SEARSPORT, Maine — There is a community on Sears Island, naturalist Mike Shannon of Knox told a group on a nature walk on the island Saturday.

“The community on Sears Island begins with organisms,” he said of the numerous species of birds, mammals, fish, amphibians and plant life.

Shannon and Scott Dickerson, executive director of the Coastal Mountains Land Trust of Camden and a member of the Sears Island Joint Use Planning committee, led eight hikers along the island road and trail for a little more than a mile through stunning scenery Saturday morning.

“We’ll talk about the natural history of the island, and when we get to the end of the trip, I’ll talk a little bit about what’s been going on, on Sears Island for the past 40 years,” Dickerson told the group, which met at the end of the causeway connecting the island to the mainland.

He cited the historical contests over proposed uses, such as an “oil refinery, ports, aluminum smelting, nuclear plants and what have you,” he said.

Shannon called Sears Island a “substantial island with 936 acres and about 5 miles of shoreline.”

“This is not a small, isolated little island stuck out here. This is a big, prominent island, one of the larger islands in Penobscot Bay,” Shannon said.

The word “Wassumkeag,” or shining beach, as the island was called by American Indians, is painted in large letters on the pavement at the end of the causeway, built in the early 1990s over a gravel bog that had been exposed at low tide.

Named for David Sears of Boston after he agreed to grant a large sum toward the founding of Searsport in 1845, the island once served as his farm, to which he retreated in his later life, Dickerson said.

The causeway was built to serve a prospective port on the island. “It changed the characteristic of the place quite a bit by providing vehicular traffic,” Dickerson said.

The change occurred around the time the state Department of Transportation bought the island from the Bangor & Aroostook Railroad, which had owned the property since the late 19th century.

The company had built the initial railroad to the island in 1906 in an attempt to have a resort for people from Bangor, said Dickerson.

Within a few minutes on the walk, hikers took on the enthusiasm of wild plant stalkers, stopping every few yards to examine bushes, plants, and trees. Some started identifying birds flying overhead: song-birds, a hawk, and a family of black-throated green warblers, with the mother bird feeding her two fledglings.

The roadway changed from pavement to dirt and grass, and hikers saw dogwood berries growing on bushes. As the berries change color to black or dark red, catbirds know they are ripe for eating, Shannon said. The group also viewed the late-summer foliage and some other fauna.

At the end of the trip, Dickerson reviewed the latest activities of the 17-member Sears Island Joint Use Planning Committee, which is drafting its final report to the Legislature’s Transportation Committee, the body responsible for approving use, jurisdiction and ownership of Sears Island.

According to the conceptual plan, 341 acres will be reserved for potential marine transportation needs. The remaining 600 acres will be protected by a permanent conservation easement held by Maine Coast Heritage Trust, Dickerson said.