A fish biologist with an environmental group has suggested that fish farms could be a contributing factor behind a stunning drop in the expected return of Fraser River sockeye.
Stan Proboszcz, who works for Watershed Watch Society, told the Georgia Straight there are three theories that could help explain why Fisheries and Oceans Canada has missed the mark on its forecast.
”¢ Ocean temperature changes are affecting the food dynamics for juvenile sockeye on their way out to sea.
”¢ Warming temperatures in the Fraser River are stressing juvenile salmon, which could have an impact on mortality.
”¢ Salmon farms in Georgia Strait are infecting juvenile sockeye with sea lice.
“I’m sure it’s a combination of factors,” Proboszcz said.
He noted that a 2008 study by fisheries researcher Alexandra Morton demonstrated that juvenile sockeye salmon travelling near the Discovery Islands area off the east coast of Vancouver Island were infected with sea lice.
The study’s abstract noted that sample sizes were too low to support a formal statistical analysis.
“She sampled pinks; she sampled chums; and she sampled sockeye,” Proboszcz said. “This is where the discovery came about where she saw elevated levels of sea lice on sockeye.”
The peer-reviewed study appeared in the North American Journal of Fisheries Management, which is published by the American Fisheries Society.
"Watershed Watch is involved with the Raincoast Conservation Foundation and the Pacific Salmon Commission, and we’re following up on that sockeye research," he added. "We have some preliminary results that indicate the sockeye that migrate around the farms in Discovery Islands are indeed Fraser River stocks.”
Later this month, Fisheries Minister Gail Shea is heading a Fisheries and Oceans Canada delegation to an aquaculture conference, Aqua Nor 2009, in Norway. Critics say the federal government is in a conflict of interest as a promoter or aquaculture at the same time that it's regulating the industry.
Initially, the federal government expected six million to 10.6 million salmon to return to the Fraser River this year. According to Jeff Grout, regional resource manager-salmon, the government now expects between one million to 1.7 million to return.
In an interview with the Straight, Grout rejected any suggestion that fish farms could be a contributing factor behind the shockingly low returns.
“We certainly don’t have scientific evidence that suggests lice from the farms have caused the poor marine survival across all of our sockeye groups,” Grout said. “We have seen poor returns in the Skeena as well, and there aren’t any salmon farms situated along the migration routes there.”
He noted that his department forecast two million Skeena sockeye to return this year. “The accounting of the run is still going on there, but we’re expecting it to be probably just less than a million,” Grout said.
He pointed out that a couple of years ago, there were widespread poor returns across a range of species, including pink, coho, Chinook, and chum salmon.
“It appeared related to the year they went into the ocean,” Grout said. “There were very warm conditions. Plankton levels appeared to be low for the species”¦.We may have had warmer water predators moving up into that warm water.”
Proboszcz said Fisheries and Oceans Canada can’t do much about climate change, but it should stop denying the science concerning the impact of sea lice from fish farms on juvenile wild salmon. He described it as a “worldwide epidemic”.
“The science has been published over and over again in country after country after country,” Proboszcz said. “So we really need to seriously consider the negative effects of salmon farms in this situation. Removing the farms from the outmigrating areas would be a great start. It’s the easiest thing to do.”