Drew’s Cove in Lake Tashmoo could become a no-anchor zone for the next three years to protect fragile eelgrass beds near the head of the saltwater estuary.

This was the recent recommendation of a seven-member committee appointed by the Tisbury selectmen in May to review available information about eelgrass beds in town waters and devise a protection plan.

Considered key to the health of saltwater ponds, eelgrass has been on the decline in waters the Island in recent years due to pollution.

Using maps from the Massachusetts Ocean Resource Information System and Department of Environmental Protection, aerial photographs and underwater photographs, the Tisbury eelgrass committee documented three large eelgrass beds in Lake Tashmoo and one small bed in the Lagoon Pond.

In Tashmoo, eelgrass was found inside the inlet close to the town dock, and in Drew’s Cove. In the Lagoon, occasional patches were found, the largest one near the drawbridge.

At a recent meeting the committee told the Tisbury selectmen that a three year no-anchor zone in Drew’s Cove would allow the town to establish a monitoring program to see if prohibiting anchoring helps.

“There is no question that a boat going into a eelgrass bed dropping an anchor and dragging that anchor and then pull that up, they’ll be taking some eelgrass with them,” said Gerry Hokanson, chairman of the committee. “The challenge is it’s a relatively small area of eelgrass, how quickly will it grow back.”

Mr. Hokanson said the challenge for the town will be to strike a balance between establishing no-anchor zones, enforcing the rules and the possibility that on a busy summer day they would have to turn boats away.

Other factors affecting eelgrass beds include nitrogen, green crabs, waterfowl and poor water clarity (eelgrass needs sunlight to grow).

“You can protect the eelgrass with no anchoring and mooring changes, but without dealing with the full compliment of stressors to the eelgrass it may not recover, at least as well as we would want it,” Mr. Hokanson said.

The committee left other recommendations to be decided by the harbor management committee and harbor master.

Selectmen will continue the discussion on Sept. 13.