AFSC/NMML: Video Analysis for Group Count and Calf Proximity of Beluga Whales in Cook Inlet, Alaska, 2005 - 2022

As a part of NMFS management of the endangered beluga whale population in Cook Inlet, Alaska, aerial surveys have been conducted during summer since 1993 to monitor their distribution and abundance. When beluga whale groups are found, observers make counts from the bubble windows while one observer records the group with a video camera. The video has been used to count the number of animals in the group to correct for missed animals in the observer counts. In 1996, a second video camera was added; the first video camera had a lens set at a wide angle to view the entire beluga group while the second video camera was zoomed to approximately 10x to magnify a subsample of individual whales in the group. The zoomed video has been used to examine color ratios of white adults relative to smaller and darker juveniles and calves and correct for those individuals missed due to their size or coloration. In 2005, a computer program was designed to digitize the process for analyzing the video, which had been conducted manually prior to that year. The program allows an analyst to digitally mark and number each individual whale image, track it across the screen, and measure relative whale size. The dataset described here includes the data from the years that video was analyzed using the computer program, 2005-2012, 2014, 2016, 2018, 2021, and 2022.