Extreme heat boils Canada's waters and shellfish

"It's never smelled like this, never smelled like this before."

A recent heatwave is turning some of Canada's Pacific waters into a graveyard.

On Denman Island in the Baynes Sound, mussels, clams and sea stars are being plucked fresh out of the water but they're already baked to a crisp.

In the surrounding Salish Sea coastline, tens of thousands of oysters and shellfish have also been found cooked to death.

Oyster picker Dale Warren was shocked at the sight.

"We knew the heat might have been bad but we weren't expecting to see what we saw. Or what we are seeing, definitely."

Joe Tarnowski owns Baynes Sound Oysters - a business started by his father 65 years ago.

He says this part of Canada's coast is known for its cool, crisp waters and ideal growing conditions for shellfish.

But the changing weather can now only mean catastrophe for many like him in the industry.

"It basically cooked the oysters, clams, mussels. Most of the mussels around here are all gone. My clams, you see that sand dollars and stuff, they are all dead."

"(I've lost) probably about between 30 and 40 percent of my oysters and my clams are a little higher. They really didn't like the heat."

A team of researchers estimate more than a billion marine animals along the coastline were killed by extreme temperatures after a record-breaking heatwave in June that also killed hundreds of people in the Pacific Northwest.

According to one study, it's heatwave that would have been 'virtually impossible' without climate change.

Scientists say climate change has made such a heatwave in the region 150 times more likely.

They also warn that the extreme event could begin occurring every five to ten years by the 2040s if current greenhouse gas emissions continue.

Another heatwave is expected to strike parts of Canada and the United States later this week.