sharks

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Scientists catch a shark threesome on camera

Three sharks, two cameras

Three leopard sharks mating - near surface

Moving the action closer to the surface. Credit: Hugo Lassauce/UniSC-Aquarium des Lagons

Lassauce had two GoPro Hero 5 cameras ready at hand, albeit with questionable battery life. That’s why the video footage has two interruptions to the action: once when he had to switch cameras after getting a “low battery” signal, and a second time when he voluntarily stopped filming to conserve the second camera’s battery. Not much happened for 55 minutes, after all, and he wanted to be sure to capture the pivotal moments in the sequence. Lassauce succeeded and was rewarded with triumphant cheers from his fellow marine biologists on the boat, who knew full well the rarity of what had just been documented for posterity.

The lengthy pre-copulation stage involved all three sharks motionless on the seafloor for nearly an hour, after which the female started swimming with one male shark biting onto each of her pectoral fins. A few minutes later, the first male made his move, “penetrating the female’s cloaca with his left clasper.” Claspers are modified pelvic fins capable of transferring sperm. After the first male shark finished, he lay motionless while the second male held onto the female’s other fin. Then the other shark moved in, did his business, went motionless, and the female shark swam away. The males also swam away soon afterward.

Apart from the scientific first, documenting the sequence is a good indicator that this particular area is a critical mating habitat for leopard sharks, and could lead to better conservation strategies, as well as artificial insemination efforts to “rewild” leopard sharks in Australia and several other countries. “It’s surprising and fascinating that two males were involved sequentially on this occasion,” said co-author Christine Dudgeon, also of UniSC, adding, “From a genetic diversity perspective, we want to find out how many fathers contribute to the batches of eggs laid each year by females.”

Journal of Ethology, 2025. DOI: 10.1007/s10164-025-00866-4 (About DOIs).

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Marine biologist for a day: Ars goes shark tagging


We did not need a bigger boat

Go shark fishing on the RV Garvin, get hooked on the ideas behind it.

Image of three people kneeling over a large brown shark, as two others look on.

Field School staff made sure the day out was a safe and satisfying experience.

Field School staff made sure the day out was a safe and satisfying experience.

MIAMI—We were beginning to run out of bait, and the sharks weren’t cooperating.

Everybody aboard the Research Vessel Garvin had come to Miami for the sharks—to catch them, sample them, and tag them, all in the name of science. People who once wanted to be marine biologists, actual marine biologists, shark enthusiasts, the man who literally wrote the book Why Sharks Matter, and various friends and family had spent much of the day sending fish heads set with hooks over the side of the Garvin. But each time the line was hauled back in, it came in slack, with nothing but half-eaten bait or an empty hook at the end.

And everyone was getting nervous.

I: “No assholes”

The Garvin didn’t start out as a research vessel. Initially, it was a dive boat that took people to wrecks on the East Coast. Later, owner Hank Garvin used it to take low-income students from New York City and teach them how to dive, getting them scuba certified. But when Garvin died, his family put the boat, no longer in prime condition, on the market.

A thousand miles away in Florida, Catherine MacDonald was writing “no assholes” on a Post-it note.

At the time, MacDonald was the coordinator of a summer internship program at the University of Miami, where she was a PhD student. And even at that stage in her career, she and her colleagues had figured out that scientific field work had a problem.

“Science in general does not have a great reputation of being welcoming and supportive and inclusive and kind,” said David Shiffman, author of the aforementioned book and a grad school friend of MacDonald’s. “Field science is perhaps more of a problem than that. And field science involving what are called charismatic megafauna, the big animals that everyone loves, is perhaps worse than that. It’s probably because a lot of people want to do this, which means if we treat someone poorly and they quit, it’s not going to be long before someone else wants to fill the spot.”

MacDonald and some of her colleagues—Christian Pankow, Jake Jerome, Nick Perni, and Julia Wester (a lab manager and some fellow grad students at the time)—were already doing their best to work against these tendencies at Miami and help people learn how to do field work in a supportive environment. “I don’t think that you can scream abuse at students all day long and go home and publish great science,” she said, “because I don’t think that the science itself escapes the process through which it was generated.”

