SCIENTISTS from Alaska's National Oceanic and Atmospheric Administration's Fisheries Science Center announced that the 2012 abundance estimate for the endangered Cook Inlet beluga whale population is 312 animals, a small, but not scientifically significant increase over last year.
The populations have been as low as 278 whales and as high as 366 during the past decade.
The overall population trend for the past 10 years for Cook Inlet beluga whales shows them not recovering and still in decline at an annual average rate of 0.6 per cent, indicating these whales are still in danger of extinction in the foreseeable future.
For scientists, the year-to-year changes in population estimates are less important than the long-term trend.
Estimates can vary from year to year based on different sighting or survey conditions, weather, or changes in beluga behaviour or distribution.
Scientists say this year's survey had one unusual finding: whales venturing into relatively new waters.
A group of belugas was observed just offshore of West Foreland swimming north into upper Cook Inlet.
"Beluga whales have not been observed in this area during our surveys since 2001," said Kim Shelden, a NOAA scientist and chief scientist on the survey. "This group of 12 to 21 whales then moved into Trading Bay where they remained for the duration of the survey, not far from the mouth of the McArthur River.
"Groups of this size have not been seen during our beluga whale surveys south of North Foreland since 1995."
Every June, scientists with NOAA's Alaska Fisheries Science Center conduct aerial surveys of Cook Inlet.
From a small plane with bubble windows, scientists look for and count the beluga whales, and make video recordings of the whale groups.
The video and observer counts are analysed to produce the annual estimate.
Population estimates for the scope of the report are:
* 2003: 357
* 2004: 366
* 2005: 278
* 2006: 302
* 2007: 375
* 2008: 375
* 2009: 321
* 2010: 340
* 2011: 284
* 2012: 312
Reports on the survey and the analysis are available publicly on the Cook Inlet beluga web page.
The Cook Inlet beluga whale, one of five beluga populations recognized within US waters, was listed as endangered under the Endangered Species Act in 2008.
NOAA designated critical habitat for the population in April 2011. NOAA is currently developing a recovery plan for Cook Inlet beluga whales and continues to fund research on the species.
NOAA's mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources.