SANDY POINT - A Balance of Nature and of Nature Lovers

ON summer weekends, hundreds of sailors and sunbathers flock to Sandy Point, a sandy island in Little Narragansett Bay where hundreds of herring gulls tend their nests. To protect the fragile island and its creatures but also to let people enjoy the island's popular beaches, the Mashantucket Land Trust and the Stonington Community Center have joined forces.

ON summer weekends, hundreds of sailors and sunbathers flock to Sandy Point, a sandy island in Little Narragansett Bay where hundreds of herring gulls tend their nests. To protect the fragile island and its creatures but also to let people enjoy the island's popular beaches, the Mashantucket Land Trust and the Stonington Community Center have joined forces.

The two have different goals: the trust owns the island and maintains it as a nature preserve, while the center manages the island as a recreational site. But together, they are providing a daily patrol in summer to deal successfully with such problems as littering or rowdy crowds that have long plagued the island.

The arrangement works, said Ann Nalwalk, president of the land trust. ''It works because we both care and want to keep the island a special place.'' she said. ''I think this is something land trusts need to look for - creative ways to manage. Different groups can work together.'' Hurricane Forms Channel

Sandy Point's 35 acres of sand and beach grass lie partly in Rhode Island and partly in Connecticut, not far from the tip of Stonington Borough. The land was once the farthest reach of Napatree Point in Westerly, R.I., but during the 1938 hurricane, the high water in Little Narragansett Bay receded with such force that a new channel was formed and Sandy Point became an island. Narrowest at its middle, and buffeted by tides and currents, Sandy Point is still changing shape.

Migratory birds stop at Sandy Point in spring and fall; American oyster catchers and a few snowy egrets have been spotted there, and gulls - especially herring gulls - nest in the grass. But since the island is only a short boat ride from marinas in Connecticut and Rhode Island, Sandy Point is a mecca for boaters. They relax, picnic and play on the sand, only a few feet from fuzzy gull chicks scurrying through the grass.

''It's a great place to relax,'' said Michael Blair, the Mayor of Stonington Borough, who visits the island with his wife and their three children. ''There are no telephones. You can see the kids, not worry about them. You see your friends and neighbors. We go there as often as we can.''

Hamilton Salsich who, with his assistant, Heather Dustin, regularly patrols the island said: ''The island really gets heavily used on summer weekends. Mostly, they're very good, concerned people. But some - only a minority - don't have any respect for the island.'' A Loose Arrangement

Until 1982, Sandy Point belonged to the late Alfred Gildersleeve of Stonington and his family. ''My father loved islands,'' said Judith Gildersleeve duPont of Stonington. ''He purchased Sandy Point after the 1938 Hurricane. In those days very few people had boats with outboard motors, but he did, and we enjoyed the island as a family for many years.''

The family had what Ms. duPont called a loose arrangement with the community center, which issued Sandy Point memberships at very nominal cost. Some people recall $5 memberships. But as more people became boat owners, more people took notice of Sandy Point, and many nonmembers began using the island. People trampled beach grass, built bonfires and left litter.

''You can't put a fence around it,'' Ms. duPont said. ''When it was private, it was a great concern to us that people could hurt themselves or abuse the island. My two older brothers and I decided it really did not belong in the hands of private individuals.''

So in 1982, Ms. duPont and her brothers, Alfred Gildersleeve Jr. of North Stonington and Richard Gildersleeve of Orange, donated the island to the Mashantucket Land Trust to be used as a nature preserve. Most of the 600 acres that the trust maintains in Griswold, Groton, Ledyard, North Stonington, Preston, Stonington and Voluntown is open to the public.

The Gildersleeves also urged that the land trust work with the community center, of which Ms. duPont is a board member. The plan was to restrict use of the island to those who purchased memberships from the community center and to set up regular patrols of the island. But, all agree, arrangements were too loose. Not enough money was collected, patrols were not regular and problems grew. Complaints arose about loud drinking parties on the island.

''People had a very cavalier attitude that they had every right to be there and do what they wanted,'' Ms. duPont said.

As the 1988 season approached, the community center and the land trust worked out a tighter plan. The center, as manager, would collect agreed-upon fees to cover the cost of regular patrols, a patrol boat, a two-way radio, insurance, taxes and a brochure explaining that Sandy Point is a nature preserve.

Last year, season membership fees were $15 for center members, $30 for nonmembers, while daily-use fees for those without season passes were $3 for a group. This year, season memberships are $20 for center members, $50 for nonmembers. Daily use fees are $5 for one to four people, $1 for each additional person. Higher fees had been considered this year, but were rejected because the land trust representatives feared that they might keep away school groups.

''We'd like to encourage educational groups to use the island,'' Ms. duPont said. ''The only way to deal with Sandy Point is to enlist people's support and get people on our side, to protect the island.''

Mr. Salsich said: ''I felt that we should make coming here a special privilege. If you love it, you'll pay a few extra dollars, and you'll take better care of it.''

Mr. Salsich, who teaches English and history at Pine Point School in Stonington, hands out brochures as he collects the daily fees from island visitors. The brochure tells visitors pets, tents, overnight camping and walking on the grass are not permitted on the island, and reminds them to put out fires and remove their refuse.

Polite and firm, Mr. Salsich makes sure that every island visitor is aware of the rules.

He also chats with visitors, discussing the gulls and pointing out the few manmade features of the island like a pyramid of granite blocks called the Folly just offshore. ''Old-timers tell me that when they were boys, the shore was 50 feet farther over, and the Folly marked the outside of the channel,'' he said.

If a a visitor becomes irate. Mr. Salsich radioes the police in Connecticut or Rhode Island. ''But I usually find politeness and gentleness get me through,'' he said.

Some restrictions on use of the island might have to be considered in the future, because of the heavy volume on weekends, said Garrison Valentine, president of the center. ''People are welcome there,'' he said, ''but it can become overburdened.''

In general though, Ms. duPont said, things are now going well on Sandy Point. ''I was out last Saturday, and it was loaded with people,'' she said. ''But every one was on the sand, not the grass; everyone was observing the rules, and the gulls seemed to be going forward with raising their young.''