Metal levels in large-bodied fishes near impacted lakes near Yellowknife, NWT

Regions: North Slave Region

Tags: contaminants, environmental monitoring, fish, mercury, metals

Principal Investigator: Somers, Gila L (3)
Licence Number: 15950
Organization: GNWT ENR Water Resources
Licenced Year(s): 2017 2016
Issued: Aug 24, 2016
Project Team: Pete Cott (Co-led, University of Alberta), Mark Poesch (Researcher, Univesrity of Alberta), Katherine trembath (field support, GNWT ENR ), Ryan Gregory (field support, GNWT ENR ), Madison Hurst (field support, GNWT ENR ), Laura Krutko (field support, GNWT ENR )

Objective(s): To establish a long-term community monitoring program for contaminants in fish; and to monitor potential spatial and temporal trends in metal concentrations (including mercury) in fish tissues within the Yellowknife region.

Project Description: The objectives of this project are to collect fish tissue samples from species of subsistence importance to 1) establish a long-term community monitoring program for contaminants in fish; and 2) to monitor potential spatial and temporal trends in metal concentrations (including mercury) in fish tissues within the Yellowknife region. The data acquired will be added to existing and concurrently collected data from other researchers, and will tie into other biotic attributes and ecosystem functions in understanding impacts and changes in the Northwest Territories.

The research team will be using fish will be captured using single monofilament multi-paneled broad-scale monitoring (BSM) gillnets, which are a combination of the Ontario Small Mesh gillnets (ON2) and the North American Large Mesh gillnets (NA1). Mesh size will range from 0.5 to 5.0 inches. In addition to the BSM gillnets, angling will be used as required. The BSM gillnets will be set during the months of August/September for a duration of up to 24 hours, nets will be reset after being checked until desired sample sizes are attained. A targeted 30 fish per species per site will be collected for two species. This sample size was chosen to allow for the data to be useable for consumption guideline criteria by public health agencies as appropriate. The most common species captured during a site sampling event will be selected as the target species. Non-targeted species killed during fishing efforts will be kept and analyzed or archived for later analysis - all captured fish can provide valuable data, thus no bycatch is anticipated. The captured fish will be euthanized by receiving a stunning blow to the head followed by cutting of the gills. All collected fish will be processed for further measuring of attribute data (length, weight and sex), age determination through the extraction of otoliths and cleithra (for pike)

Results from this study will be shared publicly. Additionally, community members may assist the Government of Northwest Territories (GNWT) staff in the collection of fish in the Yellowknife region. All data generated from this study will be shared publicly and will inform local residents about the health of their aquatic environments and the fish they are eating.

Data and reports will be made publically available and shared with all communities. In the fall of 2016 plain language summary reports will be included as part of the NWT Environmental Research Bulletin and data/progress reports will be uploaded to the NWT Discovery Portal. It is also anticipated that community workshops will be held and a fish component will be added as part of the GNWT Water Resources Annual Water Strategy Workshop to reflect work completed as part of this project.

The fieldwork for this study will be conducted from August 24, 2016 to September 30, 2016.