PORTLAND, Ore. (KOIN) — Recreational crabbing season is closed in parts of Southern Oregon due to unsafe levels of domoic acid found in localized populations of Dungeness crab. A naturally occurring neurotoxin produced by algae, domoic acid is not believed to be harmful to shellfish but can cause illness or death when ingested by humans. 

The Oregon Department of Fish and Wildlife announced on May 1 that the closure is in effect from Cape Blanco to areas eight miles north of Winchester Bay. While the Oregon Department of Agriculture tests toxin levels in local shellfish twice per month, regulations state that two consecutive tests showing approved domoic acid levels must be completed before a crabbing zone can be reopened. As a result, the region will remain closed for at least a month.

Because domoic acid primarily accumulates in the crabs’ internal organs, an evisceration notice has been issued, requiring commercial crabbers to remove the viscera or “crab butter” from all catches in the region since April 27.

The Washington Department of Fish and Wildlife provides the following warning about domoic acid poisoning:

Cooking or freezing shellfish does not destroy domoic acid in shellfish. Domoic acid can be fatal to people if consumed in high doses. There is no antidote for domoic acid, which causes a condition called amnesic shellfish poisoning. Symptoms include vomiting, nausea, diarrhea, and abdominal cramps within 24 hours of ingestion. In severe cases, neurological symptoms develop within 48 hours and include headache, dizziness, confusion, loss of short-term memory, motor weakness, seizures, profuse respiratory secretions, cardiac arrhythmia, and coma.