Water quality tests at Great Rock Bight in Chilmark have improved significantly this week, though earlier spikes in enterococci bacterial levels have led the Martha's Vineyard Land Bank Commission to reaffirm their swim-at-your-own risk advisory.

Due to poor water quality, the Martha's Vineyard Land Bank is advising visitors at Great Rock Bight in Chilmark to swim at their own risk.

The 911 call came at about 6:45 p.m. that a person was in the water off Great Rock Bight and in distress. Chilmark and Aquinnah police, Coast Guard station Menemsha and Massachusetts Environmental Police all responded. Two people were pulled from the water and transported to Menemsha to waiting EMS.

A large dead leatherback turtle that was more than five and a half feet long washed up at Great Rock Bight beach on the north shore last Tuesday afternoon. The beach is owned by the Martha’s Vineyard Land Bank. Land bank property foreman Matthew N. Dix said the New England Aquarium was contacted, but then the turtle washed back out into the Sound.

Mr. Dix speculated that the turtle may have been killed by a boat, as it had large gashes on it that could have come from a propeller.