So they started to think about how they might extend that to the wider ocean science community. The “no assholes” Post-it became a bit of a mission statement, one that MacDonald says now sits in a frame in her office. “We decided out the gate that the point of doing this in part was to make marine science more inclusive and accessible and that if we couldn’t do that and be a successful business, then we were just going to fail,” she told Ars. “That’s kind of the plan.”

But to do it properly, they needed a boat. And that meant they needed money. “We borrowed from our friends and family,” MacDonald said. “I took out a loan on my house. It was just our money and all of the money that people who loved us were willing to sink into the project.”

Even that might not have been quite enough to afford a badly run-down boat. But the team made a personal appeal to Hank Garvin’s family. “They told the family who was trying to offload the boat, ‘Maybe someone else can pay you more for it, but here’s what we’re going to use it for, and also we’ll name the boat after your dad,'” Shiffman said. “And they got it.”

For the day, everybody who signed up had the chance to do most of the work that scientists normally would. Julia Saltzman

But it wasn’t enough to launch what would become the Field School. The Garvin was in good enough shape to navigate to Florida, but it needed considerable work before it could receive all the Coast Guard certifications required to get a Research Vessel designation. And given the team’s budget, that mostly meant the people launching the Field School had to learn to do the work themselves.

“One of [co-founder] Julia’s good friends was a boat surveyor, and he introduced us to a bunch of people who taught us skills or introduced us to someone else who could fix the alignment of our propellers or could suggest this great place in Louisiana that we could send the transmissions for rebuilding or could help us figure out which paints to use,” MacDonald said.

“We like to joke that we are the best PhD-holding fiberglassers in Miami,” she told Ars. “I don’t actually know if that’s true. I couldn’t prove it. But we just kind of jumped off the cliff together in terms of trying to make it work. Although we certainly had to hire folks to help us with a variety of projects, including building a new fuel tank because we are not the best PhD-holding welders in Miami for certain.”

II: Fishing for sharks

On the now fully refurbished Garvin, we were doing drum-line fishing. This involved a 16 kg (35-pound) weight connected to some floats by an extremely thick piece of rope. Also linked to the weight was a significant amount of 800-pound test line (meaning a monofilament polymer that won’t snap until something exerts over 800 lbs/360 kg of force on it) with a hook at the end. Most species of sharks need to keep swimming to force water over their gills or else suffocate; the length of the line allows them to swim in circles around the weight. The hook is also shaped to minimize damage to the fish during removal.

To draw sharks to the drum line, each of the floats had a small metal cage to hold chunks of fish that would release odorants. A much larger piece—either a head or cross-section of the trunk of a roughly foot-long fish—was set on the hook.

Deploying all of this was where the Garvin‘s passengers, none of whom had field research experience, came in. Under the tutelage of the people from the Field School, we’d lower the drum from a platform at the stern of the Garvin to the floor of Biscayne Bay, within sight of Miami’s high rises. A second shark enthusiast would send the float overboard as the Garvin‘s crew logged its GPS coordinates. After that, it was simply a matter of gently releasing the monofilament line from a large hand-held spool.

From right to left, the floats, the weight, and the bait all had to go into the water through an organized process. Julia Saltzman

One by one, we set 10 drums in a long row near one of the exits from Biscayne Bay. With the last one set, we went back to the first and reversed the process: haul in the float, use the rope to pull in the drum, and then let a Field School student test whether the line had a shark at the end. If not, it and the spool were handed over to a passenger, accompanied by tips on how to avoid losing fingers if a shark goes after the bait while being pulled back in.

Rebait, redeploy, and move on. We went down the line of 10 drums once, then twice, then thrice, and the morning gave way to afternoon. The routine became far less exciting, and getting volunteers for each of the roles in the process seemed to require a little more prodding. Conversations among the passengers and Field School people started to become the focus, the fishing a distraction, and people starting giving the bait buckets nervous looks.

And then, suddenly, a line went tight while it was being hauled in, and a large brown shape started moving near the surface in the distance.

III: Field support

Mortgaging your home is not a long-term funding solution, so over time, the Field School has developed a bit of a mixed model. Most of the people who come to learn there pay the costs for their time on the Garvin. That includes some people who sign up for one of the formal training programs. Shiffman also uses them to give undergraduates in the courses he teaches some exposure to actual research work.

