2015 Aerial Surveys of Arctic Marine Mammals

May 01, 2015

This report describes field activities of the Aerial Surveys of Arctic Marine Mammals (ASAMM) project conducted during summer and fall (1 July–31 October) 2015 and data analyses used to summarize field activities. Surveys were based in Barrow, Alaska, and Deadhorse, Alaska, and targeted the northeastern and southcentral Chukchi and western Beaufort seas, between 67°N and 72°N latitude and 140°W and 169°W longitude.

Sea ice cover in the study area in 2015 was generally light compared with historical (pre-2007) sea ice cover. In early July, sea ice in the eastern Chukchi Sea remained north of 71.5°N. By late July, sea ice remained in the Hanna Shoal area, but was otherwise absent from the Chukchi Sea study area. Sea ice persisted in most of the western Beaufort Sea through August. From early September through mid-October, sea ice was largely absent from the ASAMM study area although some grounded ice remained nearshore between Camden Bay and Deadhorse. By late October, new ice was forming in the northern blocks and in shallow nearshore areas in the western Beaufort Sea study area. The northeastern Chukchi Sea study area remained almost completely ice free through late October, with sea ice present only in shallow nearshore areas.

A total of 105 survey flights were conducted. The Barrow-based aerial survey team conducted surveys from 2 July through 30 October 2015, and the Deadhorse-based aerial survey team conducted surveys from 19 July through 8 October 2015. Total combined flight time was 521 hours, including 248 hours of transect survey effort. Over 132,000 km were flown, with 54,016 km of effort on transect. Surveys were conducted in the western Beaufort Sea in summer (mid July through August) for the fourth consecutive year and in block 23 (southcentral Chukchi Sea) for the second consecutive year.

There were 3,679 sightings of 93,180 marine mammals observed during all (transect, search, and circling) survey modes.

  • 594 sightings of 1,042 bowhead whales (Balaena mysticetus)
  • 259 sightings of 465 gray whales (Eschrichtius robustus)
  • 10 sightings of 17 humpback whales (Megaptera novaeangliae)
  • 17 sightings of 22 fin whales (Balaenoptera physalus)
  • 6 sightings of 6 minke whales (Balaenoptera acutorostrata)
  • 602 sightings of 1,799 belugas (Delphinapterus leucas)
  • 73 sightings of 87 unidentified cetaceans
  • 556 sightings of 86,229 Pacific walruses (Odobenus rosmarus divergens)
  • 13 sightings of 13 bearded seals (Erignathus barbatus)
  • 1,534 sightings of 3,379 unidentified pinnipeds
  • 15 sightings of 121 polar bears (Ursus maritimus).

Additional Resources

Last updated by Alaska Fisheries Science Center on 03/12/2019

Marine Mammal Protection Act Research in Alaska Aerial Surveys of Arctic Marine Mammals