It’s Surprisingly Difficult to Euthanize a Whale

Wild Things
Slate’s animal blog.
May 2 2014 11:48 AM

The Humane New Way to Kill a Whale

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A needle just behind the head delivers the initial sedative.

Courtesy of Karen Clark

In January of 2009, a right whale calf became stranded on a North Carolina beach. Because of the remote location and rough weather, it took three days before a rescue crew could work with the animal for long. By then, the calf’s skin was already blistered and peeling from sunburn, its back had buckled under the weight of gravity, and gulls were starting to eat it alive.

The responders were forced to abandon all hope of rescue and shift their focus toward putting the whale out of its considerable misery. But for this new objective, the crew was woefully underequipped.

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They pumped the calf full of all the drugs they brought—sedatives, analgesics, and anesthetics—and administered isoflurane gas, a form of ether, to the blowhole. The drugs worked as expected and dulled the whale’s reflexes and awareness, but the team just didn’t have a large enough quantity to tip the animal into cardiac or respiratory arrest. They had to make a choice—leave the whale to suffer through another 24 hours of exposure and scavengers while they sought enough drugs to seal the deal, or open the animal’s veins and let it bleed out while under the effects of the drugs they’d already administered. They chose the latter.

“There’s an awful lot of blood in a whale,” says Craig Harms, zoological medicine expert at the North Carolina State University Center for Marine Sciences and Technology and one of the responders there that day. Harms remembered how the blood gathered in an enormous pool and seemed like it’d never stop flowing. Full exsanguination took the entirety of an hour.

Dead whales wash up on beaches fairly regularly—a 60-ton blue whale carcass found in Newfoundland this week is getting a lot of attention because it was in danger of exploding. However, live whale strandings are pretty rare, which probably seems at odds with how often you hear about them on the news. And nobody’s paying a team of superhero scientists to fly around the world to save each poor stranded cetacean.

That means Craig Harms is one of the few people on earth with the unfortunate privilege of being an expert on whale euthanasia. “It’s kind of funny,” he says, “you deal with two or three of these and you become the go-to person. That’s more experience than most people get.”

Harms told me that the way things ended with the right whale calf traumatized some of the members of his team, and by the way he talked about it, I think it’s safe to say it had quite an impact on him, too. When he and the team published an account in the Journal of Wildlife Diseases, they wrote, “This experience was strong incentive for the development of alternative strategies.”

A live stranding is a brutal affair. Even a moderately sunny day causes the animal’s skin to erupt in massive blisters. When broken, they unleash quarts of fluid and leave open sores. The animal can’t defend itself, so crabs and birds pick at the dying animal’s blubber wherever they can. The whale’s soft, fleshy eyes—in a young humpback, about the size of a small grapefruit—are another scavenger favorite. Worst of all, a stranded whale can languish like this for more than a week.

Why don’t we follow the advice of that old bumper sticker and just save the whales?

First of all, whales beach for a reason. These can include injuries, entanglements, emaciation, gastrointestinal obstructions, and generally poor health. Dragging the animal back out into the surf does nothing to fix most of these problems. Furthermore, there are relatively few facilities equipped to rehabilitate a whale of any size, so even if we could safely remove them from the beach, there’s not much we could do with them. (One notable exception is the gray whale calf affectionately known as J.J. that beached close to SeaWorld of California back in 1997.) Finally, and this probably goes without saying, but it’s really, really difficult to move a whale.

“The fluke looks like a really nice handle, something easy to put a rope around,” says Harms, “but you don’t want to do that on a live animal because you can dislocate the fluke.”

Harms says lifting an animal that weighs upwards of 22,000 pounds—as some of the juvenile humpbacks they’ve encountered weighed—just “kind of bends them and breaks their back.” You can dig a trench to let water in and try to coax the animal back into the ocean, but this is also perilous because if the whale tips over, its blowhole can get covered in water or sand and the animal will suffocate. Many of the places where whales beach are too shallow for boats big enough to tow and too remote to call in equipment such as a crane. (The rotting whale carcass in Newfoundland is lying on the doorstep of a town of 600 that has no way to safely move the beast.)

Most importantly, all of this requires time. So even if all the conditions are right for a rescue, if you can’t get the resources to the whale fast enough, then the animal will have already deteriorated to the point where a rescue is futile.

