The California Department of Public Health (CDPH) is lifting the April 4 and April 28, 2014 health advisories warning consumers not to eat recreationally harvested bivalve shellfish or the internal organs of commercially or recreationally caught anchovy, sardines, or crab taken from Monterey and Santa Cruz counties. Recent testing shows concentrations of domoic acid have declined to safe or undetectable levels. Domoic acid is a naturally occurring nerve toxin that can cause illness or death in humans. There have been no reported illnesses associated with these events.
While these two health advisories have been lifted, the annual quarantine of sport-harvested mussels remains in effect for the entire California coast, including all bays and estuaries.
This quarantine, which went into effect May 1, 2014, is intended to protect the public from paralytic shellfish poisoning (PSP) and domoic acid poisoning (DAP). Both of these toxins are linked to plankton consumed by filter-feeding animals such as bivalve shellfish, like mussels and clams.
Commercially harvested shellfish are not included in the annual quarantine. That’s because all commercial shellfish harvesters in California are certified by the state and subject to strict testing requirements to ensure that all oysters, clams and mussels entering the marketplace are free of toxins.
Early symptoms of PSP include tingling of the lips and tongue, which may begin within minutes of eating toxic shellfish. These symptoms are typically followed by a loss of balance, lack of muscular coordination, slurred speech and difficulty swallowing. In severe poisonings, complete muscular paralysis and death from asphyxiation can occur.
Symptoms of DAP, also known as amnesic shellfish poisoning (ASP), can occur within 30 minutes to 24 hours after eating toxic seafood. In mild cases, symptoms may include vomiting, diarrhea, abdominal cramps, headache and dizziness. These symptoms disappear completely within several days. In severe cases, the victim may experience difficulty breathing, confusion, disorientation, seizures, permanent loss of short‑term memory, coma and death.
To receive updated information about shellfish poisoning and quarantines, call CDPH’s toll-free “Shellfish Information Line” at (800) 553-4133. For additional information visit CDPH’s Natural Marine Toxins: PSP and Domoic Acid Web page.