Red Tide Continues Southward Expansion
BOSTON — One of New England’s worst “red tides” in decades continued its southward expansion this week, rounding Cape Cod and forcing the closure of some of the region’s most prolific shellfish beds.
The toxic algae bloom began in the waters off Maine last month and spread quickly. It had already shut down shellfish beds as far north as New Hampshire. On Thursday, Massachusetts officials closed the highly productive flats of the Monomoy Natural Wildlife Refuge, off Chatham, to shellfishermen. About half the state’s shellfish beds are now closed.
For the first time ever, the red tide also traveled through the Cape Cod Canal into Buzzards Bay, but it’s unlikely to have any impact on summer beachgoers on the Cape and elsewhere, experts said.
Still, it’s the worst red tide to hit Massachusetts since 1972, when the state enacted a blanket closure of all shellfish beds, said Don Anderson, a red tide expert at the Woods Hole Oceanographic Institution.
And this year’s red tide shows little sign of abating, said state shellfish biologist Michael Hickey.
“It’s spreading,” he said.
The algae that causes red tides off New England’s coast is not the same as that growing in the waters off southern states like Florida, causing noxious fumes, shutting down beaches and poisoning sea life.
Scientists say the northern algae contaminates only shellfish, making them unsafe for animals and humans to eat. Swimmers, fish, and popular sea foods such as lobster or shrimp are unaffected, as are scallops because people don’t eat the part that absorbs the poison.
Anderson said shellfish that reaches the market is safe because testing standards are so rigorous. But retailers and shellfishermen say prices could rise if local beds are shut down much longer and the state’s shellfish industry, with an annual wholesale value of about $24 million, sees its catch drop.
Rob McClellan, a Wellfleet seafood retailer who also raises quahogs and oysters, said many shellfishermen are fine for now because they dug up the bulk of their catch for the Memorial Day holiday. But if new clams reach market size while the red tide keeps clam flats closed, businesses will take a hit, he said.
“If it does drag on four to six weeks, that’s going to hurt,” McClellan said.
Terry Cellucci, owner of J.T. Farnham’s Seafood & Grill in Essex, said this may be the first time the red tide has lasted long enough to affect business. Already, publicity about the red tide has dampened demand for clams, and that’s kept prices down.
But with Fourth of July weekend the busiest time of the year, she anticipates a major price hike over the next month. In the meantime, she’s telling customers that her clams, which come from Maine, are safe.
“You have to verbally reassure them,” she said.
The toxic algae, called Alexandrium, is called red tide because it colors the water a rusty color at extremely high concentrations, Anderson said. Each year, a bloom of the algae moves from the Gulf of Maine to Cape Ann, off Boston’s North Shore. Usually, the wind isn’t right to push it into westward into Massachusetts Bay, but this year, strong east and northeast winds, including from two May nor’easters, blew in a particularly heavy algae bloom, and it flourished in the bay’s warmer waters.
The number of Alexandrium cells is about 100 to 200 in a typical liter of water, but on Saturday, cell counts of 40,000 were found near Cohasset and Sandwich. The state closes shellfish beds when it hits 1,000.
“It’s pretty amazing. Astounding is probably a good word,” said Hickey.
The bad news is it may not be confined to the current outbreak. Recent sampling indicates some of the algae were transforming into armored cysts that drop to the ocean floor and act like seeds for future red tide blooms. In addition, a second, particularly toxic bloom is now headed south from Maine. If weather and water conditions are right, the state could take another hit soon, Anderson said.
“I’m sure (the algae cells) are coming down here,” he said. “It’s just a matter of whether they’re in the right place at the right time.”