Understanding and Predicting Mercury in Dehcho Lakes, Northwest Territories

Samples/data collected by joint University-community monitor team during on the land camps in 2018-2020. Data Collection: a. Fish (15-20 individuals/species, up to 4 food fish species/lake: captured with gill nets and dissected) • Mercury concentration in fish flesh, stable isotopes of carbon and nitrogen in fish flesh, fish age.

b. Benthic Invertebrates and sediments (min. 3 samples/taxa at 5 sites/lake) • Profundal and littoral invertebrates collected with Ekman dredges and kick nets; • Samples coarsely sorted in the field to Order, divided in half, and: i) preserved in ethanol for taxonomic identification; ii) frozen for stable isotope and total and methyl Hg analysis; • Sediments collected with an Ekman dredge, frozen for analysis of Hg and MeHg.

c. Zooplankton (min. 3 sample/size fraction at 3 sites/lake) • Collected with vertical tows, size-fractioned in the field; • Half of each size fraction preserved in ethanol for community composition analysis, other half frozen for stable isotope and total and methyl Hg analysis.

d. Water (min. 3 sites/lake – top and bottom) • Filtered and unfiltered water samples collected from each lake, and from influent streams and wetlands. Ultra-trace sampling methods used for mercury.

e. Abiotic • Catchment size and slope, lake area and volume, % wetlands and hydrology in catchment, underlying geology determined using GIS.

Laboratory Analysis: a. Standard water chemistry: University of Alberta (ions, nutrients, chlorophyll-a); b. Total and methyl mercury analyses: Western University (ISO-accredited); c. Stable isotope ratios of carbon and nitrogen: University of Waterloo; d. Fish age: AAE Tech (Manitoba).

Identifier
Source https://www.polardata.ca/pdcsearch/PDCSearchDOI.jsp?doi_id=13080
Metadata Access http://www.polardata.ca/oai/provider?verb=GetRecord&metadataPrefix=fgdc&identifier=13080_fgdc
Provenance
Creator Swanson, Heidi; Low, George
Publisher Canadian Cryospheric Information Network
Contributor Polar Data Catalogue
Publication Year 2019
Rights Research programs, CCIN, or ArcticNet take no liability for the use or transmission of this data
OpenAccess true
Contact hswanson(at)uwaterloo.ca; pdc(at)uwaterloo.ca
Representation
Language English
Format Computer file
Discipline Ecology;Chemistry
Spatial Coverage (-123.084W, 60.186S, -117.492E, 63.414N)
Temporal Coverage Begin 2018-08-01T00:00:00Z
Temporal Coverage End 2020-09-29T00:00:00Z