NOAA changes Cook Inlet beluga survey schedule from annual to biennial
Careful monitoring of this important population will continue
NOAA Fisheries is reducing the frequency of abundance estimate surveys for endangered Cook Inlet beluga whales, switching from an annual to a biennial schedule. The aerial surveys, conducted over Cook Inlet every summer since 1994, will now be flown during even years only, with the next survey scheduled for June 2014.
We have been discussing a switch to a less frequent survey schedule for some time, as it is a more efficient and almost equally effective way to estimate population abundance and trends,” said John Bengtson, director of NOAA’s National Marine Mammal Laboratory, part of the Alaska Fisheries Science Center. “For scientists, determining the year-to-year changes in population estimates is less important than the long-term trend. That can be assessed just as easily, and at lower cost, with biennial surveys.”
The overall population trend for the past 10 years for Cook Inlet beluga whales shows that they have declined at an average annual rate of -0.6 percent. The population estimates have been as low as 278 whales and as high as 375 during the past decade.
A scientific analysis indicates that under a biennial aerial survey schedule, it would take only one or two years longer than with annual surveys to document a significant change in the population’s trend.
“The results of our analysis are fortuitous,” said Bengtson, “because decreased funding and rising costs are making it increasingly difficult to support these important surveys without compromising their scope and extent. The change in schedule will allow us to continue conducting the thorough surveys and analyses we have undertaken in the past.”
NOAA will continue to try to assess why the Cook Inlet beluga population is not recovering. Scientists will update and archive existing data, review photo identification data collected by research partners, and collaborate with other research groups studying the healthy beluga population in Bristol Bay to obtain information that is applicable to Cook Inlet belugas. If there is sufficient funding in 2014, NOAA plans to initiate a biopsy program to collect skin and blubber samples that will be used to determine the whales’ reproductive status as well as contaminant and stress levels, and age. This information can be added to the data for individual whales obtained through the photo identification studies.
The Cook Inlet beluga whale, one of five beluga populations recognized within U.S. waters, was listed as endangered under the Endangered Species Act in 2008. NOAA designated critical habitat for the population in 2011. NOAA Fisheries is currently drafting a recovery plan for Cook Inlet beluga whales and continues to fund research for the species.
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Posted: June 3, 2013
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