One day in September, a team of scientists climbed into a small boat and traveled to the Salish Sea, searching for an endangered population of orcas. Southern Resident killer whales, one of the few unique orca communities living in the Pacific Northwest, can be elusive, so researchers were delighted to find a small pod of them. But as they approached, a foul smell permeated the boat.
The scientists looked at each other suspiciously before it dawned on them: The smell was coming from clouds of mist that the whales were expelling from their blowholes. “Everyone is allowed to have bad breath now and then, but it’s not just bad breath,” says Dr. Hendrik Nollens, the vice president of wildlife health for San Diego Zoo Wildlife Alliance, who is in the boat. “Something happened.”
Bad breath can be a sign of illness or infection, but the cause can be anything from a tooth abscess to a life-threatening case of pneumonia. Fortunately, scientists are armed with an experimental diagnostic tool: a breath-collection drone. The technology — essentially a flying petri dish that can be delivered to an orca’s plume — is still under development, but it’s about to face an unexpected real-world test. “We are concerned,” said Dr. Nollens, “and so we launched our drone.”
It’s not easy to perform a veterinary exam on a wild, multi-ton marine mammal that can appear for only a few seconds at a time. But for the past five years, a team of veterinarians, marine biologists and engineers have been developing tools to do just that. Their goal is to perform regular, remote health checks to each of the Southern Residents — and, if necessary, to intervene in personalized medical care.
This is an unconventional approach to conservation, which generally aims to promote the health of populations rather than individual animals. But the Southern Residents, listed as endangered in 2005, are in serious trouble, threatened by pollution, boat traffic and declining stocks of wild salmon, their preferred food source. Despite ongoing conservation efforts, the population is around 75 whales.
“We are in a dire, dire situation,” said Dr. Joe Gaydos, the science director of SeaDoc Society, a marine conservation program at the University of California, Davis, School of Veterinary Medicine. “We’re at a point where the health of every individual matters.”
A sick whale
That became painfully clear five years ago, when another sick Southern Resident known as J50 initiated the project.
When he was born in 2014, the J50 was a sign of hope; it has been more than two years since the last successful birth in the Southern Resident population. The calf was covered in scars, calling her Scarlet, but she seemed healthy and energetic, becoming known for her playful demeanor. “Everyone loved him,” said Dr. Gaydos.
In later years, the National Oceanic and Atmospheric Administration, or NOAA, worked with a nonprofit organization called SeaLife Response, Rehabilitation and Research to keep an eye on the Southern Residents, using aerial photography to monitor the size and condition of the whales. In the summer of 2018, photos showed that Scarlet had become freaking skinny. Behavioral observations suggested that he was weak, sometimes in the back of his pod.
NOAA assembled an emergency response teamworking with many organizations and experts including Dr. Gaydos in the SeaDoc Society and Dr. Nollens, then a veterinarian at SeaWorld.
The scientists looked for signs of respiratory infection, a common and dangerous ailment among whales, by placing a petri dish on a long pole and holding it above Scarlet’s blowhole when she exhaled. They scoop fecal samples from the water, analyzing them for parasites.
They found no clear answers, leaving the team with a specific choice: They could try to do something, or they could watch Scarlet disappear. “Do we have to sit here and watch this poor whale die?” Dr. remembered Gaydos thought.
So they tried the few treatments they had, using a dart gun to administer antibiotics and depositing live salmon in the starving whale’s path.
Scarlet continued to deteriorate, and in September she passed away. After an intensive, fruitless search, Scarlet was pronounced dead.
It was a great loss not only for the people who fell in love with Scarlet but also for the Southern Resident population, who desperately needed young women to survive and reproduce. Other young orcas have also died in recent years. “Trying to understand why they’re losing populations early is a big challenge,” said Brad Hanson, a wildlife biologist at NOAA’s Northwest Fisheries Science Center.
Experts have already discussed the need to develop techniques to diagnose, and potentially treat, sick whales, but Scarlet’s death has sparked that push. “We realized, wow, we don’t have a lot of tools in the toolbox,” said Dr. Gaydos. “We’re doing, like, Civil War medicine.”
