Threatened, Endangered & Declining Species
contaminants have been implicated in the decline of some wildlife
populations. Therefore, the Service studies threatened and declining
species in Alaska to assess the role contaminants may play in the decline of these populations. In addition to studying
species listed under the Endangered Species Act, studies are also
conducted on non-listed, declining species. Proactive investigation
of factors contributing to these declines may help stem further population
reductions and preclude future listing of these species.
The Service manages three marine mammal species (polar bear, sea otter
and walrus). As top predators in the Arctic food web, polar bears
bioaccumulate some persistent contaminants. Polar bears, therefore,
may serve as sentinel species which reflect contaminant trends in
the Arctic. Because both polar bears and walrus are harvested for
subsistence, there is considerable interest in contaminants data for
these species. While sea otters are not hunted for food, they frequent
nearshore marine environments, where they are particularly vulnerable
to spills. The nearshore distribution and site fidelity of sea otters
contribute to their usefulness as a sentinel species. The
Marine Mammal Management Office, in partnership with the Alaska
Sea Otter and Steller Sea Lion Commission, maintains a biosampling
program that incorporates contaminant analyses. Both polar bears and
walrus inhabit marine habitats, and therefore must also be considered
when evaluating the potential impact of spills on resources managed
by the Service.
Contaminants can affect various bird species managed by the Service.
For example, seabirds are frequently impacted during marine oil spills.
The Service may also study avian species experiencing population declines,
species that are harvested for subsistence, or species that exhibit
abnormalities or diseases that might be linked to contaminant exposure.
Anadromous and Interjurisdictional Fisheries
Salmon and other anadromous fish are vitally important subsistence
resources for Alaska residents. When these fish return to spawning
areas, they also are consumed by freshwater and terrestrial predators.
Only recently have contaminants data been collected from salmon in
Alaska. The Service (through our Fairbanks Fish and Wildlife Field
Office) and the Alaska Department of Environmental Conservation have
coordinated efforts in recent years to ensure that high quality data
are obtained for Alaskan salmon.