Submitted by the Lopez Historical Society and Museum.
The record heat wave that struck the Pacific Northwest last summer, with temperatures reaching over 100 degrees for several days, coincided with a stretch of afternoon low tides that proved deadly to marine life in the intertidal zones of the Salish Sea.
Melissa Miner, a marine biologist based in Bellingham, said that over the following several weeks, dead barnacles, sea stars, anemones and desiccated seaweed washed up along beaches from British Columbia to South Puget Sound.
“These are hardy organisms adapted to survive wave shock and extreme temperature fluctuations, but the combination of extreme heat and low tides pushed them beyond their physical limits in many areas,” she said.
On Saturday November 19, Miner will talk about the effects of the heat wave on rocky intertidal communities in the Salish Sea and the prospects for recovery. Sponsored by the Lopez Island Historical Society as part of its 2022 Speakers’ Series, the talk will start at 7:30 p.m. at Woodman Hall.
For nearly three decades, Miner, a research specialist with the University of California Santa Cruz, has played a key role in collecting and analyzing data for the Multi-Agency Rocky Intertidal Network (MARINe). The group, which includes scientists, resource managers, educators and community members, monitors sea life at sites
along the west coast, including 10 sites within the Salish Sea.
Miner said that findings from the long-running study help scientists determine whether any one event is part of normal population fluctuations or the cumulative effects of multiple adverse conditions.
“What used to be once in a hundred or once in a thousand climate events can no longer be considered rare,” she said. “The increasing frequency really influences our long-term predictions of how these intertidal communities will fare.”
MARINe researchers also tracked the sea star wasting disease that struck the populations along the west coast from Alaska to Mexico in 2013/14.
Miner said that while sea star die-offs had previously occurred in the 1970s, 80s and 90s, none had been of the magnitude or over such a wide geographic area as the recent one. In the Salish Sea, she said, the mortality rate for ochre stars was between 50 and 90 percent.
The 26-arm sunflower stars were also hard-hit with massive die-offs observed just north of Vancouver, B.C. While ochre stars are beginning to return to some sites, she said, many other species have still not bounced back, and their long-term recovery prospects are uncertain.
Miner said the causes are still under investigation and may include both biological and environmental factors such as warming sea water.