Water Quality

Algae in the river
Algae in the Lower Wilderness

NPS Photo

Algal Blooms

Blue-green algae occur naturally in many lakes and rivers and have been found in many parks of the country, including the Ozarks region. Algae are more abundant in summer and may appear as green or yellow streaks or scum on the surface of the water or as green globs floating below the surface.

Nice sunny days, warm water, and increased nutrients are the perfect recipe for algae to grow. Low rainfall increases the opportunity for algae to bloom, and increased lawn and agricultural runoff into waters can create ideal conditions for algae blooms. Some algae growth is important to a healthy ecosystem. Most species of algae are not dangerous.

However, some species of algae are toxic to humans, animals, and the environment. Harmful algae and the water around it can cause allergic reactions and illness in people and pets. Symptoms include eye and skin irritation, coughing, sneezing, itchy throat, watery eyes, rashes, abdominal pain, cramps and diarrhea. If you have a pre-existing condition, such as asthma, these symptoms may be more severe. Contact your doctor or veterinarian if you or your pet have any symptoms or sudden illness.


Algal Blooms and Health Concerns

The Buffalo River and many other area waterbodies have experienced significant algae growth this summer, but no cases of illness directly linked to algae have been confirmed. The Center for Disease Control (CDC) notes that some species of algae are toxic to humans, animals, and the environment. Exposure to cyanotoxins or cyanobacteria from harmful algae can result in serious health problems. Areas with visible algae concentrations should be avoided for primary contact such as swimming. Avoid ingesting the water around these blooms, being especially careful if children are in your group. Dogs are also very susceptible to algae toxins. For more information, go to the CDC’s website at https://www.cdc.gov/habs/general.html.

Arkansas Department of Environmental Quality (ADEQ) has created an app to report nuisance and harmful algae blooms. A person may also submit the form online:

● Nuisance Algae Bloom Complaint Form:

● Harmful Algae Bloom Complaint Form:

The National Park Service (NPS) and US Public Health Service encourage visitors who believe they or their animals have become ill after exposure to algae in the Buffalo River, to report the illness during business hours to the Arkansas Department of Health (ADH) Communicable Disease Nurse at 501-537-8969. After hours, people can call the ADH Emergency Communication Center at 1-800-651-3493. Visitors can also report illnesses to the NPS Epidemiology Branch Chief for the Office of Public Health, at e-mail us.

Tips for Staying Safe

  • Never drink untreated water
  • Keep children out of areas with thick algae
  • Keep your pets from drinking water or swimming in water with algae present
  • Don't let your pets eat dead fish found in algae

Last updated: August 9, 2018

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