Back

Document Title:

Contaminants and Sea Ducks in Alaska and the Circumpolar Region.

AUTHOR(S):
Deborah D. Rudis Charles J. Henny Thomas J. Roffe Everett Robinson-Wilson


VOLUME:
103
ISSUE:
S4
PAGES:
41 - 49

PUBLICATION DATE: May 1995

ABSTRACT:
We review nesting sea duck population declines in Alaska during recent decades and explore the possibility that contaminants may be implicated. Aerial surveys of the surf scoter (Melanitta perspicillata) , white-winged scoter (M. fusca) , black scoter (M. nigra) , oldsquaw (Clangula hyemalis) , spectacled eider (Somateria fischeri) , and Steller's eider (Polysticta stelleri) show long-term breeding population declines, especially the latter three species. The spectacled eider was recently classified threatened under the Endangered Species Act. In addition, three other diving ducks, which commonly winter in coastal areas, have declined from unknown causes. Large die-offs of all three species of scoters during molt, a period of high energy demand, were documented in August 1990, 1991, and 1992 at coastal reefs in southeastern Alaska. There was no evidence of infectious diseases in those scoters. The die-offs may or may not be associated with the long-term declines. Many scoters had elevated renal concentrations of cadmium (high of 375 µg/g dry weight [dw]) . Effects of cadmium in sea ducks are not well understood. Selenium concentrations in livers of nesting white-winged scoters were high ; however, the eggs they laid contained less selenium than expected based on relationships for freshwater bird species. Histological evaluation found a high prevalence of hepatocellular vacuolation (49%) , a degenerative change frequently associated with sublethal toxic insult. Cadmium and selenium mean liver concentrations were generally higher in those birds with more severe vacuolation ; however, relationships were not statistically significant. We do not know if sea duck population declines are related to metals or other contaminants.

PUBLICATION:
Environmental Health Perspectives

PUBLISHED BY:
National Institute of Environmental Health Sciences

DOCUMENT LINK:
http://www.ehponline.org/docs/1995/Suppl-4/henny-abs.html

NOTE: This link will take you to a site outside of the U.S. Fish and Wildlife Service. We do not control the content or policies of the site you are about to visit. You should always check site policies before providing personal information or reusing content.

ADDITIONAL LINKS:

USFWS Alaska

Last updated: February 13, 2013