Concentrations of metals and trace elements in blood of spectacled and king eiders in northern Alaska, USA

Abstract

In 1996, we measured concentrations of arsenic, barium, cadmium, lead, mercury, and selenium in blood of adult king (Somateria spectabilis) and spectacled (Somateria fischeri) eiders and duckling spectacled eiders from northern Alaska, USA. Concentrations of selenium exceeded background levels in all adults sampled and 9 of 12 ducklings. Mercury was detected in all adult spectacled eiders and 5 of 12 ducklings. Lead concentrations were above the clinical toxicity threshold in one duckling (0.64 ppm) and two adult female spectacled eiders (0.54 and 4.30 ppm). Concentrations of cadmium and mercury varied between species; barium, cadmium, mercury, and selenium varied between sexes. In female spectacled eiders, mercury concentrations increased during the breeding season and barium and selenium levels decreased through the breeding season. Selenium declined at 2.3 +/- 0.9% per day and levels were lower in spectacled eiders arriving to the breeding grounds in northern Alaska than in western Alaska. The variation in selenium levels between breeding areas may be explained by differences in timing and routes of spring migration. Most trace elements for which we tested were not at levels currently considered toxic to marine birds. However, the presence of mercury and elevated lead in ducklings and adult female spectacled eiders suggests these metals are available on the breeding grounds.

Elevated mercury levels in a wintering population of common eiders ( Somateria mollissima ) in the northeastern United States

“…Wayland et al (2008a) reported a mean blood Hg concentration of 0.19 lg/g wet weight (range: 0.06-0.47) in white-winged scoters in Canada. While some field studies across North America have investigated the presence of Hg in blood tissue of multiple eider species on their breeding grounds (Wilson et al, 2004;Wayland et al, 2008bWayland et al, , 2007Wayland et al, , 2001a, none have thoroughly examined the dynamics of Hg exposure in wintering eiders. It is important to consider the entire annual cycle when examining and comparing Hg values across different studies.…”

A Blood Survey of Elements, Viral Antibodies, and Hemoparasites in Wintering Harlequin Ducks (Histrionicus Histrionicus) and Barrow's Goldeneyes (Bucephala Islandica)

“…High blood selenium concentrations also have been described in otherwise healthy Alaskan waterfowl including Emperor Geese (Chen canagica), Long-tailed Ducks, Spectacled Eider, King Eider (Somateria spectabilis), and Common Eider (Franson et al, 1999Stout et al, 2002;Wayland et al, 2003;Franson et al, 2004;Wilson et al, 2004). Similarly, high tissue concentrations have been described in ducks from Canada (Henny et al, 1995;Wayland et al, 2001Wayland et al, , 2003Braune and Malone, 2006) and Russia (Stout et al, 2002).…”

“…Samples have usually been collected from nesting birds when they are most easily caught. Blood concentrations declined through the breeding period in Emperor Geese (Franson et al, 1999) and Spectacled Eiders (Wilson et al, 2004), suggesting exposure occurs on marine wintering grounds.…”

Use of lead isotope ratios to identify sources of lead exposure in Alaska Natives

“…Recent studies report elevated lead concentrations in eiders, a commonly hunted waterfowl, from the Yukon-Kuskokwim Delta region of western Alaska (11,12). The Alaska Native communities living around this region (e.g., Bethel) rely largely on a subsistence diet that includes waterfowl killed with lead shot.…”