Biologist Warns British Columbia Wild Salmon 
Near Collapse from Fish Farm Disease 

FISHLINK SUBLEGALS 18oct02

Dr. Alexandra Morton, a renowned fishery biologist, along with the Coastal Alliance for Aquaculture Reform, a coalition of 10 organizations opposed to open-ocean fish farming on the British Columbia coastline, have issued a joint warning of the danger posed to B.C.'s natural salmon stocks from infection by sea lice from Atlantic salmon net pen aquaculture operations. At a conference announcing her findings, says the 25 September National Post, Dr. Morton showed a wild salmon smolt covered with sea lice, which are thriving in the fish farms off the B.C. coastline and which she and other biologists say are now to blame for the disappearance of millions of naturally spawning salmon.

"Sea lice are natural in the environment," said Morton. "They infect the farmed fish and then they explode in numbers over the winter because the conditions are just right. They moved back to the wild stocks last spring, just when the pinks were migrating through. This is not theory. I've done the science on this." Amidst controversy and against the advice of many of its own agency biologists, the Canadian government recently lifted its moratorium on issuing new salmon fish farm permits in British Columbia (see Sublegals 5:18/04; 5:06/05; 5:05/09). The problems of fish farms becoming disease and parasite reservoirs that can then spread to wild populations has also been confirmed by other recent studies (see e.g. Sublegals 5:02/11) and has become a pervasive problem in salmon farms in Scotland and Norway. 

Sea lice are external parasites that feed on the skin and mucous of fish. Fish infected by lice may suffer from stress, secondary infections, and even osmoregulatory failure and death. Sea lice are common on wild and farmed salmon. Yet they can occur in unnaturally high densities in salmon farms, where they pose a severe threat to passing wild salmon, especially the juveniles.

• More on Sea Lice at Watershed Watch: Salmon Society