Scientists shed new light on sockeye salmon dynamics in ocean – Competition, climate, and salmon farms linked to Fraser sockeye declines
May 17, 2012
Vancouver—Several factors—including farmed salmon—appear to be responsible for the plight of Canada’s most valuable salmon, according to research published today in the journal Conservation Letters. The study, carried out by an international group of scientists and sponsored in part by Watershed Watch Salmon Society and The SOS Marine Conservation Society, found that declines in Fraser River sockeye salmon abundance are linked to interactions among three factors: pink salmon abundance, exposure to farmed salmon, and ocean temperatures.
According to the research, increasing numbers of pink salmon across the North Pacific Ocean appear to be leading—directly or indirectly—to increasing competition for food with Fraser sockeye salmon, especially in years when the juvenile sockeye salmon first migrate past large numbers of farmed salmon. While the direct casual mechanism of fish farm impacts was not investigated, potential disease impacts from farms received substantial attention in the ongoing federal inquiry into the decline of sockeye.
The study is also timely given recent concerns over the accuracy and transparency of federal and provincial agency monitoring of diseases on farms. “Once again, science highlights salmon farms as a real threat to wild fish,” said Stan Proboszcz, a Watershed Watch fish biologist. “A transparent monitoring program of diseases on farms in B.C., and one that is at arms-length from government, is vital.”
This research adds to the already overwhelming weight of scientific evidence detailing the serious threats open net-pen salmon aquaculture poses to wild fish, including: numerous published papers; consensus statements from recent academic think tanks; and a recent report from a panel of experts commissioned by the Royal Society of Canada. “Our study highlights the need to focus research on evaluating the effects of disease from farms along sockeye migration routes,” said the paper’s lead author, Dr. Brendan Connors, of Simon Fraser University.
This research helps to unravel the complex nature of factors affecting sockeye salmon, including large scale factors such as climate and competition at sea and local effects such as salmon farming. “Impacts from open net-pen salmon farms are something we can control, especially in comparison to other issues such as climate change, and this research provides more evidence of the need to transition this risky industry to land–based closed containment facilities to reduce the risk of disease spreading to our wild fish,” said Dr. Craig Orr of Watershed Watch.
For more information contact:
Dr. Brendan Connors, Simon Fraser University: Skype 253-200-4025 *Note: may be difficult to reach due to being in an isolated area conducting field work
Dr. Craig Orr, Watershed Watch Salmon Society: (604) 809-2799
Stan Proboszcz, Watershed Watch Salmon Society: (604) 314-2714
Abstract available online: