Another major concern is the amount of oxygen depleted from the water as large masses of lake weeds die off, stressing fish and other aquatic animals.
For treating large areas, there are few reasonable alternatives at present. Mechanical harvesting can be costly, and for many types of aquatic weeds harvesting actually stimulates more growth. Introducing weed-eating carp and insects has sometime proven effective for large expanses of water, but the research has often been hit or miss.
So for treating entire lakes, aquatic herbicides remains the most viable option at this time.
But for controlling lake weeds in specific areas, such as swimming beaches and around docks and boat lifts, benthic barriers, often called lake mats are a great alternative to aquatic herbicides.
The way they work is simple. Lake mats prevent sunlight from reaching the weeds, depriving them of the energy needed to conduct photosynthesis. In short: they can't grow in areas covered by a lake mat.
A second benefit is lake mats create a barrier to the lake bottom (hence the term, "benthic barrier"), preventing new lake weeds from taking root.
Yet a third benefit is a lake mat changes the balance of fatty acids in the soil beneath it, discouraging rhizome plants such as lily pads and cattails from spreading in the area covered by a lake mat.
Best of all, there are no aquatic herbicides or other chemicals to apply. No electricity is required as with roller type, lake weed products and there's very little labor involved. A lake mat can be installed in just a few minutes and are a very affordable alternative to aquatic herbicides.
The question for you, the consumer is, do you really need to control a large area of lake weeds, or do you actually want to control them in specific areas where you interact with your waterfront?
If you chose to control a large are of lake weeds, aquatic herbicides may still be the only cost effective answer. But if your main concern is controlling lake weeds in your swimming area, beach front, or around your dock and lifts, a lake mat is a truly great, "green" solution.