Water quality, WHAM speciation, PARAFAC components, and elemental concentrations in water, sediments, and animals from Yellowknife (Northwest Territories, Canada, 2024)

Water samples were collected from approximately 2 m depth in triplicate, including unfiltered and 0.45 μm filtered fractions. Surface sediments were collected from the deepest zone and from the littoral zone of each lake in triplicate. H. azteca were sampled from shoreline sediments using a kick net.

In Yellowknife Bay, H. azteca were also sampled using an Ekman grab and sieved (500 μm mesh size) at two sites. Bulk zooplankton samples were collected by horizontal transects approximately 2 m below the surface using a plankton net (1 m diameter, 200 µm mesh). All methods are described in detail in the associated article.

The first file (Excel format) contains integrated environmental and biological data. It includes the station metadata (sampling date, GPS coordinates, weather conditions, altitude, and lake depth) and in situ water quality measurements (pH, chlorophyll, conductivity, dissolved oxygen, redox potential (ORP), turbidity, water temperature and pressure). The dataset also includes direct carbon measurements (DIC, DOC) and dissolved organic matter (DOM) characterization, including fluorescence indices and PARAFAC-derived components (C1-C5), as well as nutrients (TP, TN) and major ions (PO43-, F-, Cl-, Br-, NO2-, NO3-, SO42-).

Also included are the elemental concentrations measured by ICP-MS/MS, including REEs, U, Th, Fe, and As in filtered and unfiltered surface waters, as well as in bulk zooplankton, amphipods, and sediments. Speciation results are also provided for As(V), obtained using high performance liquid chromatography (HPLC) and quantified using ICP-MS/MS with Aglient MassHunter (v4.6) software. Stable isotope data (d13C, d34S) are included for animals and sediments.

Parameter units, detection limits, and certain analytical details are also provided, with remaining details provided in the associated article. This dataset was developed to evaluate the potential of H. azteca and zooplankton as biomonitors of REEs, U, Th, and As across the Yellowknife region. The data support the assessment of contaminant distribution, elemental geochemistry in aqueous systems, and relationships between water physiochemistry, metal speciation, and bioaccumulation patterns across multiple environmental compartments.

The second file (db7 format) is compatible with WHAM software and contains the constants used in WHAM speciation models, along with their sources, to support further geochemical modelling.