A test of the possible influence of seabird activity on the (210)Pb flux in high Arctic ponds at Cape Vera, Devon Island, Nunavut: implications for radiochronology

作者：Michelutti N^*; Blais J M; Liu H; Keatley B E; Douglas M S V; Mallory M L; Smol J P

来源：Journal of Paleolimnology, 2008, 40(3): 783-791.

DOI：10.1007/s10933-008-9198-2

• (210)Pb radiochronology
• paleolimnology
• Arctic ponds
• biovectors
• northern fulmars
• polychlorinated biphenyls
• contaminants

A large seabird colony of northern fulmars (Fulmarus glacialis) at Cape Vera on Devon Island in the Canadian high Arctic has been shown to act as an effective biological pump, transporting large quantities of marine-derived nutrients and contaminants to the ponds beneath their nesting sites. Previous research has shown that seabirds also have the potential to elevate radionuclide concentrations in their immediate surroundings. Here, we assess the influence of the Cape Vera seabird colony on the (210)Pb budgets of six affected ponds and one control site, and discuss potential implications with respect to (210)Pb dating methodologies. In general, fluxes of (210)Pb at Cape Vera were similar to, or less than, those measured at other Arctic locations not influenced by seabirds. Plots of unsupported (210)Pb activity versus depth showed a number of non-monotonic features in all sediment cores, necessitating the use of the constant-rate-of-supply (CRS) model to derive age-depth profiles. We conclude that seabird activity has not dramatically increased the (210)Pb flux to the ponds at Cape Vera. Overall, the low flux of excess (210)Pb made accurate dating problematic for some of the study cores, necessitating the use of independent dating markers (e.g., (137)Cs and PCB concentrations) to verify the reliability of the chronologies.

• 出版日期2008-10
• 单位浙江大学