Red Tide Affects Moon Snails, Too, EPA Official Warns

Add moon snails to the list of creatures that shouldn't be harvested and eaten when beaches are closed because of paralytic shellfish poisoning, or red tide.

"It's not just clams, mussels, oysters and scallops that carry PSP toxins," says John Armstrong, a marine biologist with the Environmental Protection Agency's regional office in Seattle. "If a beach has been closed because of paralytic shellfish poisoning, there's a good chance the toxins are in the moon snails that feed on the shellfish."

PSP toxins interfere with human nerve impulses but apparently do not affect shellfish or snails. Symptoms including numbness, tingling or burning of the lips, gums, tongue and face may begin minutes after eating contaminated food. Left untreated, PSP can cause death.

Armstrong initiated a recent report that concludes dangerous levels of PSP can build up in moon snails and other marine invertebrates in the Puget Sound area. Concern is growing because unlike clams and mussels, the harvest of moon snails is not regulated by the state.

"That means you can take as many as you want, in any size you want," Armstrong says.

Moon snails are harvested year-round but especially during summer daylight low tides.