In a Monday front page story in the Santa Rosa Press Democrat there was a call to clean up Clear Lake. If this sounds familiar it’s been a hot topic for years. During the past 30 years there have been a number of groups wanting to change the lake dramatically and they range from dredging the lake to a depth of more than 100 feet to spraying the lake with a herbicide to kill the weeds and algae.
Assembly bill 707 has been introduced to clean up the lake. Looking through AB 707 I have some problems with it. It states that the mercury in the lake makes the fish dangerous to eat. Actually, in comparison to the surrounding lakes the fish have less mercury than Lake Berryessa and Lake Pillsbury. The mercury in the lake comes from the old mercury mine near Rattlesnake Island. It was a Super Fund Cleanup Site and a lot has been done.
The bill also calls for eliminating some of the aquatic weeds and algae. It’s a great idea if it can be done. The lake has experienced algae blooms for thousands of years. The one factor that would help is to restore the wetland,s which for eons acted as a filter for the lake. Unfortunately many of the tules have disappeared in the last 50 years.
Down through the years there have been a multitude of suggestions to change Clear Lake and they range from rerouting the Eel River through Clear Lake so as to flush it out; to treating the lake with thousands of gallons of aluminum sulfate to rid the lake of algae; and even dredging the lake to a depth of more than 100 feet. While all have sparked interest at the time, they have all failed to occur because biologists and geologists have said that the harm to the environment would far outweigh the benefits.
Let’s look at the history of one of the oldest lakes in North America. Clear Lake has been a shallow lake for thousands of years. Ten years ago an organization called California Association of Lakebed Management held a three-day seminar in Lake County for scientists from throughout the state. A number of the eminent scientists who had studied Clear Lake said it always has been considered a shallow and fertile lake. Hundreds of years ago there were some deep holes in the south end of the lake but the main body of the lake has always been less than 30 feet deep.
As for the algae, it does present problems during the hot summer months, however, most of the year the lake is relatively free of it. Actually, some algae is good for the lake because zoo plankton feed on the algae and the fish eat the plankton. When Dr. Livingston Stone visited Clear Lake in 1872 he wrote that during the month of August the algae was so thick in some areas that you couldn’t push a boat through it. In those days very few people lived in the county. There was also little or no agriculture to create run-off into the lake.
There are more than 130 different species of algae in the lake. There are good species of algae and bad ones. Clear Lake has the highest population of fish in the nation and many of these species of native fish feed on zoo plankton, which in turn feed on the algae. Without these types of algae our fish population would only be a shadow of what it is now. Among plants on the lake, algae are among the least studied.
Algae are tiny water plants that cycle normally between the bottom and the surface, floating up and sinking down. During the day, algae generate oxygen within the lake and at night they consume oxygen. Algae are among the oldest living organisms on our planet, going back at least 2 billion years. Without question algae are the most important plants on earth. They generate more than 70 percent of the oxygen in the atmosphere and without algae there would be no life on the planet.
We also have to be very careful about disturbing the bottom of the lake. There are residues of pesticides resting on the bottom such as the now-banned DDT and DDD that were sprayed extensively years ago on Clear Lake to get rid of the gnats. Would these pesticides rear their ugly heads and have an effect on the fish and bird life that call Clear Lake home? Some of the biologistsI have spoken with are definitely concerned.
I do think the passing of AB 707 would benefit the county and the lake by creating a blue ribbon committee to study and protect the lake. While it’s encouraging that a local group of citizens want to improve the lake, a number of scientists and biologists have told me that great care should be used before attempting to change the oldest lake in the country.