“Over spring break this year, Georgetown undergrads flew down to Miami with me and spent a week living on Garvin, and we did some of what you saw,” he told Ars. “But also mangrove, snorkeling, using research drones, and going to the Everglades—things like that.” They also do one-day outings with some local high schools.

Many of the school’s costs, however, are covered by groups that pay to get the experience of being an ocean scientist for a day. These have included everything from local Greenpeace chapters to companies signing up for a teamwork-building experience. “The fundraiser rate [they pay] factors in not only the cost of taking those people out but also the cost of taking a low-income school group out in the future at no cost,” Shiffman said.

And then there are groups like the one I was joining—paying the fundraiser rate but composed of random collections of people brought together by little more than meeting Shiffman, either in person or online. In these cases, the Garvin is filled with a combination of small groups nucleated by one shark fan or people who wanted to be a marine biologist at some point or those who simply have a general interest in science. They’ll then recruit one or more friends or family members to join them, with varying degrees of willingness.

For a day, they all get to contribute to research. A lot of what we know about most fish populations comes from the fishing industry. And that information is often biased by commercial considerations, changing regulations, and more. The Field School trips, by contrast, give an unbiased sampling of whatever goes for its bait.

“The hardest part about marine biology research is getting to the animals—it’s boat time,” Shiffman said. “And since they’re already doing that, often in the context of teaching people how to do field skills, they reached out to colleagues all over the place and said, ‘Hey, here’s where we’re going. Here’s what we’re doing, here’s what we’re catching. Can we get any samples for you?’ So they’re taking all kinds of biological samples from the animals, and depending on what we catch, it can be for up to 15 different projects, with collaborators all over the country.”

And taking those samples is the passengers’ job. So shortly after leaving the marina on Garvin, we were divided up into teams and told what our roles would be once a shark was on board. One team member would take basic measurements of the shark’s dimensions. A second would scan the shark for parasites and place them in a sample jar, while another would snip a small piece of fin off to get a DNA sample. Finally, someone would insert a small tag at the base of the shark’s dorsal fin using a tool similar to a hollow awl. Amid all that, one of the Field School staff members would use a syringe to get a blood sample.

All of this would happen while members of the Field School staff were holding the shark in place—larger ones on a platform at the stern of the Garvin, smaller ones brought on board. The staff were the only ones who were supposed to get close to what Shiffman referred to as “the bitey end” of the shark. For most species, this would involve inserting one of three different-sized PVC tubes (for different-sized sharks) that seawater would be pumped through to keep the shark breathing and give them something to chomp down on. Other staff members held down the “slappy end.”

For a long time, all of this choreography seemed abstract. But there was finally a shark on the other end of the line, slowly being hauled toward the boat.

IV: Pure muscle and rage?

The size and brown color were an immediate tip-off to those in the know: We had a nurse shark, one that Shiffman described as being “pure muscle and rage.” Despite that, a single person was able to haul it in using a hand spool. Once restrained, the shark largely remained a passive participant in what came next. Nurse sharks are one of the few species that can force water over their gills even when stationary, and the shark’s size—it would turn out to be over 2 meters long—meant that it would need to stay partly submerged on the platform in the back.

So one by one, the first team splashed onto the platform and got to work. Despite their extremely limited training, it took just over five minutes for them to finish the measurements and get all the samples they needed. Details like the time, location, and basic measurements were all logged by hand on paper, although the data would be transferred to a spreadsheet once it was back on land. And the blood sample had some preliminary work done on the Garvin itself, which was equipped with a small centrifuge. All of that data would eventually be sent off to many of the Field School’s collaborators.

Shark number two, a blacktip, being hauled to the Garvin. Julia Saltzman

Since the shark was showing no signs of distress, all the other teams were allowed to step onto the platform and pet it, partly due to the fear that this would be the only one we caught that day. Sharks have a skin that’s smooth in one direction but rough if stroked in the opposite orientation, and their cartilaginous skeleton isn’t as solid as the bone most other vertebrates rely on. It was very much not like touching any other fish I’d encountered.

