title: Microplastic contamination in Lake Winnipeg, Canada.
abstract: Microplastics are an emerging contaminant of concern in aquatic ecosystems. To better understand microplastic contamination in North American surface waters, we report for the first time densities of microplastics in Lake Winnipeg, the 11th largest freshwater body in the world. Samples taken 2014 to 2016 revealed similar or significantly greater microplastic densities in Lake Winnipeg compared with those reported in the Laurentian Great Lakes. Plastics in the lake were largely of secondary origin, overwhelmingly identified as fibres. We detected significantly greater densities of microplastics in the north basin compared to the south basin of the lake in 2014, but not in 2015 or 2016. Mean lake-wide densities across all years were comparable and not statistically different. Scanning electron microscopy with energy dispersive X-ray spectroscopy indicated that 23% of isolated particles on average were not plastic. While the ecological impact of microplastics on aquatic ecosystems is still largely unknown, our study contributes to the growing evidence that microplastic contamination is widespread even around sparsely-populated freshwater ecosystems, and provides a baseline for future study and risk assessments.
authors.affiliation: IISD-Experimental Lakes Area, 111 Lombard Ave. Suite 325, Winnipeg, MB R3B 0T4, Canada.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Anderson
authors.affiliation: Department of Biological Sciences, University of Manitoba, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada.
authors.forename: Sarah
authors.initials: S
authors.lastname: Warrack
authors.affiliation: Department of Biology, Lakehead University, 955 Oliver Road, Thunder Bay, ON P7B 5E1, Canada.
authors.forename: Victoria
authors.initials: V
authors.lastname: Langen
authors.affiliation: Department of Chemistry, University of Manitoba, 360 Parker Building, Winnipeg, MB R3T 2N2, Canada.
authors.forename: Jonathan K
authors.initials: JK
authors.lastname: Challis
authors.affiliation: Department of Environment and Geography, University of Manitoba, 127 Dysart Road, Winnipeg, MB R3T 2N2, Canada.
authors.forename: Mark L
authors.initials: ML
authors.lastname: Hanson
authors.affiliation: IISD-Experimental Lakes Area, 111 Lombard Ave. Suite 325, Winnipeg, MB R3B 0T4, Canada; Department of Biological Sciences, University of Manitoba, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada; Department of Biology, Lakehead University, 955 Oliver Road, Thunder Bay, ON P7B 5E1, Canada. Electronic address: mrennie@lakeheadu.ca.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Rennie
mesh_terms: D002170:Canada; D017753:Ecosystem; D004784:Environmental Monitoring; D060106:Lakes / Q000737:chemistry*; D010969:Plastics / Q000032:analysis* / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D010969:Plastics; D014874:Water Pollutants, Chemical
keywords: Contaminant trends; Exposure assessment; Great Lakes; Plastic fibres