It is normally applied to an impoundment in the liquid form in order to eliminate unwanted fish populations, or as a means of collecting fish for scientific studies. Different fish species are able to withstand different concentrations of Rotenone. For example, rainbow trout die when subjected to 22.5 ppb, while channel catfish can only withstand Rotenone concentrations between 2.6 and 2.8 ppb. It is a common mistake to think that Rotenone removes oxygen from the water. However, this is not the case.
Rotenone kills fish by inhibiting their ability to utilize oxygen for metabolism.
It is a powerful inhibitor of mitochondrial electron transport. In effect, the fish suffocates while going about its regular business. Fish are particularly susceptible to Rotenone poisoning because Rotenone is easilyabsorbed through the fish's gill membranes. However, fish are not the only aquatic creatures effected by Rotenone. Tadpoles, gill breathing, immature frogs, are killed by Rotenone.