by Peter Kilkus, 4/8/18
I’ve been at Lake Berryessa since 1997 and have seen algae and seaweed come and go but have never heard a report of a dog dying from algae poisoning in the lake. I also just spoke with a local businessman who has spent every summer for 25 years on and about the lake. He said he had never heard of a dog dying from swimming in the lake.
The worst recent algae blooms were in September 2011 and resulted in several news articles and warnings reproduced below. But even then there were no reports of dogs getting sick or dying from Lake Berryessa water.
The rumors of dogs dying of algae poisoning at Lake Berryessa in 2017 were simply false. Two dogs did die after swimming in a scum-covered pond in the Huichica Creek Unit located at the end of Milton Road near Cuttings Wharf in south Napa County.
With the lake water still being cold, there should not be any large algae blooms yet. Please let me know if there are. In the interest of full disclosure I’ve published various historical items about the previous 2011 algae blooms in Lake Berryessa below:
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Residents report ‘green slime’ at Lake Berryessa
Napa Register. JAMES NOONAN | Posted: Thursday, September 1, 2011 12:00 am
Some long-time residents of Lake Berryessa are reporting a thick, green slime littering the lake’s northern shore, an occurrence that they say is unlike any in recent memory. “It’s so sick with algae,” said Berryessa Pines resident Gerry Cooper. “I never seen it like this.” Cooper, who has lived along the shores of Berryessa for more than 20 years, said that in the past few days the normally crystal blue water at the lake’s north end had been colored green by algae blooms extending well into the center of the lake.
After first becoming aware of the water’s odd emerald tint, Cooper ventured farther south to Spanish Flat where the water was equally slime-ridden, she said. “You wouldn’t want to swim in this. There’s no way I’d get in,” Cooper said.
Peter Kilkus, editor of the Lake Berryessa News, said he had yet to see anything unusual along the lake’s southern shore, but had heard reports of jet-skiers and boaters encountering algae patches north of Berryessa’s “Big Island.” Big Island is roughly at the midpoint of the lake, separating the northern and southern sections. Many times, the slime was so unsettling that boaters stuck to the southern portion of the lake, Kilkus said.
While the occasional algae bloom isn’t uncommon at Berryessa, recent conditions at the lake have scientists scratching their heads. Over the past month, Ken Davis, an aquatic biologist who contracts with the Solano County Water Agency, has noted a specific type of blue-green algae as the dominant plankton species in the lake. The algae have a tendency to form thick, floating mats in the lake’s shallower coves, Davis said, producing the so-called “slime” being described by lakeside residents.
While the algae are always present in the lake, the amount suspended in the water now is much higher than usual. Also, blue-green algae blooms typically take place in the fall, Davis said. The lake’s slime is surfacing earlier than usual. The reason behind the exploding algae population remains a mystery. “I’m really at a loss,” Davis said, noting that he would be returning to the lake later this week and will eventually be issuing a report on Berryessa’s algae.
Meanwhile, Terry Sparkman, general manager of the Pleasure Cove Resort, said he had experienced the slime first-hand. On Tuesday morning, while boating from Pleasure Cove up to the Monticello Ski Club, Sparkman said he encountered a 40-to 50-yard-wide algae bloom in the middle of the lake. “It was kind of green and slimy,” he said. Sparkman noted that he has seen similar blooms take place in other lakes, but that this his first at Berryessa.
In 2009, Clear Lake in Lake County experienced a massive, lake-wide algae bloom that sent ripples through the area’s tourism industry and killed off large populations of fish. Berryessa’s conditions have yet to cause similar problems, Davis said, noting that oxygen levels in the lake are still high enough to support fish life. The algae don’t pose any serious threat to humans either, he said.
Solano County residents, who rely on Berryessa for their drinking water, also won’t be affected. Water is drawn from the bottom of the lake and is treated before it reaches the tap, said David Okita, general manager of the Solano County Water Agency.
Pete Lucero, a spokesman for the Bureau of Reclamation, said beaches at bureau-operated sites were free of any slime, and asked residents of the lake to report future sightings to the Berryessa field office. Reclamation will also be testing the water for blue-green algae and posting signs regarding the blooms as necessary, Lucero said.
Moving forward, Davis said that the large population of blue-green algae in the lake’s water column could lead to even larger blooms during the fall months, when the event normally takes place. “I have some concerns,” he said. “I’ll be watching very closely in the coming months.”
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September, 2011
The Lake Berryessa News received calls and emails about the recent algae growth in Lake Berryessa. Several came from long-time lake users who said they had not seen anything like it before. Biologist Ken Davis has done some further analysis of the algae situation at the lake and has this to say:
There are three separate issues there – well actually two. Over the last week, I’ve taken a good look at many sites on the lake, collected samples, and examined them using a compound microscope. Note that all of the algae mentioned below are commonly found in plankton samples from Lake Berryessa, just not in the density that I’ve seen lately.
1. The floating particles (filaments) are the blue-green (cyanobacteria) that I reported a month ago – that’s an algae called Phormidium.
2. When Phormidium and other algae die, they produce a gas and float to the surface where they form the familiar brown mats we have all seen. Typically they are windblown and end up in windblown coves.
3. The green slime (film) is another blue-green algae called Oscillatoria. It can also be found commonly in the water column, but weather conditions cause it to come to the surface and form the green slime and eventually a green, very flat mat on the surface.
4. There is a third blue-green in the mix, but it’s rare. That’s called Lyngbya.
5. They can also be mixed in the same “scum” and they are not easy to identify without the proper equipment.
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Blue Green Algae at Lake Berryessa
September 2, 2011
Bureau of Reclamation Press Release
With long summer days and heat, Lake Berryessa becomes an ideal habitat for cyanobacteria. Cyanobacteria, also referred to as blue-green algae, are a common and natural component of the microscopic plants (plankton) in Lake Berryessa. Some types of blue-green algae produce natural toxins or poisons. When these algae die and break down, toxins can be released into the water.
Blue-green algae are usually present in lake water in low numbers. But once the water warms up in shallow areas, blue-green algae can become very abundant in some sections of Lake Berryessa. Under calm conditions, blue-green algae can accumulate in thick layers at the surface or along the shoreline. These accumulations are frequently referred to as “blooms” or “scums.” Wind can blow these accumulations around the lake.
While blue-green algae toxins have been detected at many locations in Lake Berryessa, the highest concentrations of toxins are usually found in blooms and shoreline scums. These dense accumulations pose the greatest potential health risks. Watch for dense accumulations of algae and avoid these areas.
Blooms generally have the following properties:
· Water may appear cloudy and look like thick pea soup.
· Blooms are generally green or blue-green in color, although they can be brown or purple.
· A thick mat or foam may form when a bloom washes onto shore.
Weather influences where blue-green algae will accumulate in a given location. During extended periods of calm and sunny days, blooms can accumulate at the surface in any location. Wind and waves may cause them to form along shorelines or in protected areas. Shifts in wind direction can move a bloom from one location to another.
Recreational contact, such as swimming with water not visibly affected by a blue-green algae bloom is not expected to cause health effects. However, some individuals could be especially sensitive to even low levels of algal toxins and might experience mild symptoms such as skin, eye or throat irritation or allergic reactions.
Direct contact or breathing airborne droplets containing high levels of blue-green algal toxins during swimming or showering can cause irritation of the skin, eyes, nose and throat and inflammation in the respiratory tract.