PT12 Metals and Bioaccumulation
Exhibit Hall
8:00 AM - Tuesday
(PT161) Metals in apex predators of the Arctic.
Fisk, A1, Bechtol, W2, Svavarsson, J3, Letcher, R4, Norstrom, R5, Nagy, J6, Taylor, M7, Muir, D8, 1 University of Georgia, Athens, GA, USA2 Alaska Department of Fish and Game, Fairbanks, AL, USA3 University of Iceland, Reykjavík, Iceland4 University of Windsor, Windsor, ON, Canada5 Carleton University, Ottawa, ON, Canada6 Government of the Northwest Territories, Inuvik, NWT, Canada7 Government Nunavut, Iqaluit, NU, Canada8 Environment Canada, Burlington, ON, Canada
ABSTRACT- The polar bear (Ursus maritimus) is recognized as the apex predator of the Arctic and has been shown to occupy the 5th trophic level. Several other Arctic species that could potentially be classified as apex predators include the Greenland shark (Somniosus microcephalus), Pacific sleeper shark (Somniosus pacificus), and glaucous gull (Larus hyperboreus). As top predators these organisms are exposed to a wide range of metals and can accumulate high concentrations of mercury due to the process of biomagnification. Concentrations of 22 metals were determined in these species collected in Alaska (S. pacificus), Iceland (S. microcephalus), and Canada (all but S. pacificus). Differences in the biology of these species, and collection sites, may provide insights on mechanisms that influence metal distribution and accumulation in arctic biota. Concentrations of metals varied among species, with relative concentrations depending on the metal examined. For example, mercury concentrations were greatest in polar bears, followed by glaucous gulls, Greenland sharks and Pacific sleeper sharks. Whereas, cadmium concentrations were greatest in glaucous gulls and Greenland sharks, followed by Pacific sleeper sharks, and low levels in polar bears. Statistical analysis of all metals will be presented and related to the biological characteristics of the species examined.
Key words: seabird, polar bear, shark, mercury