LAKE COUNTY — Lake County officials moved into action last week at the early signs of a seasonal algae bloom, which emerged in recent days on Clear Lake, in limited areas such as Redbud, Austin and Highlands parks in the City of Clearlake and Island Park in Clearlake Oaks; the vast majority of the lake is not impacted.
At early reports of sightings, Water Resources staff implemented the Department”s multi-pronged approach designed to help minimize the impact of the algae, working with specialized contractors to treat the blue-green algae. The algae mitigation efforts are part of the county”s focused approach that is funded by a $1.4 million appropriation by the Board of Supervisors to protect Clear Lake”s ecosystem and to enable residents and visitors to enjoy the lake to the fullest extent possible this summer.
Scott De Leon, director of the county”s Water Resources Department, said the appropriation provides the funding necessary to work to mitigate nuisance algae and weeds. De Leon said in addition to the chemical treatment, the department”s algae-mitigation efforts also include assisting citizens and resort owners with the installation of pumps to provide aeration and circulation by spraying water onto the surface of algae mats that can help to knock down the algae around private docks and beaches.
De Leon also is investigating the potential of a mechanical harvesting technique that would essentially vacuum the algae mats and through the use of a centrifuge, de-water the material, perhaps making it possible to dispose of only the algae material.
Several species of blue-green “algae” (also known as cyanobacteria) are present in Clear Lake, but the predominant species in this year”s bloom is lyngbya. The ultraviolet rays of sunlight kill the blue-green algae cells, which then produce an extremely foul odor and create floating mats that turn turquoise, purple, orange and yellow.
As in past years, Lake County Health Officer Dr. Karen Tait and officials from the county”s Environmental Health Division recommended that people and pets stay out of areas of the water where visible algae mats or scum are present and re-emphasized that untreated lake water should never be used for drinking. Health Department officials posted advisory signs at the impacted public beaches and continue to respond to calls and e-mails from concerned members of the public.
Tait said, “Last year, despite heavy blooms in some locations, measured toxin levels had been within safe recreational water levels. I am hopeful this will be the case again this year.” She said the mix of algae types and extent of production can fluctuate and tests are not available for all possible toxin types. Based on research being done on the lake water, only minimal and mostly no measurable toxins have been detected.
For more information about the algae bloom and efforts to mitigate its impacts, contact the Lake County Department of Water Resources at 263-2344. For health-related questions, contact the Lake County Health Services office at 263-1164.
