Monitor skipper Henri Gignous launched the 18-foot Lund boat into the fog and glanced down at his GPS while weaving through lobster buoys, specks of color in a gray world. Ahead were the seven islands our group had been assigned to clean. Gignous stood at the stern, watching for rocks over the heads of his crew: Executive Director of the Maine Island Trail Association Doug Welch, MITA member Wesley Norton and me.

Our metal craft, one of the four boats navigating through the archipelago off Stonington on Oct. 1, shuttled volunteers to pluck trash from the 20 islands of the Maine Island Trail Network in that region. Fourteen people — sailors, kayakers, conservationists and power boaters — were on a mission to cleanse the granite islands of flotsam and jetsam.

“The thing we all have in common is that we come together to take care of the islands,” said MITA Development Officer and Stewardship Manager Peter Kenlan, in charge of the fall island cleanups. “In my opinion, this is how conservation is done, period, by people — people who care about these places.”

The hull of the boat vibrated as we skipped over the small waves, and rain began to fall. Loons warbled and ducks mingled with gulls on rocks and sandbars. Our first island — one of the many “Sheep” islands — emerged and took shape long before our bow reached its shores.

We stuffed trash bags into our PFDs and jumped ashore Sheep Island to search for the usual soda bottles and Styrofoam debris wedged into its pink-tinged granite ledges. Around the campsite, spruce trees were slowly dying in unison, and light green lichen hung from nearly every branch.

“The basic premise of MITA is that the people who go out and use these islands will be interested in taking care of them,” said Welch. “Then the next people who go to them will feel as if they are the first one to step foot on that wild, beautiful spot.”

This Sheep Island is one of the many privately owned islands that have been added to the Maine Island Trail since its inception in 1987 with 40 state-owned islands. A year later, Dave Getchell Sr., founded MITA to care for the trail.

Over the years, a number of private islands have been offered up to the trail system to be accessible to MITA members, which now number near 4,000. Today, the 375-mile trail includes more than 150 islands and mainland sites, of which half are privately owned, and serves as a model for water trails springing up across the continent.

Since Sheep Island is privately owned, it would typically remain unnamed for the owner’s privacy, save for the fact that there are many “Sheep” islands in the region because, at one time, they were used to house flocks of sheep.

On Sheep Island and the other six islands we visited, most of the trash rested near the high tide line, having been washed up from the ocean. Bleach bottles, Styrofoam boat insulation and lobster buoys constituted the bulk of the debris — materials commonly used by fishermen, pointed out Bill Baker, owner of Old Quarry Ocean Adventures, a campground and recreation center that partners with MITA for the cleanup.

“They’re polluting their own stomping ground,” Baker said. “They need to learn to care.”

To improve treatment of the islands, MITA distributes educational brochures and organizes “Leave No Trace” seminars and informational booths at boating shows.

Island users seem to be heeding their message. For the most part, campsites are trash-free, said Welch, though one type of inland trash always seems to pop up — the “white rose,” a wad of toilet paper that may or may not contain a “man-made” surprise. The sight of them always causes cleanup volunteers to pause.

But the not-so-fragrant flower is nothing compared to the porcelain toilet that Gignous stumbled upon on our second Sheep Island. It broke to pieces when he lifted it from the forest floor, and it took three of us to haul it to the boat. Gignous, a monitor skipper for MITA since its inception, said though they’ve found some strange debris, it was his first discarded toilet.

After washing our hands off in the ocean, we passed around a bag of homemade cookies, found seats amid the growing pile of trash, and motored off to the next island in high spirits.

“It seemed like a fun thing to do and a good way to get out on the water for a day,” said Norton, a Peaks Island native who grew up sailing and kayaking and decided to join MITA this year.

Each island on the trail has a small logbook for visitors. During the fall island cleanup, these books are collected and taken to MITA headquarters in Portland to be entered into a database to gain some idea of recreational use of the islands, though only 60 percent of the people who visit the islands sign into the log, according to a recent MITA survey.

As we cruised away from Shivers Island, a state-owned island new to the trail this year, Welch popped open the Tupperware containing the log, curious to see if many had visited the small island. Half the book was filled with names, including a couple from Santa Cruz, Calif., who had rode their bikes down from Quebec and somehow ended up exploring the small island.

Our last stop was Hells Half Acre, which was surprisingly pristine, and then we were headed back to Stonington. By the time our Lund was tied to the dock at 3 p.m. we had trash bags filled with debris, mostly bottles, our porcelain prize and an enormous lost antenna lashed to the side of our boat. All 14 volunteers lugged the trash to Baker’s pickup truck. He would bring it all to the dump, where it belonged.

MITA maintains a partnership with the Maine Bureau of Parks and Lands. Currently, 17 conservation organizations and nonprofits who share MITA’s values have included their properties in the trail system. For information, visit Become a MITA member to gain access to the entire trail and receive a guidebook.

Aislinn Sarnacki

Aislinn Sarnacki is a Maine outdoors writer and the author of three Maine hiking guidebooks including “Family Friendly Hikes in Maine.” Find her on Twitter and Facebook @1minhikegirl. You can also...