NASA-NOAA Feasibility Report

The western stock of Steller sea lions and the Aleutian stock of harbor seals both experienced
dramatic declines in abundance during the past few decades, particularly in the central and
western Aleutian Islands. Both stocks have continued to decline in recent years, thus are a high
priority for routine monitoring.

NOAA’s Marine Mammal laboratory (MML) has conducted aerial surveys of marine mammals throughout coastal Alaska to monitor trends in population abundance and distribution for more than 20 years. These surveys have typically been conducted from a twinengine aircraft, such as a DHC-6 Twin Otter, operated by NOAA pilots and crewmembers. Aerial surveys in the Aleutian Islands present significant challenges and higher risks due to their remoteness, rugged terrain, and extreme weather. To evaluate the feasibility of transitioning from manned to unmanned aerial surveys in this region, thereby reducing risks to NOAA personnel and high-value aircraft, we propose to conduct test survey flights in the Near Islands of Alaska using a medium-sized, fixed-wing UAV (NASA’s SIERRA-B aircraft) with a nadir-aimed imaging payload.

Survey flights are planned to be conducted during daylight hours on days with VFR
conditions and less than ~20 knot winds at altitudes of 800-1200 feet. Survey imagery, including
thermal video and high-resolution color photos, would be collected at known Steller sea lion
and harbor seal sites along the coastlines of Shemya, Nizki, Alaid, Agattu, and Attu Islands. The
planning team will request approval and support from the US Air Force to conduct this project
at Eareckson Air Station (Shemya Island, AK) during the month of September 2022 when
weather conditions in the western Aleutian Islands are expected to be optimal.