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STUDYING GREAT WHITE SHARKS
Great white caught off Montauk
Scientists study great white shark with long-term, long-distance tags that can communicate via satellite. Seasonal aggregations in key feeding areas along the coast allows researchers to study them throught direct observation. NOAA Fisheries studies the biology of white sharks as well as monitors their populations and manages fisheries that may incidentally catch them.
Mauricio Hoyos Padilla, a shark expert and researcher, who studies great white shark at Guadalupe Island, Mexico, told Newsweek researchers are discovering new things about the species all the time. "We just published two very interesting papers about white sharks interacting with big squids, and a paper about social behavior in white sharks, something that nobody knew about their interactions," he said. "Also, we filmed white sharks sleeping for the first time in a second documentary." Hoyos Padilla said the main focus for now, is the behavior and movement patterns of juvenile white sharks in Guadalupe island, their interactions with squids, and the "presence of pregnant females with a submersible ultrasound."[Source: Robyn White, Newsweek, May 25 2022]
To get elusive up-close shots of a great white shark in Cape Cod, photographer Brian Skerry and his team relied on a seal decoy, months of patience, and a lightning-quick finger on the camera shutter according to National Geographic.
Old School Great White Shark Study Methods
Scientists often resort to chumming the water to attract great white sharks. In areas where swimmers are present in South Africa they rely on the help of spotters who position themselves on coastal mountains with high powered binoculars looking for sharks. The spotter’s primary duty is alerting lifeguards of the presence of sharks in the area. National Geographic photographers ghave gotten close-range shots of a great white by placing cameras in seal-shaped pieces of plywood.
Ian Gordon is a Australian shark behaviorist who has studied sharks, including great white shark, often by swimming with them and provoking them to attack. “We put ourselves so to speak, in harms way, to dissect or analyze attacks. By getting a shark to physically attack us, we understand a little bit more about the animal.” He has never been seriously hurt but does carry a few “love bite” scars.
Gordon once used himself as a guinea pig to lure a great white out of a pen full of tuna. Another time he checked a shark repellant device on a great white. Venturing outside a protective cage, he was given instruction not to turn the devise on until the shark was within two meters. He did as he was told. “We hadn’t really planned what to do if it didn’t work,” he told Reuters. “I would have tried to duck very fast I’d imagine. The great white shark was aware we had a ‘sting’ so to speak and decided to leave us alone.”
South Africa, scientists catch great whites with a pair of baited hooks that are attached to a chain and old tire and buoy. After the shark tires from diving while attached to the tire a small boat pulls up next to the shark and it is fitted into a sling used to hoist it onto a large boat. Once on the large boat a wet towel is placed over sharks eyes, aerated water is hoses in its mouth is outfit with a transmitter. researchers say the sharks are remarkably docile and cooperative. At the Farallon Islands near San Francisco, scientists maneuver great whites on to platforms that rise out of the water, allowing the scientists to weigh and tag the shark and take DNA samples.
How Little We Know About Great White Shark and The Difficulty Studying Them
There is still much we don't know about great white sharks. Many basic questions about their abundance, life history, habitats, and movements remain unanswered. Erik Vance wrote in National Geographic: ““The great white shark is the ocean’s iconic fish...and much of what we think we know simply isn’t true. White sharks aren’t merciless hunters (if anything, attacks are cautious), they aren’t always loners, and they may be smarter than experts have thought. Even the 1916 Jersey Shore attacks famously mentioned in Jaws may have been perpetrated by a bull shark, not a great white. [Source: Erik Vance, National Geographic, July 2016]
We don’t know for sure how long they live, how many months they gestate, when they reach maturity. No one has seen great whites mate or give birth. We don’t really know how many there are or where, exactly, they spend most of their lives. Imagine that a land animal the size of a pickup truck hunted along the coasts of California, South Africa, and Australia. Scientists would know every detail of its mating habits, migrations, and behavior after observing it in zoos, research facilities, perhaps even circuses.
But the rules are different underwater. Great whites appear and disappear at will, making it nearly impossible to follow them in deep water. They refuse to live behind glass — in captivity some have starved themselves or slammed their heads against walls. (Several aquariums have released them for their own safety or because they were attacking tank-mates.)
Studying Great White Shark Behavior at Seal island
R. Aidan Martin and Anne Martin wrote in Natural History magazine, “ Nowhere is that social and foraging behavior on more vivid display than at Seal Island, a rocky, five-acre islet in False Bay, twenty-two miles south of Cape Town. The island is home to some 64,000 Cape fur seals, plus thousands of cormorants, gulls, penguins, and other seabirds. Mother fur seals give birth here in the spring, around the end of December. By early May the pups are joining their older siblings on fishing trips into False Bay and beyond. That's when the white sharks start showing up--from parts unknown--to hunt the young-of-the-year pups. [Source: R. Aidan Martin, Anne Martin, Natural History magazine, October 2006]
Chris Fallows and Rob Lawrence, South African naturalists based in Simon's Town on False Bay, discovered the site's attractions in 1995, when they observed the sharks' vigorous seasonal predatory activity and their remarkable aerial hunting style. (Both behaviors can be observed elsewhere, but far less frequently than at Seal Island.) At Fallows and Lawrence's invitation, we visited Seal Island in 2000 to see for ourselves. Since then we have returned each southern winter to continue studying the remarkable behavior of the white shark.
