Evaluation of Satellite Imagery Monitoring Pacific Walruses haulouts
This is a graphical abstract for a publication by the USGS that evaluates satellite imagery for monitoring large Pacific walrus haulouts in northwestern Alaska. Pacific walruses are using coastal haulouts to rest between foraging bouts in the Chukchi Sea more often and in larger numbers in late summer, because climate warming has reduced availability of sea ice that historically had provided resting platforms near their preferred benthic feeding grounds. The USGS evaluated the consistency of visual interpretations among trained observers and evaluated those interpretations against ground truth imagery collected by a small unoccupied aerial system. They found that optical satellite sensors with moderate resolution and high revisitation rates demonstrated robust and repeatable qualities for monitoring walrus haulouts; however, clouds imposed temporal gaps. Radar imagery also demonstrated robust capabilities for monitoring the study haulout and was only limited by satellite overpass timing.
More information can be found in the following publication:
Fischbach, A. S., and D. C. Douglas. 2021. Evaluation of Satellite Imagery for Monitoring Pacific Walruses at a Large Coastal Haulout. Remote Sensing 13, no. 21: 4266. doi:10.3390/rs13214266
Graphic by: Andres A. Aceves for USGS through the Virtual Student Federal Service program.