The California Department of Public Health (CDPH) has lifted the shellfish safety notification today related to sport-harvested mussels, scallops, and most types of clams from Del Norte County. An advisory for razor clams in Del Norte County remains in effect. The safety notification was issued July 16, 2024, due to dangerous levels of naturally occurring paralytic shellfish poisoning (PSP) toxins in mussels that can cause illness or death in humans. Recent testing shows PSP toxins have decreased to safe or undetectable levels for bivalve shellfish in this area.
A warning against eating sport-harvested razor clams from Del Norte County remains in effect as razor clams are a high risk for long-term elevated levels of domoic acid. Dangerous levels of naturally occurring domoic acid, also referred to as Amnesic Shellfish Poisoning, have been detected in the razor clams. Razor clams are known to retain domoic acid toxin in their meat and tissues much longer than other species of bivalve shellfish.
This warning does not apply to commercially sold mussels, clams, scallops, or oysters from approved sources. State law permits only state-certified commercial shellfish harvesters or dealers to sell these products. Shellfish sold by certified harvesters and dealers are subject to frequent mandatory testing to monitor for toxins.
PSP toxins affect the nervous system, producing a tingling around the mouth and fingertips within a few minutes to a few hours after eating toxic shellfish. These symptoms are typically followed by 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 amnesic shellfish poisoning 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 within several days. In severe cases, the victim may experience trouble breathing, confusion, disorientation, cardiovascular instability, seizures, excessive bronchial secretions, permanent loss of short-term memory, coma, or death.
