Blue-Green Algae Harmful to People, Pets and Livestock

Water containing high levels of blue-green algae may appear greenish in color and, occasionally, some shades of blue, brown, or white.

(Indianapolis, Ind.) - As the summer weather is here to stay, the Indiana Department of Environmental Management (IDEM) and the Indiana Board of Animal Health (BOAH) are warning Hoosiers about the dangers of blue-green algae.

Blue-green algae blooms typically occur in Indiana from late spring to early fall and may produce toxins that can be harmful to people, pets, and livestock.

According to BOAH, dogs are particularly susceptible to blue-green algae poisoning because the scum can attach to their coats and be swallowed during self-cleaning. More information about protecting pets and livestock from harmful algal blooms can be found on BOAH's blue-green algae website.

Each year, IDEM samples water from state recreation area beaches and state parks for blue-green algae toxins. Water sample results and alerts are posted to IDEM’s Indiana Reservoir and Lake Update website.

The public is encouraged to review this website before heading to the lake or recreational areas.

Water containing high levels of blue-green algae may appear greenish in color and, occasionally, some shades of blue, brown, or white.

Some appear to have a thick, paint-like scum on the surface. Blooms may appear for only a few hours or remain unchanged for weeks, depending on water and wind conditions. Factors that promote significant algal growth, or blooms, include sunlight, warm weather, low turbulence, and nutrient sources such as phosphorus and nitrogen.

Public health officials suggest avoiding contact with waters visibly impacted by algae, and showering or bathing with warm, soapy water after recreating in reservoirs, lakes, rivers, and streams. For more information on blue-green algae, visit algae.in.gov.