With all the worries plaguing aviators these days, the thing that's got Trade Winds airport manager Joe Costa all worked up is dog droppings - on the runway and taxi lane.

A couple days ago, you could find Mr. Costa out there, striding across this grassy airport in Oak Bluffs with a small cardboard box in one hand and a cedar shingle in the other. He'd been out scooping, and the fact that his shoebox-sized container was getting heavy had him in a foul mood.

"Fifty years I've been flying in and out of here," he said to a pair of dog walkers. "It's lousy what these people are doing to this property."

The problem is that this is no ordinary airport. It's also a public nature preserve, 71 acres with more than a mile of walking trails around the perimeter. Back in 1989, when the Martha's Vineyard Land Bank bought the airport property, the goal was to preserve an expansive meadow while also saving a rare species - the grass field airport.

But lately, this dual-purpose setting has come under strain, and on Monday night at the Oak Bluffs School, the tensions were laid bare when more than 60 people showed up for a hearing held by the land bank commission and advisory board. Part of an annual series of meetings in each of the six different Island towns, the Oak Bluffs event was devoted largely to the brewing dispute between dog defenders and Mr. Costa, who is himself an airplane pilot.

At issue is more than just the dog droppings which Mr. Costa argues are a potential hazard to airplane brakes if pulled under a plane's wheels. A dog suddenly dashing across the runway puts both pet and the pilot at serious risk, according to Mr. Costa.

But for dog owners, the Trade Winds preserve is a last bastion of freedom for them and their pooches. Pushed off most Island beaches by various regulations, they now cling to this place. And like a dog with the proverbial bone, they aren't about to let go.

"As a resident of Martha's Vineyard, I'm sick and tired of the list of things I cannot do," said Joanne Philbrick of Oak Bluffs. "If you tell me I can't walk my dog on land bank property, I will go to jail over it, because I am doing it."

In sheer numbers alone, dogs appear to outnumber airplanes and pilots. While 87 people hold permits to land at Trade Winds, a land bank survey found that there were only 102 flights in the last year, a flight counting as a take-off and landing combined.

To be sure, this is no bustling transportation hub. The windsocks were blowing in the breeze, but under blue skies this Wednesday, the hangars and runway were sleepy as a ghost town. "To call it an active airport is a misnomer," said one man.

But despite their ample ranks, most dog owners were not pushing for a takeover of the airport, but rather some plan for peaceful coexistence.

"It is a wonderful place to take a dog not on a leash, because they can run and get exercise," said Charles Ratte. "But I plead with dog owners to take Joe's concerns to heart. I think we can make the trails compatible with the air strips."

Mr. Ratte suggested better signage and possible modifications to the trails to keep dogs from straying onto the taxi lane or runway. Others asked for more pooper-scoopers. Currently, there is just one pair and a supply of plastic bags.

Another problem is confusion over parking. Kerry Scott told the land bank commissioners that a "Do Not Enter" sign at the head of Farm Neck Road is misplaced and ends up causing dog owners to park their cars closer to the hangars. The result is eager dogs relieving themselves too close to where planes will taxi.

In the debate, which was often punctuated by rousing applause, Mr. Costa also tried to strike a conciliatory note. He admitted that he had strewn moth balls around the preserve in an attempt to keep dogs off the runway.

"Someone told me that to keep dogs out, you put mothballs down," he said, while standing up to address the crowd. "It was wrong, and I apologize."

Still, Mr. Costa could not contain his frustration. "There are paths all around the property so they don't have to be on the runway," he said.

While clearly in the minority, he did find at least one ally in the room. It was Aquinnah land bank commissioner Michael Stutz, also a pilot.

"The threshold problem is people with unleashed dogs running around an active airport," he said. "We can't have that. I was flying last week, and I heard a pilot on the radio say he had to make a low pass to get the dogs and people off the runway. The question of dogs in the vicinity of an active runway? We wouldn't do this at the Martha's Vineyard Airport or Katama."

Dog owners reacted with skepticism when confronted with claims of canines running rampant on the runway. "I walk there twice a day," said Donna Joyce, "and I rarely cut across the airpath."

At one point, the debate found people arguing about just what kind of toilet facilities dogs prefer - the buzz-cut lawn or the tall grass. "Dogs like to go into the woods to do their dirty work," said Mr. Ratte. In his view, dogs just don't like the low grass. "I walked around the entire perimeter and found just three dried-up poops in the taxi-way," he said.

Officials at the land bank won't make any decisions until they have finished their round of hearings in all the towns. For now, it's status quo at Trade Winds. Mr. Costa is still watching out for scofflaws, barking at them to pick up the poop.

Peter and Barbara Duart don't seem to mind too much. Out for a walk on Wednesday, Mrs. Duart was busy scooping up after their new chocolate lab, Muffin. And Mr. Duart reflected for a moment on what this place means. "Everybody knows everyone's dog's names," he says. "Even if you don't know the people."