Actually, the best chance a whale has is to save itself. That’s why rescuers always wait for one or two high tides before attempting anything. Harms says sometimes it’s pretty clear the whale won’t be able to self-rescue and that rescue attempts will be futile, but that observing the high tide rule is important for the humans involved—nobody wants to put down a whale that might have otherwise survived.

For doomed whales, euthanasia is the most humane option, and there’s one really easy way to do it—a shot of pentobarbital. Pentobarbital is a reliable drug that’s commonly used by veterinarians to euthanize everything from cats to horses. It’s one of the drugs used in humans during lethal injections and physician assisted suicides.

In short, pentobarbital is a barbiturate that kills things dead, lickety-split. Unfortunately, this makes it a really nasty thing to unleash into the environment.

As I noted earlier, many animals come to feast on a dead whale, and when you pump a carcass full of pento, all of them are at risk of relay toxicosis, or being poisoned by eating something poisoned. And guess what else loves dead things? That’s right—your dog. In one case that we know of, an Australian shepherd that ingested scraps from a whale euthanized with a pentobarbital solution fell into a 24-hour coma. By the way, this was 23 days after the whale was removed from the beach and buried. (And that’s nothing—two dogs once died after digging up the carcass of a horse that had been put down with pentobarbital. The horse had been buried for two years.)

As fate would have it, Harms and his colleagues were called to attend to four more live strandings from 2011 to 2013—three juvenile humpbacks and a minke whale. All of the animals had suffered irreparable injuries. Most people would consider that many strandings a plague, but to Harms and crew, it was also an opportunity.

Working with researchers from the University of North Carolina-Wilmington, Woods Hole Oceanographic Institution, the Virginia Aquarium, and several state and federal agencies, Harms and his fellow responders used the deluge to design a better way to kill a whale. This included inventing not only a new cocktail of less toxic drugs, but also a sophisticated, custom-made needle and pumping system with which to administer them. (It looks a lot like the thing you’d use to spray weeds in your driveway.) The needle had to be strong enough to penetrate whale skin, long enough to bypass the animals’ thick layer of blubber, and designed in such a way so as to not get clogged with all that tissue on the way in.

The new recipe of drugs ensures that the animal is first sedated with a shot of valium-like drugs into the neck muscles. The whale barely acknowledges the shot, so thick is its skin and blubber. (The easiest place to reach a vein for an I.V. is in the tail, but this is usually avoided because even a young, beached humpback can crush a human with a flick of its fluke.) Once the whale is nice and sedated, the needle is then inserted directly into the heart for a shot of life-ending potassium chloride.

The new system is so effective, it’s been distributed throughout the U.S. Marine Mammal Health and Stranding Response Program.

I should probably also say that lethal injection is only one way to go. In Australia, they use explosives.

This sounds crazy, but Harms says it’s actually rather impressive. Shaped explosive charges are directed at the whale’s brainstem and then covered in sandbags. The blast, which is really more of an implosion, renders instant death. Just as if the whale were a bridge or building being demolished, the procedure can only be carried out if the conditions are perfect. Perhaps most impressive of all, the explosives don’t leave behind a crater of gore in the whale’s head, as you might expect. Instead, the explosives create a small divot.

Culturally, Harms says it seems unlikely that the implosion method will be implemented in North America anytime soon. “I think we’re much more comfortable with the experience of euthanasia with the injectable approach.” He also noted that explosion presents some safety hazards for the crew and bystanders and requires a level of training not often possessed by the kinds of people who respond to whale strandings. “It’s outside of my skillset,” he said.

Whether it’s explosives or intravenous drugs, as long as large, live marine mammals continue to wash up where we can see them, the call for euthanasia will remain. Many argue that it’s none of our business to interfere with a natural death. Others would say we owe the whales a little mercy, since strandings are often caused by human activity such as military and oil industry sonar. In Harms’ own study, one whale showed evidence of fishing line entanglement, and another had four fresh propeller wounds that cut straight through the blubber layer and into the muscle.

I’ll leave you with this. Sometimes, as a whale finally succumbs to its fate, the body will erupt in a series of muscle spasms and reflexive movements. As if death weren’t a breath away, the fins and fluke rise and fall with renewed vigor. The technical phrase is “terminal fluking.”

But Harms says those who have seen it know the whales’ movements by another name: the last swim.

Jason Bittel serves up science for picky eaters on his website, BittelMeThis.com. He lives in Pittsburgh. Follow him on Twitter.

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