Waters on the Lagoon Pond side of Eastville Beach are closed to swimming as of Friday morning, according to David Caron from the Oak Bluffs board of health. The beach near the Martha’s Vineyard Hospital is used for clamming and occasionally for swimming, but test results for bacteria have come back slightly elevated, with a reading of 113 when the top of the acceptable range is 100. It will remain closed for the weekend; the town will retest on Monday.

All the main swimming beaches in Oak Bluffs are open to swimming, Mr. Caron said.