Monterey County lifts domoic acid shellfish warning

Shellfish foragers along Monterey Bay can again take home clams, scallops and oysters. The California Department of Public Health (CDPH) lifted its safety warning for sport-harvested bivalve shellfish from Monterey County on Monday, Oct. 12.

The agency said testing showed domoic acid had decreased to safe levels in local waters, according to a CDPH notification posted the same day. CDPH had issued the original warning on Sept. 14 after detecting dangerous concentrations of the naturally occurring marine biotoxin in mussels from the county.

Domoic acid causes amnesic shellfish poisoning (ASP), which CDPH said can lead to illness or death. Cooking does not destroy the toxin. Symptoms can appear within 30 minutes to 24 hours and range from vomiting, diarrhea and abdominal cramps to trouble breathing, confusion, seizures, permanent short-term memory loss and coma, according to the agency's September advisory.

Mussel quarantine continues through at least Oct. 31

One catch for foragers: the annual statewide mussel quarantine remains in effect. CDPH announced the quarantine on April 24, and it took effect May 1. It prohibits sport-harvesting all species of mussels for human consumption along the entire California coast, including all bays and estuaries. During the quarantine, mussels may only be harvested for use as bait.

The quarantine will continue through at least Oct. 31, according to Monterey County's announcement. CDPH has not announced a specific end date beyond that minimum.

The Oct. 12 clearance applies only to recreationally harvested shellfish. Commercially sold shellfish from state-certified harvesters and dealers are subject to separate, frequent mandatory testing under state law.

CDPH also noted that separate domoic acid advisories remain active for sport-harvested razor clams in Humboldt County and Del Norte County.

Residents who want to check the latest shellfish safety status can visit CDPH's shellfish advisories page.