title: Hidden plastics of Lake Ontario, Canada and their potential preservation in the sediment record.
abstract: Microplastics are a source of environmental pollution resulting from degradation of plastic products and spillage of resin pellets. We report the amounts of microplastics from various sites of Lake Ontario and evaluate their potential for preservation in the sediment record. A total of 4635 pellets were sampled from the Humber Bay shoreline on three sampling dates. Pellet colours were similar to those from the Humber River bank, suggesting that the river is a pathway for plastics transport into Lake Ontario. Once in the lake, high density microplastics, including mineral-polyethylene and mineral-polypropylene mixtures, sink to the bottom. The minerals may be fillers that were combined with plastics during production, or may have adsorbed to the surfaces of the polymers in the water column or on the lake bottom. Based on sediment depths and accumulation rates, microplastics have accumulated in the offshore region for less than 38 years. Their burial increases the chance of microplastics preservation. Shoreline pellets may not be preserved because they are mingled with organic debris that is reworked during storm events.
authors.affiliation: Department of Earth Sciences, University of Western Ontario, London, Ontario N6A 5B7, Canada. Electronic address: pcorcor@uwo.ca.
authors.forename: Patricia L
authors.initials: PL
authors.lastname: Corcoran
authors.affiliation: Department of Earth Sciences, University of Western Ontario, London, Ontario N6A 5B7, Canada.
authors.forename: Todd
authors.initials: T
authors.lastname: Norris
authors.affiliation: Department of Earth Sciences, University of Western Ontario, London, Ontario N6A 5B7, Canada.
authors.forename: Trevor
authors.initials: T
authors.lastname: Ceccanese
authors.affiliation: Surface Science Western, University of Western Ontario, London, Ontario N6G 0J3, Canada.
authors.forename: Mary Jane
authors.initials: MJ
authors.lastname: Walzak
authors.affiliation: Environmental Monitoring and Reporting Branch, Ontario Ministry of the Environment, Toronto, Ontario M9P 3V6, Canada.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Helm
authors.affiliation: Aquatic Contaminants Research Division, Environment Canada, Burlington, Ontario L7R 4A6, Canada.
authors.forename: Chris H
authors.initials: CH
authors.lastname: Marvin
mesh_terms: D000327:Adsorption; D004784:Environmental Monitoring / Q000379:methods; D004787:Environmental Pollution; D019015:Geologic Sediments; D060106:Lakes; D008903:Minerals / Q000737:chemistry; D009864:Ontario; D010969:Plastics / Q000032:analysis*; D045483:Rivers; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D008903:Minerals; D010969:Plastics; D014874:Water Pollutants, Chemical
keywords: Accumulation rates; Lake Ontario; Lake-bottom sediment; Microplastics; Pellets