Sea lice from fish farms threaten Fraser River sockeye: biologist
Sea lice from fish farms may be a greater threat to Fraser River sockeye salmon stocks that conservationists previously thought.
That’s according to research conducted by the Coastal Alliance for Aquaculture Reform and the Raincoast Conservation Foundation.
Raincoast biologist Michael Price said that sockeye salmon from as far up the river as Prince George are catching sea lice from fish farms in the Pacific Ocean, Strait of Georgia, and Broughton Archipelago.
Price told the Straight in a phone interview from Clayoquot Sound today that the recent decline in sockeye stocks may be attributable to the sea lice.
Those fish are small juveniles when they migrate to the coast.
In Scotland, Ireland, and elsewhere in Europe, he said, scientists have found that sea lice can kill juvenile salmon and trout, which are 14 to 20 centimetres long.
In B.C., these juvenile salmon are about 10 centimetres. So in theory, he said, they’re even more vulnerable.
“We’re not sure whether juveniles are being lethally effected,” Price said. “We need to do the science.”
Price was careful to state that the research has not been peer reviewed or published yet, and the results of the study are preliminary.
But the scientist said the province should be alarmed.
In 2007, about 60 percent of the sockeye sampled east of Vancouver Island—in the heaviest salmon farming region in the province—were from the Fraser River. In 2008, 90 percent were from the Fraser, according to Price.
“Salmon is the thread that holds this coast together,” he said.
Until four years ago, Price studied B.C. bears and wolves, but he shifted his focus to salmon because they’re key to conserving terrestrial carnivores.
“They are connected to almost all other life that appears on this coast....Sockeye are of high economic, social, cultural, and spiritual significance to not only First Nations but people throughout this province. It’s a food source for many, many people. It’s a food source that could be eliminated.”
According to the B.C. Ministry of the Environment, aquaculture’s contribution to the provincial GDP is $71.4 million; capture fisheries contribute $135.4 million. B.C. is the world’s fourth largest producer of farmed salmon.
Price said that needs to change.
“We know what to do. We can close farms,” he said, noting that Fisheries and Oceans Canada has received several applications to expand fish farms. “Or, we can reduce the number of fish they produce. Or, we can find the technology to move them onto land.”
Mar 24, 2009 at 1:44pm
Note that all this talk about salmon farms' lice impacting the wild salmon assumes that the farmed salmon have lice and haven't been treated for lice. Salmon farms don't want lice either and they do treat for lice, if they get them. If they don't have lice on the farm, that can't be the source for the problems with with wild fish. The better farms publish their lice treatments and similar information, but that is never used in the so call "scientific studies" on fish lice and wild salmon. Correlation does not equal causation.
Aug 13, 2009 at 10:04am
The lice grow in the dung of the farmed fish that piles up under the farms. The farmed salmon don't get it because they're treated for it but the Wild salmon that swim by get it because they're not. No fish farms means no sea lice which means more wild salmon
Mar 10, 2010 at 5:17pm
Jeffrey - you need to get your facts straight - sea lice to not grow in dung. Your comment has no validity and demonstrates your lack of understanding on this topic