Red Tide Found Along Massachusetts Coastline Prompts Shellfishing Ban

BOSTON — A harmful red tide has swept into the shoreline of Massachusetts, and it is prompting state officials to initiate a shellfishing ban.

According to the Division of Marine Fisheries, red tide is the name of a toxic algal bloom that can create biotoxins that accumulate in shellfish, which makes it harmful for them to eat.

Paralytic Shellfish Poisoning is a serious illness caused by eating shellfish contaminated with harmful neurotoxins. The Division of Marine Fisheries says these neurotoxins are produced by microscopic algae that can bloom in certain environmental conditions.

"We are in a full closure of all of the North Shore of Massachusetts," said Gloucester Shellfish Warden Peter Seminara in a Facebook post adding that "consuming shellfish dug in Gloucester can be harmful or fatal."

The most recent monitoring has caused the Division of Marine Fisheries to close shellfishing in Gloucester, Newburyport, Essex, Ipswich, Newbury, Rockport, Rowley, and Salisbury along with other beaches across the North Shore.

On June 23, North Shore cities and towns were notified of closing indefinitely to the harvesting of blue mussels due to the red tide. Those towns include Beverly, Danvers, Manchester, Marblehead, Peabody, Revere, Salem, and Swampscott.

But the full ban on shellfishing currently extends from the North Shore down to the South Shore, a Paralytic Shellfish Poisoning map indicates.

The Massachusetts Division of Marine Fisheries is also closing blue mussel harvesting on South Shore beaches including Hull, Cohasset, Scituate, Marshfield, Duxbury, Plymouth, the City of Boston, Marshfield and Kingston on June 22.

Local restaurant owners will have to buy clams from other locations at a likely hefty markup.

When toxin levels exceed 80µg (micrograms), affected areas close to allow for sampling of the water, the Division of Marine Fisheries said. Once three consecutive samples result in levels below 80µg, the areas will reopen. Biologists say they will continue to monitor the toxins.