Diverse studies document intricate relationships among volcanoes, honey, salmon, and Indigenous peoples as part of a complex geochemical puzzle in the Pacific Northwest of North America

Abstract:

Vancouver (Canada) is a growing, modern city located at the interface of various natural and cultural environments, situated within complex and long-standing Indigenous histories that include extensive ancient long-distance trade and exchange. In addition to rapid developments in urban geochemistry, Vancouver’s unique geographic and socio-cultural setting warrants the use of trace elemental and isotopic analyses to assess the environmental impacts of anthropogenic activities on the ecological and human health. At the Pacific Centre for Isotopic and Geochemical Research, we established the local geochemical context (e.g., Garibaldi volcanic belt, Wrangellia flood basalts, and Cascadia Basin sediments) and apply multidisciplinary and multiproxy approaches to analyze honey and other beehive products, Pacific salmon, aerosols, as well as archaeological and other heritage materials to determine source apportionment, transport, and fate of metal pollutants and Indigenous belongings/artifacts. We find that honey and other hive products are useful biomonitors for modern, city-scale metal distributions, notably elucidating geospatial lead (Pb) trends using a combination of Pb isotopes and land use mapping. On a regional scale, Pb isotopic investigations of Pacific salmon and coastal species (e.g., herring, bivalves; all staple food sources for this region since antiquity) reveal a coastal, anthropogenic isotopic composition that matches that observed in honey from Metro Vancouver’s city centre. This further indicates the presence of a measurable, anthropogenic input to the local and regional geochemistry. We integrate Indigenous science and oral history with Western scientific analytical techniques (e.g., elemental concentrations, structural characteristics, and radiogenic isotope ratios) to provide multifaceted evidence for how and from where ancient people procured resources, such as obsidian. The intersection of geology, urban geochemistry, archaeology, and Indigenous science brings the anthropogenic geochemistry of this region into sharp focus at the city and regional scale. We witness the linkages between people and the environment in both the past and present, while looking to the future as the Anthropocene continues to shape the geochemistry of our world.