Officials will soon start installing boulders to block illegal off-roaders at Wawamalu Beach, part of the effort to protect the area’s critical marine habitat and the endangered monk seals that sometimes haul up there.

East Honolulu community groups have been pushing for such barriers for about a decade, but jurisdictional issues between the state and city previously stymied progress, according to Hawaii Kai Neighborhood Board member Kim Hollandsworth.

On Thursday, city and state officials will join with Oahu’s Surfrider Foundation and Sierra Club chapters to announce a plan to place the boulders and other barriers on either side of Wawamalu. The goal is to block off-road vehicles from the sand while maintaining access for swimmers, surfers, fishers and other beachgoers. Parking will still be available next to the beach.

At least some of those boulders are already on site. They could be moved into place as early as Thursday, officials with the city’s Parks and Recreation Department said.

The beach is part of the Kaiwi coastline in east Oahu. Footage provided by the Surfrider Foundation shows how the illegal off-roading at Wawamalu disrupts monk seals resting on the sand nearby.

The seals, which are protected under the Endangered Species Act, need about 50 feet of space to get sufficient rest during pup season, officials say. Nonetheless, off-road vehicles sometimes come in close contact with the animals at Wawamalu.

Wawamalu contains critical habitat for other native marine wildlife. It once served as a Native Hawaiian fishing and farming village, according to the Parks and Recreation Department. Efforts to restore the vegetation and sand dunes will continue in restricted areas there, while the beach remains open to the public, a department release says.

“The community plans to malama (care for) this area and the stones will provide an unambiguous signal that the beach and coastal dunes are treasured for the enjoyment of all people and wildlife,” Mike Foley, a volunteer beach protection coordinator for the Surfrider Foundation, said in a statement. “We do not want to risk losing public access, which may happen if an endangered animal were harmed by a vehicle on the beach.”