NWT RESEARCH DATABASE

Tags: physical sciences, contaminants, mercury, fish health

Objective(s): To establish a long-term community monitoring program for contaminants in fish within the Gwich’in Settlement Area; and, to monitor potential spatial and temporal trends in metal concentrations (including mercury) in fish tissues within the Mackenzie River watershed and 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 within the Gwich’in Settlement Area; and (2) to monitor potential spatial and temporal trends in metal concentrations (including mercury) in fish tissues within the Mackenzie River watershed and 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. All sampling will be conducted during the winter months. In the Yellowknife region, 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, baited long-lines and ice-fishing (angling) will be used as required. The BSM gillnets and baited long lines will be set under-ice during the month of March for a duration of up to 48 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 if possible. This sample size was chosen to allow for the data to be useable for consumption guideline criteria by public health agencies as appropriate. To reduce impact to fish community, however, sampling efforts will cease once a single target species sample reaches n=30 or when two target species samples reach n=20, whichever happens first. The targeted species have not yet been determined. 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 frozen and shipped to the University of Alberta in Edmonton, AB, for further measuring of attribute data (length, weight and sex), age determination through the extraction of otoliths and cleithra (for pike) and analysis of tissue metal concentrations. In the Gwich’in Settlement Area fish will be acquired from the local peoples. If fish numbers are not great enough to reach the desired n=30 additional under-ice sampling will be conducted in the area to complete the dataset. Fishing methods will mirror those used in the Yellowknife region as described above. The objective of this project is to establish a long-term community monitoring program for contaminants in fish within the Gwich'in Settlement Area. Individual fish will be aquired from local peoples, if sample sizes aren't great enough, local community members will assist in the capture of more fish. Results from this study will be shared publically and it is anticipated that a fish component will be added to the Government of the Northwest Territories (GNWT) Water Resources Community Monitoring Program workshop, which is offered to community member across the Northwest Territories. Additionally, North Slave Metis Alliance community members will assist the GNWT staff in the collection of fish in the Yellowknife region. All data generated from this study will be shared publically 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. 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 March 2, 2016 to December 31, 2016.