US issues red tide warning
Tests show algae may affect Massachusetts sooner than usual
By Victor Tine
NEWBURYPORT — Local clammers will be watching the wind this summer.
The National Oceanic and Atmospheric Administration has issued a warning that the poisonous algae known as red tide could cause significant problems in New England shellfish beds, starting this spring.
NOAA scientists based their warning on a sea floor survey in the Gulf of Maine that found a substantial increase in the number of seed-like cysts of an organism that causes blooms of red tide, which causes an illness called paralytic shellfish poisoning.
The name red tide comes from the reddish-brown tint that colors waters with a large algae presence.
Red tide algae is ingested by filter feeders, such as clams and mussels. The algae causes no harm to the shellfish, but can cause paralysis in humans who eat them.
While NOAA declined to predict where and when the red tide would appear, the scientists found that the cysts' presence appears to have expanded southward, which means the red tide could affect Massachusetts Bay sooner than it has in the past.
Cysts are deposited in the fall and hatch the following spring.
"Last fall, the abundance of cysts in the sediment was 60 percent higher than observed prior to the historic bloom of 2005, indicating that a large bloom is likely in the spring of 2010," NOAA said in a prepared statement.
"Our research has shown that cyst abundance in the fall is an indicator of the magnitude of the bloom the following year," said Dennis McGillicuddy, a senior scientist at the Woods Hole Oceanographic Institution.
Jeff Kennedy of the state's Marine Fisheries Division said the cyst beds extend south and east from roughly around Portsmouth, N.H.
"They're in closer proximity than we've ever seen it before, at least since we've been monitoring," he said.
The density of the cysts is also a cause for concern, he said.
But as Newbury shellfish constable Charles Colby observed, "It all depends on which way the wind blows."
Colby said the red tide algae float on top of the water. If the prevailing wind is from the west, as it usually is, the algae bloom will stay offshore where it won't affect the local shellfish beds, he said.
If the red tide does come ashore, clammers will have no choice but to stop harvesting, Colby said.
"There are no options," he said.
Kennedy said the Marine Fisheries Division monitors shellfish beds weekly, more frequently as algae levels rise, and close the areas when red tide reaches toxic levels.
He said the 2005 red tide bloom was the worst in recent memory. It closed Massachusetts shellfish beds from the New Hampshire border to Cape Cod for about two months.
Typically, a bloom on the North Shore will last about two weeks, he said.
Dishes containing shellfish are staples on the menus of a number of Newburyport-area restaurants, and NOAA said in its statement that restaurateurs may want to make plans for alternate supplies.
Gary Greco, owner of the Starboard Galley on Water Street, said that previous red tide outbreaks haven't affected supplies but can impact prices.
"Usually it just shifts," he said. "If I can't get them from Maine, I get them from Maryland."
Greco said he gets all his seafood from David's Fish Market in Salisbury, where owner Gordon Blaney confirmed that a red tide bloom leaves him with two choices, stop carrying clams or find another supply.
"We'd love to have good, wholesome stuff from our own area, but if we can't, we look elsewhere for the product," he said.
That usually means paying higher prices, Blaney said.
"It doesn't matter if it's oranges freezing in Florida or red tide in clams in Massachusetts, when a normal supply is disrupted, it affects the price," he said. "It's just supply and demand."