LAMOINE (AP) – Around the south end of Mount Desert Island, 6,300 acres of fishing grounds have been reopened.

Some areas had been closed to shellfish harvesting for more than two decades.

Officials said red tide warnings curbed the impact of the re-openings during the summer.

The Maine Department of Marine Resources is working statewide to identify discharge sources and reopen as much water to fishing as possible, according to department water quality specialist John Fendl.

Water quality experts walked the shorelines of Mount Desert to find sewage discharges and get them cleaned up.

Waters off Southwest Harbor and Mount Desert extending to the Cranberry Isles were closed in the mid-1980s due to pollution concerns, Fendl said.

Most of the reopened territory stretches from around King’s Point in Southwest Harbor to Ingraham Point in Mount Desert and south to the Cranberry Isles.

Fendl said some relatively small zones around Great and Little Cranberry islands are still off-limits for fishermen.

“Nothing’s perfect, but we do a good job. We probably get 95 percent of the pollution sources out there,” he said.

Acadia National Park installed a new sewage treatment system at Seawall Campground in Southwest Harbor this year, bringing an end to a decades-long practice of discharging treated wastewater into the ocean.

The park announced this week that 44 acres of harvestable shellfish area in the Seawall areas had been returned to open fishing because of the campground upgrade.

Blue Hill shellfish dealer Rob Bauer suggested the state could better use its money in other places.

“It’s a lot of hoopla, and a lot of acres, but not a lot of economic impact,” he said, adding that real estate agents on Mount Desert would probably benefit more from the discharge cleanups than the fishing industry.