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For Immediate Release
July 24, 2020


Chris Nash, Shellfish Program Coordinator
(603) 568-6741

Atlantic Coast Reopened for Shellfish Harvest

Concord, NH - The New Hampshire Department of Environmental Services and the New Hampshire Fish and Game Department announce that the ban on harvest of shellfish due to a harmful algal bloom, often referred to as "red tide," is lifted for all species of shellfish along the Atlantic Coast. The precautionary harvest closure was originally implemented on June 4, 2020 for the Atlantic Ocean, in response to very high concentrations of a microscopic marine algae capable of producing a neurotoxin, domoic acid, that causes Amnesic Shellfish Poisoning, or ASP.

"The extremely high concentrations of this marine algae observed in late May and June began to subside in early July, and have been declining ever since," said Chris Nash, Shellfish Program Manager for NHDES. "Repeated testing of shellfish tissues along the coast, in Hampton/Seabrook Harbor, and near the commercial oyster farms in Little Bay have all shown results that are below the detection limit of the tests."

Nash cautioned that the issue is not necessarily gone for the year. "There are several species of the marine algae that causes ASP in the Gulf of Maine, and it is common for different species to become dominant over the course of the summer and fall. Some of those species can be highly toxic. We will continue to monitor the situation to ensure public health protection for those who consume New Hampshire shellfish. Changes to the open/closed status of shellfish waters will be announced on the Clam Flat Hotline (1-800-43-CLAMS) and on the NH Coastal Atlas (

Although the red tide harvest closure is being lifted, NHDES and NHF&G remind residents that the recreational harvest season for both softshell clams and oysters remains closed. Weather permitting, recreational harvest for these species will resume when their seasons reopen in early September.