NWT RESEARCH DATABASE

Regions: Dehcho Region, South Slave Region

Tags: contaminants, mercury, climate change, fish, monitoring, lake trout

Objective(s): To investigate trends in mercury, metals and persistent organic contaminants in lake trout.

Project Description: The objectives of this project are to: 1) continue to investigate trends in mercury, metals and persistent organic contaminants (POCs) in lake trout harvested from two locations (West Basin near Hay River, East Arm at Lutsel K’e) and burbot harvested from one location (West Basin at Fort Resolution) in Great Slave Lake in 2017 to further extend the long-term (1993-2015: POCs, 1993-2016 mercury and metals) database; 2) participate in and contribute information to Arctic Monitoring and Assessment Program (AMAP) expert work groups for trend monitoring of POCs and mercury, Environment and Climate Change Canada (ECCC’s) Climate Change, Clean Air Regulatory Agenda (CARA) and Chemical Management Plan (CMP) programs; 3) communicate results to Great Slave Lake partners and other communities in a timely manner. As part of this, contribute where requested to local community based monitoring programs such as that at Fort Resolution and the Tlicho Aquatic Ecosystem Monitoring Program (TAEMP); and, 4) continue other collaborations including with X. Zhu in his fish stock assessments studies in western Great Slave Lake. Fish are provided in the fall from the commercial fishery operating out of Hay River (20 lake trout), the domestic fishery at Fort Resolution (20 burbot and 20 pike) and Lutsel K'e (20 lake trout and 20 burbot). Fish are shipped to ECCC at Saskatoon. Fish are measured (length, weight, liver weight, gonad weight), sexed, stomach contents examined, and visually examined for obvious disease and parasites; aging structures are removed. Fillet is analyzed for mercury and stable isotopes. Lake trout fillet and burbot liver (Fort Resolution only) are examined every two years for a broad suite of organic contaminants. Results are reported annually and during community visits Fish are provided from three locations in Great Slave Lake by community members from their domestic or commercial fisheries. The research team maintain good dialogue with Fort Resolution, Hay River and Lutsel K'e, typically visiting once a year to go over study results and discuss issues of mutual interest. This year the team have worked extensively on posters summarizing the mercury findings which are of much interest to Great Slave Lake and other communities with implications to the domestic, commercial and recreational fisheries. The research team typically have one visit annually to Great Slave Lake where results are discussed. Timing is usually based on an invitation to an organized meeting with other visits made at that time. In addition, copies of reports, scientific papers, and posters can be sent. We recently have worked on posters of the mercury findings designed for community distribution. This year's Northern Contaminants Program workshop will be Yellowknife, September 26-28th. The fieldwork for this study will be conducted from July 15, 2017 to December 31, 2017.