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2014 Cook Inlet beluga count 340
The National Oceanic and Atmospheric Administration’s Alaska Fisheries Science Center said March 30 that the 2014 “abundance estimate for the endangered Cook Inlet beluga whale population is 340 animals, a slight but not scientifically significant increase over the 2012 survey, when the population was estimated at 312 whales.”
The survey, conducted for more than two decades, was annual from 1993 to 2012 and then became biennial.
Rod Hobbs, a population biologist with the Cetacean Assessment and Ecology Program at the Alaska Fisheries Science Center, said in a statement that small changes in the survey “don’t tell us 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,” he said.
The agency said that during the past decade population estimates have ranged from 278 to 375, but the overall trend for the decade has shown an annual average decline rate of 0.4 percent, “indicating these whales are still in danger of extinction in the foreseeable future.”
The Cook Inlet beluga whale population was listed as endangered under the Endangered Special Act in 2008, NOAA designated critical habitat for the population in 2011 and is developing a recovery plan for the population.
Cook Inlet belugas There are five stocks of beluga whales in the waters surrounding Alaska, with the most isolated the Cook Inlet stock, separated from other stocks by the Alaska Peninsula, NOAA said.
The small size of the population and the geographic and genetic isolation of the Cook Inlet whales, “has made this stock vulnerable to anthropogenic impacts,” including an unregulated Native subsistence hunt which occurred until 1999.
In 2000, Cook Inlet belugas were designated as depleted under the U.S. Marine Mammal Protection Act and are now managed with a small, regulated, Alaska Native subsistence hunt. Cook Inlet belugas were designated a distinct population segment when they were listed as endangered in 2008.
The survey The survey, typically conducted in June, effectively covers 32 percent of Cook Inlet and 100 percent of the coastline, NOAA said in its report on the 2014 aerial survey, released in March.
The survey is performed by aircraft and timed to coincide with a concentration of belugas near river mouths or in shallow bays during late spring and early summer, especially in the Susitna delta, Knik Arm and Chickaloon Bay. NOAA said the concentrations are likely associated with migration of anadromous fish, particularly eulachon and several species of Pacific salmon.
The report says that research protocol and coverage area “have been kept consistent to minimize variables in inter-year analyses. The type of aircraft, window configuration, altitude, air speed, and coastal search patterns were constant, and most of the observers have been on many or all of the surveys, maintaining continuity in effort.”
As for timing, all but one of the 21 surveys were done in the first half of June.
- Kristen Nelson
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