Rotenone in Fisheries: Are the Rewards Worth the Risks?

10. Utah’s Procedure for Mixing Powdered Rotenone into a Slurry

Charles W. Thompson, Craig L. Clyde, Douglas K. Sakaguchi, and Leo D. Lentsch

doi: https://doi.org/10.47886/9781888569339.ch10

Abstract.—-An aspirator, was developed by the Utah Division of Wildlife Resources to mix rotenone slurry used to eradicate undesirable fish species from Strawberry Reservoir, Utah, in 1990. An aspirator was the best method that Utah has developed for mixing powdered rotenone into a slurry. Slurry characteristics were as good or better than those achieved by any other mixing technique tried. The system utilized a high pressure pump that forced water through the aspirator creating suction used to vacuum powdered rotenone from bulk bags (1,000 lb capacity). The powder and water combined inside the aspirator chamber forming a slurry. The slurry was discharged directly on to the reservoir surface or delivered into barge tanks from the aspirator nozzle. Rotenone loss in the form of dust was significantly reduced compared to other mixing techniques and there was limited exposure of the chemical to personnel. One person could operate the aspirator efficiently.