SOUTH FREEPORT (AP) – Every day during the summer, lobstermen berth their boats, buy bait and fuel, and sell their catch at Harraseeket Lobster Co. as tourists enjoying lobster rolls and fried clams watch the goings-on at the dockside takeout restaurant.

How long this quintessentially Maine scene can continue is an open question.

Because of fast-rising property values and taxes and mounting development pressures along Maine’s rugged coast, many fishermen fear that working piers such as this will be torn down to make way for expensive homes, yacht-filled marinas or fancy restaurants.

On Tuesday, Mainers will vote on a constitutional amendment to offer a tax break to preserve fishing docks.

The measure would allow waterfront land used for commercial fishing to be assessed at its current use rather than its most profitable potential use. A similar ballot measure was rejected by less than 1 percentage point five years ago.

The aim is to preserve the Maine fishing industry, which supporters say provides nearly 40,000 jobs and generates $750 million in annual revenue. The state already gives tax breaks to farmers and foresters.

Fishing is also a big contributor to tourism, with visitors coming to eat lobster and seafood and see fishermen at work, said Brendon Alterio, manager at Harraseeket Lobster, where property taxes have nearly doubled in the past five years. Without some kind of break, Harraseeket in time could be squeezed out, he said.

“If we were to lose this, the fishermen would be lost, too,” he said.

Critics say that the amendment will merely shift taxes, and that every dollar saved by waterfront property owners will have to be made up with higher taxes on everybody else. Nobody has estimated the fiscal implications to towns, the state or taxpayers.

But others say a Maine tradition is in jeopardy and needs relief from taxes that have been escalating as waterfront values have soared in recent years, in large part because of an influx of Bostonians, New Yorkers and others who are buying themselves oceanfront homes.

Exactly how much working waterfront has been lost to development is unclear. But the nonprofit Island Institute said that only 25 miles of Maine’s coast can be classified as working waterfront, and that only six miles support commercial fishing.

“Once it’s lost, it’s lost forever,” said state Sen. Dennis Damon, who grew up in a fishing family. “When was the last time you saw a mansion torn down and a lobster wharf built in its place? It doesn’t work that way.”