Russian River beach warning signs posted after more blue-green algae found

Sonoma County officials are posting warning signs at 10 Russian River beaches after recent sightings of potentially harmful blue-green algae at Patterson Point in the lower river corridor, and, later, near Healdsburg and Fitch Mountain.

As of Tuesday night, no toxic substances have been confirmed in the river this season, according to Rich Fadness, whose job with the North Coast Regional Water Quality Control Board includes monitoring and testing water for contaminants.

But lab results from samples collected upstream of Healdsburg, around Del Rio Woods, were still pending, and the substance found there is known to produce hazardous toxins, he said.

Technically called cyanobacteria, the blue-green algae collected off Patterson Point, downstream from Monte Rio, wasn’t yet producing toxins but still can, Fadness said.

“We are just now entering the hottest part of the summer, and the flows are the lowest they’ve been since perhaps the drought of 1976,” Fadness said. “Though we do not have reports of cyanobacteria in other portions of the river, we expect that it is growing in other locations, as we’ve seen in years past, and has just not been identified by people recreating in the river.

“By being proactive in this manner, we are hopeful that those folks out enjoying the river will be a bit more diligent in exercising caution in the locations that they swim and play, and keep their children and pets away from areas where the cyanobacteria is growing, he said.

Different types of cyanobacteria can cause kidney or liver failure or produce chemicals that cause neurological illness, often with tremendous speed, in humans and other mammals.

It typically grows on the bottom of the river and eventually comes loose, gets into the stream and accumulates on the banks, Fadness said.

Children and dogs are especially at risk because they are more likely to touch the slimy stuff and ingest it.

Health officials recommend river visitors use “healthy water habits” that include washing after swimming or playing in the water, never drinking or using river water to wash dishes, and paying careful attention to children and pets.

More information is available at Sonoma County Health and Human Services.

You can reach Staff Writer Mary Callahan at 707-521-5249 or mary.callahan@pressdemocrat.com. On Twitter @MaryCallahanB.