No one can doubt that Clear Lake has undergone some dramatic changes this summer and fall, both in fishing and water quality. For example, the results of the past three major bass tournaments reveal some startling facts about the lake’s fishery.
Whereas a few years ago it took at least a 5- or 6-pound average per fish to win a bass tournament, the past three tournament winners have produced a fraction of that. For example, the pro winner in last weekend’s FLW tournament averaged only 3.5 pounds per fish to beat out a field of 100 pros. That’s unheard of at Clear Lake.
Contributing factors to the smaller tournament averages have been massive fish die-offs as well as algae blooms. The fish die-offs were caused by massive algae blooms that depleted the water of dissolved oxygen. The die-offs are over, at least for now, but the water color is still a dark brown.
Clear Lake has more than 130 species of algae and they consist of two major groups, green algae and cyanobacteria, frequently referred to as blue-green algae. Green algae are tiny water plants that float within the water column. Green algae are an important part of the food chain and lead to the high fish and wildlife populations in and around Clear Lake. Cyanobacteria are actually photosynthetic bacteria and not true algae at all. The plant cycles normally between the bottom and the surface, floating up and sinking down. Cyanobacteria can dominate the lake ecosystem by remaining at the surface and reducing the light available to green algae. During the day, both green algae and cyanobacteria generate oxygen within the lake. At night they consume oxygen.
There are five different species of the blue-green algae or cyanobacteria. The various species of algae bloom throughout the hot days of the summer.
Scientists say algae and cyanobacteria in Clear Lake are part of the natural food chain and keep the lake fertile and healthy. Because of the lake’s relative shallowness and warm summer temperatures, the algae serve another important purpose. They keep the sun’s rays from reaching the bottom, thus reducing the growth of water plants which would otherwise choke off the lake. The improved springtime clarity since 1990 has increased the number of water plants in the lake, which in turn has provided important shelter for fish and other aquatic creatures.
There have been rumors claiming the reason the lake is brown in color is because of the spraying of herbicides to kill weeds. In truth, there has been very limited spraying. A good example are the state hydrilla crews that can be seen daily cruising the lake in their airboats. I have spoken several times to the airboat crews and they say they have done practically no spraying this year. Their sole job is to look for hydrilla. To date they have found few plants. Most of the time when you see the airboats on the lake they are throwing giant hooks looking for hydrilla plants. As for spraying for other weeds, Lake County Water Resources has issued few permits for private companies to spray for weeds.
This year also has seen a lack of aquatic weeds in the lake. Normally there are hundreds of acres of surface weeds, but not this year. One thing that could explains this are the the algae blooms, which may have cut off sunlight from reaching the lake’s bottom.
As to why there are fewer large bass showing up these days, no one knows the answer. One theory is the fish die-offs earlier this year killed not only thousands of bait fish and small bass but also large bass as well. Clear Lake has undergone massive changes for years. It’s just the nature of the oldest lake in the world. The water should start to clear up by November and remain relatively clear throughout the winter.
