OMG: What a feeding frenzy in the Atlantic ocean

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.Chip Michalove also hooked and tagged two of the sharks for research. (Courtesy of Taylor Horton)

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.a fish swimming under water: One of the sharks Chip Michalove and his crew saw off the coast of South Carolina (Courtesy of Taylor Horton)

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.

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.a large body of water: An aerial photog of Cottontail when he was first spotted entangled in October 2020, taken under a Center for Coastal Studies permit. (Courtesy of the Center for Coastal Studies)

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.

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