Black Earth Creek Included in Statewide Neonic Study of Impacts on Trout Streams
Matt Mitro - WDNR Office of Applied Research, Fisheries Research and Andy Morton - BECWA Board of Directors
The prolific use of neonicotinoids to protect crops from insects in agricultural areas across the Midwest has raised concerns about the health of aquatic ecosystems and potential effects on important fisheries, such as the Black Earth Creek trout fishery. Neonics are generally of low toxicity to vertebrates such as fish, but fish populations feed and depend on organisms, such as aquatic insects and crustaceans that may be sensitive to neonic pesticides. Much remains unknown about neonic concentrations in trout streams, levels and effects of neonic exposure on stream macroinvertebrates, and indirect effects of neonics on trout fisheries.
Power point about the Effects of Neonicotinoids on Wisconsin Trout Streams:
WDNR is currently studying levels of three neonicotinoids in cold water trout streams in selected watersheds throughout Wisconsin. The three neonicotinoids most commonly used in Wisconsin include clothianidin, imidacloprid, and thiamethoxam. This study will also evaluate how observed neonic levels in streams impacts aquatic macroinvertebrates and evaluate how neonics indirectly impair trout fisheries and stream ecosystems.
In the first year of the study, we sampled neonic levels in a wide variety of trout streams and watersheds. Currently in the second year of the study, some streams were resampled and additional effort was put into weekly surveys in four Dane County streams (including those in the Black Earth Creek Watershed) to evaluate how neonic concentrations vary over time. We also sampled stream macroinvertebrates at all study sites, and will make use of available and future Fisheries Management fish surveys as needed.
