Data for relationships of pyrethroids, amphipods, wetland quality, and land use in Minnesota from 2019-2020

We investigated relationships among amphipod abundances (specifically, Gammarus lacustris and Hyalella azteca), land uses, and pyrethroid insecticide contamination in wetlands of Minnesota in years 2019 and 2020. Our study design targeted a large gradient of amphipod abundances and accounted for water quality, hydrology, and habitat metrics that commonly influence invertebrates. We found a significant, negative relationship between pyrethroid concentrations and the abundance of the two amphipod species. Pyrethroids were detected at relatively low concentrations (<2.5 ng/g sediment) in 44% of study wetlands and occurred most frequently in intensively cropped watersheds with low vegetative filter strip coverage. Wetlands on state and federal wildlife reserves had similar occurrence of pyrethroids to croplands.