Drones fly through blow sprays of humpback whales for health checks
A humpback whale breaches in Haro Strait.
Researchers are using a drone to obtain samples from the blow sprays of humpback whales on the B.C. coast and analyzing the contents as a way to measure health.
Lance Barrett-Lennard, a whale scientist with the Vancouver Aquarium, said Saturday that a drone used last August off northern Vancouver Island flew three to four metres above humpbacks.
In an interview at a marine mammal symposium at the University of B.C., Barrett-Lennard said that the drone is flown off a small motorized research vessel, first conducting flights at an altitude of about 45 metres to obtain images of the overall health of the whales.
Then new batteries are put in the drone for a separate flight in which it hovers low and flies right through the blow plume collecting "whale snot, basically," he said.
"They have a V-shaped blow," he noted. "Sometimes we'd be right in the middle. It takes a while to get used to. It's flying through a cloud with droplets in it. The drone ends up all slimy and rusty."
The drone is then swabbed off and samples sent to the provincial animal pathology lab in Abbotsford and to Woods Hole Oceanographic Institution in Massachusetts.
The information should provide information on fungal, bacterial, and viral organisms in the respiratory tract of a living whale, something that cannot be duplicated during a necropsy on a dead one. Ultimately, the research is meant to offer more detail into what a healthy whale looks like.
Barrett-Lennard said that drones are a cost-efficient alternative to helicopters and are quieter and less invasive. Humpbacks give no indication of being bothered by them flying low overhead.
"We haven't been able to detect any reaction on their part ... or reason to think they even recognize the drone as something interesting," Barrett-Lennard said. When feeding, humpbacks often attract seabirds and are "presumably used to small objects" close by, he added.
Drones have been used on the B.C. coast since 2014 on resident orcas to assess body size and health, including pregnancies. Drones are currently being used only on humpback blow sprays due to the large size.
Reduced body size can reflect age as well as lack of food, which for resident orcas tends to be chinook salmon. The killer whales are known to share their salmon catches.
The research is in cooperation with the U.S. National Oceanic and Atmospheric Administration.
The symposium learned there are 12 distinct populations of orcas in regional waters: four are fish-eating residents; seven are mammal-eating transients or Bigg's killer whales; and one is labelled as an off-shore group, known to eat sharks, among other species.
Southern residents have the lowest genetic diversity by one study measure, while eastern Aleutian transients and southern Alaska residents have the highest.