ROCKPORT – Maine has about 4,600 islands dotting its ragged shore, providing habitat not only for wealthy tourists, but also for bald eagles, egrets, several species of gulls, and rare seabirds such as puffins, terns and razorbills.

Most of the islands, ranging from chunks of rock rising from the sea to acres of wooded wilderness, have been visited by Brian Benedict.

As deputy manager of the Petit Manan National Wildlife Refuge Complex, Benedict and his five-person staff oversee the protection of 46 federally owned or protected islands scattered from Smuttynose Island in the southwest to Old Man Island in the northeast, as well as just over 4,000 acres of mainland refuge in Washington and Hancock counties – all sites that are crucial habitat for seabirds, from puffins to ducks.

Now, Benedict is promoting a federal plan to acquire 87 more islands someday for the national refuge to ensure that seabird habitat is permanently conserved in Maine.

“By going after as many of these islands as possible, we’ll protect the best habitat that’s out there,” Benedict said.

This week, the U.S. Fish and Wildlife Service will hold a series of public meetings to learn what Mainers think of a 15-year plan that recommends buying islands to increase the refuge’s size by 154 acres.

The process that led to this plan began nearly 12 years ago when Petit Manan staff met with state biologists, conservation groups and land trusts to determine which of Maine’s 616 historic seabird islands are worth protecting.

After months of study, 377 islands were deemed nationally significant for wildlife, meaning that 1 percent or more of a valuable seabird species, such as the federally protected roseate tern, used the island as habitat, or that the island was a nesting area for bald eagles. Of these, 226 islands are protected already, leaving 151 vulnerable.

The 87 islands listed in the U.S. Fish and Wildlife Service’s plan are the best of the best, and they’re increasingly at risk, Benedict said.

“Many of the islands that we never considered developable in the past now have houses on them. People who have the means are finding ways,” he said.

Realistically, it’s probably not feasible that all 87 islands will come up for sale during the 15 years covered by the plan, but Benedict hopes to acquire as many islands or easements as possible with the funds at his disposal.

“The valuations for islands are going up, so our dollar doesn’t go as far as it did 10 years ago,” he said. “We’ve been doing very well getting funding, but that may change. In the current budget climate and with things happening overseas, there will be fewer dollars to go for.”

Responding to community rumors, Benedict made a point to state that no islands will be taken by eminent domain.

“The process is really only for willing sellers,” he said.

Some islands are more valuable than others, but a study completed by Charles Colgan, a professor of public policy at the University of Southern Maine, found that some towns would lose significant property tax revenue.

In total, the ownership change would cost Maine towns about $130,000 in taxes annually. Kittery would see the biggest impact, with a property tax loss of nearly $31,000. Frenchboro, though losing only $6,300, would have to raise its mill rate by 9 percent to keep its municipal budget balanced, Colgan found.

However, Colgan also estimated that new opportunities for seabird viewing – already a $5 million to $10 million business in Maine – could provide substantial revenue in the long term. Without some island preservation, the industry will lose ground, he predicted.

If the U.S. Fish and Wildlife Service’s plan is approved, six new seabird-nesting colonies also will be established during the next 15 years. Petit Manan staff and interns working in cooperation with the Audubon Society, the state and other groups now maintain nesting islands for puffins and three species of terns on six islands – Machias Seal Island, Ship Island, Matinicus Rock, Metinic Island, Petit Manan Island and Pond Island.

By luring colonial birds with decoys and recordings of calls, then destroying the nests of aggressive gulls that might feed on the other birds’ eggs, biologists have increased some populations more than a hundredfold since the program began in 1984. The six islands now harbor 98 percent of all the Atlantic puffins in America, 94 percent of the Arctic terns outside Alaska, and more than 95 percent of the nation’s federally endangered roseate terns.

“We have huge populations on our small islands,” Benedict said. “They’re very susceptible to disease outbreak, predation and food supply shortages.”

The six new islands haven’t been selected yet, but they will likely fill “geographic gaps” between existing colonies, he said.

Despite growing kayaking and bird-watching industries, the islands will remain off-limits during nesting season, according to the plan.

“We’re a national wildlife refuge, not a national park. Once we’ve met the needs of wildlife, then we meet the needs of people,” Benedict explained.

But Colgan estimated that a larger refuge could draw 25 percent more visitors, totaling more than 11,750 people annually by 2020.

To ensure preservation in the face of tourism, the plan also proposes that 13 islands be federally designated as wilderness, including the Cross Island Complex, Halifax Island, Inner Sand Island, Bois Bubert Island, John’s Island, Little Marshall Island, Outer White Island and Outer Heron Island. All are important bald eagle habitats, Benedict said.

The wilderness designation, which would be a first for the Petit Manan refuge, wouldn’t keep visitors off the islands, but it would ban any future construction of facilities such as roads or outhouses, and would require that refuge biologists not interfere with the natural habitat by cutting trees or chasing away gulls. The islands would remain in their natural state, permanently, he said.

“We really looked for something that, as a visitor, the experience would be one of solitude, would give you that sense of wilderness,” Benedict said. “These are the best of the best.”

Despite a plan by Friends of Sears Island to lobby for a seabird education center, the Penobscot Bay location is not on Petit Manan’s acquisition list. The conservation plan calls for an education center, but leaves decisions about its location to a future set of public hearings. Ideally, the location would be farther south, to balance the National Wildlife Refuge Complex’s existing offices in Milbridge and Rockport, but all possible sites will be considered, Benedict said.

“One of the things that we’re finding as we look for land is that with zoning and the competition for parcels along Route 1, there isn’t much land available,” he said.

The education center and the island acquisitions will require partnerships with landowners, local conservation groups and the state, age-old coalitions that have made Petit Manan possible throughout its history, Benedict said.

“All of the conservation community will play a role in saving these islands,” he said.

Public meetings have been scheduled for:

Wednesday, June 2, Milbridge Town Hall, School Street, open house 2-4 p.m. and 6-7 p.m., public hearing 7-9:30 p.m.

Tuesday, June 8, Pine Tree State Arboretum, 153 Hospital St., Augusta, open house 2-4 p.m. and 6-7 p.m., public hearing 7-9 p.m.

Wednesday, June 9, Falmouth Public Library, 5 Lunt Road, open house 2-4 p.m. and 6-7 p.m., public hearing 7-9 p.m.

To view the full plan, visit the U.S. Fish and Wildlife Service Web site at http://www.northeast.fws.gov/planning.

Written comments may be submitted through July 1, to Nancy McGarigal, Planning Team Leader, U.S. Fish and Wildlife Service, 300 Westgate Center Drive, Hadley, Mass. 01035, or by e-mail to northeastplanning@fws.gov.