These veterinarians make home visits for orcas

One day last September, a team of scientists climbed onto a small boat and headed out into the Salish Sea in search of an endangered population of killer whales. The Southern Resident killer whales, one of several killer whale communities that inhabit the Pacific Northwest, can be elusive, so the researchers were pleased to find a small group of them. But as they got closer, a putrid smell washed over the boat.

The scientists looked at each other suspiciously before it dawned on them: the smell was coming from the clouds of mist that the whales expelled from their blowholes. “Everyone may have bad breath every now and then, but this wasn’t just bad breath,” says Dr. Hendrik Nollens, vice president of the Wildlife Health department for the Zoo Alliance of San Diego, who was on the boat. “Something was going on.”

Smelly breath can be a sign of illness or infection, but the cause could have been anything from a tooth abscess to life-threatening pneumonia. Fortunately, the scientists were armed with an experimental diagnostic tool: a breath-collection drone. The technology – essentially a flying petri dish that can be sent into an orca’s plume – was still in development, but was about to undergo an unexpected, real-world test. “We were concerned,” said Dr. Nollens, “and that’s why we launched our drone.”

It is not easy to conduct a veterinary examination on a multi-ton wild marine mammal that can only surface for a few seconds at a time. But over the past five years, a team of veterinarians, marine biologists and engineers have developed tools to do just that. Their goal is to perform regularly, remotely health assessments on each of the Southern Residents – and, if necessary, to intervene with personalized medical care.

It is an unconventional approach to conservation, typically focused on supporting the health of populations rather than individual animals. But the Southern Residents, classified as endangered in 2005, are in serious trouble and threatened by pollution, boat traffic and declining stocks of wild salmon, their favorite food source. Despite ongoing conservation efforts, the population numbers approximately 75 whales.

“We are in a dire, dire situation,” says Dr. Joe Gaydos, the scientific director of the SeaDoc association, a marine conservation program at the University of California, Davis, School of Veterinary Medicine. “We have reached a point where the health of every individual is important.”

A distressed whale

That became painfully clear five years ago, when another sickly Southern resident, known as J50, initiated the project.

When she was born in 2014, J50 was a sign of hope; it had been more than two years since the last successful birth in the Southern Resident population. The calf was covered in scars, earning her the nickname Scarlet, but she appeared healthy and vigorous and became known for her playful behavior. “Everyone loved her,” said Dr. Gaydos.

In the years that followed, the National Oceanic and Atmospheric Administration, or NOAA, partnered with a nonprofit called SeaLife response, rehabilitation and research to monitor the southern residents, using aerial photography to monitor the size and condition of the whales. In the summer of 2018, photos revealed what Scarlet had become shockingly thin. Behavioral observations suggested that she was weak and sometimes fell far behind.

NOAA compiled an emergency response teamin collaboration with many organizations and experts, including Dr. Gaydos from the SeaDoc Society and Dr. Nollens, who was a veterinarian at SeaWorld at the time.

The scientists looked for signs of a respiratory infection, a common and dangerous condition in whales, by attaching a petri dish to a long pole and holding it over Scarlet’s blowhole as she exhaled. They collected fecal samples from the water and analyzed them for parasites.

They found no clear answers, leaving the team with a stark choice: they could try to do something, or they could watch Scarlet wither away. “Are we just supposed to sit here and watch this poor whale die?” Dr. Gaydos remembered thinking.

So they tried the few treatments they had: They used a dart gun to administer antibiotics and introduced live salmon into the starving whale’s path.

Scarlet continued to deteriorate and in September she disappeared. After an intensive, fruitless search, Scarlet was pronounced dead.

It was a tremendous loss, not only for the people who had come to love Scarlet, but also for the population of the Southern Residents, who desperately needed young females to survive and reproduce. Other young orcas had also died in recent years. “Trying to understand why they are disappearing prematurely from the population has been a major challenge,” said Brad Hanson, NOAA’s wildlife biologist. Northwest Fisheries Science Center.

Experts had already discussed the need to develop techniques to diagnose and possibly treat sick whales, but Scarlet’s death made that effort urgent. “We realized, wow, we didn’t have a lot of tools in the toolbox,” said Dr. Gaydos. “We were doing Civil War medicine.”

