ABSTRACT
This chapter addresses two specific areas: Arctic marine mammals and selected inorganic pollutants. The species covered include cetaceans [bowhead (Balaena mysticetus), beluga (Delphinapterus leucas), and narwhal whales (Monodon monoceros) ], pinnipeds [ringed (Pusa hispida), bearded (Erignathus barbatus), spotted or largha (Phoca largha), ribbon (Histriophoca fasciata), harp (Pagophilus groenlandicus), and hooded (Cystophora cristata) seals; Pacific (Odobenus rosmarus divergens) and Atlantic walrus (O. rosmarus rosmarus) ] and polar bears (Ursus maritimus). Arctic marine mammals are long-lived, develop large fat depots and frequently occupy high trophic levels. Bowhead whales are known to live more than 100 years (George et al., 1999). These biological factors are key to the entry and magnification of the persistent and lipophilic forms of metals in this lipid-dependent food web, and for elements with non-lipid-dependent accumulation mechanisms. High trophic-level feeding (piscivory) sets the stage for biomagnification and bioaccumulation (increased levels in the predator versus the prey), where some chemicals can biomagnify (BMF = [X]predator/[X]prey > 1.0; where BMF = biomagnification factor and [X] = contaminant concentration). Polar bears feed on seals and are apex predators.
