title: Ecological and Landscape Drivers of Neonicotinoid Insecticide Detections and Concentrations in Canada's Prairie Wetlands.
abstract: Neonicotinoids are commonly used seed treatments on Canada's major prairie crops. Transported via surface and subsurface runoff into wetlands, their ultimate aquatic fate remains largely unknown. Biotic and abiotic wetland characteristics likely affect neonicotinoid presence and environmental persistence, but concentrations vary widely between wetlands that appear ecologically (e.g., plant composition) and physically (e.g., depth) similar for reasons that remain unclear. We conducted intensive surveys of 238 wetlands, and documented 59 wetland (e.g., dominant plant species) and landscape (e.g., surrounding crop) characteristics as part of a novel rapid wetland assessment system. We used boosted regression tree (BRT) analysis to predict both probability of neonicotinoid analytical detection and concentration. BRT models effectively predicted the deviance in neonicotinoid detection (62.4%) and concentration (74.7%) from 21 and 23 variables, respectively. Detection was best explained by shallow marsh plant species identity (34.8%) and surrounding crop (13.9%). Neonicotinoid concentration was best explained by shallow marsh plant species identity (14.9%) and wetland depth (14.2%). Our research revealed that plant composition is a key indicator and/or driver of neonicotinoid presence and concentration in Prairie wetlands. We recommend wetland buffers consisting of diverse native vegetation be retained or restored to minimize neonicotinoid transport and retention in wetlands, thereby limiting their potential effects on wetland-dependent organisms.
authors.affiliation: †School of Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5CB, Canada.
authors.forename: Anson R
authors.initials: AR
authors.lastname: Main
authors.affiliation: ‡Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5AB, Canada.
authors.forename: Nicole L
authors.initials: NL
authors.lastname: Michel
authors.affiliation: §Watershed Hydrology and Ecology Research Division, Water Science and Technology Directorate, Environment Canada, Saskatoon, Saskatchewan S7N 3H5, Canada.
authors.forename: John V
authors.initials: JV
authors.lastname: Headley
authors.affiliation: §Watershed Hydrology and Ecology Research Division, Water Science and Technology Directorate, Environment Canada, Saskatoon, Saskatchewan S7N 3H5, Canada.
authors.forename: Kerry M
authors.initials: KM
authors.lastname: Peru
authors.affiliation: †School of Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5CB, Canada.|∥Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada.
authors.forename: Christy A
authors.initials: CA
authors.lastname: Morrissey
mesh_terms: D000691:Anabasine / Q000032:analysis; D018556:Crops, Agricultural; D017753:Ecosystem; D065948:Grassland; D007306:Insecticides / Q000032:analysis*; D008962:Models, Theoretical; D010944:Plants; D012044:Regression Analysis; D012525:Saskatchewan; D014874:Water Pollutants, Chemical / Q000032:analysis*; D053833:Wetlands
chemical_list: D007306:Insecticides; D014874:Water Pollutants, Chemical; D000691:Anabasine