The things we can learn from whale snot.
Using drones to capture the mist from humpback whale blowholes, a team of Australian researchers has found viruses related to human pathogens like ones that cause the common cold.
And while we don’t yet know whether those viruses make humpbacks sick, the work helps us better understand how viruses evolve between hosts, and it also allows us to study daily whale-being in a less invasive way. Scientists think they can use the drone-collection method to track species’ health less intrusively in an ocean continuously impacted by human action.
“The proxies that we have for whale health at the moment health are only from stranded animals and animals whose health has already been compromised,” said Jemma Geoghegan, a virologist from Macquarie University in Sydney who led the study. “If we could sample from seemingly healthy whales in their natural environment, it might tell us more about this aquatic virosphere that we know so little of at the moment.”
To get whale “blow,” which is kind of like a long whale sneeze, scientists have to get really close to whales in boats, and reach over their blowholes with long poles attached to collection devices. It’s dangerous, said Geoghegan, but that mist is an important biological specimen. Like human snot, blow is a fount of biological diversity — bacteria, viruses, and cells from the animal itself. Cataloging the contents of a whale’s respiratory system in action gives scientists a snapshot of the health of animals that cover thousands of miles in the quest for space to breed and hundreds of feet up and down in the quest for food.
With the growing use of unmanned aerial vehicles to track wildlife, Geoghegan said a local drone maker specially designed her team’s flying laboratories, including a remote-controlled Petri dish that could be opened in presence of blow mist and closed before returning to the boat from which it was deployed.
The drone had to be waterproofed. It had to be able to launch and land from a boat that was moving because of the sway of the ocean. And, of course, it had to house a camera.
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— Vanessa Pirotta (@VanessaPirotta) January 11, 2018
“We went through a few different revisions,” said Geoghegan, recounting some of the troubleshooting in waterproofing and calibrating the drone. “Eventually, it worked perfectly.”
In a spot a few miles offshore from Sydney, the team tracked 19 whales during the 2017 northern migration from Antarctica to Northern Australia. Researchers used the special drones to collect blow, and then pooled the samples. Through genetic sequencing, and comparing sequences, they found a plentitude of DNA and RNA viruses, both bacteriophages (their previous study cataloged the respiratory bacteria of humpbacks) and eukaryotic viruses that could be infecting whale cells. One of those families is the picornavirus family, which is tied to the common cold, but also febrile illness, encephalitis, and a type of hepatitis.
The work is exciting, said Kenneth Stedman, a virologist and professor of biology at Portland State University who was not involved in the study. He said it sets a baseline of the viruses that live within whales, giving researchers a standard by which to compare an unhealthy whale, but also opening up questions about which viruses just coexist with them, and on the flip side, which viruses may be critical for whale survival.
“The more that we learn about them, the more that we learn that viruses are an integral part of most ecosystems,” he said. “Maybe we need viromes as well to survive.”
He pointed to the abundance of a family of viruses in whales called circoviruses. They’re pretty much everywhere, he said. Another idea that the research brings up is that, like our microbiomes, an imbalance of “good” viruses may be a indicator of health, just as much as the presence or absence of a known pathogen.
He said one follow-up experiment might be to try to determine if groups of whales, called pods, have their own viral signatures, or, if, like microbes, changes in the relative abundance of viral families in whales could be an indicator of health or sickness.
To answer these questions and others that the team is interested in, the drones will have to go back out. And as cool as the application is (Stedman said he showed the video in the tweet above to a class of his earlier in the week), the use of drones in wildlife research hasn’t been without question.
In a 2015 study that received wide attention, Minnesota researchers showed that black bears’ heart rates sped up when drones were around them, and a French experiment found that depending on the direction, water birds responded to the presence of drones. Even if physiological response may not be an indicator of distress, it might confound an experiment.
Geoghegan and her colleagues hope to expand their work in humpbacks, but also to other whale species, and they also want to see if their protocol could capture hormones and other indicators of whale health.
“The hope is that we’ll be able to test different species and be able to understand how the host ecology is shaping the microbiome and the virome of these different species,” she said.