After we had all literally gotten our feet wet, the shark, now bearing the label UM00229, was sent on its way, and we went back to checking the drum lines.

A short time later, we hauled in a meter-long blacktip shark. This time, we set it up on an ice chest on the back of the boat, with a PVC tube firmly inserted into its mouth. Again, once the Field School staff restrained the shark, the team of amateurs got to work quickly and efficiently, with the only mishap being a person who rubbed their fingers the wrong way against the shark skin and got an abrasion that drew a bit of blood. Next up would be team three, the final group—and the one I was a part of.

V: The culture beyond science

I’m probably the perfect audience for an outing like this. Raised on a steady diet of Jacques Cousteau documentaries, I was also drawn to the idea of marine biology at one point. And having spent many of my years in molecular biology labs, I found myself jealous of the amazing things the field workers I’d met had experienced. The idea of playing shark scientist for a day definitely appealed to me.

A shark swims away from the camera.

Once processed, the sharks seemed content to get back to the business of being a shark. Credit: Julia Saltzman

But I probably came away as impressed by the motivation behind the Field School as I was with the sharks. I’ve been in science long enough to see multiple examples of the sort of toxic behaviors that the school’s founders wanted to avoid, and I wondered how science would ever change when there’s no obvious incentive for anyone to improve their behavior. In the absence of those incentives, MacDonald’s idea is to provide an example of better behavior—and that might be the best option.

“Overall, the thing that I really wanted at the end of the day was for people to look at some of the worst things about the culture of science and say, ‘It doesn’t have to be like that,'” she told Ars.

And that, she argues, may have an impact that extends well beyond science. “It’s not just about training future scientists, it’s about training future people,” she said. “When science and science education hurts people, it affects our whole society—it’s not that it doesn’t matter to the culture of science, because it profoundly does, but it matters more broadly than that as well.”

With motivations like that, it would have felt small to be upset that my career as a shark tagger ended up in the realm of unfulfilled potential, since I was on tagging team three, and we never hooked shark number three. Still, I can’t say I wasn’t a bit annoyed when I bumped into Shiffman a few weeks later, and he gleefully informed me they caught 14 of them the day after.

If you have a large enough group, you can support the Field School by chartering the Garvin for an outing. For smaller groups, you need to get in touch with David Shiffman.

Listing image: Julia Saltzman

Photo of John Timmer

John is Ars Technica’s science editor. He has a Bachelor of Arts in Biochemistry from Columbia University, and a Ph.D. in Molecular and Cell Biology from the University of California, Berkeley. When physically separated from his keyboard, he tends to seek out a bicycle, or a scenic location for communing with his hiking boots.

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A shark scientist reflects on Jaws at 50


We’re still afraid to go in the water

Ars chats with marine biologist David Shiffman about the film’s legacy—both good and bad.

Roy Scheider starred as Chief Martin Brody in the 1975 blockbuster Jaws. Credit: Universal Pictures

Today marks the 50th anniversary of Jaws, Steven Spielberg’s blockbuster horror movie based on the bestselling novel by Peter Benchley. We’re marking the occasion with a tribute to this classic film and its enduring impact on the popular perception of sharks, shark conservation efforts, and our culture at large.

(Many spoilers below.)

Jaws tells the story of Chief Martin Brody (Roy Scheider), the new police chief for Amity Island, a New England beach town and prime summer tourist attraction. But that thriving industry is threatened by a series of shark attacks, although the local mayor, Larry Vaughn (Murray Hamilton), initially dismisses the possibility, ridiculing the findings of visiting marine biologist Matt Hooper (Richard Dreyfuss). The attacks keep escalating and the body count grows, until the town hires a grizzled shark hunter named Quint (Robert Shaw) to hunt down and kill the great white shark, with the help of Brody and Hooper.

Benchley wrote his novel after reading about a sports fisherman named Frank Mundus, who captured a very large shark in 1964; in fact, the character of Quint is loosely based on Mundus. Benchley wrote an early draft of the screenplay, which underwent multiple revisions during production. In the end, he estimated that his contributions amounted to the basic storyline and the mechanics. Spielberg wasn’t the studio’s first choice for director; initially they hired Dick Richards, but Richards kept referring to the shark as a whale. Eventually, he was fired and replaced with the 26-year-old Spielberg, who had just finished his first feature film (The Sugarland Express).

