The March 30 report from NOAA’s Alaska Fisheries Science Center notes that the Cook Inlet belugas, one of five beluga populations recognized within US waters, were listed as endangered under the Endangered Species Act in 2008.
NOAA designated critical habitat for this population of whales in April 2011 and is developing a recovery plan for them while continuing to fund research.
Rod Hobbs, a population biologist with the Cetacean Assessment and Ecology Program at the Alaska Fisheries Science Center in Seattle, said that to determine whether a population is recovering or declining, small changes from survey to survey don’t inform as much as the trend over a period of 10 to 20 years.
“Estimates can vary from year to year based on weather, oceanographic conditions, changes in beluga behavior or distribution and statistical variability in the data,” Hobbs said.
The Cook Inlet beluga population estimates have been as low as 278 whales and as high as 375 whales 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 0.4 percent, an indication that these whales are still in danger of extinction in the foreseeable future.
NOAA Fisheries biologists have been conducting aerial surveys of Cook Inlet for over two decades.
In Cook Inlet, they said, belugas concentrate near river mouths or shallow tidal bays during late spring and early summer in the northernmost reaches of the inlet. It is likely that the whales gather in these areas to feed on migrating fish, particularly eulachon and several species of North Pacific salmon.
Reports on the survey and the analysis are online at http://alaskafisheries.noaa.gov/protectedresources/whales/beluga/research.htm#ci.