State officials are warning recreational water users and dog owners to avoid parts of Isabella Lake where tests indicate there has been a potentially harmful algal bloom.
Toxins capable of sickening people and animals were detected near the shore at all 13 areas where samples were taken in early August, the State Water Resources Control Board announced Wednesday.
Danger signs have been posted at the eastern end of the lake at Stine Cove and Kissack Bay. Advisories against swimming were posted at most of the other sampling locations, while a "caution" warning was placed at the southwestern Auxiliary Dam Boat Launch where the threat is deemed to be lowest.
The algal bloom is caused by cyanobacteria, which is classified as a neurotoxin that can cause rashes or even death. It looks like bright or dark green material near the surface of the water. It sometimes appears to be spilled paint.
Isabella Lake suffered algal blooms as recently as two years ago. Such phenomena have become more common around the state in recent years.
Kern County public-health officials said they are monitoring the situation, adding they have received no reports of illness associated with the bloom. They have posted an interactive map pinpointing the potentially harmful areas at https://kernpublichealth.com/cyanobacteria-blooms-blue-green-algae/.