BIRCH BAY, Wash. – Shellfish harvesting is now closed in all of Whatcom County.

Health officials said that routine testing found unsafe levels of paralytic shellfish poisoning, or PSP, in many parts of the county.

Mussels and varnish clams are especially risky, as they can contain some of the highest levels of PSP in any shellfish species.

PSP cannot be eradicated through cooking or freezing.

Symptoms of PSP poisoning can include difficulty breathing, paralysis, and can cause death within 30 minutes of ingesting contaminated shellfish.

Harvesters looking to gather shellfish in other parts of the state are encouraged to check the Washington state Department of Health website for information on other closures.