Walrus Haulout Photographs Near Pt. Lay Alaska, September 2014

Two sets of aerial photographs taken at 25 and 27 September at approximately 10:20 and 17:30 AKDT by the U.S. Geological Survey (USGS). We photographed the haulout through the belly port of an Aero Commander twin-engine aircraft. The plane flew at a speed of about 100 knots and a target altitude of 915 m (3,000 ft), but the actual altitudes varied. Photographs were taken using a hand held Nikon D800E with a Nikkor AF-S 80-400mm 1:4.5-5.6G ED VR lens with a shutter speed of 1/2000th of a second, F/5.3 and digital ISO-6400. Photographs were taken as the aircraft flew parallel to the coastline. Photographs were taken continuously at two frames per second to provide adequate overlap between frames to ensure a continuous photographic record of the haulout. In an unrelated survey, an additional photograph of the haulout was taken on 27 September at 11:34 AKDT during the NOAA Aerial Surveys of Arctic Marine Mammals (ASAMM) project, which periodically flew a coastal transect 1 km offshore between Point Barrow and Point Hope in autumn using the same aircraft that USGS used. The ASAMM photograph was oblique and of too low a resolution to use for counting walruses directly, but comparison of landmarks visible in both sets of photographs indicated that the herd footprint in our photographs at 17:30 represented an area that was occupied by a larger herd seen in the ASAMM photograph at 11:34.