LAKE COUNTY — That dreaded stench that plagued Clear Lake last summer is creeping up again, calling for constant monitoring and proactive response. The lyngbya, a form of cyanobacteria that many mistook for raw sewage last year, began surfacing about a week ago; however, no health advisories have been issued at this time.
“We are seeing some of the lyngbya but certainly not in the numbers that we saw last year,” Water Resources Director Scott De Leon said. “The wind has been keeping the algae suspended and we are not seeing a lot of matting at this time. We are encouraging people to aerate, spray with water and do what they can daily to keep those mats from forming.”
De Leon said this is the first real significant algae bloom seen this season. According to Harry Lyons, Lake County professor and biology expert, while lyngbya appears to be the principal form of algae at present, there is a mixture of more historically important forms of blue-green algae currently in bloom that serve as the basis of the aquatic food chain during the summer.
“We are seeing the same stuff we saw last year. However, mixed in with it is a little more of other species,” Lyons said. “Principal form is lyngbya. Mixed in minority is a form that we had in some fairly good years. One we had in reasonable conditions is gloeotrichia, a spherical form, which is found more frequently in years where there was less of an algae problem.”
Lyons said the lake is also seeing what he referred to as long term bloomers: Aphanizonenon and Anabaena.
According to UC Davis Biologist Greg Giuisti, blue-green algae is the engine of the lake and gives it the ability to produce so much life. “The richness of this lake is expressed with the algae we see,” he said. “Whether it”s blue-green algae or green algae, it”s the floor of the food chain. It”s how the lake recharges its trophic level.”
While the typical blue-green algae are essential to aquatic life in the lake, the lyngbya causes particular concern for resort owners, property owners, lake users and the community in general as it contributed to economic crisis last year. De Leon said that constant monitoring is occurring on a daily basis with various volunteers, community groups and government agencies and representatives contributing to the effort. He said that the lyngbya is being seen in areas where algae are normally seen in the lower arm of the lake.
“The wind pushes the algae into those coves, so we”re seeing it in those usual places,” De Leon said. “We are also seeing it on the west side of Buckingham Point and Horseshoe Bend. The wind and wave action has been keeping that fairly stirred up.”
De Leon continued, “We get asked daily what the smell is from. The smell is from the algae that has died and is on the surface. So, you want to keep that agitated and break those mats up. That will help with the smell, but obviously in large bays, it”s hard to do that.”
According to the Bioremediation Services Web site, lyngbya is particularly difficult to control using traditional copper sulphate and chelates. The algae grow in colonies forming small spongy masses of mucilage. These blue-green, black or gray clumps will lie on the bottom or float to the surface. Because of its protective mucilage, chemical control is difficult.
Lake County Health Medical Officer Karen Tait, MD said that no health advisories have been issued at this point. She said “rule of thumb” is if there is not a heavy, visible bloom there should be no health risks.
Additional information regarding aquatic life on Clear Lake is available on the county Web site at www.co.lake.ca.us under the Water Resources page.
Contact South County reporter Denise Rockenstein at drockenstein@clearlakeobserver.com or call her directly at 994-6444, ext. 11.
