Co-sampled fruticose and foliose epiphytic lichens as spatial biomonitors of airborne mercury and arsenic in a historical \"Gold Rush\" mining district

Historical gold mine tailings may have elevated total mercury (THg) and total arsenic (TAs) concentrations. We collected and analyzed the fruticose lichen genus Usnea and the foliose lichen genus Platismatia for biomonitoring airborne sources of Hg and As at the historical Montague Gold Mine District in Nova Scotia, Canada. We investigated spatial trends of Hg and As measured from 112 Usnea (10 species) and 113 Platismatia (2 species) lichen thalli collected across four sampling grids covering both tailings and non-tailings areas. Usnea consistently had higher THg concentrations, while Platismatia showed higher TAs concentrations. Areas where there was evidence of known past mining activities (i.e. mine shafts, stamp mills, Hg-amalgamation sites) were found to be hotspots for both Hg and As in the lichen samples collected nearby. These areas likely received greater inputs of these elements from windblown tailings or volatilization processes, or indirectly from the interception of these ..., , # Co-sampled fruticose and foliose epiphytic lichens as spatial biomonitors of airborne mercury and arsenic in a historical \"Gold Rush\" mining district

Dataset DOI: [10.5061/dryad.zgmsbccsc](https://doi.org/10.5061/dryad.zgmsbccsc)

## Description of the data and file structure

The goals of our research were (1) to assess the feasibility of co-sampling two morphologically different epiphytic lichens (fruticose vs foliose spp.) for biomonitoring airborne mercury (Hg) and arsenic (As) at the Montague gold mine tailings site in Nova Scotia, and (2) to investigate the fine-scale geospatial distribution patterns of Hg and As concentrations in the co-sampled lichens at Montague and interpret any spatial trends along a distance gradient from the tailings. Lichens (*Usnea* and *Platismatia* spp.) were sampled from spruce (*Picea* spp.) trees in July and August of 2019 across four sampling grids at Montague. Each sample was identified to the species level, homogenized, and analyzed for total m...,