Alaskan Beluga Population Critical
White Whales of Cook Inlet Decline Despite End of Subsistence Hunt
Feb 26, 2008
The beluga whale (Delphinapterus leucas) tends to exist in separate small populations and this is part of what is contributing to the decline of the Cook Inlet discrete population segment. The multitude of activities in and around Anchorage, Alaska which have an impact on these whales makes it very difficult to determine which actions will be most critical to their survival.
Critically Endangered Status For Cook Inlet Population
The IUCN listed the Cook Inlet population of belugas as Critically Endangered in 2006. But the US government is just now considering listing this population as endangered under the Endangered Species Act since efforts to halt their decline by cutting subsistence hunts have failed. Since 1999 only five Cook Inlet beluga have been taken. In fact, in three out of the last nine years, Native Americans volunteered not to hold their annual subsistence hunt at all.
Habitat Loss and Ocean Noise Affect Belugas
Seismic exploration for gas and oil make ocean noise a concern for this species which depends on vocal interaction to maintain pod integrity and echolocation to find food. As if that weren’t enough, a sonar array in the inlet is being proposed to protect the bay from attack.
Habitat loss is expected to continue to be a problem for the Cook Inlet beluga whales. The Port of Anchorage has expansion plans that include filling in 135 acres. A plan to build a bridge linking Anchorage and Point MacKenzie would further decrease habitat for the belugas and likely add to the ocean noise level. Giving these whales endangered status would allow critical habitat to be established for them. This designated habitat would then receive greater protection.
Water Pollution An Important Factor
Beluga whales have been called sea canaries because of their melodious vocalizations. Now these animals can be considered coal mine canaries-giving a warning of the condition of the waters in which they live. Proximity to Anchorage exposes the Cook Inlet belugas to pollution from runoff and sewage discharge and a nearby military bombing range adds to the toxin exposure.
In the 1990s scientists learned that the white whales of the Saint Laurence Seaway were suffering from exposure to chemical contaminants, which resulted in high levels of unusual cancers. Although no similar studies have been done on Alaska's belugas, the two populations live in similar environments-largely enclosed waterways near areas of significant industrial development.
Predation by Killer Whales
Predation by killer whales was looked at as a possible contributing factor in the decline of Alaska's belugas. The orca, who are facing pollution related damage themselves, take about one Cook Inlet beluga a year which may not sound like much until it is compared with a total population estimate of 350 or less. Each adult taken from this beluga population significantly reduces their chance of recovery due to the loss of reproductively active animals.
With all these challenges it does not look good for the Cook Inlet belugas. The US government has been notoriously slow in giving deserving species endangered status. And this is a population that needs protection fast if it is to survive.
 |
