B.C. heat wave cooked to death more than a billion intertidal invertebrates, say researchers

If you hit the beach during the heatwave, you likely first felt the swelter, then noticed the smell.

“It smelled like death and decay,” Chris Harley, a marine biologist with UBC. “It just sort of hit you like a wall as soon as you set foot on the beach.”

The summer stink isn’t your usual low tide smell. The record-breaking heatwave, which killed hundreds of British Columbians, was also deadly for our oceans.

Barnacles, sea snails, mussels, clams, and other small animals that call the Salish Sea coastline home, hit 50 degrees celsuis according to Harley and his team who measured the heat using thermal imagery.

The heat actually baked mussels, right in their shells.

“You can find between 50 and 100 dead mussels in an area that’s the size of a coaster. If you scale that up to something the size of your stovetop, there might be a few thousand, and if you think about how many stovetops fit into a place like Stanley Park, and how many Stanley Parks can fit in the Salish Sea, you’ll quickly get to some really large numbers,” said Harley.

Harley estimates more than a billion intertidal animals, living along the Salish Sea coastline, died in the extreme heat.

He says he’s seen reports of the die-off affecting species all the way from Washington state all the way up to Klemtu, just north of Bella Bella, and is predicting the wipeout will temporarily affect water quality, as mussels and clams help filter ocean water.

Scientists say that it will take a while for life in the Salish Sea’s intertidal ecosystems to recover. Harley predicts mussels may spring back next year or the year after that. Other species, he expects, will take longer.

Meanwhile, the scorching heat also tipped the scales for the typically hearty kelp and seagrasses.

“The combination of a record-breaking heatwave and these low tides that were kind of happening in the middle of the day were absolutely frying a lot of the seaweeds and kelps,” said Brian Timmer, a kelp forest researcher at UVIC.

“It really goes to show that climate change is happening now, and we’re already seeing the effects of it,” said Timmer.

Climate scientists say these heatwaves are going to become more common, and more intense due to climate change. And researchers expect that is going to change the face of B.C.’s coastline.

“Our system is going to start to look more like the ecosystems you have much further south,” said Harley, referring to the relatively bare rocks of Mexico and California.

“That is a sobering proposition.”

As climate change cooks our coast, both Timmer and Harley are predicting a decline of B.C.’s shoreline habitats and diversity,

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