Using drones to fly into the misty “blows” of exhaling humpback whales, scientists have found for the first time that the whales had a common set of microorganisms—a respiratory microbiome that may help maintain their health.
In recent years, scientists have learned that vast communities of symbiotic microbes live in and on humans and play crucial roles in supporting people’s immune systems and metabolisms. The discovery of a shared respiratory “microbiome” in whales could help scientists monitor the health of whales.
In turn, “whales can be sentinels of ocean health,” said Amy Apprill, a scientist at Woods Hole Oceanographic Institution. “The more we understand about their health and the causes of decline in their health, the more we can understand about the health of the ocean.”
Apprill and her colleagues wanted a new way to collect samples of whales’ blow—the moist breath that whales spray out of their blowholes. Traditionally, scientists tracked whales in a small boat, getting close enough to hold a long pole with a large petri dish at its tip as close as possible to the blowholes. The method works, but it can potentially stress the whales and change their behavior.
Seeking a less intrusive approach, the researchers turned to the skies and some high-tech equipment—a custom-made, remotely controlled hexacopter. The research team also included scientists from the National Oceanic and Atmospheric Administration (NOAA), SR3 (Sealife Response, Rehabilitation and Research), and the Vancouver Aquarium.
The scientists were using a camera on the hexacopter to take high-resolution aerial images of whales to assess their body conditions and overall health, NOAA scientist John Durban said. “Because of the stable flight performance of our hexacopter, we quickly learned that we could reliably fly through whale blow without disturbing the animals.”
Durban, WHOI biologist Michael Moore, and SR3’s Holly Fearnbach collected their first samples using a drone off Patagonia in early 2015. They brought the technique back to sample the blows from 17 humpback whales off Cape Cod and nine humpbacks off Vancouver Island, Canada, collaborating with Lance G. Barrett-Lennard of the Vancouver Aquarium.
Fearnbach called positioning directions at a rapid pace that would rival that of a veteran auctioneer, and Durban piloted the hexacopter several feet above the blowhole. Some of the blow landed on a sterilized petri dish on top of the drone.
“The whales don’t seem to know the aircraft is there,” Moore said. “We want to study whale health, but not affect their behavior. The drone helps us do just that.”
Apprill and WHOI laboratory colleague Carolyn Miller identified 25 bacterial groups present in all of the whale samples. “This strongly suggests that regardless of where the animals live, or even their age or sex, they have a shared blow microbiome,” Apprill said.
Next, the researchers will take samples from whales with poor body conditions that possibly indicate illness.
“From this study, we have a good idea of what a normal, healthy whale microbiome looks like,” Apprill said. “Now we need to understand what the microbiome of an unhealthy whale looks like.”
The new study was published in October 2017 in mSystems, a journal of the American Society for Microbiology. The research was funded by the Ocean Life Institute at WHOI.