Visitors of El Dorado East Regional Park should stay clear of its waterbodies as state and local environmental and public health agencies have discovered harmful algae blooms that could be dangerous if ingested.

Scientists with the Los Angeles Regional Water Quality Control Board confirmed the presence of cyanobacteria harmful algal blooms (cyanoHABs), known as harmful or blue green algae blooms, after they sampled surface water along the shoreline near recreation areas and discovered the blooms earlier this month, according to an April 20 release from the regional water board.

This is the first confirmed cyanoHAB reported for the region this season.

“Field and lab results show that the surface water contains high concentration of cyanobacteria,” the release stated. “Lab testing confirmed the presence of cyanobacteria species capable of producing many cyanobacteria toxins and low levels of the neurotoxin Anatoxin-a was detected.”

Those levels of Anatoxin-a exceeded the caution trigger level recommending caution signs be posted near recreational areas and any area that provides access to the water, officials stated.

Those signs have since been posted by the city’s Department of Parks, Recreation and Marine.

While the concentration of toxin is low and doesn’t pose a threat to people swimming in the water, it could be dangerous if algal material (like scums and mats) are ingested. Children should be kept away from the algal material in the water and on the shore.

Health officials warned that the most high-risk groups are dogs and wildlife who eat the algal material and drink the water.

“Dog, fish and wildlife deaths have occurred in California every year from algal blooms, so keep your pets out of the water and away from algal material accumulated on the shore,” officials stated.

If pets do swim in the water, rinse them off with fresh water to remove any algal material from their fur.

Cyanobacteria toxins can be present even though a bloom is not visible. HABs vary in color and may range from vibrant to dark green, blue-green, yellow, brown, black or red.

For more information, visit the Los Angeles Regional Water Quality Control Board website here. 

Above, left photo taken at South Pond in Area III shows algal bloom, bright green in color. Courtesy of the control board.