Sacramento, California - The annual quarantine on sport-harvested mussels gathered along the California coast begins May 1, 2014, announced Dr. Ron Chapman, director of the California Department of Public Health (CDPH) and state health officer. This quarantine applies to all species of mussels harvested along the California coast, as well as all bays and estuaries.

“This quarantine is in place to protect the public against poisoning that can lead to severe illness, including coma and death,” said Chapman. “It is critical that the public honor the quarantine because the toxins found in mussels have no known antidotes and they are not reliably destroyed by cooking.”

This quarantine 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. The majority of human cases of PSP illnesses occur between spring and fall.

In Santa Cruz and Monterey counties, an advisory remains in effect to avoid eating any bivalve shellfish sport‑harvested in these two counties. A second advisory, to avoid eating the internal organs of commercially or recreationally caught anchovies, sardines, or crab taken from Monterey and Santa Cruz counties, also remains in effect.

Commercially harvested shellfish are not included in the annual quarantine or the advisory for Santa Cruz and Monterey Counties. 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.

More information about the quarantine, PSP and DAP can be found on the CDPH Annual Mussel Quarantine - Frequently Asked Questions (FAQ) Web page. For updated information on quarantines and shellfish toxins, call the CDPH Biotoxin Information Line (1-800-553-4133).