Toxic blue-green algae in three Suffolk ponds

Toxic blue-green algae has been found in three ponds in Suffolk County, the county health department announced Tuesday.

The three ponds are Mill Pond (also called Duck Pond) in Stony Brook, Donahue’s Pond in Manorville and Poxabogue Pond in Sagaponack.

Mill Pond has tested positive for cyanobacteria several times in the past, according to a spokeswoman from the Suffolk County Department of Health Services.

Blue-green algae, or cyanobacteria, occurs naturally in freshwater (and sometimes in brackish water) but can become a health hazard when it proliferates — and it tends to proliferate in warm temperatures, so it’s becoming more common with global warming. The algae can cause nausea and vomiting as well as irritation to the eyes and throat. Ingesting it is life-threatening to dogs.

The health department spokeswoman said she was not aware of anyone becoming sick from contact with the water in the three ponds.

Stony Brook University researchers, who test bodies of water when they receive reports from the public of a possible bloom, found the cyanobacteria after testing samples from the three ponds.

Though some algae are harmless, it’s advisable to stay out of water that develops a green or blue-green scum on the surface, and to keep dogs out as well. Anyone who inadvertently makes contact with blue-green algae should rinse as soon as possible, experts say, and dogs should be thoroughly bathed.