A southern stretch of the beach along Holmes Harbor has been closed to shellfish harvesting due to persistent high levels of fecal coliform.

Fecal coliform contamination that exceeds safety standards for harvesting shellfish has been found in drainage discharges and marine waters of the southern portion of Holmes Harbor. Island County, in consultation with the state Department of Health, has closed all beaches of the southern portion of Holmes Harbor, including Freeland Park, to recreational shellfish harvesting.

The closure includes all beaches south of a line extending from the eastern end of Ships Haven Drive east to the western end of Twin Oak Lane.

The source of the contamination isn’t known at this point. The cause could be from a stormwater drainage pipe at Freeland Park, from animals, from failing septic systems or a combination of factors, said Kathleen Parvin, an environmental health specialist with the county health department.

Parvin posted warning signs along the beach and also went door-to-door Monday to warn shore side property owners of the shellfish harvesting closure.

The closure includes clams, oysters, mussels, scallops and any other species of molluscan shellfish. Crab is not included in the closure, but health department officials warn that the “crab butter” should be discarded and only the meat of the crab should be eaten.

The closure will stay in place until water quality improves.