The state Department of Water Resources is asking the public to avoid Pyramid Lake until further notice because harmful blue-green algae has infiltrated its water.
Beaches will be closed and individuals should avoid eating fish from the lake, the department said.
Bloom conditions can quickly change because wind and wave patterns move algae into different areas within the lake. Algae can concentrate into mats or foam on the surface and along the shoreline. Colors range from blue, green, white or brown, according to a department news release.
Health risks from exposure to the algae's toxins include eye irritation, allergic skin reactions, mouth ulcers, vomiting, cold- and flu-like symptoms and diarrhea. Pets are also in danger and should be kept away from the water, the department stated. It advised people to get medical treatment immediately if they believe contamination may have occurred.