FOX ISLAND, Va. — In the hallway of a weatherworn lodge that has stood on stilts in the Chesapeake Bay for more than 90 years, a negotiation is underway.

Who will take the maps? The arrowheads? The turtle skeletons adorned with wigs and leis? How much student art, accumulated over more than 40 years of field trips, should be saved?

Captain Larry Laird lifted an electric drill to the wall of the cabin that has been the heart of the Chesapeake Bay Foundation’s island education initiative. He pressed his trigger finger. Screws separated from the wood with a whir. The boat captain let out a low sigh.

Generations of middle and high school students have come here to learn about the fragile ecosystem of the bay. Now, the Virginia island, about six miles from Cris­field, Md., off the Eastern Shore, has succumbed to the very forces these educational programs have sought to fight: a warming climate, rising sea levels and disappearing shores.

Schoolchildren have come to the Fox Island learning center by the busload for nearly half a century. For many, it was like being in another world.

They slept in bunk beds and used compost toilets. They stargazed and combed the beach for terrapin eggs. They mucked through sea grass and dove into heaps of mud. They analyzed their home water usage and devised ways to lessen their carbon footprint. On the walls, they left footprints, names and a message, scrawled over and over again: “SAVE THE BAY.”

In the past 40 years, foundation officials said, water has swallowed about 70 percent of Fox Island — so named because when viewed from above, the land once resembled a fox plodding along through the waves.

In 1773, when the island was first discovered, its land stretched for about 426 acres, said Tom Horton, an author and former Baltimore Sun reporter who has written eight books about the Chesapeake Bay.

When the Chesapeake Bay Foundation conducted a satellite survey earlier this year, the group found there were about 34 acres left.

“What we’re talking about . . . is not just losing a part of our own history as an organization or a fantastic field trip. What we’re really talking about is the loss of habitat and the loss of land,” said Karen Mullin, the foundation’s director of professional learning. “Yes, there is erosion, but the ­forces of climate change have accelerated erosion to the point that we’re losing valuable land and habitat that we’re just not getting back. . . . These islands aren’t shifting, they’re disappearing.”

Built by a group of waterfowl hunters in 1929, the lodge was protected by the archipelago of islands that surrounded it. They created a circular cove, sheltering the structure from breaking waves and high winds.

When the Chesapeake Bay Foundation acquired the building in 1976, the organization transformed the hunting lodge into a classroom.

Children from schools across the region — the District, Delaware, Maryland, Pennsylvania and Virginia — took canoe trips through the sheltered cove and learned to identify species of plants and animals. During the summer months, Chesapeake Bay Foundation educators led teachers-only retreats and teen leadership courses.

The Fox Island lodge was the nonprofit organization’s first island education center and the start of an immersive curriculum that has grown to encompass four island centers in the Chesapeake Bay. The organization runs about 80 overnight trips per season among the four locations, each with 20 to 30 visitors.

But this year, program leaders declared the Fox Island site too dangerous for the usual activities, said Paul Willey, the foundation’s director of education operations.

Erosion chipped away at the protective semicircle of islands that kept the waters calm. Canoeing was out. When the tide rolls in and the water overtakes what’s left of the land, so, too, is hiking.

“When your bread and butter is getting student groups out into nature, you have to check in and ask yourself, ‘Are we running a safe program?’ ” Willey said. “At a certain point, with the land loss and high exposure out here, the risk was too high to keep bringing kids out.”

What’s left of the tiny dot of land is mostly marshland, thick sea grasses that can survive submerged in saltwater. Efforts to save the island would have been costly, foundation officials said, with no guarantees of success.

The winding walkway from the dock to the lodge was built over land, with tall blades of salt marsh cord grass on either side. Now, the waves lap beneath the weathered wood boards. Entire species of vegetation have gone, said Norah Carlos, the foundation’s education engagement manager.

Even the skies have grown quiet. Once home to a cacophony of laughing gulls, royal terns and black skimmers, Mullin said, the island’s bird population has disappeared with its shoreline.

“The noise we would be hearing right now is the constant call of those laughing gulls,” she said, standing on the deck of the foundation’s Fox Island ferryboat. “I loved them all, and they’re all gone.”

The lone holdout is Gerald, the flightless one-winged pelican the staff has somewhat adopted.

The stewards of Fox Island are learning to say goodbye, piece by painstaking piece.

The last group of children to spend a night on the island — a class of middle-schoolers from Halifax, Pa. — left Oct. 15. In a visitor’s log book, the students wrote their farewells.

“I am so honored that I had the chance to come here. I can’t wait to take what I learned back with me,” wrote one student. “We will make a difference!”

Seventh-graders from Georgetown Day School in the District stopped at Fox Island this week. They were the last school group to step foot on the marshy ground.

“It was really shocking just to see that it was not there anymore,” said Elsa, 13, who was instructed by a teacher only to give her first name. “I think it’s just really sad that we can’t preserve that because it’s just eroding into the ocean. . . . The fact that whole islands might not be here in 50 years, I think that’s pretty scary.”

The property and the land surrounding it are for sale at the appraised value of $210,000.

Programs the foundation used to run at Fox Island will continue at its Port Isobel Island facility, off the coast of Tangier Island, home to a storied community of more than 500 people.

Even Gerald, the one-winged pelican, will be ushered away from the sinking islet to safety.

For those who have lived and worked on the island, dismantling the lodge has been an exercise in nostalgia.

Laird, the foundation’s Fox Island captain, chuckled as he remembered scaring school groups with ghost stories of the island’s old caretaker, Merrel, who, foundation staff said, embodies the spirit of the place.

He, like the island, was a relic from another time: a waterman with worn features, calloused hands and an ability to live peacefully in the sometimes harsh conditions of the bay.

Laird grew up on nearby Smith Island, a small landmass split by the Maryland-Virginia state line. He knows better than most what water can give — and take away.

Fox Island is sinking more rapidly than ever before, Mullin said. It’s not clear how many years it has left.

As the clouds hang low, blurring the line between sea and sky, the island itself seems to shrink and fade into the horizon. Already, it has begun to feel like a memory.