The state Department of Water Resources urged the public Tuesday to avoid contact with water at Silverwood Lake in San Bernardino County until further notice due to toxic blue-green algae.
A warning advisory is in effect for the entire lake, and all swimming beaches are closed. Boating is allowed, but swimming and other water-contact recreation and sporting activities, including jet or water skiing, are not considered safe due to potential adverse health effects, the department said.
Do not drink, cook or wash dishes with untreated surface water from the area under any circumstances, the department warned. Common water purification techniques such as camping filters, tablets and boiling do not remove the toxins. And, do not eat shellfish from this water.
Blue-green algae is natural and the rapid growth that becomes a bloom typically occurs when water is warm, still and certain nutrients are present, according to the department.
Advisories are based on the potential health risks from algae. Exposure to toxic blue-green algae, also known as cyanobacteria, can cause eye irritation, allergic skin rash, mouth ulcers, vomiting, diarrhea and cold- and flu-like symptoms.
Pets and livestock should also be kept away from the water, as they can be especially susceptible because they tend to drink while in the water and lick their fur afterwards.
Bloom conditions can change rapidly, and wind and waves may move or concentrate the bloom into different regions of the reservoir, the department said. The bloom can accumulate into mats, scum, or form foam at the surface and along the shoreline, and range in color from blue, green, white or brown.
Meanwhile, lab results also showed an increase in toxin levels at San Luis Reservoir in Merced County, reaching danger level, the department said.
Seek immediate medical treatment if you think that you, a family member, friend, pet, or livestock might have been poisoned by blue-green algae toxins. Also make sure to contact the local county public health department.