By Eli Francovich, The Sportsman-Review

Walking onto a beach recently exposed by a receding sea, Eric Sparkman paused and looked at an expanse of sun-baked shells.

“Oh, here we go,” he said, bending down and prying apart a Manila clam and revealing an empty interior picked clean by scavengers. “Here is some death.”

Documenting that death was the mission Friday, as Sparkman and Rana Brown, both biologists with the Squaxin Island Tribe toured Hammersley Inlet and Oakland Bay southwest of Seattle studying how three straight 100-degree days in late June impacted shellfish in the Puget Sound.

“He’s alive, but is he dying?” Sparkman said later while examining a moon snail. “I don’t know.”

That’s the question biologists and managers are asking up and down the Puget Sound and the Salish Sea following a record-breaking heat wave that coincided with some of the lowest tides of the year.

Yes, it was bad for shellfish.

But how bad?

Some early modeling done by a Canadian biologist suggests more than a billion sea creatures — including moneymaking clams, geoducks and oysters — died along the Salish Sea’s 4,000 miles of coastline. But experts in Washington State urge caution when tossing numbers about, noting that conditions — and thus, mortality — vary tremendously from bay to bay and beach to beach.

“We have no idea what the numbers are,” Brown said. “It’s kind of a scary thing. You don’t know what impact it’s going to continue to have.”

That variability was clear Friday.

On one beach Sparkman recorded mortality rates around 40% for oysters. Meanwhile nearly 50% of clams on another beach died. However, just a mile or less away, other beaches had minimal death. Overall, Sparkman was surprised by how many creatures died.

Those deaths — if widespread enough — may have ecological impacts as shellfish filter phytoplankton, which contributes to overall water quality. For instance, a large market-sized oyster can filter about 50 gallons of water per day.

And the die offs will likely damage Washington’s $150-million shellfish industry; the largest in the U.S. and one already struggling with unhealthy ocean conditions, a toxin-related die off in 2018 and cutbacks in demand due to the pandemic.

But perhaps more than anything, the heat wave and its impact — both aquatic and terrestrial — highlight the necessity of preparing for climate change, said Nick Bond, an atmospheric scientist at the University of Washington and the state’s climatologist.

“That we could get something of this magnitude is shocking and sobering,” he said, although he noted that the heat wave was “an extremely unusual weather event” made worse by climate change.