Long-term changes in Wolf Lake (Sudbury region, Ontario) situated in Mi’iangan Zaagagan Preserve: a proposed Indigenous conservation area
Data files
Dec 04, 2025 version files 55.94 KB
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Diatom_Assemblage_Count_Data.csv
42.14 KB
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Environmental_Data.csv
4.44 KB
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README.md
2.77 KB
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Sedimentary_Metal_Data.csv
6.59 KB
Abstract
Aquatic ecosystems in northern Ontario (Canada) have been widely studied for responses to anthropogenic activities. Specifically, the adverse effects from metal smelting has cause atmospheric deposition of acidic and metal pollution. Sudbury (Ontario) has been considerable researched for the effects of century long large-scale mining and smelting operations; however, local Indigenous freshwater resources have been largely ignored. Wolf Lake, located ~50 km northeast of Sudbury, is a culturally important site to the Wahnapitae First Nation and local community, providing many ecosystem services. Given its significance, the lake and surrounding old growth red pine (Pinus resinosa) forest is being proposed as an Other Effective area-based Conservation Measure. To determine pre-disturbance conditions to inform management decisions for the proposed conservation site, paleo-ecotoxicological approaches were applied. Here we use a multi-proxy approach of water chemistry records and sedimentary metals, chlorophyll a, dissolved organic carbon, and diatom assemblages from a dated sediment core to reconstruct long-term changes in Wolf Lake. A 40-year water chemistry dataset was analyzed from the Ministry of Environment, Conservation and Parks to reconstruct long-term lake water metal concentrations against sedimentary metal concentrations. Sedimentary metal concentrations were used to plot against threshold and probable effect concentrations and calculate enrichment factors. Chlorophyll a values were used to infer paleoproduction while dissolved organic carbon was used to infer past lake water conditions. The diatom assemblage was applied to a regional transfer function to estimate past lake water pH. Results indicated that Wolf Lake experienced lake water acidification and metal pollution linked to atmospheric deposition and complete recovery has yet to occur.
Dataset DOI: 10.5061/dryad.jwstqjqpw
Description of the data and file structure
Data was collected between 2022-24. The sediment core was retrieved from the lake in 2022 and sectioned into 0.5 contiguous intervals. Then analyzed for sedimentary metals, diatoms, geochronology, chlorophyll-a, dissolved organic carbon, and calculated pH transfer function.
This study was conducted in collaboration and co-authored with the Wahnapitae First Nation and permitted for publication and distribution.
Files and variables
File: Diatom_Assemblage_Count_Data.csv
Description: Species data was collected for 35 intervals spanning the core. Minimum 500 valves were enumerated per interval. The data is reported in relative abundance. Diatoms were identified to general and species level when possible.
Variables
- Depth - midpoint of interval in cm.
- Genera/species name across the top with relative percent abundance.
File: Sedimentary_Metal_Data.csv
Description: Geochemical sediment analysis was conducted at the Canadian Centre for Inland Waters. Metals data shows results for elemental concentration in sediment for 20 intervals spaced down-core. This data is reported in mg/kg, excluding Hg which is reported in ng/g.
Variables
- Depth - midpoint of interval in cm.
- 60 elements and their concentration by interval (mg/kg) excluding Hg (ng/g).
File: Environmental_Data.csv
Description: This data shows information of observed and calculated environmental variables by interval. Blanks represent intervals with no data.
Variables
- Depth (cm) - range of interval in cm.
- Year | CRS - 210Pb chronology estimates in y.
- Midpoint (cm) - midpoint of interval in cm.
- THg (ng/g) - total mercury in sediment in ng/g.
- Chl-a (mg/g dry wt.) - reconstructed chlorophyll a in mg/g.
- DOC (mg/L) - reconstructed dissolved organic carbon in mg/L.
- MATpH - modern analogue technique results for pH transfer function using Dixit et al. 2002.
- OBSpH - pH from lake water chemistry results.
- OBSDOC - dissolved organic carbon concentration from lake water chemistry results.
Code/software
All proxy data were plotted using the riojaPlot software (Juggins 2022) in R (R core team 2024).
Access information
Other publicly accessible locations of the data:
Data was derived from the following sources:
- Historical water chemistry for the lake was analysed from Inland Lakes Annual Chemistry Sudbury Area project facilitated by the Ontario Ministry of the Environment, Conservation, and Parks (OMECP).