The Department of Natural Resources issued an advisory on Lake Monroe, asking people to take extra precautions because while toxin concentrations are below thresholds, they still require attention.
The DNR says that its "yellow advisory" for blue-green algae means people should shower after being in the lake and avoid contact with algae.
Pets shouldn't swim or drink water where algae is present. Dogs are at a higher risk than humans of harm from the water, the DNR said.
Shallow bays with little water movement presents the greatest risk, although blue-green algae isn't limited to those areas.