2021-22 - Final Report - Understanding fish mercury concentrations in Dehcho lakes (CIMP154)

File Identifier: {265FA726-F445-445F-8B19-C3E0AF4D883C}

Metadata Language: en

Responsible Party:

Organisation Name: GNWT ENR

Role: Point Of Contact

Contact Info:

E-Mail Address: sebastian_toner@gov.nt.ca

Metadata Date: 2022-08-02

Metadata Standard Name: ISO 19139/19115 Metadata for Datasets

Metadata Standard Version: 2003

Abstract: In this project, Dehcho AAROM and University of Waterloo have been working together for ~ 10 years to investigate why mercury levels in fish vary among lakes in the Dehcho region, and how mercury levels in fish might change in the future in response to ongoing environmental change. In this three-year phase of the project, we sampled several more lakes (Fish Lake, Greasy Lake, Deep Lake) for fish, water, benthic invertebrates, sediment, and zooplankton. Catchments for all lakes in the study were also characterized. We compiled all available data for this project (dating back to 2013) to model mercury levels in Northern Pike from 11 lakes using piecewise structural equation models. Integrating feedback, ideas, and knowledge from Indigenous Guardians who work together with University researchers on the land each summer, we developed a model that explains >80% of the among-lake variation in mercury levels in Northern Pike. The among-lake variation in fish mercury levels is explained by a complex interaction of catchment characteristics, water chemistry, levels of mercury in lower trophic levels, and fish ecology. Levels of mercury in Northern Pike are lower in lakes that are large relative to their catchments, and which are located in less steep catchments that have proportionally less forest cover. Relatively large lakes located in less forested catchments with shallow slopes have clearer water (less dissolved organic carbon) and lower concentrations of mercury in water and sediment. These lakes also have lower levels of mercury in benthic invertebrates, faster-growing fish, and ultimately lower levels of mercury in Northern Pike.

Language: en

Citation:

Contact Info:

Title: 2021-22 - Final Report - Understanding fish mercury concentrations in Dehcho lakes (CIMP154)

Date:

Date: 2022-08-02

Date Type: Publication Date

Topic Category: Environment and Conservation

Keyword Collection:

Keyword: Fish Habitat / Population / Harvest

Keyword: Fish Quality

Keyword: Human Health and Community Wellness

Keyword: Water and Sediment Quality

Spatial Extent:

West Bounding Longitude: -127.7092

East Bounding Longitude: -113.2919

North Bounding Latitude: 65.6409

South Bounding Latitude: 60.1813

Transfer Options:

URL: https://nwtdiscoveryportal.enr.gov.nt.ca/geoportaldocuments/2021-22%20-%20Final%20Report%20-%20Understanding%20fish%20mercury%20concentrations%20in%20Dehcho%20lakes%20(CIMP154).pdf

Distributor:

Distributor Contact:

Organisation Name: Cumulative Impact Monitoring Program (CIMP)

Role: Point Of Contact