Boaters and swimmers are urged to avoid contact with the water at Pyramid Lake in Los Angeles County because it contains toxic blue-green algae.
Officials issued the warnings after tests Thursday confirmed the harmful blooms. The algae can pose health risks, particularly to children and pets, according to the California Department of Water Resources.
Officials said the algae can appear blue-green or white, or can look like brown foam. It can float on the water's surface and accumulate on the shoreline and boat ramp, officials said.
Exposure to it can cause eye irritation, allergic skin rash, mouth ulcers, vomiting, diarrhea, and cold and flu-like symptoms.
Officials issued the following precautions:
- Stay out of the water until further notice.
- Do not touch scum in the water or on shore.
- Do not let pets go into or drink the water, or go near scum on the shoreline.
- Do not drink lake water or use it for cooking. Boiling or filtering will not make the water safe.
- Do not eat fish or shellfish from these waters.