Red tide has closed shellfishing beds in Eastham and Orleans. An outbreak of potentially toxic red tide has closed all shellfishing beds in Eastham and Orleans. Michael Hickey, chief shellfish biologist for the state Division of Marine Fisheries, said Wednesday the beds will remain closed until at least Tuesday.
Red tide contains a naturally occurring toxin dangerous to humans in high concentrations.
Hickey said the levels found in samples taken Tuesday showed 118 micrograms of the toxin per 100 grams of mussel meat. State regulations require closures when toxin levels reach 80 micrograms. Hickey said the algae producing the toxin normally show up later in the spring, when water and air temperatures are on the rise. He said the Cape Cod red tide is the first he has heard of anywhere in New England this year. The toxin, paralytic shellfish poisoning, or PSP, is produced by a planktonic, microscopic algae.