Using Stable Isotopes and Mercury as Tracers of Paleoenvironmental Change in the Gulf of Alaska

• Main Authors: Hirons, Amy, Murray, M. S., Duffy, L. K., Schaaf, J. M.
• Format: Conference Object
• Language: unknown
• Published: NSUWorks 2006
• Subjects: Contaminant and organic biogeochemistry; Isotopic composition and chemistry; Marine systems; Paleoclimatology and paleoceanography; Food webs and trophodynamics; Marine Biology; Oceanography and Atmospheric Sciences and Meteorology; Arctic; Gulf of Alaska; Pacific; Alaska
• Online Access: https://nsuworks.nova.edu/occ_facpresentations/313

In this paper we present new proxy data bearing on Holocene paleoenvironmental change in the Gulf of Alaska region. The analysis of marine faunal frequencies in archaeological deposits, combined with paired studies of the stable carbon and nitrogen isotope ratios and mercury (Hg) and methylmercury (MeHg) values in the bone collagen of Holocene-era sea otter (Enhydra lutris) remains, sheds light on changes in the marine system which may reflect wider changes in the North Pacific and Arctic climate systems. Preliminary data indicate that incidences of increased mercury in sea otters also correspond to increased δ15N levels. These results may have resulted from the otters foraging at a higher trophic level, such as fish, and making them more susceptible to mercury contamination. We are exploring the connection betweens food web length, ocean production and mercury bioaccumulation and consider the implication of such research for understanding human/ marine environment interactions in the past, present and future, especially in light of projected global change scenarios.