5d5c20ed-00d1-47e3-b78f-c76780401637 eng; CAN Polar Data Catalogue Canadian Cryospheric Information Network (519) 888-4567 x32689 200 University Avenue West, University of Waterloo Waterloo Ontario N2L 3G1 Canada pdc@uwaterloo.ca 2022-04-08T12:58:58 North American Profile of ISO 19115:2003 2009-01-01 https://www.polardata.ca/pdcsearch/PDCSearchDOI.jsp?doi_id=976 Mercury Concentrations and Rates of Biogeochemical Transformations in Marine Waters of the Canadian Arctic Archipelago 2016-04-06 Vincent St. Louis Igor Lehnherr Jane L. Kirk Unpublished with approval from Vincent St. Louis Sample collection took place during both legs of the 2005 CCGS Amundsen cruise, during Leg 1 in 2006 and during Leg 3 in 2007. Water samples were collected using Teflon-lined Niskin bottles mounted on the ship¿s rosette system, at sites ranging from Hudson Bay, the North Open Water Polynya, the Northwest Passage and the Beaufort Sea. The water column was sampled at the surface, middle and bottom in 2005 and 2006 and at the surface and chlorophyll maximum in 2007. The resulting water chemistry dataset includes concentrations of total Hg, MMHg, DMHg and GEM in water. In addition, samples were also analyzed for sulfate and dissolved organic carbon in 2007 and for sulfate only in 2006. To quantify rates of biogeochemical Hg transformations in the water column, some water samples were amended with Hg stable-isotope tracers, namely 198Hg(II) and MM199Hg, and incubated on-board the ship for up to 25 hours before being preserved by acidification or freezing. Samples were then analyzed for MMHg, DMHg and GEM, using various mass-spectroscopy techniques at either the University of Alberta or Trent University. Thus, the rate of transformation of the 198Hg(II) tracer into MM198Hg, for example, could be quantified. This dataset includes rate constants for the following water column processes: the methylation of Hg(II) to MMHg, the methylation of MMHg to DMHg, the demethylation of MMHg, the reduction of MMHg to Hg(0) and the reduction of Hg(II) to Hg(0). Mono-methylmercury (MMHg), a toxin which biomagnifies through foodwebs, is found in some Arctic marine mammals at concentrations that may be harmful to Northern Peoples consuming these animals as traditional food. The key process resulting in the contamination of organisms with mercury (Hg) is the methylation of inorganic Hg(II) to MMHg, which is much more readily bioaccumulated than Hg(II). Unfortunately, the sources of MMHg in Arctic aquatic ecosystems are not known. Therefore, the data was collected for three principal purposes: 1) To characterize the spatial distribution of the four principal chemical species of mercury in marine waters of the Canadian Arctic Archipelago (CAA), including total Hg, MMHg, dimethyl mercury (DMHg) and gaseous elemental mercury (GEM). 2) To quantify the flux of gaseous mercury species (GEM and DMHg) at the air-water boundary at the sites sampled and determine whether the marine waters of the CAA are a source of GEM or DMHg to the atmosphere. 3) To experimentally quantify the rates, using Hg stable-isotope tracers, of the major biogeochemical processes involved in the cycling of mercury in marine waters of the CAA. The processes for which rates were quantified include: production of MMHg from Hg(II), production of DMHg from Hg(II) and MMHg, demethylation and reduction of MMHg, and reduction of Hg(II) to Hg(0). Polar Data Catalogue Canadian Cryospheric Information Network (519) 888-4567 x32689 200 University Avenue West, University of Waterloo Waterloo Ontario N2L 3G1 Canada pdc@uwaterloo.ca polardata.ca http https://metadata.arice-h2020.eu/geonetwork/srv/api/records/5d5c20ed-00d1-47e3-b78f-c76780401637/attachments/map.png Bioaccumulation Biogeochemistry Canadian Arctic Archipelago Contaminants Hudson Bay Mercury Mercury speciation Methylmercury Total gaseous mercury Polar Data Catalogue Thesaurus (Canada) 2021-06-02 Canadian Cryospheric Information Network (519) 888-4567 x32689 200 University Avenue West, University of Waterloo Waterloo Ontario N2L 3G1 Canada pdc@uwaterloo.ca polardata.ca http https://www.polardata.ca/pdcinput/public/keywordlibrary Canadian Arctic Archipelago and Hudson Bay Terms of Use of the Polar Data Catalogue: https://www.polardata.ca/pdcinput/public/termsofuse eng; CAN environment -133.6 -64.8 54.7 79 Time period can be either covered by the content of the dataset or the date when the data has been collected. 2005-08-16 2008-08-08 Summary: Not Applicable Research Program(s): ArcticNet. For further information: vince.stlouis@ualberta.ca false Digital file 1.0 Polar Data Catalogue Canadian Cryospheric Information Network (519) 888-4567 x32689 200 University Avenue West, University of Waterloo Waterloo Ontario N2L 3G1 Canada pdc@uwaterloo.ca This metadata was generated from the PDC metadata database at 2021-06-02 Polar Data Catalogue Canadian Cryospheric Information Network (519) 888-4567 x32689 200 University Avenue West, University of Waterloo Waterloo Ontario N2L 3G1 Canada pdc@uwaterloo.ca