'Red tide' closes shellfishing on Atlantic coast, Hampton/Seabrook Harbor

Josie Albertson-Grove, The New Hampshire Union Leader, Manchester
·2 min read

May 31—Much of New Hampshire's coastal waters are closed to taking mussels, clams and oysters, with a "red tide" contaminating the shellfish with a potentially-fatal toxin.

The state Department of Environmental Services and the Fish and Game Department announced Friday that elevated levels of Paralytic Shellfish Poisoning in blue mussels collected from the Hampton/Seabrook Harbor on Wednesday. Paralytic Shellfish Poisoning is a condition stemming from an algal bloom sometimes called a "red tide."

The state samples shellfish weekly, and found elevated toxin levels in the mussels from the harbor, according to a news release.

The toxin can be fatal to humans, according to the state Department of Environmental Services, and cooking does not make it safe to eat contaminated shellfish.

Until testing shows toxicity levels dropping, the state Department of Environmental Services and the New Hampshire Fish and Game Department closed New Hampshire's Atlantic coastal waters, and the waters of Hampton/Seabrook Harbor, to the taking of all species of "molluscan shellfish" — mussels, clams and oysters.

"Red tide toxicity levels are increasing right now in New Hampshire's coastal waters and in Hampton/Seabrook Harbor and tributaries," said Chris Nash, Shellfish Program Manager for NHDES. "It is too soon to know how severe this algae bloom will be, or how long it might last." He noted that weekly sampling will continue from now until October.

Blue mussels collected from Hampton/Seabrook early this week showed low toxin levels, but samples collected on Wednesday, May 25, exhibited rising toxin levels. Blue mussels from Star Island, Isles of Shoals, collected earlier this week also indicated the presence of the toxin.

Other New Hampshire shellfish harvesting areas, including oyster beds around Nannie Island and Adams Point in Great Bay, and the commercial oyster farms in Little Bay, are still open, with tests showing no toxicity.

Lobster is not affected by the red tide closure, though state officials continue to advise consumers to avoid eating lobster tomalley, the soft green substance inside the lobster's body.