Can the toxic effects of rotenone be neutralized?
A. If biologists want to neutralize the effects of rotenone in lakes or rivers, potassium permanganate or chlorine can be used. These are added to the water at a 1:1 ratio with the concentration of rotenone applied plus sufficient additional compound to satisfy the chemical oxidation demand caused by organic matter that may be present in the treated water. The toxicity can be reversed by placing affected fish in a water solution of methylene blue. If fish are captured early during a treatment, they may also be revived by placing them in untreated water. Success can be enhanced if the water is highly oxygenated or contains an oxidizing agent to detoxify any residual rotenone that may be on the gills or body surface.
