It has other uses, including use as a garden dust to control insects and as an insecticide for use on cattle, dogs, and sheep. Rotenone works by inhibiting a biochemical process in the fish cells, resulting in an inability of fish to use oxygen in the release of energy during normal body processes. In effect, the fish suffocate due to lack of oxygen. But, contrary to popular belief, rotenone does not remove oxygen from the water. Fish treated with rotenone move to the shallow water or to the surface of deeper water, gasping for oxygen within a few minutes of exposure to the chemical.
Rotenone is an unstable compound that breaks down when exposed to the environment.
It is ultimately converted to carbon dioxide and water. The breakdown process is rapid and is affected by temperature, light, oxygen, and alkalinity. At 80 degrees Fahrenheit, treated water will detoxify in about 4 days. Most waters are safe for restocking within 5 to 6 weeks. In general, the cooler the water, the longer rotenone persists.