Clearer than normal water and a low lake level means Clear Lake will probably see an explosive growth of aquatic weeds this summer. This year the water clarity is exceptionally good and in some areas you can see down to a depth of 6 feet or more. The lake level is also 2 feet below normal.
The low and clear water allows the sunlight to penetrate to the bottom, which causes the weeds to grow. The result is that many of the lakeside homeowners will see their docks choked by weeds come July.
The big question lakeside homeowners are asking is what can they do about the weeds that will be closing access to the lake from their docks. In fact, the weeds are already reaching the surface of the water in many areas north of Lakeport and in the Nice-Lucerne area.
Lakeside homeowners realized years ago that when there is algae, the weed growth is down, but when the water is clear, such as this year, the weeds come back with a vengeance.
Years ago, when the lake was covered with algae, there was very little weed growth because the sunshine couldn”t penetrate to the bottom to stimulate the weed growth. That all changed about 10 years ago when the water clarity started to improve because of less nutrient loading.
The other factor is the number of new species of weeds that keep showing up in the lake each year. Currently Clear Lake is home to approximately 36 different species of aquatic weeds. Some are native but many are not.
The primary weeds in Clear Lake are Sago pondweed, potomogeton, coontail and water primrose. All are native to the lake. Eurasian waterfoil is a foreign plant but is becoming common in the lake. The other weed of concern is the hydrilla, a nonnative plant that first appeared about 15 years ago. To date, the state and county have been very successful in curtailing the growth of this plant.
The aquatic weeds provide both good news and bad news to people who use the lake. The good news is that the weed growth supplies rich oxygen to the lake, which in turn helps the fisheries. In addition to providing cover for the juvenile fish, the weeds attract plankton and other microscopic creatures that are on the bottom of the food chain. For example, a small aquatic species called daphnia is now in the lake by the billions. Daphnia provides a valuable food source for young bass, crappie and bluegill. Daphnia also feed on blue-green algae, which has plagued the lake in the past.
The other good news is that as long as there is an overabundance of weeds, there will be less of the foul smelling blue-green algae. The weeds use up the nutrients algae requires.
The bad news is that heavy weed growth chokes off entrances to the docks and harbors, making boating almost impossible. In the past, many of the lakeside residents weren”t been able to use their boats for a good part of the summer because of the weeds.
Lakeside residents are allowed to spray the water around their docks with an approved herbicide to control the weeds. However, there are certain conditions they must follow. They must first obtain a permit from the Lake County Department of Public Works. They also must hire a state-licensed herbicide applicator.
Spraying weeds isn”t cheap. Typically it will cost in the neighborhood of $1,000 or more to apply a single application of herbicide around the average dock. Often is takes several applications of a herbicide to control the weeds for the summer. Last summer there was only limited spraying. However, that could all change this year, depending on the weed growth.
Many of the fishermen complain about the spraying because they claim it kills the fish. While that”s true in some cases, in many cases there is little alternative because the heavy weed growth can close off vast areas. It”s a fine line the county has to tread.
There also have been complaints that the spraying kills the lake”s tules. According to county officials, there hasn”t been any herbicide spraying done in tule areas.
The other method of getting rid of the weeds around the docks is by mechanical harvesting. However, the problem is that many of the weed areas also contain hydrilla, a noxious weed that the state has spent millions of dollars trying to control. If a stalk of hydrilla is cut and then drifts off, the chances are good that it will re-root itself in another area of the lake.
The county also must give permission to do any mechanical harvesting and then a permit is only given if no hydrilla has been found within a quarter-mile of the site where the weed harvesting is requested.
Without a doubt, Clear Lake is a dynamic body of water. It offers some of the best fishing in the nation and also is popular for other water sports. Coping with unwanted weeds and mussels is just another problem that we have to deal with if we want to live in Lake County.
