Effect of Potassium Permanganate Treatments on New Zealand Mud Snail Behavior and Survival and Rainbow Trout Growth and Condition

Abstract

AbstractThe New Zealand mud snail (NZMS) Potamopyrgus antipodarum, a nonnative species recently introduced into North America, has been shown to negatively influence ecosystem function. Methods to control or eliminate NZMS are needed. Twenty‐four‐hour treatments with 2 mg of potassium permanganate (KMnO4) per liter of water were evaluated against NZMS held for 24 h in artificial stream sections that contained refuge areas. The snails did not seek refuge when placed into an area that contained KMnO4 and also had neutral preference when provided the opportunity to select between artificial stream sections with and without KMnO4. In a separate series of experiments, NZMS and rainbow trout Oncorhynchus mykiss were placed into hatchery raceway sections that were treated with a 2‐mg/L KMnO4 solution for 2 h/d over a period of 14 consecutive days. Mortality of NZMS and rainbow trout was not elevated in these raceways relative to nontreated control raceways. There was evidence, however, that the presence of the KMnO4 depressed fish growth (i.e., Fulton's condition factor). The KMnO4 treatment did not cause significant gill damage in rainbow trout. Our results show that KMnO4 at 2 mg/L is not effective in controlling or eliminating NZMS populations.