Thursday, September 25, 2014


A report on the widespread presence of blue-green algae (BGA) blooms in Prospect Park Lake was confirmed through water sampling on September 15th, and no change has been reported through today. The blooms that produce BGA can be toxic.

When blooms are widespread, they affect the entire lake, a large portion of the lake, or most to all of the shoreline.

While confirmation of the presence of blooms doesn't mean that harmful toxins are in the lake, blue-green algae can still be irritants to some people. Stay out of the lake, and keep children and pets away from it.

Blooms have been reported in the lake other times this year. On June 25th and August 12th, they were reported to have ended. When multiple reports are made about a site, it could mean that bloom conditions change frequently.

BGA 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.
The possible effects of BGA on living creatures are

  • skin and eye irritation from external contact,
  • asthma-like symptoms from inhaling water or spray, or
  • gastro-intestinal and neurological symptoms if you've ingested it.

Read more on the Department of Environmental Control website. See photos of toxic blue-green algae blooms. 

If you believe you have been exposed to a bloom and are experiencing symptoms, seek immediate medical attention and contact the New York City Department of Health.

If people or pets are exposed to a bloom, rinse with clean water.