When it comes to the Vineyard’s coastal ponds, the time has arrived to move from study to action. And credit for taking the lead on that front goes to Michael Loberg and the Tisbury board of health for their forward-thinking initiative announced last week to curb nitrogen entering the watersheds of Lake Tashmoo and Lagoon Ponds. Tashmoo and the Lagoon are two of the most compromised ponds on the Vineyard.

The problems in the ponds are well known and well documented, thanks in part to years of sampling and intensive study by the Massachusetts Estuaries Project. Every coastal pond has been compromised to some degree by too much nitrogen entering the watershed. Most of that nitrogen is coming from septic systems, the primary wastewater disposal method for private homes here. The rest comes from road runoff, acid rain and waterfowl.

By now most Islanders can recite the biology lesson by heart: An excess of nitrogen fuels the growth of too much algae in saltwater ponds, which in turn blocks sunlight and takes up oxygen in the water column needed by aquatic plants and shellfish. Reduced to its simplest terms, too much nitrogen upsets the balance of saltwater ponds. Allowed to reach the extreme, the result is shellfish dieoffs and anoxic conditions.

The so-called “no new nitrogen” rules being proposed in Tisbury would make property owners who add nitrogen to the two pond watersheds from new development accountable by assessing fees. Under the rules, all new development would trigger a semi-annual fee based on water usage and the type of wastewater management applied. The fees would be reduced for property owners who use denitrifying septic systems or toilets.

The fees are not pulled from thin air but have been carefully calculated using an assumption that removing nitrogen by sewering would cost the town three hundred dollars per pound. The formula also factors in the amount of nitrogen not finding its way into the treatment system, and the small amount that conventional septic systems are thought to remove. Money from the fees would be used to help reduce nitrogen entering the watershed in areas not served by the town sewer system, such as along the State Road commercial district.

Public hearings begin next month on the draft rules, which the board of health has the power to enact. The rules were unveiled at the end of a daylong conference hosted by the Martha’s Vineyard Commission last week to explore innovative solutions for protecting coastal ponds. Commission executive director Adam Turner has made coastal ponds a top priority for the regional planning agency this year. He believes there will be not one solution, but many.

Tisbury has set the ball rolling. Mr. Loberg said he hopes the rules help raise awareness while giving property owners a stake in solutions.

“We want the homeowners and the people building the homes to become familiar with their choices,” he told the Gazette this week. “We want them to think about: How can I reduce the nitrogen I’m putting into the watershed and the groundwater? What kind of tools do I have?”

In the end, the rate of development on the Island will determine how much time is left for the ponds. At Lagoon Pond, for example, the estuaries study found that the pond has already lost significant resources from nitrogen. If development around the pond reaches full buildout, nitrogen levels will increase by about thirty five per cent.

As reported by the Gazette in its series on coastal ponds, Islanders could consider themselves lucky. Widespread development has already devastated most of the estuaries on Cape Cod.

Swift intervention will be needed to avoid going down the same road.