Spielberg was given a $3.5 million shooting budget and a timeframe of 55 days for filming. However, the production was troubled from the start, largely due to the director’s insistence on shooting on location in Martha’s Vineyard; Jaws was the first major film to be shot on the ocean. Spielberg later admitted, “I was pretty naive about Mother Nature and the hubris of a filmmaker who thinks he can conquer the elements was foolhardy.” Unwanted boats kept drifting into the frame; cameras kept getting waterlogged; Carl Gottlieb (who played the local news editor Meadows) was nearly decapitated by a propeller; Dreyfuss nearly got stuck in the shark cage; and several actors suffered from seasickness. Frustrated crew members took to calling the movie “Flaws.”

A shark strikes

“duh-duh-duh-duh-duh-duh….” Universal Pictures

There were three pneumatically powered full-sized mechanical sharks built for the shoot, nicknamed “Bruce,” and they kept malfunctioning. The pneumatic hoses kept taking on seawater; the skin was made of neoprene foam, which soaked up water and became bloated; and one of the models kept getting tangled up in seaweed. In the end, Spielberg opted to shoot most of the early scenes without ever showing the actual shark, which actually heightened the tension and suspense, especially when combined with John Williams’ ominous theme music (“duh-duh-duh-duh-duh-duh…”).

In the end, shooting ran for 159 days, and the budget ballooned to $9 million. All the delays gave Spielberg and his writers (especially Gottlieb) extra time to refine the script, often just prior to filming the scenes. A lot of the dialogue was improvised by the actors. And it was all worth it in the end, because Jaws went on to become a major summer box office success. All told, it grossed $476 million globally across all its theatrical releases and won three Oscars, although it lost Best Picture to One Flew Over the Cuckoo’s Nest.

Jaws inspired many, many subsequent films, including Ridley Scott’s Alien in 1979, described in pitch meetings as “Jaws in space. Audience reactions were often extreme, with many people becoming fearful of swimming in the ocean for fear of sharks. And while the sequels were, shall we say, underwhelming, the original Jaws has stood the test of time. Ars spoke with marine biologist and shark conservationist David Shiffman, author of Why Sharks Matter, to discuss the film’s depiction of sharks and its enduring place in popular culture.

Ars Technica: Let’s start by talking about the enormous impact of the film, both good and bad, on the general public’s awareness of sharks.

David Shiffman: A lot of folks in both the marine science world and the ocean conservation communities have reported that Jaws in a lot of ways changed our world. It’s not that people used to think that sharks were cute, cuddly, adorable animals, and then after Jaws, they thought that they were bloodthirsty killing machines. They just weren’t on people’s minds. Fishermen knew about them, surfers thought about them, but that was about it. Most people who went to the beach didn’t pay much mind to what could be there. Jaws absolutely shattered that. My parents both reported that the summer that Jaws came out, they were afraid to go swimming in their community swimming pools.

No, really, the water’s fine!

“You knew.” The young boy’s mother (Lee Fierro) confronts Brody. Universal Pictures

David Shiffman: I have encountered people who were so scared that they were afraid to go in the bathtub. A lot of movies are very scary, but they don’t have that real-world impact. I love Jurassic Park, but I’m not afraid that a T. rex is going to eat me when I go into an outhouse, even though that’s about as realistic as what’s portrayed in Jaws. There’s something called the “Jaws Effect” in public policy literature, which is a way of measuring how fictional portrayals of real-world issues affect what citizens think about that issue and what policy preferences they support as a result. It’s fascinating how a fictional portrayal can do that, because I cannot stress enough: That is not what sharks look like or how they behave.

The movie also was the first time that a scientist was the hero. People half a generation above me have reported that seeing Richard Dreyfuss’ Hooper on the big screen as the one who saves the day changed their career trajectory. “You can be a scientist who studies fish. Cool. I want to do that.” In the time since Jaws came out, a lot of major changes have happened. One is that shark populations have declined globally by about 50 percent, and many species are now critically endangered.

