Base de données de recherche des TNO

Régions: North Slave Region

étiquettes: contaminants, phytoplankton, arsenic, polution

Objectif(s): To identify lakes in the Yellowknife region that show evidence of ecological impairment from arsenic pollution and to determine how seasonality affects arsenic toxicity to plankton.

Description du projet: This licence has been issued for the scientific research application No.5180. This project has two objectives. Objective 1 is to identify lakes in the Yellowknife region that show evidence of ecological impairment from arsenic pollution, in order to quantify the ecological impacts of arsenic pollution on Yellowknife lakes at a regional scale and determine which lake characteristics make lakes more (or less) vulnerable to arsenic. Objective 2 is to determine how seasonality affects arsenic toxicity to plankton in Yellowknife lakes, in order to identify the times of the year when freshwater life is most vulnerable to arsenic pollution. Both objectives will assess climate change risk and adaptation strategies for freshwater conservation in a cumulative effects framework that considers the role of legacy pollution. The research team will undertake a field sampling campaign of lakes in the Yellowknife region, collecting plankton and water samples. The research team will select lakes that span a gradient of distance from Giant Mine and represent the range of lake ecological conditions that exist in the Yellowknife region. The research team aims to: 1) identify lakes that have low plankton productivity and limited biodiversity that might be evidence of impairment from arsenic pollution; and 2) determine whether lake nutrient status and depth modify arsenic toxicity to plankton – in other words, two lakes may have the same arsenic concentration, but the impact on aquatic life is different because of the role of individual lake ecosystem factors in modulating arsenic toxicity. The research team will document seasonal fluctuations in arsenic cycling by sampling water and plankton in April, May, June, September, and November in Frame Lake, Handle Lake, Jackfish Lake, Fiddler Lake, and Stuart Lake. Arsenic and its different chemical forms will be measured and characterized in lake waters and plankton tissues, and linked to seasonal fluctuations in lake temperature, oxygen, and nutrient dynamics. At the same time, plankton community structure, biomass, and biodiversity will also be measured to infer how seasonal fluctuations in arsenic cycling may impact the lake food web. The research team will communicate the research plan and findings to the Yellowknives Dene through annual in-person meetings (following appropriate COVID19 protocols), beginning with project start-up this year through until the final results are analyzed and the project concludes. The research team will also prepare one-page plain language summaries of the project goals and findings to the Yellowknives Dene First Nation (YKDFN), the Giant Mine Remediation Team (GMRT), Office of the Chief Public Health Officer, and the GNWT Department of Environment and Natural Resources. All data and publications arising from the project will be made publicly available. The fieldwork for this study will be conducted from April 15, 2022 to November 27, 2022