Authorities are conducting tests after reports of toxic blue-green algae blooms appeared on two Lake Tahoe beaches.
The investigation began shortly after a woman posted a video on TikTok claiming her dog died of algae poisoning after swimming at El Dorado Beach and Nevada Beach, two popular spots on the South Coast.
On Monday, warning signs at El Dorado Beach in South Lake Tahoe warned visitors about the harmful blue-green algae, also known as cyanobacteria, that may be present in the water. They urged swimmers to stay away from the algae and not to drink water from that part of the lake or eat shellfish. Authorities also advised children and animals to stay away from algae scum.
“Tahoe is really clean and clear and fun to recreate in. But pay attention to signs, go online. Be careful,” said Jeff Cowen, spokesman for the Tahoe Regional Planning Agency. “In general, there are no health concerns in the Lake Tahoe Basin … but watch out for children and pets. Smaller bodies cannot withstand certain blue-green algae inputs.”
So far, water quality officers have collected samples and conducted visual inspections for blue-green algae at El Dorado Beach. The results of the samples are expected to be released by Friday, according to the planning authority.
The water at Nevada Beach, which is near Zephyr Cove on the Nevada side of the lake, has also been tested for blue-green algae by the Nevada Division of Environmental Protection. Results are also expected Friday.
How to identify harmful blue-green algae
Blue-green algae are a natural part of Lake Tahoe’s ecosystem, but they can become harmful when they bloom in high enough concentrations. If consumed, the bacteria can cause rashes, headaches, flu symptoms and sinus infections.
Here are some signs that cyanobacteria are present in a body of water:
▪ Small blue-green, white or brown particles float in the water;
▪ The water is covered with streaks of algae that look like spilled paint.
▪ Foam or spray forms on the surface of the water or along the shoreline.
▪ The water smells fishy or like gasoline.
Harmful algal blooms are more common in Northern California because the region suffers from longer droughts and drier, hotter summers. Shallow water levels and warm weather encourage the rapid growth of the dangerous algae.
Visitors to other Lake Tahoe beaches have already been warned to be cautious during their recreational activities. On June 15, the U.S. Forest Service posted on X that slow-moving waters at Kiva Beach and Taylor Creek could lead to toxic algae growth and disease.
“Before allowing pets to drink/swim in affected waters, educate yourself on water quality and associated risks,” the post warned.
