SALEM, Ore. — Oregon authorities have closed the state’s entire coastline to mussel fishing due to an “unprecedented” outbreak of shellfish poisoning that has sickened at least 20 people.
They have also closed parts of the Oregon coast to the harvest of razor clams, bay clams and oysters.
“We have had a crippling shellfish poisoning in Oregon that we have never seen in the state,” said Matthew Hunter, shellfish program manager for the Oregon Department of Fish and Wildlife, during a briefing on Friday. The unprecedented nature of the outbreak was due both to the number of species affected and the number of people who became ill, he said.
The Oregon Department of Fish and Wildlife and the Department of Agriculture announced the new closures Thursday. Elevated levels of toxins were first detected in shellfish on the state’s central and north coasts on May 17, Hunter said.
State health officials are asking people who have harvested or eaten Oregon shellfish since May 13 to complete a survey intended to help investigators identify the cause of the outbreak and the number of people sickened.
Paralytic shellfish poisoning, or PSP, is caused by saxitoxin, a naturally occurring toxin produced by algae, according to the Oregon Health Authority. People who eat shellfish contaminated with high levels of saxitoxins usually start feeling sick within 30 to 60 minutes, the agency said. Symptoms include numbness of the mouth and lips, vomiting, diarrhea and shortness of breath, and irregular heartbeat in severe cases.
According to the agency, there is no antidote for PSP. Treating severe cases may require mechanical ventilators to assist with breathing.
Authorities warn that cooking or freezing contaminated shellfish does not kill the toxins and does not make it safe to eat.
Officials in neighboring Washington have also closed the state’s Pacific coast to harvesting shellfish, including mussels, clams, scallops and oysters, according to a shellfish safety map prepared by the Washington State Department of Health.
Under the new restrictions from Oregon, razor clam harvest is closed along about 180 miles of coastline, from the central coastal town of Yachats to the California state line. Bay shell harvesting is closed along the North Coast, from the Washington state line about 100 miles to Cascade Head.
Agriculture officials have also closed commercial oyster harvesting in Netarts and Tillamook bays on Oregon’s north coast.
The Oregon Department of Agriculture says it will continue to test for shellfish toxins at least twice a month, tides and weather permitting. Reopening an area closed due to biotoxins requires two consecutive tests showing toxin levels are below a certain threshold, according to the agency.