And shark science has become much more professionalized. The American Elasmobranch Society—I’m on the board of directors—was founded in 1983, and now we have about 500 members in the US, Canada ,and Mexico. There have since been subsequent organizations founded in Australia and the Pacific Islands, Europe, South America, and a new one starting this year in Asia.

And then, from a cultural standpoint, we now have a whole genre of bad shark movies.

Ars Technica: Sharknado!

David Shiffman: Yes! Sharknado is one of the better of the bunch. Sitting on my desk here, we’ve got Sharkenstein, Raiders of the Lost Shark, and, of course, Shark Exorcist, all from the 2010s. I’ve been quoted as saying there’s two types of shark movie: There’s Jaws and there’s bad shark movies.

Ars Technica: Populations of the tiger shark, the great white, and couple of other species have declined so dramatically that many are on the verge of extinction. Is it just a coincidence that those declines started shortly after Jaws came out? 

David Shiffman: The short answer is not that Jaws caused this, but that perhaps Jaws made it easier for it to happen because people weren’t outraged the way they might’ve been if it happened to say, whales, whose populations were also declining around the same time. The number one threat to shark species as a whole is unsustainable overfishing practices. People are killing too many sharks. Sustainable fisheries for sharks can and do exist, and the US largely has done a good job with this, but around the world, it’s a bad scene.

“A whole genre of bad shark movies”

For instance, shark fin soup started to be a problem around the 1980s thanks to the economic boom in China and the emergence of a new middle class there. Shark fin soup is a traditional Chinese and Southeast Asian delicacy. It’s associated with the emperor and his court. It’s not shark meat that’s used. It’s the little skeletal fin rays from the fins that are basically a bland, noodle-like substance when they’re dried and boiled. The purpose of this was for people to say, “I have so much money that I can eat these incredibly rare delicacies.” That was not caused by Jaws. But perhaps it was allowed to happen because there was less public sympathy for sharks.

It’s worth noting that shark fin soup and the shark fin trade is no longer the biggest or only threat to sharks. It hasn’t been in about 20 years. Ironically, a lot of that has to do with Chinese government efforts not to save the ocean, but to crack down on public corruption. A lot of government officials used to throw extravagant banquets for their friends and family. The new Chinese government said, “We’re not doing that anymore.” That alone saved a lot of endangered species. It was not motivated by concern about the state of the ocean, but it had that effect.

Ars Technica: People have a tendency to think that sharks are simply brutal killing machines. Why are they so important to the ecosystem?

David Shiffman: The title of my book is Why Sharks Matter because sharks do matter and people don’t think about them that way. These are food chains that provide billions of humans with food, including some of the poorest humans on Earth. They provide tens of millions of humans with jobs. When those food chains are disrupted, that’s bad for coastal communities, bad for food security and livelihoods. If we want to have healthy ocean food chains, we need a healthy top of the food chain, because when you lose the top of the food chain, the whole thing can unravel in unpredictable, but often quite devastating ways.

 So sharks play important ecological roles by holding the food chain that we all depend on in place. They’re also not a significant threat to you and your family. More people in a typical year die from flower pots falling on their head when they walk down the street. More people in a typical year die falling off a cliff when they’re trying to take a selfie of the scenery behind them, than are killed by sharks. Any human death or injury is a tragedy, and I don’t want to minimize that. But when we’re talking about global-scale policy responses, the relative risk versus reward needs to be considered.

Ars Technica:  There’s a scene in Jaws where Hooper is talking about his personal theory: territoriality, the idea that this rogue great white came in and made this his personal territory and now he’ll just keep feeding until the food runs out. Is that a real scientific premise from the 1970s and how valid is it?

The hunt begins

The town hires grizzled shark hunter Quint (Robert Shaw) to kill the great white shark. Universal Pictures

David Shiffman: Rogue sharks are nonsense. It is nonsense that is still held by some kooks who are ostensibly in my field, but it is not supported by any evidence whatsoever. In all of recorded human history, there is proof that exactly one shark bit more than one human. That was the Sharm el-Sheikh attacks around Christmas in Egypt a few years ago. Generally speaking, a lot of times it’s hard to predict why wild animals do or don’t do anything. But if this was a behavior that was real, there would be evidence that it happens and there isn’t any, despite a lot of people looking.

