Minimizing the spread of New Zealand mud snails through decontamination of fishing gear: A comparison of approaches

New Zealand mud snails (NZMS) are an invasive species recently discovered in economically important trout streams in the Great Lakes region. NZMS are thought to be transported by attaching to fishing equipment. To help control NZMS spread we evaluated the effectiveness of several chemical compounds (Virkon Aquatic, Formula 409, bleach, and water as a control), 2 application methods (soaking and spraying) and two application durations (10 and 20 minutes) at decontaminating fishing waders. Following chemical exposure, we assessed NZMS mortality at timed intervals after placing snails in recovery chambers. One hour after exposure we observed differences in mean NZMS mortality (+/- SD) among chemical treatments, with the greatest caused by Formula 409 (100% +/- 0.0). Virkon resulted in 56.3% +/-23.94, bleach resulted in 68.8% +/- 23.94, and water had no effect on NMZS mortality. Neither application method nor duration had a significant effect on mortality. These results show that Formula 409, a readily available household cleaning product, holds promise as a practical way to decontaminate fishing gear, and minimize the spread of NZMS in aquatic ecosystems.