Summit on Lagoon Weighs Dredging, Controlling Growth


Dredge the pond. Control growth. Upgrade septic systems. Encourage homeowners to curb the use of high-nitrogen fertilizers on their lawns.

These were the central themes this week when an array of shellfish officials and Vineyard residents gathered for a summit meeting of sorts to discuss the latest water quality crisis in the Lagoon Pond.

"It's not a very stable pond and it's time we addressed some of these issues," said Rick Karney, director of the Martha's Vineyard Shellfish Group.

Three weeks ago Mr. Karney reported that some four million juvenile shellfish had died at the group's Lagoon Pond hatchery because of poor water quality in the pond.

Mr. Karney said marine scientists in Woods Hole are analyzing samples of the dead shellfish to determine the exact cause. But he said there is no question that poor water quality in the Lagoon led to the die off.

"The bottom line is that no matter what we did all these things are related to the eutrophic conditions in the Lagoon and if we're going to help the Lagoon we've got to do some dredging and improve the circulation," Mr. Karney said.

Held in the Katharine Cornell Theatre on Wednesday afternoon, the meeting was attended by about 40 Vineyard residents, including a number of people who have worked on waterfront issues for many years. A panel at the head of the room included the shellfish constables from the three down-Island towns, Mr. Karney and two planners from the Martha's Vineyard Commission.

Oak Bluffs shellfish constable David Grunden said he has documented anoxic conditions in the deep water holes in the Lagoon for three weeks running. "The oxygen levels are very low - almost to the point of zero. We are concerned that it doesn't gobble up the oxygen and spread," Mr. Grunden said.

Tisbury shellfish constable Derek Cimeno reiterated that the adult shellfish in the Lagoon are healthy; he said a good scallop crop is expected again this year. But he also said that poor water quality in the Lagoon has been documented going back as far as 1987, and that it is time to act.

"We need to begin to take steps, including steps toward dredging. The process takes some time and we need to get started," Mr. Cimeno said.

William Wilcox, the water quality planner for the commission who has been monitoring the Lagoon for a number of years, said the pond has been experiencing large algae blooms as a result of too much nitrogen. The source of the nitrogen is both natural and manmade - some comes from acid rain while some comes from septic systems and lawn fertilizer.

"We can't deal with acid rain on a local level, but we can begin to deal with septic systems and fertilizers," Mr. Wilcox said. He also joined the chorus of people who advocated improving the circulation in the pond by dredging.

But dredging costs money and the permitting process is long and complicated, town officials said.

There was some discussion about the recently announced state project to rebuild the Lagoon Pond drawbridge - shellfish officials are concerned about the plan to build a temporary drawbridge at a cost of some $3 million. The plan calls for putting more fill at the entrance to the Lagoon for the supports for the temporary drawbridge.

Local criticism of the plan is already growing; Mr. Cimeno said shellfish constables were not notified when state officials held a recent public hearing on the project. Some said when it comes to state highway projects "temporary" can in fact mean long-term. "When Mass Highway talks temporary it usually means 30 years," Mr. Grunden said.

On the positive side, some said the bridge project could open the regulatory door for some dredging , at least at the entrance to the Lagoon.

Mr. Wilcox said the entrance to the pond is one place that needs dredging. He said there are also sandbars at Hines Point and the area in front of the old sailing camp park. He cited a 1937 coastal survey map that shows the sandbars in the same location. "They were the same then as they are now - they have probably been that way for a thousand years," Mr. Wilcox said. He said dredging is a relatively short-term solution compared with the longer-term solution that includes dealing with old septic systems, road runoff and the use of fertilizers by homeowners.

JoAnn Taylor, the coastal planner for the commission, unveiled an array of pertinent numbers. She said the nitrogen carrying capacity for the Lagoon is 17,000 kilograms. A study done of the Lagoon by the commission several years ago found that the pond was carrying just about 17,000 kilograms of nitrogen. "The Lagoon was at or slightly over its limit," she said.

Ms. Taylor said the commission had also calculated that the nitrogen load in the Lagoon at maximum build-out will be 21,000, 22,000 or 27,000 kilograms, depending on how build-out takes place. She said there are 4,400 acres in the total watershed for the Lagoon, and 1,500 of those acres are undeveloped. Of the vacant land in the watershed, only 56 acres have been protected.

"This tells us that long-term growth management strategies are important and we shouldn't lose track of nitrogen inputs as we talk about taking steps to improve circulation," Ms. Taylor said.

Other steps were recommended.

Mr. Wilcox said he hopes that the Lagoon Pond will shortly become included in the Massachusetts Estuaries Management Program, a state plan where scientists collect information about the pond and develop computer models. The town and the state share in the cost of the work, with the town paying 40 per cent and the state paying 60 per cent. Mr. Wilcox said the program can be very helpful. Shellfish officials from Edgartown, where the program is in place in the Edgartown Great Pond, chimed in with an endorsement.

"It sounds complicated but it's not. They'll come and set up a lab at your town highway barn," said Edgartown shellfish constable Paul Bagnall. "What I like about it is it feeds the town knowledge but it doesn't tell you what to do," he said. The town paid $40,000 last year for its share of the Edgartown Great Pond program.

Citing experience, Edgartown shellfish officials also gave the thumbs-up to dredging. Mr. Bagnall said the scallop crop in Cape Pogue Pond had seen a period of decline but has improved since the town did a judicious dredging project a couple of years ago. Edgartown owns a dredge which is available for hire.

The discussion returned to an earlier theme: septic system upgrades and homeowner education. Mr. Karney said the shellfish group had applied for a grant last year to produce a pamphlet for homeowners, but the grant application was not successful and the project had to be put on hold.

One Oak Bluffs resident who attended the meeting called it a key issue.

"One of the biggest problems is lawns," said William Shay. "Look around the Lagoon and you can easily see that there seems to be a competition for who has the greenest lawn. We need to help people understand that a brown lawn is an honorable one," he said.

The group agreed to continue the discussion in the fall.