title: Spatial distribution and trends of total mercury in waters of the Great Lakes and connecting channels using an improved sampling technique.
abstract: Environment Canada recently developed a clean method suitable for sampling trace levels of metals in surface waters. The results of sampling for total mercury in the Laurentian Great Lakes between 2003 and 2009 give a unique basin-wide perspective of concentrations of this important contaminant and represent improved knowledge of mercury in the region. Results indicate that concentrations of total mercury in the offshore regions of the lakes were within a relatively narrow range from about 0.3 to 0.8 ng/L. The highest concentrations were observed in the western basin of Lake Erie and concentrations then declined towards the east. Compared to the offshore, higher levels were observed at some nearshore locations, particularly in lakes Erie and Ontario. The longer-term temporal record of mercury in Niagara River suspended sediments indicates an approximate 30% decrease in equivalent water concentrations since 1986.
authors.affiliation: Water Quality Monitoring & Surveillance, Environment Canada, 867 Lakeshore Road, Burlington, ON L7R 4A6, Canada. Alice.Dove@ec.gc.ca
authors.forename: A
authors.initials: A
authors.lastname: Dove
authors.forename: B
authors.initials: B
authors.lastname: Hill
authors.forename: P
authors.initials: P
authors.lastname: Klawunn
authors.forename: J
authors.initials: J
authors.lastname: Waltho
authors.forename: S
authors.initials: S
authors.lastname: Backus
authors.forename: R C
authors.initials: RC
authors.lastname: McCrea
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D006114:Great Lakes Region; D060106:Lakes / Q000737:chemistry*; D008628:Mercury / Q000032:analysis*; D009864:Ontario; D011792:Quebec; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014877:Water Pollution, Chemical / Q000706:statistics & numerical data
chemical_list: D014874:Water Pollutants, Chemical; D008628:Mercury