Part of the Tisbury Great Pond is about to become an oyster reef, thanks to a project sponsored by The Nature Conservancy and the towns of Chilmark and West Tisbury.

The propagation projects calls for putting down 100 cubic yards of sea clam shells as culch and then planting 250,000 juvenile oysters.

As subdivisions go, the plan for Flat Point Farm in West Tisbury could hardly be more carefully balanced between the need to plan for family succession and the desire to maintain the farming tradition, so threatened on Martha’s Vineyard.

Yet it has served to raise a whole raft of questions that go to the very heart of the Island farming methods, which contribute disproportionately to the Vineyard’s most pressing environmental problem, pollution of the great ponds by excessive nitrogen.

Vineyard ponds may be in peril, but somebody forgot to tell that to the Tisbury Great Pond which is loaded with wild oysters this year, the biggest natural spawning of oysters in recent memory.

“It is huge,” said Rick Karney, who has been director of the Martha’s Vineyard Shellfish Group for over 30 years. “I’ve never seen anything like it,” Mr. Karney said.

Lambert’s Cove Beach, Seth’s Pond, Long Cove Pond and Tisbury Great Pond were all closed to swimming on Thursday after results from routine water testing revealed a spike in the bacteria enterococcus.

West Tisbury health agent John Powers said he expects the tests to be an anomaly and anticipated the beaches would be open again by today. He said the contamination at Lambert’s Cove may be in part due to a breach at James Pond.

The commercial oyster season is underway, and the early reports from the Tisbury Great Pond in West Tisbury and Chilmark are good. Oyster fishermen in those towns are getting their daily limit, although the off-Island market is soft.

The retail price on Island fluctuates; this week wild oysters were selling for 50 cents apiece.