The Washington State Department of Health has upgraded its water quality rating for a stretch of tidelands near Hoodsport in southern Hood Canal, certifying that clams and oysters there are now safe to eat.

Those beaches have been closed to harvesting for 45 years. They are opening after four years of cleanup efforts, according to the Puget Sound Institute at University of Washington Tacoma.

The stretch of tideland is 66 acres and includes both public and private properties. Two public beaches could be opened for recreational harvesting next spring, depending on shellfish quantities and approval from the port, according to the institute.

The Washington Department of Fish and Wildlife credited the Skokomish Tribe for advocating for the project and helping with water-quality sampling, Mason County Public Health for identifying the sources of pollution and the Hood Canal Coordinating Council for securing funding for the work.

Tribes are entitled to half the naturally produced shellfish found in their traditional areas, according to federal law. The Skokomish tribe launched its first oyster harvest in April to estimate the quantities of shellfish, according to the institute.

Pollution largely came from eight failing septic systems, including five commercial systems, and public restrooms managed by the Port of Hoodsport, which have been shut down.