TORONTO -- A large swath of warm water spanning thousands of kilometres from the Bering Sea to Mexico, nicknamed by scientists as “the Blob,” has returned to the West Coast, threatening marine life and fisheries.

The Blob was christened in 2014, after a similar natural event that spanned two years devastated the salmon industry, damaged ecosystems and disrupted wildlife like whales, sea lions and crabs. 

“This is a massive pool… of warm water that’s in the Pacific, that is thousands of kilometres huge,” said senior climatologist for Environment Canada David Phillips on CTV’s Your Morning Tuesday. “This one stretches from the Bering Strait, the Bering Sea, right through the Gulf of Alaska, right through to California, British Columbia, and down to Mexico.”

Phillips says the water currently isn’t as warm as the last Blob, but experts say that is because it has only been around for a few months.

Explaining that the Blob phenomenon is not due to water “warming up,” Phillips says the Blob is about “the fact that it’s not cooling down,” and the warmer surface water is not mixing with the cooler, deep water.

The lack of mixing is due to “the weather for the past four or five months,” says Phillips, adding that there has been a “high pressure area” sitting over the Pacific.

That high pressure area has resulted in weather that means lack of events such as waves or storms that would normally force the surface and deep water to mix together, he said.

Phillips says that marine life is affected in major ways when events like this occur, from fish “moving father north” to feed, the salmon harvest potentially being “an eighth of what they [fisheries] expect it to be,” and toxic algae blooms poisoning fish and plankton alike.

Global warming is a “contribution” to events like the Blob, says Phillips, and that there will be more events like the Blob in the future due to warmer oceans and major changes in weather, such as melting snow and ice in the Arctic and warmer winters.