Towns up and down Maine’s coast have grappled for more than a decade with the changes that come with a growing aquaculture industry.

In the last several years, some have gone further, considering local ordinances meant to restrict state-issued leases for large aquaculture projects in their waters.

It has brought to the forefront tensions between traditional uses of Maine’s coast and the growth of aquaculture, an industry that has grown by about 2 percent annually for the last two decades and brings in more than $85 million in sales each year. It has also highlighted disagreements about which entity — the state or the municipality — has the authority over those uses, creating an ongoing impasse.

In Maine, the state Department of Marine Resources issues leases and licenses for various types of aquaculture projects, including oyster, scallop, mussel and fin fish farms. As part of that process, it accepts public comment and holds public hearings on the applications when residents request them, but makes the final decision on whether to grant a permit.

The department says it’s clear that state law gives it exclusive authority to lease coastal waters outside the intertidal zone, although towns can regulate shellfish harvesting inside that zone.

The agency’s website currently lists 149 active standard and experimental leases and 671 small, short-term limited purpose ones. Department data shows it has issued around 200 new limited purpose approvals yearly between 2017 and 2021, up from less than 50 a decade earlier.

But a statewide organization formed in 2020 believes that communities can control aquaculture projects off their shores and has been visiting towns for several years asking select boards to consider ordinances that restrict what it calls large-scale, industrial aquaculture projects.

Protect Maine’s Fishing Heritage Foundation argues that the state’s home rule laws give towns the right to control their coastal waters. It was among the groups that helped push back against the failed proposal by a Norwegian-backed company to start a large salmon farm in Frenchman Bay. 

It now promises to cover any legal costs towns face if they enact an aquaculture ordinance provided by the foundation. Towns can also adjust that ordinance’s language to make different restrictions around whether leases are allowed, how big they can be and whether they require a local permit.

No towns have yet faced court challenges over their ordinances, and the state this week said it isn’t planning legal action against municipalities.

The towns of Cutler and Penobscot have approved permanent ordinances, while Waldoboro and Winter Harbor passed moratoriums that could be followed by ordinances.

Others have considered them or put in temporary moratoriums, including Damariscotta, Jonesport, Lubec and South Bristol, but stopped short of a vote. Some were concerned about opening themselves up to legal challenges.

Deer Isle voters were set to decide on such an ordinance at their annual town meeting this year, but local officials reversed course last week.

“This was a kind of roll out-roll back situation,” Town Manager Jim Fisher said.

The town’s legal counsel and the Maine Municipal Association warned Deer Isle about pursuing the rules due to conflicts with state policy, according to Fisher. The local marine resources committee later reversed its support. At a public hearing, some residents pushed back, while aquaculture lease holders said the current process is already lengthy. The Select Board unanimously withdrew the proposal.

Local officials might revisit the idea next year, Fisher said. But neighboring Stonington, which decided not to pursue the same ordinance two years ago, is less likely to, he said. The two towns try to keep the same marine resource policies.

It’s a different story in the nearby town of Penobscot, where aquaculture operations on the Bagaduce River, and the state leasing process for them, have long been controversial.

In 2024, voters approved an ordinance restricting leases, but the debate dates back more than 25 years, when residents formed the Bagaduce Watershed Association in 1999 because of their concerns about state aquaculture leases.

In 2023, the midcoast town of Waldoboro pushed for an even stricter version of the foundation’s ordinance, not allowing leases of any size on the Medomak River. Local officials were motivated by concerns that aquaculture would change conditions on the river and reduce soft shell clam populations or otherwise displace the roughly 150 clammers who make their living on the mudflats.

Advocates of aquaculture say it provides economic opportunity for working waterfronts and local communities. The heritage foundation agrees, Executive Director Crystal Canney said, but it only supports projects on a small, local scale.

“Maine is known for its independent working waterfront,” she said. “Large-scale aquaculture replaces that independent fishing model.”

Her foundation is focusing on individual towns because efforts to change state policy have been unsuccessful, she said. The foundation lists further concerns including department oversight of lease sites, potential environmental consequences of farming operations, sites owned by large, corporate operators outside of the country and what it sees as a lack of a long-term plan for Maine’s aquaculture future.

The Department of Marine Resources said it doesn’t plan legal action against any towns that adopt moratoriums or ordinances.

“State law is clear,” spokesperson Jeff Nichols said this week. “Under state law, the Commissioner of the Department of Marine Resources holds exclusive jurisdiction to lease lands in, on and under the coastal waters.”

The department has sent letters to towns saying as much, and said it’s working to expand its communication with towns about the leasing process. Nichols also said the public can give input on potential aquaculture sites. State decisions may require the lease holder to allow fishing onsite, and law says a lease can’t interfere with fishing or other local uses.