By Dr. Holly Fearnbach, Marine Mammal Research Director
Today the Washington Department of Fish and Wildlife (WDFW) issued an emergency rule requiring commercial whale-watching vessels to stay at least one-half nautical mile away from 11 vulnerable Southern Resident whales this summer, and encouraging all boaters to Be Whale Wise and do the same.
Using measurements from drone photographs, SR3’s Dr. Holly Fearnbach and Dr. John Durban identified one late-stage pregnancy among the Southern Resident killer whale population and 10 members in poor body condition when they were last imaged between September 2022 and June 2023 (as recently as last week). These whales were designated as vulnerable by the emergency rule, which is intended to limit disturbance from vessel noise to maximize the whales’ chances of finding and catching their primary prey, Chinook salmon.
The SR3 research team also documented several additional pregnancies when those individuals were last measured, but based on the timing of when the images were taken, most of the pregnancies have likely ended as of summer 2023. These whales may have calves with them when they return to the Salish Sea, but many pregnancies in Southern Residents result in miscarriages or the death of newborn calves. There are additional whales that also had shape profiles consistent with earlier stages of pregnancy, when viewed from the drone’s unique aerial perspective (see image), but measurements indicated that they had not yet advanced to late stage (defined as the last six months of a 17-18 month pregnancy). We will continue our year-round research to monitor the success of these pregnancies and hope to document improvements in the body condition of the vulnerable whales.
“With this designation, we’re really helping to provide further protection for the most vulnerable of this already vulnerable population,” said Dr. Julie Watson, the WDFW killer whale policy lead. For more information, see WDFW’s news release.
Aerial images showing shape differences of two adult female Southern Resident killer whales during health research in the Salish Sea in spring 2023. Photogrammetry measurements have revealed the whale on the left (J16) to be in poor body condition compared to other adult females and the whale on the right (J22) was in late-stage pregnancy (the pregnancy was unfortunately lost by late June 2023). Images collected by John Durban and Holly Fearnbach (SR3; Sealifer3.org) flying a drone non-invasively at >100ft above the whales, authorized by NMFS research permit #22306.