The Dangers of Using Copper Sulfate to Clean Waterways
In the ongoing battle against water weeds in ponds, rivers, lakes, and wetlands across the nation, the temptation to turn to chemicals for a quick fix is understandable, especially when facing a major infestation of invasive water weeds like Hydrilla, Eurasian Watermilfoil, Duckweed, Water Chestnut, Water Hyacinth, and Phragmites. These infestations can feel overwhelming, with dense mats of vegetation seemingly impossible to remove. In such situations, the idea of a chemical assault becomes appealing. Despite knowing it’s not ideal and worrying about the ecosystem’s impacts, copper sulfate might seem like the only realistic option. After all, it’s widely used and touted as effective and safe. However, in this article, we’ll present a series of arguments against the use of copper sulfate.
Everyone’s Using Copper Sulfate, so it Must be Safe, Right?
You might stumble across a simple piece of advice while searching for a solution to a problem related to aquatic plants in your pond or lake. In one forum, a person was asking how to go about decreasing the amount of silt flowing into a pond, which was resulting in too many aquatic plants in the water. One response detailed a great way to address the silt input problem, and then went on to say this:
This will do nothing about vegetation in your pond. That can only be controlled by chemical treatment at least once a year. Granular Copper Sulfate works pretty good. Either mix the granules with water in a bucket and then sprinkle the pond or put the granules in a gunny sack or any perforated sack and drag it behind a boat to dissolve it into the pond water.
You can see how there is an assumption that chemicals must be used to stop aquatic plants, and the most common choice is copper sulfate, and even more so when the water body is suffering from serious algae or cyanobacteria blooms. When you see copper sulfate being sprayed onto or pumped into a pond to reduce algae temporarily, it’s likely paid for with tax dollars. The cause of the algae is most likely excess fertilizers from nearby areas that find their way into the pond.. However, after spraying with copper sulfate, the algae sink to the bottom, along with the heavy metals in the spray. Some aquatic creatures survive, but many smaller organisms die, and the heavy metal remains in the water for decades. As noted by the Dartmouth Toxic Metals Superfund Research Program, “This chemical has serious chronic toxicity with implications for agricultural workers and the environment.”
Copper Sulfate in the Food Chain
When copper sulfate is used on a water body, much of it sinks to the bottom, bypassing the plants it’s meant to eliminate. Copper then settles into the sediment and is slowly released back into the water. This copper at the bottom poses significant problems. It can combine with other substances in the sediment or water to form toxic compounds. The immediate impact of copper in the sediment is on creatures that interact most with sediment—bacteria, phytoplankton, mollusks, insects, and other organisms, all of which are food for higher levels in the food chain. Copper is highly toxic to amphibians and bioaccumulates in fish, impacting creatures that feed on them, including humans.
Mechanical Weed Harvesting for the Future of Our Waterways
Chemical herbicides have long-term negative side effects that are well-documented. It’s time to stop poisoning our waterways. Mechanical harvesting is the only truly safe way to remove aquatic weeds without harming the environment, wildlife habitats, aquatic life, amphibians, or humans.
The Weedoo line of Workboats and Aquatic Weed Harvesting equipment offers the best solution for combating invasive and nuisance aquatic weeds. From easy-to-use electric skimmers to high-end hydraulic-powered underwater cutters and everything in between, Weedoo is the world’s foremost source for waterway management needs.