For the first time in recent years, parts of Sengekontacket Pond will be open for shellfishing at least through June.

Finally some good news,” Edgartown shellfish constable Paul Bagnall told the town selectmen Monday, when he announced that parts of the pond, from below Sarson’s island to an area near the Little Bridge, have been declared open for shellfishing by state environmental officials from May 1 through June 30. The opened areas of the pond will be subject to possible closure at times from July through October depending on rainfall amounts, shellfish constables said in Oak Bluffs and Edgartown.

Other parts of the pond, including Major’s Cove and the Cow Bay end of the pond, remain closed to shellfishing.

The closures do not apply to boaters or swimmers.

Since 2007, Sengekontacket has been closed to shellfishing in the summer because of high levels of fecal coliform bacteria in the water. The source of the bacteria is believed to be mostly waterfowl, and the levels become elevated after periods of rain contribute runoff to the pond.

This year, beyond June 30 the pond will likely be open subject to rainfall amounts, Oak Bluffs shellfish constable David Grunden said on Tuesday. A memorandum of understanding among Edgartown, Oak Bluffs and the state Division of Marine Fisheries has been signed by the state and is expected to be signed by the two towns, allowing the ponds to be opened for most of the summer.

The decision to open the pond is due to lower bacteria levels, Mr. Grunden said. “The Division of Marine Fisheries decides solely on their bacteria samples and analysis,” he said.

Once the memorandum is signed, the pond will be subject to rain closure rules from July through October, with July being the most restrictive month, Mr. Grunden said. If the area receives more than .2 inches of rain in a 24-hour period, the pond will be closed for a minimum of five days. From August through October, the level will be bumped up to one inch.

In some areas of the pond, shellfishing is prohibited at all times of year, while in others the closure is conditional and subject to conditions.

The state will check rainfall levels at 7 a.m. daily, Mr. Grunden said.

As a result, the schedule of when areas will be open or closed will change from month to month, which may cause some confusion, Mr. Grunden said. Each town will use flagpoles to indicate pond conditions; in Oak Bluffs, the pole will be near Little Bridge. When a red flag is flying, the pond is closed to shellfishing.

“We’re hoping for a dry July,” Mr. Grunden said.

“It’s great if it goes through,” he added, although “it’ll be a lot of getting used to and explaining to people what’s open and what isn’t.”