Oysters, bay clams, and other shellfish harvested in Washington and Oregon could cause paralytic shellfish poisoning, the FDA recently warned. This type of poisoning can be fatal. Here's what you need to know.
Which shellfish is the FDA warning us not to eat?
According to the FDA, shellfish that may cause paralytic shellfish poisoning (PSP), and which restaurants should not serve and consumers should not eat, include:
Oysters and bay clams harvested from growing areas in Netarts Bay and Tillamook Bay, Oregon, harvested on or after May 28, 2024.
All shellfish species from growing areas in Willapa Bay, WA, including: Stony Point, harvested between May 26 and May 30 2024; Bay Center, harvested between May 29 and May 30, 2024; and Bruceport, harvested between May 29 and May 30, 2024.
The affected shellfish may have been sold in these eight states:
Arizona
California
Colorado
Hawaii
Nevada
New York
Oregon
Washington
If you live in these states and have recently bought shellfish, check whether it may have come from Oregon or Washington. If so, the FDA recommends that you don’t eat it. (It is also advising restaurants and retailers not to sell it.)
The toxins in these shellfish cannot be destroyed by freezing, so the warning applies to frozen as well as fresh shellfish from these growing areas and harvest dates. If you notice symptoms of PSP, seek medical care.
What are the symptoms of paralytic shellfish poisoning?
According to the CDC, symptoms usually begin within 30 to 60 minutes of eating the shellfish, and may include tingling and numbness of the lips and tongue. You may also have these symptoms in the face, arms, and legs.
In severe cases, there may be more symptoms, and they can progress quickly. There can be gastrointestinal symptoms like nausea and vomiting, and neurological (nerve and brain) symptoms that may include headaches, dizziness, weakness, or a feeling of floating.
Severe symptoms include trouble walking or swallowing, and PSP can be fatal if it paralyzes the breathing muscles. If somebody has any of these symptoms, seek medical care immediately. There is no antidote to the toxin, but medical care can help a person to keep breathing until they are able to recover.
How do shellfish become poisonous?
The toxin that causes PSP is made by dinoflagellates, microscopic creatures that clams, oysters, and other sea creatures like to eat. Normally, there aren’t enough dinoflagellates in the water for toxins to build up to levels that would hurt people. But when there are toxic algal blooms (dinoflagellates are a type of algae), the sea animals that eat them can build up dangerous levels of the toxin.
This seems to be what happened to spur the current FDA warning. High levels of PSP-causing toxins were detected in samples of shellfish from the areas and dates of the warning.
You can’t tell whether shellfish are toxic from the way they look, the Washington State Department of Health says, and neither cooking nor freezing will destroy the toxins. If you collect your own seafood, check maps and warnings (like this map of Washington coastlines) to know whether harmful algal blooms are happening in your area.