The study was published online yesterday by the North American Journal of Fisheries Management.

The Campbell River area is known as the 'Salmon Capital of the World' and accounts for a significant portion of the $233 million a year provincial sport fishing tourism revenue.

The report's authors - Alexandra Morton R.P.Bio. (Salmon Coast Field Station), Dr Richard Routledge (Simon Fraser University) and Dr Martin Krkosek (University of Alberta) - examined 4,700 young wild salmon near and distant to fish farms in 2005 and 2006 throughout the Discovery Islands.

Commenting, Alexandra Morton, a marine biologist who has been described previously as "one of the leading opponents of salmon farming in British Columbia", said: “We found four times as many wild juvenile salmon were infected with sea lice near fish farms than distant from the farms. Then, in 2006, when most of the farms were empty, the sea lice declined.”

“This is the same pattern we see in the Broughton Archipelago,” added Dr Routledge. “Where there are farm fish the young wild salmon are infested with lice. Remove the farm fish and the sea lice problem disappears.”

The authors say the study looked at other variables, including salinity and temperature, but found that farmed fish were the only significant factor contributing to the infestations. Sampling was conducted by commercial fishermen.

The authors say that while pink and chum salmon were the primary study focus, juvenile herring were also examined and were found "infested" with lice. The herring were small and still lacking scales, suggesting high vulnerability. This is the first report of sea lice on herring this young.

In addition, juvenile sockeye were discovered to be "infested" near the farms, the report claims. Last summer, commercial salmon fishing was closed on the south coast because so many of the Fraser River sockeye failed to come home. Some of the sockeye that went “missing” last year were likely infested with sea lice in 2005 when they migrated to sea, it contends.

“We did not test the DNA of the sockeye we examined,” explains Dr Martin Krkosek. “However, we know that many Fraser River sockeye migrate through our study area.”

The report concludes there is urgent need to implement policy that protects wild salmon from farmed fish.

This month, BC Minister Pat Bell called for more drug use to control lice. Alexandra Morton disagrees, saying that using drugs creates concerns for environmental and human health. She claims the relevant drug has not been approved for use by Health Canada and may impact important stocks of crab, shrimp and prawns.

“The only measure that is going to work is separating farm and wild salmon. This can only be achieved by completely closed containment technology or moving the farms. If nothing is done now, I worry that Canadian salmon stocks will suffer the same fate as European salmon stocks that have declined dramatically in fish farming regions,” she concluded.

www.fishupdate.com is published by Special Publications. Special Publications also publish FISHupdate magazine, Fish Farmer, the Fish Industry Yearbook, the Scottish Seafood Processors Federation Diary, the Fish Farmer Handbook and a range of wallplanners.

Printer friendly version

Email this article to a friend