The report concludes that salmon species which spend less time in fresh water are faring better. (Photo: FIS)
Climate change contributing to sockeye decline in B.C.
Monday, August 26, 2019, 00:00 (GMT + 9)
Federal fisheries experts are painting a devastating picture of the challenges facing Pacific salmon and point to climate change as the main culprit.
A new report from Fisheries and Oceans Canada found warming ocean temperatures and marine heat waves are affecting ocean food webs and causing declining salmon stocks. Fisheries staff say factors such as human activity that degrades fish habitat and a landslide on the Fraser River blocking millions of fish from spawning upstream are making things worse.
The planet is warming, and most recent five years have been the warmest on record. The increase in global temperature above pre-industrial levels is irreversible over the coming centuries.(Photo: E-book: State of the Canadian Pacific salmon)
Andrew Thompson, regional director for fisheries management, says it's been an extremely challenging year for salmon and there have been significant declines in a number of stocks.
In one of the most dramatic shifts, the federal Department of Fisheries has adjusted the estimated number of returning Fraser River sockeye to slightly more than 600,000, down from an earlier projection of nearly five million.
Sue Grant, head of a federal program on the state of salmon and author of the report, says some of the declines are residual effects of larger climate change events.
Northeast Pacific Ocean temperatures have steadily increased since 1950. An extremely strong marine heatwave, nicknamed 'The Blob', was present from 2013 to 2017 in the Northeast Pacific Ocean, where most Canadian Pacific salmon feed and grow. (Photo: E-book: State of the Canadian Pacific salmon)
"Everything we're seeing in salmon and ecosystem trends is embedded within this larger context," she said, adding that Canada is warming at a rate double the global average and the rate increases at northern latitudes.
Less freshwater the better
But it is not just the climate impact on oceans that is stressing B.C. salmon.
Fresh water ecosystems are also feeling the brunt of climate change with more landslides and forest fires. That combines with human activity such as development and deforestation to hurt the health of these critical salmon habitats.
Grant said salmon that spend less time in freshwater, such as pink, chum, river-type sockeye and ocean-type chinook, are "generally doing well" and are not exhibiting long-term declines, suggesting they are less vulnerable to climate change.
Climate change in freshwater salmon habitats | Activar el teclado para el contenido multimedia The warming climate is causing many changes in the rivers and lakes salmon use during their critical freshwater life stages. (Photo: E-book: State of the Canadian Pacific salmon)
According to the report, chinook, sockeye and coho numbers are declining throughout the province. Warming ocean temperatures enable less-nutritious zooplankton from southern latitudes to thrive in warmer northern waters. Zooplankton is a key food source for salmon.
Federal Fisheries Minister Jonathan Wilkinson said that 2019 has been an especially difficult year in what has been a decades-long decline in stocks.
"There is no question that climate change is having a significant impact on our salmon," he said at a news conference Thursday. "Not only do these declines have direct impacts on our ecosystems and the health of our environment, but they have serious impacts on the health of our economy."
Twelve out of 13 Fraser River chinook populations have been recommended for protection under the Species at Risk Act, while coho returns in Alaska and Skeena River sockeye returns also prompted significant fisheries closures.
Wilkinson also announced CAD 2.7 million for five projects under the British Columbia Salmon Restoration and Innovation Fund.
"Part of any realistic plan to protect and ultimately restore key salmon stocks must include a comprehensive and aggressive plan to reduce carbon emissions," he said.
Source: CBC News (Read the whole article here)