The Maine Department of Marine Resources has reopened about 500 acres of clam flats in Harpswell for year-round harvesting, thanks to improvements in water quality.

The areas include Gun Point and Long Point, Gurnet Strait to Laurel Cove, and Long Reach on Great Island; as well as Beal’s Cove, Long Cove and Reed Cove on Orr’s Island. The state reopened those flats Oct. 13, according to Harpswell Harbor Master and Marine Resources Administrator Paul Plummer.

The action stems from a review of closures by the Harpswell Marine Resources Committee, according to Plummer. After the review, Plummer asked the Department of Marine Resources to take another look at several areas subject to restrictions because of poor water quality.

Most of the areas were subject to seasonal closures through the height of summer, when clam prices peak. Gun Point had a year-round prohibition on harvesting because of overboard discharges in the area, according to a report by a DMR scientist.

An overboard discharge releases treated wastewater from a business or home into the ocean. Maine no longer licenses new overboard discharges, and the overboard discharges in the Gun Point area have been removed in recent years.

The flats on the New Meadows River from Gurnet Strait to Laurel Cove had been subject to seasonal closures since 2019. Plummer said the other areas were restricted before he started working for Harpswell in 2017.

After conducting shoreline surveys this summer and reviewing the results of water testing, DMR agreed to reopen the flats.

DMR needs 36 days of water samples to reclassify an area, according to Plummer. Plummer and the town’s marine patrol deputies take the samples for most of Harpswell. DMR handles the area from Cundy’s Harbor to Gurnet Strait.

Plummer does not know exactly why water quality has improved, but believes awareness is growing that factors on land — like fertilizer use and inadequate septic systems — affect the health of the ocean.

The availability of the New Meadows flats will make the biggest difference for harvesters, because of their productivity and the size of the area, according to Plummer.

The town is working with a consulting firm, FB Environmental, to identify sources of pollution in other areas, including Morgan Cove and Spruce Cove, off-limits year-round; and Doughty Cove, closed from June through October. The town hopes to address the problems in those areas and work with the state to reopen them.

Harpswell has 55 commercial shellfish harvesters. In 2021, the value of the hard-shell and soft-shell clam harvests topped $1.26 million.