Residents should not swim or wade in Fresh Pond on Shelter Island because the water contains a new cyanobacteria bloom, also known as blue-green algae, the Suffolk County Department of Health Services advised Wednesday.
The New York State Department of Environmental Conservation confirmed the presence of blue-green algae in the water, the county agency said.
The blooms also are still present in Agawam Lake and Mill Pond in Southampton, Roth Pond at Stony Brook University, Laurel Lake in Laurel and Maratooka Lake in Mattituck, the agency said.
Pets should be kept away from those bodies of water, too.
Blue-green algae are naturally present in lakes and streams. But in certain conditions, such as warm, shallow, still waters with nutrient-rich surfaces that receive a lot of sunlight, they can become abundant and form blooms that discolor the water or produce scum on its surface, according to the New York State Department of Health.
Some blue-green algae produce toxins, and high levels can cause diarrhea, nausea, vomiting and breathing difficulties, as well as skin, eye and throat irritation, according to the health department.
Contact with water that is scummy or discolored should be avoided. Anyone who comes in contact with it should rinse with clean water immediately.
To report a suspected blue-green algae bloom in water with a bathing beach permitted by Suffolk County, contact the county’s Department of Health Services' Office of Ecology at 631-852-5760 between 8:30 a.m. and 4:30 p.m. or by email at firstname.lastname@example.org anytime.
A full list of affected bodies of water in New York state is on the DEC’s Harmful Algal Bloom Notification Page: dec.ny.gov/chemical/83310.html.