As Algae Bloom Subsides, N.H. Reopens Waters To Shellfish Harvesting | New Hampshire Public Radio

As Algae Bloom Subsides, N.H. Reopens Waters To Shellfish Harvesting

Jul 24, 2020

State shellfish program specialist Brooke Dejadon collects seawater for algae analysis. (File photo)
Credit Chris Nash, NH DES

Nearly two months after implementing a ban on shellfish harvesting in coastal Atlantic waters, environmental regulators say a potentially toxic algal bloom has subsided to safe levels.

In early June, regulators found extremely high levels of a marine algae capable of producing a neurotoxin that can build up in shellfish.

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Eating shellfish containing the toxin can cause amnesic shellfish poisoning in humans, which can have gastrointestinal effects and sometimes lead to neurological damage or death.

“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.”

The state says it will continue to monitor the waters for a range of potentially harmful algae species.