Aerial view of the edge of a large walrus haulout

Aerial view of the edge of a large walrus herd hauled out on the northwestern shores of Alaska.  The image was taken using an unoccupied aerial system, commonly referred to as a survey drone that was flown to collect imagery of walruses resting on shore in 2018 and 2019 for estimating the abundance of walruses that use the U.S. Chukchi Sea waters during the autumn. Estimates of the population size of walruses using the haulout during each year's survey period were similar to each other and more precise than historical walrus abundance estimates: approximately 166,000 in 2018 and 189,000 in 2019 (read more below). The USGS is planning additional drone surveys in 2024 that will assess body condition and determine whether satellite imagery can directly determine walrus herd abundance by comparing walrus herd densities measured from survey drones flown simultaneously to satellite imagery collections.

This survey work was conducted under Marine Mammals Protection Act permit number MA801652-7 at altitudes and in a manner that minimized potential disturbances to walruses resting on land.  Access to the lands was arranged through the landowners and authorized under the North Slope Borough permit 18-449.