SR3’s Dr. Holly Fearnbach and Dr. John Durban have restarted monitoring the body condition of the “Sounders” gray whales that have once again returned for their annual migration stopover in Puget Sound to forage on ghost shrimp. As in previous years, the team is using a remotely controlled research drone to non-invasively collect high resolution overhead images that will be analyzed to measure changes in individual condition over the spring stopover and across years. This project is a collaboration with colleagues from Cascadia Research Collective (CRC), enabling us to link our aerial images and measurements to known individuals with long sighting histories (some over 30 years!) from CRC’s photo-identification studies. So far in 2022, the team has conducted two surveys, collected aerial images of seven individuals, six of which were also measured in both 2020 and 2021. In previous years, most individuals improved in condition prior to resuming their northbound migration to Arctic feeding grounds and hopefully we will document a similar trend this year. This project will continue into early summer, providing important information on the body condition and health of gray whales during the ongoing Unusual Mortality Event.
Aerial images of a “Sounder” gray whale (CRC-723, “Lucyfer”) taken in March 2020, February 2021 and then again in March 2022. Images were collected non-invasively using a remotely-controlled drone flown at >150ft over the whales under NMFS research permit 22306. Photo by Holly Fearnbach and John Durban.