Residents are urged to steer clear of the waters of Fort Pond in Montauk and Lake Ronkonkoma because of the confirmed presence of blue-green algae, Suffolk County health officials said Friday.
The algae also persists in an unnamed pond at the corner of Silvermere Road and Shore Drive in Greenport, officials said.
That means no swimming or wading in the water, and keeping children and pets away, officials said.
Any water looking “scummy or discolored should be avoided,” health officials said. If contact does occur, rinse off with clean water and see a doctor for symptoms that can include nausea, vomiting or diarrhea; skin, eye or throat irritation; and allergic reactions or breathing difficulties, the health department said.
Blue-green algae, also known as cyanobacteria, is naturally present in low numbers, but can increase, forming blooms of green, blue-green, yellow, brown or red, as well as floating scum, the county health department said in a release.