No easy solution to weed, algae problem

Drought, low lake levels and algae blooms are capturing the headlines when the topic is Clear Lake. The bad press is also being blamed for keeping the tourists away. None of this is new and the lake has been the target of media criticism in the past.

Down through the years a number of ideas have been presented when it comes to ridding the lake of algae and aquatic weeds. They range from spraying the lake with herbicides to dredging the lake. One company promised to make Clear Lake as clear as Lake Tahoe for a few million dollars. All they had to do was dump a few thousand gallons of aluminum sulfate into the lake and the algae would disappear. This proposal so excited local politicians and residents that the company was given a contract by the county to study the project. When it was revealed that along with ridding the lake of algae aluminum sulfate would also kill most of the fish, the project was abandoned.

A few years later it was proposed the lake be dredged. Proponents of dredging said if the lake was dredged to a depth of 100 feet or more all the problems would be solved and we would have the cleanest lake in the state. Scientists said the silt alone from dredging the lake would create a mountain the size of Mount Konocti. The project was deemed unworkable by the experts and was also abandoned.

Clear Lake has remained relatively unchanged for millions of years. It has always been shallow and at one time the entire shoreline was comprised of tules. It also teemed with fish and wildlife. The local inhabitants, Native Americans, were happy with the lake and what it provided. However, in the past century man changed the character of the lake. Take the tules for example. As humans settled around the lake, more than 85 percent of the tule shoreline disappeared. The tules are an excellent filter for the water runoff that flows into the lake during the winter months, slowing nutrient loading. There are now so few left there is practically no filter action.

Actually, aquatic weeds aren’t always bad. Early in the summer the weeds use up the nutrients that the algae need. If all the weeds were killed, then the noxious algae will return. Years ago a Department of Fish and Wildlife biologist who was an expert on Clear Lake told a group of local citizens that you can either have weeds or algae, so take your pick.”He was absolutely correct. Contrary to what many people think the lake is getting clearer. The lake clarity is measured several times a year with a secchi disc, which is a flat disc painted black and white. The disc is lowered into the water and when it can no longer be seen the depth is recorded. In 1969 the readings were a little less than 3 feet. By 2008 the disc could be seen down to a depth nearly 6 feet. Every year between 1969 and 2008 the water became clearer.

That’s not to say Clear Lake shouldn’t be closely studied and efforts made to improve water quality and the shoreline. For years I have proposed that the county hire a biologist to study and make recommendations on improving the lake. A nonprofit organization recently formed will do just that. It’s called the Clear Lake Environmental Research Center. It’s purpose is to bring scientists to the lake where they will conduct extensive research. Even though Clear Lake has been studied by scientists there is a lot we don’t know. After all, how many lakes are as old as Clear Lake? It was here thousands of years before humans walked on the earth.

Clear Lake is a jewel and is the oldest lake in North America. It is rich in fish and wildlife— and often compared to a rain forest. It is also fragile and needs to be protected, not exploited.

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