Town health agents closed three Martha’s Vineyard beaches to swimmers Wednesday, after weekly water quality testing showed a higher than acceptable level of bacteria in the water.
In Chilmark, the pond at Lucy Vincent Beach is closed to swimmers until further notice. The closing does not affect the ocean side of Lucy Vincent Beach.
In Oak Bluffs, the areas of Lagoon Pond near the drawbridge, and Medeiros Cove, near the Sailing Camp, are closed until further notice. The closing does not affect Eastville Beach.
The beaches must remain closed until testing shows bacteria levels are acceptable.
All other Island beaches tested within acceptable levels.
Massachusetts Bureau of Environmental Health (BEH) scientists responsible for monitoring beach water quality say the most likely cause of high bacteria counts is rainfall, which washes pollution into the water.
The Island experienced significant rainfall on July 25, 26, and 28.
Local health agents test the water every Monday during the summer. Water samples taken Monday, July 29 showed high levels of enterococci bacteria.
Enterococci are a group of bacterial species typically found in human and animal intestines and are therefore present in sewage. While not usually dangerous, enterococci signal the likely presence of other harmful bacteria.
Any sample with a count greater than 104 cfu/100 ml is called an “exceedance,” which requires that the beach be closed to swimmers.
Monday’s samples showed 331 cfu/100 ml in Lagoon Pond near the drawbridge, and 1,050 cfu/100 ml in Medeiros Cove.
A sample taken from the pond at Lucy Vincent Beach showed 727 cfu/100 ml.
BEH advises that swimming in polluted water can cause gastrointestinal symptoms such as nausea, vomiting, diarrhea, and abdominal pain, respiratory symptoms such as sore throat, cough, runny nose, and sneezing, eye and ear symptoms including irritation, earache, and itchiness, dermatological symptoms like skin rash and itching, and flu-like symptoms such as fever and chills.
Most of these symptoms are minor most of the time, but they can occasionally be more serious, especially in sensitive populations such as those with weakened immune systems, children, and the elderly.