Hot weather and algae blooms at Clear Lake go hand in hand. This past week has seen some of the hottest days of the year and the algae is blooming, just not as bad as expected.
Unlike last summer when there were algae mats so thick the ducks were walking on them, this year the algae is more scattered. Also, the blooms are much worse in the north end of the lake, which is unusual. Whereas there have been algae blooms throughout the lake the worst by far this year are around the Nice-Lucerne shoreline and off Lakeport.
I took a drive completely around the lake on Saturday and stopped at numerous bays and other areas. What I saw surprised me. In many areas in the south end of the lake the water was relatively clear while much of the north end was terrible. For example, the water off Library Park in Lakeport resembled a cesspool, however the water off Lakeside County Park was pretty decent.
Several fishermen have reported that the aquatic weeds are starting to disappear in a few areas. This is normal. Looking over my notes going back more than 25 years I found that by the mid-August the weeds begin to die off in Clear Lake. These weeds are annuals, meaning they start from a seed and when they mature they produce flowers and seeds. The seeds fall off the plant and settle to the bottom. After the seeds are produced the plants have lost their function in life and die. It”s all part of Mother Nature”s control of all living things. The same thing happens in your garden.
This year algae has been attaching itself to many of the floating aquatic weeds and not forming the massive mats of a few years ago. One reason is a different species of algae has become more common this year. For example, the algae Lyngbya is much more common than in past years. It is a fibrous algae and floats between the surface and the bottom. It also tends to attach itself to any weeds and form mats, which can be seen in many areas.
Every summer there is a cry from county residents to do something about the algae. There is no question the algae and the aquatic weeds in the lake have an impact on tourism although the bass fishermen like the weed mats. Visitors don”t want to boat or swim in waters covered with algae and no one can blame them. A few weeks ago the Lake County Health Department even put out a warning for people and pets not to swim or wade in algae-infested areas.
The county has experimented with various techniques to get rid of the algae, including spraying the algae mats with water to sink them and installing booms in areas such as Redbud Park in Clearlake to keep the algae off the boat ramps. All have enjoyed only limited success.
The same applies to aquatic weed control. For the past two years there have been weed harvesters on the lake but a month ago the weed harvesting had to be halted in the north end of the lake because hydrilla plants were found. The fear is that the machines would cut the plants, which would float to the surface and end up in other areas of the lake. Instead, the county is spraying much of the north end with a herbicide to kill the plants.
As for the algae, any fix will take decades. There are hundreds of factors such as the lake level, weather and run-offs that come into play in controlling the algae. Most have to do with nutrients in the lake and it will take many years to deal with that. The ideal situation would be if a market could be found to commercially harvest the algae. To date, no one has offered to take the algae. In fact, the commercial company that has been harvesting the weeds has been trying to find a company to take the harvested weeds and use them for compost, but they have found no takers.
Clear Lake is a complex ecosystem that has been around for several million years and we aren”t going to change it overnight. The good news is most of the weeds and algae will be gone by next month.
