News

Red tide shuts down local shellfishing

By Richard Gaines
Staff writer
Published: May 16, 2008

The anticipated arrival of red tide forced a shutdown of Essex County's $30 million shellfish harvesting industry yesterday.

After tests from Newburyport to Gloucester showed the presence of dangerous concentrations of the Alexandrium fundyense algae in bivalves, the state Division of Marine Fisheries ordered a halt to shellfishing yesterday at 12:30 p.m.

Gloucester Shellfish Constable David Sargent said he had to hustle to warn commercial fishermen off the flats for the afternoon low tide.

The ban on harvesting covers all filter-feeding bivalves. Lobsters, crabs and scallops are not affected by red tide.

The closure was expected. Starting in Maine, closures have been moving southward for the past three weeks as an enormous bloom of red tide algae, stimulated by the ample sunshine, has been pushed shoreward by persistent easterly winds.

"It's a bad package," said Don Anderson, a red tide expert at Woods Hole Oceanographic Institution, whose research team last fall identified an enormous spread of red tide algae seeds on the ocean bottom.

Woods Hole's Gulf of Maine Toxicity Study warned that this season's seeds, under ideal conditions, could develop into a bloom that could cause more harm than the epic red tide outbreak of 2005. That bloom kept the entire coast of the Gulf of Maine closed to shellfishing for two months, costing the local economy an estimated $50 million.

Essex County's commercial shellfishermen — including 86 in Gloucester and 123 in Essex — earned $6 million for the clams and other shellfish they dug and brought to brokers last year, according to the Division of Marine Fisheries. Sargent said the economic impact multiplies four to five times as the shellfish make their way from buyers to shuckers to truckers and finally to the area's takeout windows, restaurants and fish markets.

"It is the most locally contained industry," Sargent said. "All the money stays local."

Gloucester alone has 1,200 acres of shellfishing beds, all in the Annisquam and Essex river estuaries.

Woodman's of Essex, where clams were first fried early in the last century, will buy from Canada, beyond the northernmost reach of the red tide, to satisfy demand for fried clams, which can reach 180 gallons a week during the summer, according to co-owner Steve Woodman.

Local clammers have no recourse but to wait out the red tide.

Year to year, spring's delivery of red tide algae to the estuaries — where the softshell clams are buried in the muck, filter feeding — is unpredictable. It depends on the size of the bloom, the amount of runoff that lowers salinity, the sunlight that aids the growth of the microscopic plants, and wind direction.

The outbreak in 2005 was the worst since the early 1970s. But the discovery last fall by Anderson and his team from Woods Hole of algae seed beds 30 percent more extensive than those that sparked the 2005 bloom left clammers and scientists deeply worried that this season's outbreak would be a bigger monster.

"The scenario is holding up," Anderson said. "Northwest winds and sun are a bad package."

He praised the Division of Marine Fisheries for its monitoring program for "safety and efficiency," and said the weather in coming days will determine how broad and long the closures will be.

Each spring, the algae seeds, which are deposited on the bottom at the end of the previous season's bloom, float to the surface and develop into tiny plants.

As with all flora, sunlight stimulates their growth and winds and currents determine where they go. The algae are gathered harmlessly in the flesh of filter feeders, but high concentrations are toxic to humans, and can cause paralytic shellfish poisoning.

Richard Gaines can be reached at rgaines@gloucestertimes.com