Historical Reconstructions of Hg in Puget Sound: Pre-Industrial, Environmental Regulations, and 21st Century

Mercury (Hg) is a pollutant of concern due to its tendency to bioaccumulate and cause harm to animals and humans. The Washington State sediment quality standards were established to identify the concentrations of Hg in sediment above which there is a potential for harm to humans or ecological species. The concentration of Hg can be historically reconstructed by spatial-temporal records in sediment. In order to determine if the urbanization of the Seattle/Tacoma region resulted in the transport of Hg to rural basins of Puget Sound, WA, the rural sub-basin of Carr Inlet was selected as the study site. Comparatively, urban areas typically demonstrate higher concentrations of Hg (Schuster et al, 2002). The objective of this research was to determine if the pre-industrial through 21st Century sediment concentrations of Hg in Carr Inlet exceed the sediment quality standards through time. The Carr Inlet never exceeded these standards