Clear Lake has more than 40 different species of aquatic weeds and while some are native to the lake, others were illegally introduced. Likewise some are beneficial and others are considered a nuisance.
The best example of a nuisance is hydrilla, a plant that was introduced into the lake 16 years ago. It is considered to be one of the most undesirable plants we have because it can choke off native plants and even close off some of the channels and waterways. In fact, lakes in Florida infested with hydrilla have little or no open water left.
Hydrilla was first discovered at Clear Lake in 1993. Before the plant could gain a foothold here, the state took aggressive action and for the most part it has been controlled. Often fishermen confuse some of the weed mats for hydrilla. Actually what they”re looking at is American Sago Pondweed. Hydrilla is identified by its bright green-colored long stems. Its stalks also have small whorls and it grows just under the surface.
Most boaters have never seen a hydrilla plant. Sago, which is a native plant, is often free floating with thin stalks. These large mats of Sago make ideal habitat for bass and fishermen seek them out. This is where a lure like a plastic frog comes into play. The frog is cast on top of the mat and retrieved with short jerks. It is considered one of the most exciting methods of bass fishing. I consider the Sago to be one of the good guys. The plant was here long before humans and offers fish cover during the hot summer days.
One aquatic weed that”s rapidly becoming a problem is water primrose. It is a non-native plant originally from South America. Many of the channels and bays are completely shut off because of primrose. The Clearlake Oaks Keys is a perfect example. The Keys Homeowner Association has been battling primrose for years. Most of the channels and bays around the lake are now infested with primrose.
Another plant that”s commonly seen is coontail. It”s a bright green plant that resembles a raccoon”s tail, thus its name. Coontail is a native plant and also provides valuable cover for the fish.
Another non-native plant that is starting to show up in Clear Lake is water hyacinth. It”s been called the worst aquatic plant in the world. Water hyacinth in another plant that comes from South America but is now common throughout the United States. It”s not yet common in Clear Lake but that could change during the next few years. If it become established it could be disastrous and shut down the lake to all boating. In fact, there are some channels in the Delta that are completely clogged with water hyacinth. The plant can be identified by its large green leaves and purple or violet flowers.
Aquatic weeds aren”t always bad. 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 and is a valuable food source for young bass, crappie and bluegill. Daphnia also feed on the blue-green algae, which has plagued the lake in the past.
Weeds also use up the nutrients that algae need. In fact, the lake has been pretty much free of large concentrations of the blue-green algae since the weed explosion.
Because it”s so shallow and has a rich fertile bottom, Clear Lake is the perfect haven for aquatic weeds. Whereas I have no trouble with the native weeds, it”s the non-native invasive weeds that concern me. Not only can these weeds cost millions of dollars to eradicate, but they also ruin the beauty of the lake.
