Health and water quality officials were caught off-guard last summer when they were suddenly confronted with an outbreak of toxic blue-green algae in the Russian River that presented safety concerns for swimmers and their pets. Authorities rushed to post warnings at beaches up and down the river, affecting outdoor recreation throughout the watershed.
This year, many experts are hopeful that a wet winter and cooler water temperatures will eliminate such concerns for summertime visitors.
But just in case, several local agencies have developed a coordinated plan to monitor conditions in the Russian River, as well as specific guidelines for how to respond should a harmful algae outbreak occur.
“We’re proactive this year,” said Sonoma County Health Officer Karen Milman.
The effort includes continuous tracking of water temperature, oxygen levels, pH, river flows and other data so that scientists know when conditions favorable to blue-green algae blooms exist. That discovery would trigger the start of expensive testing of water at public beaches and expand other measures needed to detect trouble.
“There’s going to be lots more eyes looking at the conditions,” said Matt St. John, executive officer of the North Coast Regional Water Quality Control Board. “We have procedures in place to take different response actions based on what we’re observing and measuring in the river.”
While conditions could change, there’s no current indication that blue-green algae will prove a problem this year, given higher river flows and cooler water temperatures than existed last year at this time.
The winter rainfall that swelled waterways, scouring them out with high flows, also could have changed riverbed habitat sufficiently to prevent pervasive blooms, water quality board staffers said.
River lovers should feel comfortable about enjoying their outings, though health officials said it’s always wise to follow good safety habits, such as not swallowing or drinking river water, washing off after swims — including pets — and keeping children and dogs away from algal mats.
Blue-green algae — also called “cyanobacteria” — occur in many water systems, typically where still, warm, shallow, high-nutrient conditions prevail. Some types produce harmful substances such as Anatoxin-a, a neurotoxin blamed last year for the deaths of two dogs on the Russian River and another dog that ingested the toxin while swimming in the Eel River in Mendocino County.
Such outbreaks are likely not new to the Russian River watershed, water quality officials said. But in favorable conditions they can reproduce quickly and accumulate, creating a significant challenge.
Last summer, after historic drought conditions led to a rise in blue-green algae blooms, prompting warnings at a half dozen water bodies around the greater Bay Area, both state and local agencies have focused new attention on the subject. One factor they are taking into consideration is the role of climate change in leading to more frequent, persistent events.
Until now, the bacteria have not been the subject of routine sampling and testing in Sonoma County or in most counties, Milman said.
Last year’s outbreak was the first time blue-green algae in the Russian River really stood out as an issue, according to Katharine Carter, with the North Coast Regional Water Quality Control Board.
Concerns first surfaced with reports in August that several dogs had become ill after swimming near Monte Rio Beach, said Clayton Creager, an environmental program manager with the North Coast water board. Blue-green algae were found in the area, and monitoring was begun for the harmful toxin sometimes linked to the blooms.