There are a large variety of methods of trying to remove weeds from lakes and ponds. Some are more effective and environmentally friendly than others.
First of all, some aquatic plants and algae are essential for a healthy aquatic environment. They photosynthesize and release oxygen into the water. When they bloom or grow excessively, though–and this is often due to the use of fertilizers on land that runs off and into lakes and ponds–they become detrimental. When they die and decompose, they remove oxygen from the water and cloud the water, preventing sunlight from getting through. As they decompose, their remains deposit onto the floors of water bodies, increasing the rate of sedimentation, and they provide footing for undesirable land plants that in turn cause further accumulation of sediment at the shoreline (though a buffer zone of shore plants can help to prevent erosion). In cases where there are large numbers of invasive species of weeds, they can also have detrimental impacts on native species of plants and animals.
Methods of reducing unwanted lake and pond weeds include:
Herbicides
Well, herbicides can certainly be effective, but they have their downsides. They kill aquatic plants indiscriminately, the die-off then decomposes and releases large amounts of organic matter into the water, causing sedimentation, cloudiness, and oxygen depletion. Some herbicidal chemicals can accumulate in animals, particularly bivalves, and can leach into surrounding soils. And beneficial aquatic plants are destroyed along with the undesirable ones.
UV Clarifiers
UV clarifiers can increase the dispersion of wavelengths that help suppress weed and algae growth. They are hard to scale up to any large size, but they do have the benefit of not being directly harmful to animal life. They do not affect floating plants such as lilies or cattails that naturally project above the water. Many of these have rhizome systems that need to be removed to suppress them, as well.
Pond Dyes and Shading
Will suppress aquatic plants that require significant light sources to photosynthesize, but they will also suppress desirable aquatic plants and alter the habitat, affecting the ecosystem. And once again, this is impossible to scale to larger bodies of water.
How EcoWaterways Handles Weed Removal
The most targeted method of weed removal by far is the one practiced by EcoWaterways. Using trained divers, we can remove the harmful, invasive species of weed that are fouling your waterfront. We pull them up by the roots, and feed them into an extraction pump tethered to a float on the water surface. This forces large quantities of mixed weed and water and sticks and other debris through nets, so that the water then passes back into the pond or lake. The pump action doesn’t kill any wildlife which might get sucked up, and it is re-released into the water as it passes through the net bags tethered to the float. The water is drained out of the bagged material during this process, and the bagged material is placed onshore to dry, when it can be transported more easily. In cases where explosive weed growth is caused by phosphate and other fertilizer runoff, the excess biochemical material is relocated well inland, where it is less likely to return to water.
Generally, after two or three treatments, the need for treatment at all is drastically reduced. The results aren’t permanent, but they become long-lasting, and the environmental impacts and unwanted side-effects are greatly reduced over more intrusive methods of weed removal. Because we allow desirable native species to flourish while removing unwanted species, we help restore lakes and ponds to their natural conditions, which in turn is beneficial to native fish and wildlife.
Give us a call for a free consultation. We have the experience, the tools, and the personnel to help.