By Dr. Holly Fearnbach, Marine Mammal Research Director
In recent months SR3’s Dr. Holly Fearnbach and Dr. John Durban have continued to collect valuable data on the health of Southern Resident killer whales (SRKWs). The team has been using an octocopter drone to non-invasively collect aerial images of SRKWs throughout the year to document seasonal changes in body condition, adding to data collected in 7/12 months in each of the past two years. In November 2022, the team was able to image the majority of the population in J, K and L pods and so far in 2023, aerial images have been collected of all 25 members of J-pod. SR3’s aerial photogrammetry data has already been used to document a link between SRKW body condition in September and Chinook salmon abundance, specifically J pod’s condition correlating with returning Fraser River Chinook and L pod’s with Chinook returning to Puget Sound. These data from a broader range of months will now allow us to investigate the nutritional health and key prey requirements at other times of the year, with an aim of identifying if and when SRKWs are prey limited and helping to inform adaptive management decisions. Our data on winter and spring body condition are also being used to identify whales in vulnerable condition, to inform adaptive management of commercial whale watch vessels by the Washington Department of Fish and Wildlife. The team will continue collecting data on SRKW whale condition throughout the year, to help guide management actions to maintain adequate year-round prey availability for this endangered population.
Aerial image of a group of J pod Southern Resident killer whales in March 2023. Image obtained using an octocopter drone that was flown non-invasively >100ft above the whales under NMFS research permit 22306.