Watching such ferocious predatory assaults and intense socializing is a shark biologist's dream. In fact, despite the white shark's reputation as the animal kingdom's uberpredator, surprisingly little is known about the basics of its foraging behavior: its hunting tactics, its feeding cycle, its preferences in prey. Its migration routes and favorite hunting grounds, aside from the waters around Seal Island and several other places, remain largely unknown. And even less is known about its social behavior. Most people--at least since the movie Jaws--assume the creatures are solitary, stupid, antisocial brutes.
But after observing the white sharks at Seal Island for eight seasons, and documenting more than 2,500 predatory attacks, we have arrived at quite a different opinion. Our research demonstrates that white sharks are intelligent, curious, oddly skittish creatures, whose social interactions and foraging behavior are more complex and sophisticated than anyone had imagined.
We have discovered, by observing both from the surface and with underwater cameras, that the social behavior of these sharks is astonishingly complex. During the past five years, we have cataloged twenty distinct social behaviors in white sharks at Seal Island, half of which are new to science. We are just beginning to understand their significance, but many are related to establishing social rank
Studying Great White Shark off Cape Cod
Erik Vance wrote in National Geographic: The waters off the cape, unlike other places inhabited by great whites, are shallow enough to spot sharks from the air. Great whites here are difficult to photograph because they aren’t attracted to chum. [Source: Erik Vance, National Geographic, July 2016]
“A 24-foot fishing boat sits just off the southern tip of Cape Cod, Massachusetts, on a perfect summer afternoon. The passengers — three scientists, two paying customers, two journalists, and the boat’s captain — lounge on the seats, looking off toward Nantucket. The voice of a spotter pilot flying 1,000 feet above breaks out over the radio in a sharp New England accent. “We’ve got a wicked nice shark over here to the south!”
“Fisheries biologist Greg Skomal perks up. He’s standing five feet off the bow on the pulpit, a fenced-in walkway resembling a pirate’s plank. If this were a Hollywood movie, he’d have a harpoon and a peg leg. Instead he carries a GoPro camera attached to a 10-foot pole. He grins like a little kid as the captain guns the engine.
Tracking Great White Sharks
experiment with a great white Klimley and Le Boeufhave and Ken Goldman of San Francisco's Steinhart Aquarium and other scientists place 30-pound transmitters in sea blubber which are swallowed by great whites. The transmitter record data about the sharks stomach temperature and location for 13 days and are eventually regurgitated by the sharks and the data is relayed to soundbouys .
Scientist also use "pop-up tags" that are attached to the sharks skin with long poles from a flat-bottomed, 17-foot skiff, and continually measure the shark’s position, depth, speed and direction. The data is stored digitally. After six months a minicomputer cause the release on electric signal that burns a magnesium wire, releasing the tag to the surface, where it releases a GPS locator signal. Satellites then find and upload the data. Tags placed on tuna, sharks and seabirds record levels of ambient lights that can be translated into longitude and latitude.
OCEARCH has been studying white sharks in the Northwest Atlantic since 2012, mainly by tagging them and observing where they go. According to the Miami Herald: Among its goals is to learn where they mate and give birth. It is also studying the impact white sharks have on preventing other species, including seals and squids, from depleting fish stocks off the East Coast. [Source: Mark Price, Miami Herald, October 3, 2020]
Describing the fate of a shark caught off Nova Scotia, named Nakumi, the Miami Herald reported: After the shark was caught researchers rushed to collect data for 21 research projects, including an ultra sound, bacteria samples off her teeth and fecal samples to learn her diet. Blood, muscle and skin samples were also taken for medical research. She is bigger than average for female white sharks. “She was full of multiple seals and was round and robust,” one scientist said. “She had a lot of scratches on her face from seals that were fighting with their claws when she was eating them.”
The shark was fitted with three tags, including one to record how deep she goes and another that will track her movements for the next five years. OCEARCH is currently tracking nearly 60 white sharks tagged in the Northwest Atlantic, and data has revealed they migrate down the East Coast, around Florida and into the Gulf of Mexico, Fischer said. Nukumi is one of a half dozen white sharks tagged during the Nova Scotia expedition, which ends next week. Among the others was a 13.7-foot, 1,700-pound shark that is the largest male white shark the agency has tagged in the Northwest Atlantic. Image Source: National Oceanic and Atmospheric Administration (NOAA); Wikimedia Commons
Text Sources: Mostly National Geographic articles. Also the New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Natural History magazine, Discover magazine, Times of London, The New Yorker, Time, Newsweek, Reuters, AP, AFP, Lonely Planet Guides, Compton’s Encyclopedia and various books and other publications.
Last updated March 2023