Lakes-Mead-Mohave-Algae-Plumes-Prompt-Swimming-AdvisoryNational Park Service officials are advising visitors to avoid swimming in areas where mats of algae are visible in Lake Mead and Lake Mohave.

Blue-green algae have been observed on both lakes. Samples have been collected and are being analyzed by the National Park Service and Southern Nevada Water Authority. Low levels of microcystin concentrations have been discovered.

As a matter of precaution, recreational visitors should follow a few safety tips where algae are present:

  • Ensure animals do not drink or go into the water;
  • avoid swimming, waterskiing or jetskiing in the area;
  •  do not touch residue on the shoreline;
  •  do not fill water tanks with water in the area;
  • if contact occurs, rinse thoroughly with clean water;
  •  and as always, don’t drink untreated water straight from the lake.

Health issues related to microcystin may range from rashes and skin irritations to gastrointestinal illness.

According to the SNWA, microcystin does not pose a threat to Southern Nevada’s drinking water. The SNWA’s water treatment plants utilize both ozone and chlorine, which represent the two most effective treatment processes for destroying microcystin and will prevent it from entering the drinking water system.

While the likelihood of people being affected by contact with blue-green algae is very low, federal, state, and local agencies in Southern Nevada will continue to proactively monitor algae composition levels in lakes Mead and Mohave.

Most areas of the lakes do not have accumulations of algae. Visitors and their pets can continue to enjoy the water where algae are not present.