LAKE COUNTY — County officials noted the presence of a different species of blue-green algae in the Lower and Oaks arms of Clear Lake this month during the county”s increased mitigation and monitoring activities.
Scott De Leon, director of Public Works and Water Resources for the county, said Water Resources staff had been on the lake throughout the summer performing regular water monitoring activities and that the presence of a different species at this time is not surprising.
The species, identified as Microcystis, is a species that tends to appear in spring and fall. Summer algal blooms in recent years have consisted mostly of a species called Lyngbya.
“Similar to other species of blue-green algae that we”ve seen, Microcystis also has the potential to release toxins, so it”s important for people to avoid areas with heavy algae accumulation or surface matting, regardless of the type,” De Leon said.
When viewed in the water, the Lyngbya species appear to be fibrous with hair-like filaments and create floating mats that turn turquoise, purple, orange and yellow. Microcystis species appear to be more granular and its presence makes the affected water look like bright-green pea soup. Both species can produce nuisance odors and may release toxins into the water.
Although the species are different, the advice of using common sense remains the same. Lake County Health Officer Dr. Karen Tait recommended that it is best to avoid areas near dense patches of algae.
“If you see signs of algae accumulation, it”s best to keep away from that area,” Tait said.
Tait and officials from the county”s Environmental Health Division continue to recommend that people and pets stay out of impacted areas, that untreated lake water should never be used for drinking water and that anyone experiencing symptoms after exposure should contact their physician.
“Clear Lake is one of many recreational water bodies around the world that are experiencing a similar increase in the presence of algae blooms,” De Leon said. He noted that, since algae mats move with the currents, the expanse of Clear Lake, combined with changing winds, can make mitigation efforts a challenge. “That also means that at any given time, there are generally many areas on Clear Lake that are not affected,” De Leon said.
Algae monitoring and mitigation efforts are part of the county”s focused approach to protect Clear Lake”s ecosystem and to enable residents and visitors to enjoy the lake to the fullest extent possible. The county”s Water Resources staff had been trying a variety of techniques to mitigate the nuisance algae all summer, including harvesting, aeration and circulation and chemical treatments. It is expected the algae will subside significantly with forecasted cooler temperatures.
For information on blue-green algae, visit the California Department of Public Health web site at:?www.cdph.ca.gov/healthinfo/environhealth/water/pages/bluegreenalgae.aspx.
For information on the county”s algae mitigation efforts, contact the Lake County Water Resources office at 263-2344.
For health-related questions, contact the Lake County Health Services office at 263-1164.
