2013 Aerial Surveys of Arctic Marine Mammals
This report describes field activities and data analyses for the Aerial Surveys of Arctic Marine Mammals (ASAMM) project conducted during summer and fall (1 July – 28 October) 2013. Surveys were based in Barrow and Deadhorse, Alaska, and targeted the northeastern Chukchi and western Beaufort seas, between 68°N and 72N, 140°W and 169°W.
Sea ice cover in the study area in 2013 was generally light when compared with historical (pre-2007) sea ice cover. Sea ice remained in much of the Chukchi Sea study area in early July, with shorefast ice present from Point Barrow to Cape Lisburne. By mid-July, sea ice in the Chukchi Sea had receded to the northernmost survey blocks and the majority of the nearshore areas in the western Alaskan Beaufort Sea had ~1% sea ice, although ~30-100% sea ice cover between Harrison Bay and Point Barrow. Remnant sea ice persisted in the northeastern Chukchi Sea study area through mid-September, but the western Beaufort Sea study area was ice-free by late August. By 23 September the entire study area was almost completely ice-free and remained open until new ice started forming in late October when the 2013 field season ended.
A total of 90 survey flights were conducted. Two aerial survey teams conducted surveys from July through September and one aerial survey team conducted surveys from 20-28 October. There was no survey effort from 1-19 October due to the partial government shutdown; that was the first time in >30 years that surveys were not conducted in early October. Total combined flight time was 403 hours, including 183 hours of transect survey effort. Over 104,000 km were flown, with 40,026 km of effort on transect. Surveys were conducted in the western Beaufort Sea in summer (mid-July through August) for the second consecutive year.