PORTLAND – A Casco Bay mussel farmer’s plan to expand to a location near Hope Island faces opposition from Chebeague Island lobstermen, who fear they’ll be forced out of traditional waters where they set their traps.

Tollef Olson already has mussel rafts on the west side of Bangs Island and the east side of Clapboard Island, both near Chebeague. His latest proposal calls for a 10-year lease on two acres of ocean bottom on the east side of Hope Island.

“Every man on this island is opposed to that lease as far as I know,” said Ernie Burgess, a Chebeague lobsterman. “We are not going to move over. This ain’t going to happen.”

There are about a half-dozen mussel aquaculture operations in Maine, and Olson’s Casco Bay operations are the farthest south. The mussels, which are harvested year round, grow on ropes under each raft and feed on plankton floating in the water.

Olson’s mussels are known as “Bangs Island” mussels and are sold in restaurants in the Portland area and around the nation.

Thanks to Olson’s process, his farm-raised mussels are better than those harvested in the wild, said Nick Alfiero of Harbor Fish Market.

“I can’t imagine any negatives,” he said, adding, “These rafts don’t take up much space. They are the size of a living room basically.”

If Olson wins a lease from the state, he plans to install three rafts, each about 1,600 square feet and each with about 450 lines underneath. He thinks each raft could produce as much as 40,000 to 50,000 pounds of mussels each year.

The Maine Department of Marine Resources will hold a public hearing on Chebeague Island on Dec. 1, and the island’s fishermen plan to voice their opposition.

The waters around Chebeague are already overcrowded with lobster traps, so every acre makes a difference, Burgess said. There are 38 licensed lobster boats on Chebeague Island, and all place traps in the proposed lease area at some point in the year, said Burgess.

“It really is a prime area for lobstering,” said James Ross, 77. “It has always been a traditional place where we have fished.”