In recent years, Dr. Hanson, Dr. Gaydos, Dr. Nollens and their colleagues experimented with a variety of techniques, including using infrared cameras to measure the whales’ body temperatures and directional microphones to record their breathing.

And they are fully committed to developing a breath collection drone. The respiratory droplets the whales exhale are a biological goldmine, allowing scientists to search for pathogens and abnormal cells. But a petri dish on a pole wouldn’t cut it.

Other researchers did used drones to collect breath samples from large whales, such as humpback whales, which produce large plumes. Orca exhalations are smaller and more difficult to collect. But using computational modeling, conservation technology experts at the San Diego Zoo Wildlife Alliance found that if they mounted a petri dish in the right spot on a drone, the air currents generated by the propellers would help direct respiratory droplets to the dish .

The team tested their prototypes and refined their approach with captive orcas at SeaWorld and more robust wild whales before the drones buzzed over the southern residents. “We have developed the techniques to do this without regularly startling the animals,” said Dr. Hanson.

Still, collecting samples proved to be a challenge. The drone pilots, skilled professionals, had to launch the machines from a small boat speeding over open water, predict where a swimming whale would surface, maneuver the drone into position before the respiratory droplets disappeared, and then return the monster safely to the water. moving boat. “They’ve said a few times now that this is, technically, the most complex mission they’ve ever flown,” said Dr. Nollens.

When the team took to sea in September, they wanted to test a new, improved drone, with more petri dishes and a longer flight time, which they hoped would collect larger amounts of breath. And then they encountered the stench.

A practical test

Orcas live in groups, but providing individualized veterinary care requires the ability to identify individuals. That can be a daunting task, but the research team had a ringer: Maya Sears, a citizen scientist in Seattle who spent years learning the art of identifying killer whales. “It may be a bit pedantic, but I tend to feel like I’m sort of recognizing the whales, rather than identifying them,” she said.

Mrs. Sears studied the cetaceans swimming in front of her. The fragrant killer whale had symmetrical saddle surfaces with a distinctive downward angle. It was J31, a 28-year-old woman known as Tsuchi.

The whales were still moving and swimming as a group, so when the drone took off, Ms. Sears pointed the pilot at Tsuchi. “It would have been easy to mix them up,” she said. When Tsuchi exhaled, the pilot steered the drone into her spout; the petri dishes returned to the boat, glistening with whale breath.

The scientists also tried to measure Tsuchi’s temperature by placing the drone, which was equipped with an infrared camera, over her blowhole and measuring how warm it was inside her body. But the results were unlikely and suggested that Tsuchi, who was behaving normally, was four degrees colder than the whales swimming next to her.

The most likely explanation, the scientists thought, was that something—a spot clot, a lump of mucus, or swollen tissue—was blocking the camera from looking deep into her blowhole.

Back on shore, laboratory analysis of the breath samples was mostly reassuring. There were no signs of a bacterial or fungal infection, but a small amount of red blood cells suggested that Tsuchi was bleeding slightly somewhere in her respiratory tract.

The cause was impossible to determine, but Dr. Gaydos suspected that Tsuchi might have suffered the orca equivalent of a nosebleed. “You know, she ran into someone else and had a little bleed,” he explained.

When the scientists encountered Tsuchi again, the smell was gone. Whatever the problem was, it was temporary.

“We’re not at the point yet 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 could quickly assess a whale that they were concerned about? “That’s a milestone for me,” he said.

The scientists are developing additional techniques with various partners, including Wild killer whalea non-profit organization with a dog that can sniff fresh whale feces. And they are interested in creating a machine learning system that can detect abnormal movements and behaviors in videos of the whales.

But they need to learn more about what is normal for these animals and have more discussion about when to intervene. Scientists’ efforts to help Scarlet received some criticism, especially when they considered the possibility of temporarily capturing the whale for diagnosis and treatment.

The scientists know they can’t save the southern residents with veterinary interventions alone, but they hope to buy the whales more time while broader conservation efforts continue..

“When we started, it was a pretty far-fetched idea to say, ‘We’re going to do veterinary studies on wild, free-swimming orcas, and they won’t even know we’re doing it,’” says Dr. Nollens said. “It’s not so far-fetched anymore.”