Blue Green Algae (Cyanobacteria)

Blue-green algae blooms have raised concerns in Connecticut and across the nation because these organisms can produce a wide array of neurotoxins, liver toxins, cell toxins and skin irritants.  In still and  warm summer waters, populations of blue green algae may increase to the extent that a normally clear surface can become thick and murky.  This overgrowth is called a “bloom”.  Blooms are considered harmful due to the potential to cause health effects in people and pets over-exposed to these organisms.

Facts about Cyanobacteria and Cyanobacterial Harmful Algal Blooms (CDC)

For more information, view the following resources:

• CT-DPH Fact Sheet: Blue-Green Algae Blooms in Connecticut Lakes and Pond
• Guidance to Local Health Departments for Blue-Green Algae Blooms in Recreational Fresh Waters-June 2019
• EPA Cyanobacterial Harmful Algal Blooms (CyanoHABs)
• Massachusetts DPH Protect Your Pets From HABs
• New York State DOH Information Bulletin
• Pipeline-Waste Water Issues Explained to the Public

Contact Information:

• To Report a Bloom:  If you believe that you have observed an algae bloom contact your Local Public Health Department or the CT Department of Energy and Environmental Protection (860 424-3020), or send an email to deep.algalblooms@ct.gov
• For Health Concerns: If you have questions about health effects or exposure concerns, contact the DPH Environmental Health Section's Public Beach Program (860 509-7758).

Circular Letters:

• 2013-37  Circular Letter to LHD for Blue-Green Algae Blooms in Recreational Freshwaters
• 2012-56 Blue-Green Algae (Cyanobacteria) Blooms in Freshwater Lakes and Ponds