The cyanobacteria bloom advisory in Chilmark Pond has been extended to include the Abel’s Hill and Doctors Creek areas in addition to the middle of the pond, which has had an advisory since June 5.

The blooms can be harmful to people and pets.

The advisory, made by the Great Pond Foundation and the Island’s boards of health, warns against swimming, kayaking, fishing, eating harvest from the pond and drinking the water. It also warns against allowing pets in the pond.

Emily Reddington, executive director of the Great Pond Foundation, said that animals are at a higher risk because they are more likely to ingest the water than a human swimmer.

“For humans you should contact your physician immediately and also the board of health in your town,” Ms. Reddington said. “For animals, you should do the same with your veterinarian and the local board of health and maybe the animal control officer. But really, physicians and veterinarians are your first line of defense.”

She urged Islanders to report algal blooms to the boards of health and the Great Pond Foundation.