By Sarah N. Mattero, Globe Correspondent

Multiple Massachusetts beaches have been closed because of high bacteria counts in the water.

In New Bedford, the East Beach located along East Rodney French Boulevard, West Beach along West Rodney French Boulevard, and the beach inside Fort Taber Park are closed to swimming today, according to the New Bedford Health Department. They were closed yesterday as a preventative measure after heavy rain fall.

All four sections of the Wollaston beaches in Quincy remain closed to swimming due to bacteria counts higher than the threshold set by the state Department of Conservation and Recreation.

Along Cape Cod, Nauset Light Beach in Eastham and Marconi Beach in Wellfleet have been closed for high bacteria counts.

In Nantucket, a total of 10 beaches have been closed: 40th Pole, Childrens Beach, Dionis Beach, Jetties Beach, Miacomet Beach, Sewerbeds Beach, Washing Pond, Washington Street, Cliffside Beach Club, and Wauwinet Bayside Beach, according to the towns website.

This widespread closure is extremely unusual but may be attributable to either the heavy rains of the night before or windblown dead seaweed on our north shore which may be fermenting and releasing bacteria during high tide cycles, said Nantucket Health Department director Richard Ray.

The Health Department tests for the bacteria enterococci, which is type of bacteria that indicates that forms of coliform bacteria are present in the water sampled. Ray believes results from yesterdays Nantucket samples will be available today around 3 or 4 p.m.

The beaches will be reopened to swimming once water returns to acceptable quality levels.

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Several Nantucket and New Bedford beaches closed because of bacteria