If you were a humpback whale, chances are that you wouldn't like having someone following along above you in a motorboat, holding a petri dish out on a pole over your blow hole. That's traditionally how researchers ascertain what types of bacteria are normally present in a whale's exhaled breath, though. Now, scientists have successfully utilized a less intrusive method of gathering what's known as the "respiratory microbiome" – they've used a drone.
"We see evidence of respiratory illnesses frequently in stranded and deceased animals," says study leader Amy Apprill, of the Woods Hole Oceanographic Institution. "Until now, little has been known about the normal respiratory microbiome of healthy whales."
As mentioned, previous efforts at gathering blasts of exhaled whale breath (known as "blow") have involved following the animals in motorboats. While this method does work, there's the possibility that it stresses the whales, causing them to deviate from their regular behaviour. It was with this in mind that the Woods Hole team – working with colleagues from the National Oceanic and Atmospheric Administration (NOAA); SR3 Sealife Response, Rehabilitation and Research; and the Vancouver Aquarium – turned to a remotely-piloted hexacopter drone.
Carrying a sterilized petri dish on top, the aircraft was flown directly into the blow of numerous healthy humpback whales. Altogether, samples were collected from 17 whales off of Cape Cod, Massachusetts, and nine whales near Vancouver Island, Canada. According to the scientists, the whales didn't seem to notice that the drone was even there.
Once analyzed, all of those samples revealed a core microbiome consisting of 25 bacterial groups. These were present in both populations, and were "very different" from the bacteria in the surrounding seawater.
"This strongly suggests that regardless of where the animal lives, or even their age or sex, they have a shared blow microbiome," Apprill says.
Plans now call for samples to be gathered from whales that appear to be unhealthy, to see how their microbiome differs from that of healthy whales. It is also hoped that viruses and fungi could be sequenced in future efforts, as opposed to just bacteria.
You can see some of the blow-sampling action for yourself, in the video below. And for another example of a group using drones to sample whale blow, check out the wonderfully-named (but unrelated) Snotbot project.
Source: Woods Hole Oceanographic Institution