Learn how scientists predict the spread of toxic algae blooms
Toxic algae that sickened and killed dogs across the country in early August is suspected in two pet poisonings at Folsom Lake and at an Auburn waterway where a dog died in recent weeks. Now state water and parks officials are urging pet owners to take caution heading into the long Labor Day weekend.
State Parks officials on Friday sounded the alarm on the potential cyanobacteria sightings at Moony Ridge in the Folsom State Recreation Area and at Auburn’s Oregon Bar on the North Fork of the American River where a dog died in late July after swimming in its waters.
California State Parks officials in a Friday news release are “encouraging recreational users of all bodies of fresh water” in both recreation areas to watch for the potential for the cyanobacteria harmful algal blooms.
“We have caution signs out. Keep pets and kids away” from Oregon Bar, Mike Howard, superintendent of Auburn State Recreation Area, said Friday afternoon. “The most important thing is that (toxic algae) is kind of everywhere, so keep them out of anywhere with that chunky algae area.”
What killed the dog at Oregon Bar remains unclear – officials did not learn of the death until weeks later, Howard said. But tests on Aug. 23 by state Water Resources Control Board staff returned readings for the toxic algae in mats growing on rocks along a side channel of the American River at the bar.
Keith Bouma-Gregson was part of the water resources team that conducted the Oregon Bar tests. The environmental scientist leads the board’s freshwater harmful algal blooms program.
His team’s water samples came back positive for anatoxin-a – a powerful neurotoxin also known by its chilling initials VFDF, or Very Fast Death Factor – the toxic byproducts of blue-green algae more commonly found in coast rivers such as the Russian River.
Dogs’ symptoms include loss of appetite, loss of energy, vomiting, stumbling and falling, foaming at the mouth, diarrhea, convulsions, excessive drooling, tremors and seizures, according to the Centers for Disease Control and Prevention.
Dogs and children are the most vulnerable because of their size and because they are more apt to swallow the contaminated water or algae, water officials say.
That was proven to lethal effect this summer with widely reported dog deaths in North Carolina and in Texas after the canines came in contact with cyanobacteria.
In California, state water officials received 190 reports of potential blooms in 2018. State and local agencies posted approximately 145 public health alerts in waters statewide, according to California Water Boards officials.
In 2017, 18 cyanotoxin-related dog deaths were reported in California, according to the California Water Quality Monitoring Council. The deaths included two dogs who died after swimming at Napa County Pond.
“With visual observation, we’ve continued to post caution signs. (The testing) confirms toxins are present and the cautions are remaining in place,” Bouma-Gregson said Friday.
The algal mats at Oregon Bar pose their own challenge to those hitting the water this weekend. Unlike blooms with their tell-tale foam, scum or paint-like mass that floats on or just below the water’s surface, mats are less visible, Bouma-Gregson said. Clumps of the stuff can attach to sticks like ones recovered by his team last week.
“What’s more challenging is that the mats are different than blooms. The water can be quite clear. Mats can get detached. That’s a problem for kids and dogs. We picked up larger sticks with patches of cyanobacteria,” Bouma-Gregson said, offering a last bit of advice heading into the holiday weekend.
“Even though the water is clear, you need to pay attention to what your dog is consuming. The concern is more how might you ingest mat material,” he said. “Mind your pets. Look for green water (and) surface scum. Make sure you’re aware of what dogs put in their mouths and what’s on their fur. Pay attention to what’s washed on shore.”
Meantime, a similar toxic algae scare on Lake Tahoe’s South Shore after a dog died after coming out of the water at Tallac Historic Site near Kiva Beach earlier in August appears to have abated after results from lab tests returned late Thursday showed no signs of toxins, Doug Smith, assistant executive officer at the Lahontan Regional Water Quality Control Board, said Friday.
Caution signs for the water there will come down, Smith said.
“We had a non-detect for Tallac – no quantifiable toxins. That’s excellent news,” Smith said.