PORTLAND – When Jim Dugan started kayaking to Maine’s coastal islands in 1991, he saw few signs of other visitors.

These days, on the more popular islands, he sees campfires, sprawling camp sites, trampled vegetation, erosion and human waste next to walking trails.

“I don’t go on overnights in July and August because that’s when everybody is there,” he said.

Use of Maine’s 46 public islands has expanded to the point where some visitors may soon face fees and restrictions on access.

The ideas are part of a 10-year plan now under development by the association that manages the islands.

In the short term, any fees and limits would affect only commercial outfitters leading multiday kayaking trips. The fees would guarantee campsites for the groups.

But the system would mark the first step toward restricted access to the islands. And the creation of a management plan represents a philosophical shift from treating the islands as wilderness areas to managing them as parks.

“The problems are only going to get worse as more and more people use these islands,” said Rachel Nixon of the Maine Island Trail Association, the group designated by the Maine Bureau of Parks and Lands to manage the islands.

The Portland-based association is creating its first management plan because of growing use and damage to fragile island resources. The group will seek state approval of its plan in the summer of 2003.

The 10-year plan does not deal with the more than 70 private island and mainland sites overseen by the trail association. Their resources are stable and not currently threatened by overuse, Nixon said.

The 46 public islands stretch along much of the coast and include well-known destinations such as Jewell Island in Casco Bay and Hell’s Half Acre off Jonesport.

Power boaters and sailors who have long used the islands now share them with passengers on schooner excursions and an influx of sea kayakers.

A network of commercial kayak outfitters and guides brings groups to the islands to camp overnight. Guided groups could be subject to fees because they generate income from the islands, Nixon said.

She said it’s clear that greater use is threatening some of the islands’ fragile resources. Islands have thin layers of topsoil, so when someone disturbs soil or vegetation, it can have a lasting impact. Campfires and disposal of human waste can cause additional problems.

It’s not clear how outfitters will react to the potential restrictions. They have not had a chance to discuss a fee and permit system, and there are still no firm proposals on costs and conditions.

But outfitters do have an appreciation of the threats facing the islands.

“I’m a commercial outfitter, but first I’m a lover of our natural resources,” said Tom Berg, owner of Maine Island Kayak Co. on Peaks Island. “I think it’ll have to go to some sort of reservation or permitting process.”

Dugan, a Rockport resident who kayaks on his own and as a guide, said fees and permits could help allocate use of the islands.

“We sort of have to get away from the idea that this is wilderness,” he said.