Recent news reports of unsafe drinking water in the Great Lakes area has drawn national attention to toxic algal blooms. In Kentucky, cyanobacteria, also known as blue-green algae, recently were found in Green River Lake, Taylorsville Lake, Barren River Lake, Nolin Reservoir, and Rough River Lake at levels that prompted a recreational advisory.

Algal blooms are accumulated populations of algae in freshwater and marine water environments. They can reduce water quality, causing animals to drink less water than they need to get them through the hot, dry summer. Of the more than 2,000 species of blue-green algae identified, at least 80 are known to produce cyanotoxins (poisons) that can seriously affect animal and human health.

“Although algal blooms can occur at any time of the year, they happen most often in the warmer months of June through September,” said Michelle Arnold, DVM, ruminant veterinarian for the University of Kentucky (UK) College of Agriculture, Food, and Environment. “In freshwater the majority of harmful algal blooms are caused by cyanobacteria.”

Blue-green algae naturally exist in wet places. They thrive in warm, stagnant, nutrient-rich water and are found often in ponds, lakes, and slow moving rivers