Cook Inlet beluga population in steady decline

Cook Inlet belugas are in long term decline and have been listed as Endangered. Credit NOAA Fisheries, NMML.

October 2009. The endangered Cook Inlet beluga whale population is not showing any sign of recovery, according to the US National Oceanic and Atmospheric Administration's (NOAA) Fisheries Service's latest annual survey and estimate. NOAA scientists, analyzing recent population estimates, find a continued trend of gradual population decline.

Aerial survey
Scientists conducted aerial surveys in early June during fish migrations, when belugas concentrate near river mouths. Between June 2 and June 9, they flew over Cook Inlet counting the beluga whales while also taking photographs and video. Later, scientists carefully examined the images to provide a more accurate estimate of the beluga whale population in Cook Inlet this year - 321 beluga whales. For both 2007 and 2008, the estimate was 375 whales.

Listed as Endangered in 2008
NOAA Fisheries Service declared the Cook Inlet beluga population depleted in 2000 under the Marine Mammal Protection Act. However, the population did not recover as predicted, and the population was listed as endangered under the Endangered Species Act in 2008.

5 beluga populations in US waters
Cook Inlet belugas are one of five beluga populations recognized within U.S. waters. The other populations summer in Bristol Bay, the eastern Bering Sea, the eastern Chukchi Sea and the Beaufort Sea. The Cook Inlet population is considered the most isolated, based on the degree of genetic differentiation and the geographic distance between the Cook Inlet population and the four other beluga populations, which are not listed as endangered or threatened.
NOAA Fisheries Service is scheduled to propose designating areas of critical habitat for Cook Inlet beluga whales later this month.

Abundance estimates for belugas in Cook Inlet with 95% confidence intervals (vertical bars). In the years since a hunting quota was in place (1999-2009), the rate of decline (red trend line) has been -1.49% per year.