On August 14 of this year I found myself piloting the Aquarium’s cetacean research vessel Skana out of Telegraph Cove into the calm waters of Johnstone Strait with an ace research team on board; one of whom had six arms and no hands. Our mission: conduct the first study of killer whales using an Unmanned Aerial Vehicle (UAV) — in this case a custom-built hexacopter. My companions were longtime friends Drs. John Durban and Holly Fearnbach from NOAA’s Southwest Fisheries Science Centre, NOAA biologist Wayne Perryman, Don Leroi of Aerial Imaging Solutions, and Mobly—as we affectionately dubbed our highly mobile hexacopter.
Drs. John Durban and Holly Fearnback with Dr. Lance Barnett-Lennard. Photo Credit: Wayne Perryman and NOAA
John and I hatched a plan for doing the study together over a year earlier, after attending a series of American and Canadian scientific workshops aimed at assessing the impact of salmon fisheries on the endangered southern resident killer whale population. The workshop findings supported an earlier study by our colleague Dr. John Ford showing a strong reliance of southern resident killer whales on Chinook salmon, as evidenced by significant increases in killer whale deaths after poor salmon seasons.
While this discovery was significant, it was still not possible to positively determine which salmon runs were the most important for the whales or to come up with strategies for managing fisheries in a way that would significantly increase resident killer whale survival. John and I felt that a more sensitive measure of food stress—thinness rather than starvation—was needed, so that the role of prey availability could be better understood and salmon fisheries could be managed with the needs of killer whales in mind.
Moberly, the unmanned hexacopter. Phoot Credit: Vancouver Aquarium and NOAA
But how to measure whether whales are fat or thin? John had developed an ingenious way of measuring killer whale length and dorsal fin height a decade earlier, by projecting dots on them exactly ten centimetres apart using parallel laser pointers. Using the dots for reference, John was able to show differences in size between males and females, estimate growth rates and compare populations—but the method didn’t reveal much about body condition.
It turns out when killer whales lose weight they replace much of the fat in their blubber layer with water in order to maintain a firm, streamlined shape. They don’t look thin from a side view until they are drastically malnourished and a large indent develops behind the blowhole – a condition researchers refer to as peanut head. When killer whales reach this point they rarely recover.
Launching the hexacopter from Skana. Photo Credit: Vancouver Aquarium and NOAA
John and Holly reasoned that an aerial view that showed the width-to-length ratio of killer whales might reveal slight changes in shape and condition long before they develop peanut head. They tested this idea in Washington by photographing southern resident killer whale from a manned helicopter in 2008 and again in 2013.
The results were promising. Not only could they distinguish thin from fat whales, they could tell which were pregnant. It was clear, however, that manned helicopters are not ideal for a study of this type. Not only are they extremely expensive, but to avoid disturbing the whales they need to remain at altitudes of 250 metres or more, making it hard to get good quality photos.
Can you spot the hexacopter? Photo Credit: Roger McDonell
John knew that Wayne was working with Don on the development of a NOAA UAV for studies of penguins, sea lions and other marine creatures and mentioned our interest in using it for killer whale work. Wayne couldn’t have been more helpful and before we knew it, Mobly had joined our killer whale research team.
From our first flight over killer whales on August 14, Mobly proved his worth. Launched from the cabin roof of the Skana and ably piloted by John, it climbed quickly to 30 metres. Holly watched Mobly’s live video feed, directing John until the hexacopter was perfectly positioned over the whales. Wayne and Don ensured that Mobly was properly programmed and in good working order. My role was easy: find the whales, pilot the Skana and make sure that we kept to the terms of our extensive set of research and flight permits.
That first day was memorable not only for images of whales, but for the amount of high-fiving that took place. Mobly performed like a dream—steady, stable, and quiet. The images of the whales were stunning, and revealed right away that we weren’t going to have difficulty distinguishing robust and thin whales. We could readily identify individuals based on scratches and scars on theirs saddle patches, which were easier to see from above than I expected, and we could positively identify pregnant females. Most importantly, the whales didn’t react to Mobly visibly; not only did they not appear disturbed, they didn’t seem to notice him at all.
The top female is noticable thin, the bottom most killer whale is pregnant and the others appear to be of a healthy weight. Photo Credit: Vancouver Aquarium and NOAA
After a week of flawless flying, Don and Wayne headed home, leaving John, Holly and I behind to take advantage of the great weather and the continuing stream of northern resident killer whales visiting the area. One morning shortly after they left I received a message from my friends Bill and Nicole Mackay about a young killer whale caught in a gillnet. We arrived on scene just after the net’s owner had cut it loose—after almost thirty minutes of entrapment.
The whale had been caught underwater for some of that time and had suffered cuts from the net. As she swam off slowly with her family we flew Mobly over her to check whether she trailing any gear or bleeding significantly but fortunately she was ok on both scores. Interestingly, however, we’d noted some days before that she was thinner that her companions. We wondered if that had anything to do with her entanglement; perhaps she was unwell and not looking out for obstacles?
We wrapped the study up on the August 27, after taking good quality aerial images of 77 members of the northern resident killer whale population and five Bigg’s (transient) killer whales. The good news: the whales were generally robust, as expected, given that it has been a relatively good year for Chinook.
The sad news: two whales that were clearly very thin, A37 and I63, were missing by the end of our very short study. A37 was relatively old for a resident killer whale so his passing wasn’t entirely unexpected. I63 had lost a newborn calf earlier in the year, and her subsequent death made us wonder if she might have been sick or injured.
Male killer whale A37 is noticeably thin. He was missing and presumed dead by the end of the research trip. Photo Credit: Vancouver Aquarium and NOAA
The interesting news: where do I start? We saw fish chases, youngsters playing, a great deal of touching and social behaviour within family groups, killer whales and dolphins swimming together peacefully and much more. The bottom line is that the method worked wonderfully well. We are convinced now that Mobly—or one of his cousins—will be an invaluable part of our research program for years to come, as we focus on recovering resident killer whale populations by, among other things, ensuring they have enough to eat.
Killer whales display head butting and other playful gestures in the wild. Photo Credit: Vancouver Aquarium and NOAA
Note: Funding and other support for this research provided by the Vancouver Aquarium Marine Science Centre, the National Oceanic and Atmospheric Administration, the SeaWorld and Busch Gardens Conservation Fund, and the Wild Killer Whale Adoption Program. The research was authorized by Fisheries and Oceans Canada Research Permit XMMS-6-2014 –Amendment 2; and Transport Canada Special Flight Operations Certificate 5812-11.
Blog post submitted by Dr. Lance Barrett-Lennard who leads the Vancouver Aquarium Marine Mammal Research Program, which has been conducting studies in the field and at the aquarium since 1956. It now operates as part of the Vancouver Aquarium Coastal Research Institute, established in May 2014.
Vancouver Aquarium Coastal Ocean Research Institute
Established to measure and monitor the health of coastal ecosystems on Canada’s West Coast, the Vancouver Aquarium Coastal Ocean Research Institute brings together scientists focused on protecting our oceans. vanaqua.org/oceanresearch