Home / Fisheries / Pond Renovation / Toxicity and Neutralization
Pond Renovation
Introduction |
What is Rotenone? |
Preparing the Pond |
Applying Rotenone |
Restocking the Pond |
Toxicity and Neutralization |
Partial Fish Kill |
Toxicity and Neutralization
Recent debates have focused on the toxicity of rotenone and its possible linkage to Parkinson's disease. (Click here to learn more about the issues surrounding the use of Rotenone.) Even with such debate, it is agreed that the toxicity of rotenone is extremely low. However, as with any pesticide, it is a good idea to handle rotenone with care to minimize contact. The rotenone formulation contains petroleum products that may be harmful. Wear protective clothing, including rubber gloves and goggles. Be sure to shower or bathe immediately after handling rotenone, and thoroughly wash your clothes before wearing them again. The label prohibits swimming in treated water until after the application has been completed.
Rotenone is safe for all livestock except swine, which are sensitive to the compound. Livestock (except swine) and pets can enter the treated pond and even drink the water with no effect. For example, a 22-pound dog would have to drink 4.2 gallons of water treated with the maximum amount of rotenone to ingest the minimum safe level. EPA has stated that there is no reason to exclude livestock (other than swine) from rotenone-treated waters. As an added safety precaution, however, try to minimize livestock or pet activity in the treated water.
Although rotenone is considered nontoxic to humans at levels that would be found in a treated pond or fish, EPA and FDA have not established the maximum acceptable residue level permitted in fish for human consumption. Therefore, human consumption of fish killed by rotenone cannot be recommended.
If rotenone is applied according to label instructions, other animals such as waterfowl and raccoons cannot ingest enough of the treated fish for the effects to be harmful. Although rotenone has been used as an agricultural insecticide and poses no threat to crops or other vegetation, label directions warn against use of treated water for irrigation.
If rotenone is washed out or otherwise escapes the pond and enters any other body of water, it can kill fish. This is a danger of rotenone application, and it is against label recommendations to apply rotenone in situations where it can enter nontarget waters. However, the rapid breakdown of rotenone minimizes the likelihood of toxic effects downstream if applied properly in a drained pond.
To neutralize the effects of rotenone, potassium permanganate (sold as Cairox) or chlorine can be used at a 1:1 or 2:1 ratio with the concentration of rotenone applied. Additionally, if fish are removed from treated waters quickly enough, they can often be revived by placing them in fresh water