Cook Inlet beluga whale population declining

Cook Inlet beluga whale. Photo courtesy of NOAA Fisheries

A biennial abundance report on endangered Cook Inlet beluga whales released Tuesday, Jan. 28, by NOAA Fisheries, says the population is estimated to be smaller and declining more rapidly than previously thought.

NOAA’s estimate is that the population size is now between 250 and 317, with a median estimate of 279.

The last population estimated, released in 2016, put the population at around 328 whales.

A number of factors are taken into account in making abundance estimates, which can vary from year to year. These include births and deaths, changes in beluga behavior or distribution, and statistical variability in the data.

Since the last population estimate NOAA has put new, more reliable methodology into use, and now estimates the 2016 abundance was more likely around 293 whales.

Jim Balsiger, Alaska regional administrator for NOAA Fisheries, said the new abundance and trend numbers are concerning.

“They indicate that we still have a long way to go to recover this iconic and highly endangered population,” he said.

The new abundance and trend estimates were developed by incorporating additional data and an improved methodology for analyzing the results of aerial population surveys. In the new report, abundance estimates dating back to 2004 have been adjusted using the new methodology.

“We’re confident that this new methodology provides a more accurate picture of the status of Cook Inlet belugas than the previous approach,” said Bob Foy, director of the Alaska Fisheries Science Center in Juneau.

NOAA Fisheries has been conducting aerial surveys of Cook Inlet belugas whales for over two decades to estimate population abundance.

The Cook Inlet stock is one of five beluga populations recognized in U.S. waters. Those whales were listed by NOAA in 2008 as endangered under the Endangered Species Act. The agency finalized a recovery plan for the Distinct Population Segment in December 2016.

Cook Inlet beluga whales are one of NOAA Fisheries’ species in the spotlight, an initiative that includes animals considered most at risk for extinction and priorities efforts for their recovery. The next population abundance survey for Cook Inlet beluga whales is set for June 2020.