ASTORIA, Ore. — An Oregon shellfish biologist says the ongoing domoic acid outbreak along the Washington and Oregon coasts could persist into fall, when razor clam seasons typically resume.
“We still haven’t seen domoic acid levels peak,” said Matt Hunter, Oregon Department of Fish and Wildlife shellfish biologist in Astoria. “As long as they are still going up it’s hard to predict when they might start coming down.”
Domoic acid, a natural toxin produced by certain types of marine algae called phytoplankton, can be harmful or even fatal if consumed in sufficient quantities. Cooking or freezing does not destroy domoic acid in shellfish.
Shellfish samples are collected every low tide series for biotoxin analysis. It takes two consecutive samples under the alert level before a harvesting area can be reopened, Hunter said.
The high levels of domoic acid that are affecting razor clams are not influencing the Oregon crab season, which remains open. Washington state’s recent closure of its southern coast to all sport and commercial crabbing has prompted concerns that Oregon might follow suit.
But according to Hunter, recent tests of crabs off the Oregon coast showed domoic acid levels were undetectable in most samples.
“It could be that the crabs off the Washington coast are eating something different, or that the Columbia River is forming some sort of north-south barrier,” Hunter said.
Bay clamming in areas south of Tillamook Head also remains open and safe, Hunter added.
Since 1991, when the toxin was first detected on the Pacific coast, outbreaks of domoic acid have prompted the cancellation of three entire razor clam seasons in Washington — the last one in 2002-03.
Kalaloch Beach, jointly managed by the Washington Department of Fish and Wildlife and Olympic National Park, also was closed for much of the 2004 season due to high toxin levels.
In 2005, Washington closed Long Beach for two days due to elevated toxin levels.