Was it commonly believed in the 1970s? No. Did Peter Benchley make it up? No. It’s a thing in some animals for sure. In some neighborhoods, people will pick up gators and move them hundreds of miles away; the gators will move back to that exact same spot. I think the same thing has been shown with bears. Wolves certainly have a home range. But for sharks, it’s not a thing.

Ars Technica: Quint has a famous monologue about surviving the USS Indianapolis sinking and witnessing crew members being eaten by sharks. How historically accurate is that?. 

David Shiffman: We don’t really know how many of the people who were killed following the sinking of the Indianapolis were killed by sharks. Certainly, firsthand accounts report that sharks were present. But those people were in the water because they were on a boat that exploded after being hit by a torpedo. That is not good for your health. So a lot of those people were either mortally wounded or killed by that initial explosion, and then perhaps were scavenged by sharks. Those are also people who are in the water bleeding, making a lot of noise. That’s an incredible scene in the movie. But the deaths Quint attributes to sharks is more people than have been reliably documented as killed by sharks in the history of the world ever.

Ars Technica: How accurate is Jaws in terms of how and why sharks attack humans? For instance, someone says that people splashing in the water mimics what sharks want to hunt. 

David Shiffman: Anyone who tells you they know exactly why a wild animal does or does not do something is someone who you should be a little skeptical of. But a leading theory, which I think makes sense, is this idea of mistaken identity. Some of the people who are most commonly bitten by sharks, though it’s still astronomically rare, are surfers. These are people who are cutting through the water with a silhouette that resembles a seal, wearing black neoprene, which is modeled after seal blubber. Sharks have been patrolling the ocean since before there were trees on land, and it’s only in the last hundred years or so that they’ve had to wonder, is that my preferred prey, or is it a human using technology to mimic my preferred prey for recreational purposes?

If you’ve been in the ocean, there’s been a shark not that far from you, and it knew you were there, and you probably had no idea it was there and had a pleasant day in the water. The sharks that do bite people, they take a little bite and they go, what is that? And swim away. That can be real bad if it hits a major artery or if you’re far from shore. Again, I don’t want to minimize the real harm. But it is not a shark hunting you because it has a taste for human flesh. They don’t have hands. They explore their environment with their mouths and most things in their environment they can eat.

I think Mythbusters tested fish blood versus mammal blood versus chicken blood, I think. And the sharks were attracted to fish blood and had no reaction to the others. So these are animals that are very, very, very well adapted for environmental conditions that in some cases don’t really exist anymore.

Man vs. great white

Brody fights off an increasingly aggressive great white. Universal Pictures

With humans, most of the time, what happens is an immediate bite, and then they swim away. With seals or large prey, they’ll often hit it really hard from below, sometimes knocking it completely out of the water. Or if they’re hunting whales or something that they can’t fit in their mouth, they just take a huge bite and swim away. With fish, they swallow them whole to the extent possible. Sometimes there’s a shaking motion to snap a neck or whatever. You see that with some land predators, too. It’s nothing like what’s seen there—but what an awesome scene.

Ars Technica: What is your favorite scene in Jaws and the one that makes you cringe the most?

David Shiffman: Oh, man. It’s really a great movie, and it holds up well. It was hailed as revolutionary at the time because you hardly ever see the shark. But the reason they did that was because the model of the shark that they built kept breaking. So they decided, let’s just shoot it from the shark’s eye view and save money and annoyance. I love the scene when Hooper realizes that the tiger shark that they’ve caught is obviously not the right species and the reaction that people have to that—just this idea that science and expertise can be used to solve problems. Whenever a shark bites someone, there are people who go out and kill any shark they can find and think that they’re helping.

One of my favorite professional experiences is the American Alasdair Rank Society conference. One year it was in Austin, Texas, near the original Alamo Drafthouse. Coincidentally, while we were there, the cinema held a “Jaws on the Water” event. They had a giant projector screen, and we were sitting in a lake in inner tubes while there were scuba divers in the water messing with us from below. I did that with 75 professional shark scientists. It was absolutely amazing. It helped knowing that it was a lake.

Ars Technica: If you wanted to make another really good shark movie, what would that look like today? 

