Drought contributes to increase in aquatic plants
If it seems as though you’ve recently spotted more aquatic plants floating on or just under the surface of your reservoir, it may not be your imagination.
Although aquatic plant abundance varies from year to year, recent drought conditions throughout the Tennessee Valley have set the stage for noticeable growth. The clear water that results from low flows and lack of runoff allows sunlight to penetrate further into the water, and plants such as milfoil, hydrilla, spiny-leaf naiad, pondweed, and coontail respond accordingly.
Aquatic plants have colonized large portions of several main-river reservoirs. Because of the wide annual fluctuation of water levels and other contributing factors, most tributary reservoirs have few or no aquatic plants.
Although considered an unsightly nuisance by many, aquatic plant coverage does have its benefits. Anglers appreciate the fact that young fish use the structure as cover and tend to thrive in areas with significant plant populations.
This time of year, boaters and other reservoir users may notice fragments of plants that have formed into floating mats. This is a seasonal occurrence, caused when the plants die and break into fragments that drift together. Unusually high flows or winds may trigger a breakup of these mats and clog intakes at water and industrial plants, as well as power generating facilities. Boaters and those using jet skis should be aware of these mats as they can also clog propellers and motors.
What you can do
If excess aquatic plants are a problem around your dock or shoreline, hand-harvesting offers a potential solution. It may be hard work, but it’s low-cost, it doesn’t leave a chemical residue in the water, and it’s easy to target specific problem areas.
The simplest harvesting method involves removing a plant’s root system by pulling from its base. Submerged plants also can be removed by raking or by using V-shaped cutters that have a rope attached to the handle. You can throw the cutter out from the shore or dock, and it cuts the plants at their base as it is pulled back in.
It is important to remove pulled or cut plants from the water so that fragments won’t take root and form new plants.
Chemical treatment is another means of temporarily controlling particular aquatic plants, but extreme care must be taken to protect the environment. Your state resource agency can provide information about necessary permits and help you find a licensed commercial aquatic herbicide applicator.