orr, phone, 604-936-9474, 604-809-2799, or e:mail: corr@telus.net.

The Sea Lice/Fish Farm Threat to Wild Salmon

Background:

Salmon Farms, Sea Lice, and Wild Salmon: A Watershed Watch Commentary on Risk, Responsibility, and the Public Interest focuses on a little-discussed but serious environmental threat from open net-cage salmon farms.

Salmon farms can be ideal breeding grounds for sea lice. There is mounting evidence that sea-lice outbreaks in wild salmon populations can originate in fish farms, where large numbers of fish penned in close quarters are vulnerable to attack by this native parasitic copepod known as Lepeophtheirus salmonis. Wild juvenile salmon swimming by an infested farm can become covered in lice. The end result is often death.

The paper sketches the basic biology of lice, the parasitic relationship of lice to salmon, the effects of infection, and the recorded occurrences of lice outbreaks. It provides a detailed summary of the biology and natural history of the sea louse, and of the pros and cons of current lice-prevention and treatment tactics.

A recent and severe lice outbreak in wild pink salmon (Oncorhynchus gorbuscha), in one of BC’s heaviest concentrations of salmon farming, the Broughton Archipelago, emphasizes the need to prevent salmon farms from becoming lethal reservoirs of lice. Though BC’s wild salmon have coevolved with lice, the advent of fish farms appears to impact an already-stressed group of fishes. Juvenile salmon are particularly vulnerable; 5 lice can debilitate a fish of 15 grams or less, and 11 or more will kill it outright.

Despite the evidence implicating fish farms, and despite the precarious plight of Pacific salmon, the federal and provincial governments seem reluctant—or unable—to apply the precautionary principle to the aquaculture industry. This report makes the case that Canada and British Columbia should do their utmost to protect wild Pacific salmon—for the people of Canada, for the people of the world, for the future, and for the fish themselves.

The matter is urgent.

The full 25-page report is available by way of a pdf file, courtesy Watershed-Watch.org.