Megan Dethier, UW Biology Research Professor and Director of Friday Harbor Laboratories, was interviewed by KUOW on the recent extreme heat wave and its effects on the shellfish on local Puget Sound beaches. Also quoted is Chris Harley, former UW Biology graduate student and current Professor at The University of British Columbia.

A record-shattering heat wave June 26-28 coincided with some of the year's lowest tides on Puget Sound. The combination was lethal for millions of mussels, clams, oysters, sand dollars, barnacles, sea stars, moon snails, and other tideland creatures exposed to three afternoons of intense heat.

A shellfish farmer on Little Skookum Inlet in south Puget Sound reported the muddy sand on his beach reaching 135 degrees.

“It was a Murphy’s Law of extreme heat and the lowest tides of the year at the same time,” said Megan Dethier, the University of Washington Friday Harbor Laboratories director.

“This was so far above normal,” she said. “The fact that it’s killing mussels, which are some of the toughest creatures around, is really striking.”

Chris Harley, a biologist with the University of British Columbia, estimated that hundreds of millions of mussels, if not more, died in the three-day heat wave in Washington and British Columbia.

“The total number of animals that died is probably well over a billion,” he said.

“It's such a large number of species over such a large area that it's just a staggering amount of death,” Harley said.

Creatures of Washington and British Columbia’s intertidal zones, which are covered by cool sea water when the tide is in and exposed to the air twice daily as the tide goes out, have evolved to handle a wide range of temperatures and conditions.

But all creatures have their limits.

“Barnacles very high on the shore can survive temperatures above 100 degrees Fahrenheit,” Harley said. “But the rocks got up to 120 degrees Fahrenheit, which is far too hot for even those really, really tough animals to live through.”

Read the full article on KUOW.