A Gruesome Feeding Frenzy in the Atlantic Ocean
A whale’s blubber is a feast for sharks, a natural end to—in this case—an unnatural death.
Updated at 10:15 a.m. ET on March 26, 2021.
A dead whale can mean many things, but to sharks, it means a feast. This is the scene Chip Michalove encountered on March 4, when he saw the dead right whale bobbing in the ocean, getting torn to pieces by great whites. Even he, a South Carolina fisherman who has caught and released enough sharks to be nicknamed the “Shark Whisperer,” had never seen a feeding frenzy like it.
“It was a once-in-a-lifetime opportunity,” Michalove told me. When we spoke four days later, he said he hadn’t slept since. “It was wild,” he said, his voice tired but still full of awe. For hours, he watched great white sharks, one after another, circle the whale and circle his boat.
Michalove had heard of dead whales being shark magnets, and he had waited years to see one for himself. When he heard about this one, he put together a crew and sailed out from Hilton Head, South Carolina. They weren’t sure what to look for at first—birds? A large black mass? Then they saw it and, unmistakably, they smelled it. “The smell was horrendous. It’s indescribable, like nothing I’ve ever smelled before,” he said. Most of the tail was gone and pieces of blubber were missing.
But the scene looked otherwise calm until they heard the first big splash. There it was, a 12-foot great white shark ripping off a hunk of blubber. Blubber is not easily tearable, and even with their sharp teeth, sharks have to thrash from side to side to get a piece. One shark would come to feed, then another. They took turns ripping pieces off the carcass.
Michalove’s crew stayed out all day; they saw at least seven individual sharks, and he guesses about 15 total were swimming in and around the area. “It's one thing to go out and hook one a day. It’s another thing to show up and you’ve got multiple great white sharks circling the boat all day long,” he said. They hooked and tagged two of the sharks for research. (He has such a reputation for finding sharks that biologists in Massachusetts have sought out his help.) The tags track the sharks through acoustic listening stations and satellites. Sharks that Michalove had previously tagged in South Carolina have been tracked hundreds of miles north, in New England, and south, in the Gulf of Mexico.
When Michalove returned to the whale again last week—this time with one of the shark biologists he works with, Greg Skomal of Massachusetts Marine Fisheries—even less of the whale remained. The calorie-rich blubber was mostly gone. Occasionally, Skomal told me, a feeding shark would puncture the abdominal cavity of the whale, which released a burst of gas trapped inside. The carcass already smelled bad, but the gas was “probably the worst smell of my life,” he said.
Sharks have an exceptional ability to smell underwater, but what is foul to humans is apparently not to sharks. “They’ll still feed on remains even if they’re pretty nasty,” says John Chisholm, a shark scientist at the New England Aquarium who has worked with both Skomal and Michalove. He’s seen photos where only blobs of blubber remained of a dead whale; even then, a great white was hanging around.
A dead whale can mean many things, but fundamentally, it is fat, flesh, and bone decomposing very slowly into nothing. All whales eventually sink; on the floor of the deep ocean, they can become “whale falls,” where ocean life dramatically blooms. But some whales briefly float—or sink and then refloat—buoyed by blubber and gas that microbes release inside the decomposing gut. Much of what we know about which whale species float or sink immediately after death comes from the old observations of whalers.
Right whales, like the one that Michalove observed, do tend to float because of their normally ample stores of fat. In fact, intact whale falls of this species are rare, says Michael Moore, a marine biologist at Woods Hole Oceanographic Institution. Right whales don’t usually sink in one piece. “It’s basically going to disintegrate in situ, and bones and other heavy things will end up hitting the bottom, but randomly,” he told me. “You’re just going to get bits raining down as they fall out of the animal.”
The whale’s floating body also forms a chum slick on the surface—a trail of blood, oil, and chunks of fat and flesh that might stretch for miles across the water. Oil, after all, is what made whales so valuable during the heyday of commercial whaling, and it leaks out when blubber begins to break down. (“The oil slick was so thick, you could almost walk on it,” said Michalove of the whale he saw.) This chum slick is what attracts sharks from afar. Seabirds are drawn to it too. The layer of whale oil actually calms the waters under it; when using a plane to locate a dead whale in the ocean, pilots look for this strip of unusually calm water.
A floating right whale can also become bloated with gas released from decomposition. Without a pressure valve—such as a shark bite—the gas inside builds and builds. The innards liquefy. Eventually, the gas and liquids find a path of least resistance, which is usually the whale’s mouth. “You get this hugely ballooned-out whale, which can become a bomb,” Moore said, “with the guts, the viscera, the lungs, and eventually the bones all departing the carcass.” If the whale is pregnant, “it has been known for the fetus to be launched, like a rocket, through the mouth,” he added. A colleague witnessed this exact event, Moore confirmed, while responding to a report of a dead right whale. The deaths of North Atlantic right whales are tracked especially closely because they are critically endangered, with fewer than 400 left in the world.
A dead whale can mean many things. This one was also a tragedy. He had a name: Cottontail. He had a name because North Atlantic right whales are now rare enough to have individual names. Whale scientists identify them by the unique markings on their head.
This is how we know that, at least four months before Cottontail died, he became entangled in fishing gear. He was spotted near Nantucket in October, with rope stuck in his mouth and trailing three to four body lengths behind him. This is common for right whales; 83 percent of them have scars from rope or other fishing equipment, says Amy Knowlton, a right whale scientist at the New England Aquarium. Often, right whales are strong enough to break free. But rope can stay wound around their tail, fins, and mouth. Moore and his colleagues have found dead whales with rope marks in their skin, blubber, and even bone. The ropes also create drag in the water, forcing the whales to expend more energy as they swim more than 1,000 miles during their migrations.
When 11-year-old Cottontail, also known as North Atlantic Right Whale No. 3920, was first seen entangled in October, he still looked reasonably healthy. When scientists saw pictures of him again near Florida in mid-February, he had lost much of his protective blubber. By February 28, he was dead off the coast of South Carolina. “It’s awful to witness what these whales endure,” Knowlton says. Cottontail’s case is not uncommon; whales may deteriorate for months before finally succumbing to infection, difficulty feeding, drag, or some combination thereof caused by entanglement. Cottontail’s death was the ninth documented North Atlantic right whale death linked to entanglement since 2017. These deaths might be preventable, Knowlton says, with the adoption of ropeless fishing gear or simply weaker ropes, like those used decades ago.
In unnatural death, Cottontail’s body has returned to the natural cycle of ocean life. Whales are so big that they literally nourish the oceans; the migration of certain whale species from feeding grounds near the poles brings nutrients in the form of feces and, eventually, their own bodies to temperate and tropical zones. And whale falls carry nutrients vertically through the water, from the surface to the ocean floor.
The great white sharks are only the most visible and perhaps charismatic part of Cottontail’s afterlife. Over weeks and months, his body might also feed smaller tiger sharks, seagulls, storm petrels, swimming crabs, bacteria mats, tube worms, and deep-sea creatures we would barely recognize as fish. The killing of whales en masse in the 19th century probably altered whole marine ecosystems in ways that were invisible to us. The death of a whale, even a single whale, temporarily changes everything around it.
This article previously misattributed the photo of one of the sharks Chip Michalove and his crew saw feeding on a whale off the coast of South Carolina. The photo was taken by the South Carolina Department of Natural Resources and Bryan Frazier, not Taylor Horton.