Off Stellwagen Bank, Chris Zadra uses his drone to approach a humpback whale from behind, positions it over the leviathan’s blowhole and waits. The cetacean surfaces, exhales, and blows snot all over Zadra’s drone.

Mission accomplished.

Zadra is not harassing the whales. He’s an Ocean Alliance researcher collecting whale snot samples that contain DNA, hormones, toxins and microbiomes, like viruses and bacteria, that tell scientists about a whale’s sex, fertility, identity, health and even whether it is pregnant.

Zadra’s drone, aptly named SnotBot—a registered trademark—flies back to researcher Alicia Pensarosa on the stern of the Ocean Alliance boat where she catches it, removes the four Petri dishes and places them in a cooler with ice until they can be processed back in the lab.

So why are researchers collecting whale snot?

“We’re learning how important whales are not only to ocean survival but humanity’s survival,” Ocean Alliance CEO Iain Kerr, tells ABC’s Chris Conte in a Channel 23 news video.

Kerr explains that up to 80 percent of the oxygen humans breathe is produced by the ocean. Much of that oxygen originates from drifting plants and algae. And those plants get a lot of their nutrients from whale poop. Kerr says, “Whales are clearly far more important to ocean health than we thought.”

Which is why the Ocean Alliance uses drones to collect whale snot. “You don’t put the animal in danger, and you don’t affect its behavior,” Kerr tells Conte.

You can watch the whales delivering their “samples” and listen to Kerr explain the entire process in this video shot by Marvin del Cid off the Dominican Republic in 2019.