Areas of Lake Zoar are currently green with visible blooms of cyanobacteria, known as blue-green algae. Some of these cells produce toxins (Microcystin) that can make people and animals sick. Not all of the cells produce the toxin. Presence of the bloom does not indicate toxicity, and testing is required to determine if the water is safe.
The U.S. EPA and CT DPH currently advise a Microcystin threshold of 8.0 parts per billion (ppb; µg/L) for recreational waters. Last week, water samples for Eichler’s Cove tested well below that level, at 0.902ppb, and all previous samples were lower. This week’s results will be posted as soon as they are received from the WCSU Cyanobacteria Monitoring Program.
Please avoid contact with blue-green blooms and pay special consideration to children and dogs.
The CT DEEP reports that “Cyanobacteria occur naturally in every lake and pond in Connecticut. Cyanobacteria can become problematic when increased nutrients are available, water temperatures are warm, and the cyanobacteria are able to rapidly multiply and release toxins into the water […] People who recreate in waters when a blue-green algae bloom is present may be exposed to toxins by ingesting water, dermal contact, or inhalation of water droplets. Potential health effects to such exposure could include:
- Irritation of the skin, nose, eyes and respiratory tract.
- Gastrointestinal upset such as vomiting or diarrhea upon ingestion.
- Liver or nervous system effects, if relatively large amounts of the algae are ingested.
Dogs are especially at risk from exposure to blue-green algae blooms. They can be exposed to the toxins in a similar manner as people. However, dogs may also drink from the tainted water and be exposed when they groom themselves after leaving the water.
Fish living in waters affected by a blue-green algae bloom may accumulate algal toxins in their muscle tissue and internal organs. The health risk posed by consumption of such fish is uncertain. Toxin levels are usually higher in internal organs than in the muscle tissue. General precautionary advice to anglers to reduce exposure includes:
- Avoid fishing in areas with visible algae blooms due to potential incidental contact with the water.
- Eat fish from water bodies with blue-green algae blooms in moderation (1-2 meals or less per week.)
- Remove skin and internal organs before cooking. Wash fillets before cooking or freezing.”