Friday, February 3rd, 2023
Friday, February 3rd, 2023

Breaking News for

Sportsmen Since 1967

NH: Atlantic Coast and Hampton Harbor Shellfishing Closed Because of “Red Tide”

CONCORD, N.H. — To protect the public from the possible
consumption of contaminated shellfish, officials from the New
Hampshire Department of Environmental Services (DES) and the New
Hampshire Fish and Game Department have 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) until further notice. This action is in response to
elevated levels of Paralytic Shellfish Poisoning or PSP, commonly
known as “red tide,” detected in blue mussels collected from the
Isles of Shoals and from Hampton/Seabrook Harbor.

“Toxicity levels are increasing right now, in both offshore and
near-shore waters, because of a ‘bloom’ of red tide, which is toxic
algae,” said Chris Nash, Shellfish Program Manager for DES. “It is
too soon to know how severe this red tide bloom will be, or how
long it might last.” He noted that additional sampling will be
necessary to track the severity and duration of the bloom.

Nash emphasized that the closure affects those who dig their own
shellfish, but it remains OK to eat shellfish from a reputable
dealer or restaurant. “These shellfish have been sourced from
shellfish beds that recently tested negative for red tide and other
contaminants.” For more information on red tide, see the Red Tide
Resource Center at

Blue mussels collected from Star Island, Isles of Shoals last
week showed low red tide toxin levels, but samples collected this
week exhibited toxin levels above the mandatory closure threshold
of 80 micrograms of toxin per 100 grams of shellfish tissue. Blue
mussels collected from Hampton/Seabrook Harbor this week are also
exhibiting high toxicity values.

Other New Hampshire shellfish harvesting areas were temporarily
closed earlier this week because of heavy rainfall, and will remain
closed until additional tests are completed. Officials from the New
Hampshire Department of Environmental Services and the N.H.
Department of Health and Human Services/Public Health Laboratory
expect to complete this week’s shellfish and seawater testing by
Friday, May 20, at which point a decision on whether or not to
reopen Great Bay and Little Bay to harvesting will be made. Changes
to the open/closed status of shellfish waters will be announced on
the Clam Flat Hotline (1-800-43-CLAMS) and on the N.H. Fish and
Game website at

The nature of red tide blooms varies from year to year,
according to Nash. Significant blooms and shellfish toxicity
occurred in New Hampshire waters in 2005, 2008, and 2009, while
2010 showed a relatively mild bloom with low toxicity.

Red tide is a condition in which filter-feeding molluscan
shellfish such as clams, oysters and mussels accumulate a potent
neurotoxin produced by a naturally occurring marine algae.
Ingesting the toxin is potentially fatal to humans, and cooking
does not make contaminated shellfish safe for consumption. Visit

Share on Social


Hand-Picked For You

Related Articles