The widespread presence of high toxins in Prospect Park Lake from blue-green algae (BGA) blooms has been confirmed. These toxins can be harmful to people and to animals. Stay out of the lake, and keep children and pets out of it and away from it. Keep dogs away from Dog Beach too.
If people or animals are exposed to a bloom, wash the skin with soap and water or rinse thoroughly with clean water.
When the blooms are widespread, as they are in Prospect Park Lake, they can affect either the entire lake, a large portion of the lake, or most to all of the shoreline.
Blue-green algae is cyanobacteria. A BGA bloom can make water look like pea soup or like green, blue, or red paint. Or, mats of blue or green pond scum can be floating on the water surface or might have accumulated along the shoreline.
Photos of toxic blue-green algae blooms are posted on the New York State Department of Environmental Conservation (DEC) here.
The possible effects of the toxins on living creatures are nausea, vomiting, diarrhea, skin or throat irritation, allergic reactions, or breathing difficulties. The toxins can also affect the liver and nervous systems if a lot of water is swallowed.
Read more about this on the DEC's website.
If you believe you have been exposed to a bloom and are experiencing symptoms, get medical help immediately and contact the New York City Department of Health.