NWT RESEARCH DATABASE

Regions: Dehcho Region

Objective(s): 1) to determine why fish mercury levels vary among lakes in the Dehcho region; 2) to identify best predictors of fish mercury levels; 3) to determine with fish have the lowest levels of mercury and the highest levels of nutrients; and, 4) to collect data on parameters that will be effected by climate change and that could potentially increase or decrease mercury concentration in food fish and/ or effect fish populations in general.

Project Description: This licence has been issued for the scientific research application No. 5590. The objectives of this research project are to: 1) determine why fish mercury levels vary among lakes in the Dehcho region; 2) identify best predictors of fish mercury levels; and, 3) determine with fish have the lowest levels of mercury and the highest levels of nutrients, 4) Collect data on parameters that will be effected by climate change and that could potentially increase or decrease mercury concentration in food fish and/ or effect fish populations in general. The methods for this project include field sampling, laboratory analysis, and data analysis and reporting. We collect food web data from each lake, which includes collecting phytoplankton, periphyton, zooplankton, benthic inverts and fish samples. The samples are then analyzed in a laboratory for stable isotopes (to determine food web structure - i.e., who eats who) and levels of total mercury. Each spring, the previous year’s results are reported back during community meetings and the regional Dehcho AAROM meeting. Collection of the samples involves hiring local community members with knowledge of the lake and fishery to go out with the researchers and assist in the collection. The collection of samples from the lakes will occur in March and August, for the most part, but this may change depending on logistics and availability of samplers. Dependence on the local fishers is crucial to catching the required amount of fish per each lake. Communication of the results back to the communities is the most important part of this research. After each field season is completed and samples have been analyzed, the results are reported to the related community (s) in plain language at community meetings. The first community meetings were held in November 2016 (Jean Marie River, Ft Providence, Kakisa), and the following rounds of meetings occurring in conjunction with the annual AAROM. Results were also communicated back during the annual NCP results workshop. The fieldwork for this study will be conducted from: July 25 - September 30, 2024