Aerial Surveys of Eastern Chukchi Sea Stock

Principal Investigators Janet Clarke and Megan Ferguson (NOAA-NMFS), Robert Suydam (NSB), Bob Small and John Citta (ADF&G), Lloyd Lowry and Kathy Frost (ABWC), Jeff Denton (BOEM)
Collaborators ABWC, NMFS-NMML, NSB, ADF&G
Participants NMFS Observers: Vicki Beaver, Elly Chmelnitsky, Cynthia Christman, Christy Sims, Dan Twyman (and several more). Clearwater Air pilots: Stan Churches, Andy Harcombe, Alex Shibakov, Baine Thorn, Jake Turner


Through collaboration among the Alaska Beluga Whale Committee (ABWC), the North Slope Borough (NSB), the Alaska Department of Fish and Game (ADFG), and the National Marine Mammal Lab (NMFS), an aerial survey is being conducted to estimate the number of beluga whales in the Eastern Chukchi Stock. The survey began on 30 June, and 9 flights totaling 35 flight hours and 8,300 kilometers were flown. The beluga surveys recorded 28 sightings of 1,445 belugas.

Belugas and a bowhead in lead. Photo credit: Amelia Brower, NMFS permit 14245

COMIDA aerial surveys, sponsored by BOEM, began 4 July, and seven flights totaling ~34 flight hours and ~8900 kilometers have been flown. The COMIDA program surveys all marine mammals and these surveys recorded 1 sighting of 1 beluga. COMIDA aerial surveys will continue through October 2012. Click here to review Final COMIDA report.


Used twin turbine, high wing aircraft at 1200 feet survey altitude. At least two dedicated observers and one data recorder were on board with the pilot(s). Collected data on all marine mammals seen on transects and circled in on beluga sightings to determine group size.

Beluga and ASAMM Surveys

Summer Beluga Aerial Surveys



Focused on distribution and abundance of Eastern Chukchi Sea Stock of belugas from late June to mid-July. Previous beluga summer surveys were conducted 1996-98 and 2001-03.

Aerial Surveys of Arctic Marine Mammals (ASAMM) Project



Broader objectives and larger study area during early July to later October. ASAMM surveys have been conducted in the NE Chukchi Sea since 2008, with fairly consistent coverage since 2009.

Both Beluga and ASAMM efforts are combining data to get a better understanding of marine mammal distribution in the Chukchi and Beaufort Seas. Of particular interest to the ABWC will be the estimates for the population size of the Eastern Chukchi Sea beluga stock.

ABWC offshore transects extended 45 nm offshore in the NE Chukchi Sea, a coastal transect from Cape Lisburne to Pt. Barrow and offshore transects covering Barrow Canyon (hatched area). ASAMM survey area extends from 140-169W and 68-72N, and also included a coastal transect from Pt. Hope to Pt. Barrow.

July to August Summer Beluga Survey Results:

Distribution of the belugas was on the outer shelf and slope of the Beaufort Sea.

Sightings totals (#sightings/#whales):

  • Beaufort July: 226/610
  • Chukchi July: 29/1737
  • Beaufort August: 169/1643
  • Chukchi August: 4/7

July to October ASAMM Survey Results:

Majority of 2012 ASAMM sightings were in July and August (429 sightings of 3998 belugas), with relatively few in September and October (~78 sightings of 191 belugas), despite very good effort. Distribution of the belugas was mostly nearshore in NE Chukchi and on outer shelf, slope and Barrow Canyon in western Beaufort Sea. Important to note that belugas seen in September-October likely included whales from the Beaufort Sea Stock as well as the ECS stock.

Here are more preliminary results on the NOAA website for the beluga surveys from the eastern Chukchi Sea stock and the Beaufort Sea Stock.

June 30 to July 15, 2012 Group Size Results:

Group sizes ranged from 1 to 300. Largest groups were seen at three entrances to Kasegaluk Lagoon: 11-mile Pass on 6 July (400 belugas), Utukok Pass on 30 June (125 belugas) and 15 July (300 belugas), and Akoliakatat Pass on 3 July (400 belugas) and 6 July (400 belugas). Beluga sightings at lagoon entrances were often recorded in two groups (one outside the lagoon and one in the pass) but there was considerable exchange between the groups.

Belugas at Utukok Pass on July 15, 2012. Photo credit: Cynthia Crestman, NMFS permit 14341

Conclusions from the Beluga and ASAMM surveys:

  • Early July survey conditions were overall “pretty good” in both nearshore and offshore areas of northeastern Chukchi Sea; sea ice held sea states in check.
  • Belugas were not seen offshore in the northeastern Chukchi Sea either in early July or during the rest of the open water season, until mid-October.
  • Belugas were seen along the northwestern Alaskan coast, particularly at entrances to Kasegaluk Lagoon in early July (Eastern Chukchi Sea stock) and in Barrow Canyon and on the outer shelf and slope in the western Beaufort Sea (Eastern Chukchi Sea and Beaufort Sea stocks).
  • Overall beluga distribution in 2012 was similar to that observed in previous years, but sightings were far fewer than expected (and similar to those documented in 2007, 2008, and 2010).
  • Distribution and occurrence can vary a lot interannually.


  • Givens GH, Ferguson MC, Clarke JT, Willoughby A, Brower A, Suydam R, 2020. Abundance of the Eastern Chukchi sea Stock of Beluga Whales, 2012-2017. Arctic 73:485-498.
  • Lowry, LF, MCS Kingsley, DDW Hauser, J Clarke, and R Suydam. 2017. Aerial survey estimates of abundance of the eastern Chukchi Sea stock of beluga whales (Delphinapterus leucas) in 2012. Arctic 70:273-286.
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