For the past few years, Dr. Hanson, Dr. Gaydos, Dr. Nollens and their colleagues used a variety of methods, including using infrared cameras to measure the whales’ body temperature and directional microphones to record their breathing.
And they’re all set on developing a breath-collecting drone. The respiratory droplets emitted by whales are a biological gold mine, allowing scientists to search for pathogens and abnormal cells. But a petri dish on a pole just won’t cut it.
Other researchers had use drones to collect breath samples from large whales, such as humpbacks, that produce large plumes. Orca spews are smaller and harder to collect. But using computational modeling, conservation technology experts at the San Diego Zoo Wildlife Alliance found that if they put a petri dish on a drone in the right place, the air currents created by the propellers could help pouring respiratory droplets into the dish.
The team tested their prototypes and refined their approach with captive orcas at SeaWorld and more robust wild whales before sending the drones buzzing over Southern Residents. “We have developed techniques to do this without regularly scaring the animals,” said Dr. Hanson.
However, sample collection proved difficult. The drone pilots, who are trained professionals, have to launch the engines from a small boat speeding across the open water, predict where a swimming whale will appear, maneuver the drone into position before they disappear. respiratory droplet and then safely steer the sample back to the moving boat. “They’ve said several times that this is, technically speaking, the most complex mission they’ve ever flown,” said Dr. Nollens.
When the team set sail in September, they wanted to test a new, upgraded drone, with more petri dishes and a longer flight time, which they hoped would collect a larger volume of breath. And then they encountered a stench.
A real world test
Orcas live in groups, but providing individual veterinary care requires the ability to recognize individuals. That can be a tricky task, but the research team has a ringer: Maya Sears, a citizen scientist in Seattle who has spent years studying the art of orca identification. “It might sound a bit pedantic, but I tend to feel like I know the whales better, rather than knowing them,” he said.
Studied by Ms. Sears the cetaceans swimming before him. The stinky orca has a symmetrical saddle patch with a peculiar downward angle. This is J31, a 28-year-old woman known as Tsuchi.
The whales are still moving, swimming as a group, so as the drone flies, Ms. Sears the pilot towards Tsuchi. “It’s easy to mix them up,” he says. When Tsuchi sighed, the pilot operated the drone on his spout; the petri dishes returned to the boat glowing with whale breath.
The scientists also tried to take Tsuchi’s temperature by positioning a drone, equipped with an infrared camera, above his blowhole and measuring how hot it was inside his body. But the results were incredible, suggesting that Tsuchi, acting normally, was four degrees colder than the whales swimming next to him.
The most likely explanation, the scientists thought, was that something – a blood clot, clump of mucus or inflamed tissue – was preventing the camera from peering inside his blowhole.
Back on shore, laboratory analysis of breath samples is usually encouraging. There was no sign of bacterial or fungal infection, but a small amount of red blood cells suggested that Tsuchi was bleeding, slightly, somewhere in his respiratory tract.
It was impossible to determine the cause, but Dr. suspected. Gaydos Tsuchi may have the orca equivalent of a nosebleed. “You know, he bumped into something else, there was some bleeding,” he explained.
When the scientists happened upon Tsuchi again, the smell disappeared. Whatever the problem, it’s temporary.
“We’re not at the point where we can say, ‘Oh, and here’s my diagnosis, and here’s my prescription and treatment,'” said Dr. Nollens. But the fact that they were able to quickly diagnose a whale they were worried about? “That for me was a milestone,” he said.
Scientists are developing additional methods with various partners, including Wild Orcaa nonprofit with sniffer dog fresh whale dung. And they are interested in creating a machine-learning system that can detect abnormal movements and behaviors in videos of whales.
But they need to learn more about what is normal for these animals and have more discussions about when to intervene. The scientists’ efforts to help Scarlet drew some criticism, especially when they considered the possibility of temporarily capturing the whale for diagnosis and treatment.
Scientists know they can’t save the Southern Residents through veterinary interventions alone, but they hope to buy the whales more time as broader conservation efforts continue..
“When we started, it was a pretty far-fetched idea to say, ‘We’re going to do veterinary tests on wild, free-swimming orcas, and they’re not going to know we’re doing it,'” Dr. .Nollens said. “It’s not far.”
