2017 Aerial Surveys of Arctic Marine Mammals
This report describes field activities of the Aerial Surveys of Arctic Marine Mammals (ASAMM) project conducted during summer and fall (1 July–27 October) 2017, and data and analyses used to summarize field activities. Surveys were based in Utqiaġvik (formerly Barrow), Alaska, and Deadhorse, Alaska, and targeted the northeastern and southcentral Chukchi and western Beaufort seas, between 67°N and 72°N latitude, 140°W and 169°W longitude.
Sea ice cover in the study area in 2017 was light compared with historical (pre-2007) sea ice cover. When surveys commenced in early July, sea ice was present in the study area from approximately 143°W to 157°W, and remained there through mid-July. By late July, sea ice persisted only in the central Alaskan Beaufort Sea, but was otherwise absent from the study area. The study area remained ice free from early August through late October, when new ice began forming in shallow nearshore areas in the study area.
A total of 97 survey flights were conducted. The Utqiaġvik-based aerial survey team conducted surveys from 3 July through 25 October 2017, and the Deadhorse-based aerial survey team conducted surveys from 19 July through 10 October 2017. Total combined flight time was 505.7 hours, including 257.9 hours of transect effort. Nearly 128,000 km were flown, with 57,435 km of effort on transect. Surveys were conducted in the western Beaufort Sea in summer (early-July through August) for the sixth consecutive year and in survey block 23 (southcentral Chukchi Sea) for the fourth consecutive year.
- 764 sightings of 1,303 bowhead whales (Balaena mysticetus),
- 440 sightings of 821 gray whales (Eschrichtius robustus),
- 10 sightings of 15 humpback whales (Megaptera novaeangliae),
- 19 sightings of 30 fin whales (Balaenoptera physalus),
- 3 sightings of 3 minke whales (Balaenoptera acutorostrata),
- 428 sightings of 2,153 belugas (Delphinapterus leucas),
- 1 sighting of 2 killer whales (Orcinus orca),
- 2 sightings of 2 harbor porpoises (Phocoena phocoena),
- 27 sightings of 28 unidentified cetaceans,
- 749 sightings of 85,330 Pacific walruses (Odobenus rosmarus divergens),
- 93 sightings of 97 bearded seals (Erignathus barbatus),
- 1,907 sightings of 8,519 pinnipeds that could not be identified to species, and
- 145 sightings of 520 polar bears (Ursus maritimus)."