Thanks to the years-long work of the Massachusetts Estuaries Study, a clear picture has begun to emerge of the biological profile of the Vineyard’s saltwater ponds and embayments. And the picture is far from pretty: left unchecked, nitrogen overload threatens to upset and eventually ruin the fragile ecosystems in many Island ponds.

Estuaries study reports are now complete for Sengekontacket Pond, Edgartown Great Pond, Farm Pond and Lagoon Pond; others remain ongoing.

But where the work of the estuaries study ends, the work of Island policymakers begins. And the Vineyard now finds itself at the threshold of confronting a complicated problem that will ultimately be difficult and expensive to solve, and will also decide what the Island will be like for future generations.

Build more sewer systems, some say; problem solved.

But it’s far more complicated than that. Sewering is hugely expensive and unless it is accompanied by zero-growth zoning policies, it can open the door to another serious issue — overdevelopment. Expanded sewering may be feasible in some places such as the down-Island towns that already have wastewater systems in their more densely-developed population centers, but not in outlying areas which includes all of up-Island.

Proven, cost-effective options are still very limited, but a great deal of research and innovation is going into developing new technologies to reduce or eliminate nitrogen in home septic systems, and there is reason to hope that these efforts will yield better alternatives to sewering in the years ahead.

Water quality planners and elected officials in Edgartown and Oak Bluffs have begun to talk in recent weeks about a plan for Sengekontacket Pond, where state environmental officials have issued what amounts to a nitrogen reduction mandate. These talks are a good start and, supplemented with research into some of the newer strategies now being tested here and elsewhere, could form the basis for a creative, forward-looking approach to a looming environmental issue.

In an interview with the Gazette this week, Martha’s Vineyard Commission executive director Mark London said a regional plan to protect the Island’s saltwater ponds from nitrogen overload is one of the critical challenges facing the Vineyard in the next five years. Mr. London predicted the plan will not be a one-size-fits-all solution and will not come easily on an Island marked by many political fiefdoms. He is no doubt correct.

But Mr. London is not just in an armchair role. He and the commission can help point the way by providing technical assistance, in the development of a regional wastewater plan, with active participation from Island towns.

The conversation with Mr. London, which appears in today’s edition, called to mind the words of an other commission executive director, the late Charles W. Clifford, in an interview with the Gazette on the commission’s twenty-fifth anniversary “The flip side of regional is paralysis,” Mr. Clifford said. “Regional is all about consensus. You have to give a little to get a lot.”

Local control is a fine sentiment for many things, but water doesn’t recognize town boundaries, as people who care about the health of Sengekontacket have already acknowledged. Sooner rather than later, the Vineyard needs an Islandwide wastewater plan if it is truly going to save its saltwater ponds.