Photo: Will Husby
Changing Climate
When Seashore Temperatures Spike – Killer Heat Dome 2021
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How a Heat Dome Works:
- Hot air expands upward
- High pressure pushes warm air down
- Air compresses, causing heat wave
- High pressure pushes clouds away
Climate scientists say this is a sign of how dangerous the climate crisis has become — and how much worse it could be. Experts fear extended periods of very high temperatures will have a devastating impact on marine life.
Christopher Harley, a marine biologist at the University of British Columbia, has calculated that more than a billion BC marine animals may have been killed by 2021’s unusual heat. Harley was struck by the smell of rotting mussels, many of which were in effect cooked by the high air temperatures at low tide and abnormally warm water. Other dead creatures decaying in the shallow water included snails, sea stars, clams, and barnacles. “It was an overpowering, visceral experience,” he said.
During the peak of the heat wave, a putrid smell covered some Bowen beaches. One resident of Tunstall Bay said for five days the beach had a very powerful stink, like a dead whale. Now there is a litter of dead mussel shells at the high tide line. On Kwilákm, Will Husby, Bowen citizen scientist, reported about conditions during the heat wave: “On my swims at high tide, I have seen lots of gaping, empty mussel shells on reefs and rocks in the upper intertidal zone in the Bay between Snug Point and well past Pebbly Beach.
However, I have also seen lots of what look to me to be healthy oysters with their siphons open (they close their shells when I touch them). I have also seen barnacles feeding in the upper intertidal.”
While the air hovered around the high 30s, Professor Harley and a student used infrared cameras to record temperatures above 50oC along the rocky shore. Mussels are hardy shellfish, tolerating temperatures into the high 30s. Barnacles are even sturdier, surviving the mid-40s for at least a few hours. “But when the temperatures get above that, those are just unsurvivable conditions,” he said.
“A lot of species are not going to be able to keep up with the pace of change,” Harley said. “Ecosystems are going to change in ways that are really difficult to predict. We don’t know where the tipping points are.”