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Found 10 records similar to Mercury in lake sediment cores of eastern and northern Canada
This dataset contains 2005 concentrations of total mercury (THg), gaseous elemental mercury (GEM), methylated mercury, dimethyl mercury (DMHg) in the water column of the Canadian Arctic. Mercury in the Arctic is an important environmental and human health issue. The reliance of Northern peoples on traditional foods, such as marine mammals, for subsistence means that they are particularly at risk from mercury exposure. Mercury concentrations on biological organisms have increased since the onset of the industrial age and are controlled by a combination of abiotic factors, food web dynamics and structure, as well as animal behavior.
Kejimkujik National Park, in Nova Scotia, Canada, is a sensitive region for heavy metal contamination, such as mercury, in part due to long-range atmospheric deposition from global and regional industrial regions. The region is remote from industrial centres, but is downwind of major pollution sources in North America and Canada, and historically had numerous gold mining sites. The region has also experienced anthropogenic acidification from sulphate deposition over the 20th century, which has resulted in limnological conditions favourable for mercury (Hg) methylation within Kejimkujik lakes. Kejimkujik is therefore known to be a hotspot for methylmercury (MeHg) bioaccumulation and biomagnification, with the highest mercury concentrations detected within common loon (Gavia immer) populations across Canada and North America.
We set out to examine possible links between climate warming and increases in mercury concentrations ([Hg]) in landlocked Arctic char (S. alpinus) in the High Arctic. Mercury concentrations vary regionally and have remained constant or increased slightly in landlocked char in lakes on Ellesmere Island and Cornwallis Island over a 12-16 year period. This, despite declining industrial mercury emissions in North America. Therefore, we hypothesized that climate warming might increase the input of mercury from catchments through permafrost melt, leading to greater associated body burden of adult char.
Lake sediment cores were collected from several locations in Canada as part of the historic mercury and heavy metal deposition trend, analysis, and research component of the Clean Air Regulatory Agenda/Climate Change and Air Pollutant (CARA/CCAP) and Oil Sands Monitoring (OSM) programs. The reason sediment core analysis is used for research purposes is the bottom of a lake can act as a record of the contaminants and all other materials which have fallen into the lake over time. The lake water acts as both a sorting device and as a preservative since the deposits fall in chronological order and if not subject to dredging are not normally otherwise disturbed by humans. In areas where depositional histories are complex, including changing contributions from local, regional and global sources, multiple dated lake sediment cores are useful tools for examining response of not only aquatic ecosystems, but their surrounding landscapes through time to changing emission/deposition scenarios.
The Flin Flon copper–zinc smelter is a site of concern as it has been the largest single source of atmospheric mercury emissions in Canada until operations ceased on July 1, 2010. The smelting and mining activities resulted in mercury contamination to the local environment. Elevated levels of mercury and other trace metals were found in soil humus, peat, plants, fish and sediment cores. The Flin Flon smelter of the Hudson Bay Mining and Smelting Company is located near the Manitoba–Saskatchewan border, 600 km Northwest of Winnipeg and over 400 km away from other major industrial complexes.This study examined nine lakes (Nekik, Douglas, Loucks, Phantom, McClurg, Cleaver, Naosep, Hamel, and Meridian) each lake was located at varying differences within 75 km of the smelter stack these lakes were selected for sediment coring analysis and heavy metal deposition trends.
Sediment from Lakes
Polycyclic aromatic hydrocarbons (PAHs), 47 elements including numerous metals, and visible reflectance spectroscopy or VRS-chla have been determined in sediment core samples collected in 2012, 2013 and 2014 from 16 small (surface area 4-97 ha; maximum depth ~1-5 m deep), hydrologically simple lakes located 30 to 120 km from major oil sands development areas. Canadian Council of Ministers of the Environment (CCME) guidelines are available for 13 of the 53 PAHs reported here. Sediment concentrations did not exceed Canadian Council of Ministers of the Environment (CCME) probable effects levels (PELs), which define the level above which biological adverse effects are expected to occur, for PAHs in any lake. Exceedances of the CCME interim sediment quality guidelines (ISQG) for the protection of aquatic life occurred for 4 PAHs (naphthalene, 2-methyl naphthalene phenanthrene, and benzo(a)pyrene) in 8 lakes.
The Experimental Lakes Area (ELA), in Ontario, Canada, is a sensitive region for heavy metal contamination, such as mercury, in part due to long-range atmospheric deposition from global and regional industrial regions. The region is remote from industrial centres, but is downwind of major pollution sources in North America and Canada, and historically had numerous gold mining sites. Supplemental Information
The Climate Change and Air Pollution (CCAP) program was established in 2016 to identify the severity and extent of adverse impacts of current and future air emissions on aquatic ecosystems to support regulatory actions and policy development. The program includes a number of components, including identifying, monitoring and defining air quality and greenhouse gas (GHG) concerns; improving our understanding of the short- and long-term effects of atmospheric pollutants on the environment; developing a plan to combat climate change; and monitoring and reducing both domestic and transboundary emissions of GHGs.
Measurements of gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM) and particulate bound mercury on PM2.5 (referred to as PBM2.5) were collected by Environment and Climate Change Canada from August to September 2013 at the Wood Buffalo Environmental Association (WBEA) Air Monitoring Station (AMS) 13 – Fort McKay South, and at WBEA AMS 4 – Buffalo Viewpoint. Monitoring resumed at WBEA AMS 13 in September 2014 with two speciated mercury instruments and is ongoing. One speciated mercury instrument monitors GEM, GOM, and PBM2.5; the second speciated mercury instrument monitors GEM, GOM, and mercury on PM10 (referred to as PBM10). These data are the first atmospheric speciated mercury measurements to be reported in the oil sands region.
Ambient concentrations of speciated mercury (Hg) have been measured at many locations across Canada. Mercury in the atmosphere is measured in three operationally-defined forms - gaseous elemental mercury (GEM), reactive gaseous mercury (RGM), and particulate-bound mercury (PBM). Under most conditions, GEM (or Hg0) is the predominant species in the air (~95-99%), while RGM and PBM concentrations are typically two orders of magnitude lower, i.e., <5% of the total atmospheric mercury concentration (Schroeder and Munthe, 1998). Reactive gaseous mercury is thought to consist of compounds such as HgCl2, HgBr2, Hg(OH)2 (Lin and Pehkonen, 1999), although the exact composition is unknown.
The purpose of this study is to examine trends over time of mercury and other trace elements, as well as legacy and new persistent organic pollutants (POPs) in landlocked Arctic char collected annually from lakes near the community of Resolute Bay on Cornwallis Island (Amituk, Char, North, Small, and Resolute) and in Lake Hazen in Quttinirpaaq National Park on Ellesmere Island. The project is also examining links between climate warming and increases or decreases in mercury concentrations in landlocked char. Sampling of water and Arctic char was aided by local people between 2005 and 2007. Many scientific publications have been produced from this project, and results have been discussed in the Canadian Arctic Contaminants Assessment Report III (2013): Persistent Organic Pollutants in Canada's North, Canadian Arctic Contaminants Assessment Report III (2012): Mercury in Canada’s North, and the Synopsis of Research Conducted under the 2015–2016 and 2014-2015 Northern Contaminants Program.