Analysis of mercury content of lichens in Nova Scotia: Potential use as passive air samplers
LE3 .A278 2017
Bachelor of Science
Mercury is a global pollutant present in a wide range of ecosystems. Atmospheric transport of elemental mercury gas enables this substance to be deposited far from its source. Quantifying mercury in biological indicator species, such as lichens, provides information about where mercury pollution may be an issue. Close to three hundred samples of Hypogymnia sp. and Usnea sp. mainly, but 11 lichen species in total were collected from trees throughout mainland Nova Scotia and analyzed for total mercury using thermal degradation-atomic absorbance analysis. The resulting concentrations and geolocations were mapped using QGIS 2.12 and ArcGIS 10.4 to produce kernel density analysis hotspot maps. From these maps, it was possible to discern areas of higher mercury concentrations and trends across Nova Scotia, Canada . The presence of high concentration features in areas with known mercury problems such as Kejimkujik National Park and National Historic Site suggested that lichens may be useful indicators of regional atmospheric mercury trends. Selected specimens were also ITS rDNA barcoded to confirm morphological identities.
The author grants permission to the University Librarian at Acadia University to reproduce, loan or distribute copies of my thesis in microform, paper or electronic formats on a non-profit basis. The author retains the copyright of the thesis.