Marine heat waves occur when ocean temperatures are much warmer than usual for an extended period, the website says. California Current Marine Heatwave Tracker, a project of the US National Oceanic and Atmospheric Administration (NOAA).
At the end of September, a marine heat wave covering more than 9 million square kilometers of ocean stretched off the west coast of North America from California to Alaska.
It was then the 2e largest heat wave recorded in the area since 1984, as far as the NOAA can go back in time.
It has since subsided somewhat, as it still covered around 7 million square kilometers in mid-November, but it could harm fishermen.
The impacts on important fish stocks such as Sockeye salmon are significant decreases in abundance and therefore their potential catch for fishing.
says Professor William Cheung of the Institute for Oceans and Fisheries at the University of British Columbia (UBC).
In addition, many species important to large animals such as orcas will be affected. [ce qui] thus indirectly affects the survival of these marine mammals.
Southern Resident Killer Whales, for example, an endangered population that frequents these waters, feed on salmon and are susceptible to their decline.
The biggest heat wave on record had been dubbed the Blob
, in 2014, and had devastating consequences for the region’s fisheries, according to the NOAA. The 3e The most significant heat wave only dates back to 2019.
Recent studies clearly show that increasing greenhouse gas emissions and, consequently, climate change increase the frequency and intensity of marine heat waves.
, notes Professor Cheung.
This trend does not bode well, he said.
Long-term changes in ocean temperature and other conditions will result in a sharp decrease in the abundance and potential catches of many fish stocks, and on top of that, during a heatwave year the impacts will be probably doubled.
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