David Shiffman: I often say that there are now three main movie plots: a man goes on a quest, a stranger comes to town, or there’s a shark somewhere you would not expect a shark to be. It depends if you want to make a movie that’s actually good, or one of the more fun “bad” movies like Sharknado or Sharktopus or Avalanche Sharks—the tagline of which is “snow is just frozen water.” These movies are just off the rails and absolutely incredible. The ones that don’t take themselves too seriously and are in on the joke tend to be very fun. But then you get movies like Netflix’s Under Paris (2024); they absolutely thought they were making a good movie and took themselves very seriously, and it was painful to watch.

I would love to see actual science and conservation portrayed. I’d love to see species that are not typically found in these movies featured. The Sharknado series actually did a great job of this because they talked with me and other scientists after the success of the first one. Sharknado II is thanked in my PhD dissertation, because they funded one of my chapters. In that movie, it’s not just great whites and tiger sharks and bull sharks. They have a whale shark that falls out of the sky and hits someone. They have a cookie-cutter shark that falls out of the sky and burrows through someone’s leg. There’s a lot of shark diversity out there, and it’d be nice to get that featured more.

Photo of Jennifer Ouellette

Jennifer is a senior writer at Ars Technica with a particular focus on where science meets culture, covering everything from physics and related interdisciplinary topics to her favorite films and TV series. Jennifer lives in Baltimore with her spouse, physicist Sean M. Carroll, and their two cats, Ariel and Caliban.

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research-roundup:-tattooed-tardigrades-and-splash-free-urinals

Research roundup: Tattooed tardigrades and splash-free urinals


April is the cruelest month

Also: The first live footage of a colossal baby squid; digitally unfolding an early medieval manuscript.

Credit: Schmidt Ocean Institute

It’s a regrettable reality that there is never time to cover all the interesting scientific stories we come across each month. In the past, we’ve featured year-end roundups of cool science stories we (almost) missed. This year, we’re experimenting with a monthly collection. April’s list includes new research on tattooed tardigrades, the first live image of a colossal baby squid, the digital unfolding of a recently discovered Merlin manuscript, and an ancient Roman gladiator whose skeleton shows signs of being gnawed by a lion.

Gladiator vs. lion?

Puncture injuries by large felid scavenging

Puncture injuries by large felid scavenging. Credit: Thompson et al., 2025/PLOS One/CC-BY 4.0

Popular depictions of Roman gladiators in combat invariably include battling not just human adversaries but wild animals. We know from surviving texts, imagery, and artifacts that such battles likely took place. But hard physical evidence is much more limited. Archaeologists have now found the first direct osteological evidence: the skeleton of a Roman gladiator who encountered a wild animal in the arena, most likely a lion, based on bite marks evident on the pelvic bone, according to a paper published in the journal PLoS ONE.

The skeleton in question was that of a young man, age 26 to 35, buried between 200–300 CE near what is now York, England, formerly the Roman city of Eboracum. It’s one of several such skeletons, mostly young men whose remains showed signs of trauma—hence the suggestion that it could be a gladiator burial site. “We used a method called structured light scanning [to study the skeleton],” co-author Tim Thompson of Maynooth University told Ars. “It’s a method of creating a 3D model using grids of light. It’s not like X-ray or CT, in that it only records the surface (not internal) features, but since it uses light and not X-rays etc, it is much safer, cheaper, and more portable. We have published a fair bit on this and shown its use in both archaeological and forensic contexts.”

The team compared the pelvic lesions found on the subject skeleton with bite marks from modern animal specimens and concluded that the young man had been bitten by a “large feline species,” most likely a lion scavenging on the body around the time of death. The young man was decapitated after death for unknown reasons, although this was a ritualistic practice for some people during the Roman period. While the evidence is technically circumstantial, “we are confident with our conclusions,” said Thompson. “We’ve adopted a multidisciplinary approach to address this issue and have drawn on methods from different subjects, too. Our use of contemporary comparison zoological material is really what gives us the confidence.”

PLoS ONE, 2025. DOI: 10.1371/journal.pone.0319847  (About DOIs).

Tattooed tardigrades

False-colored SEM image of the tardigrade after rehydration and fixation, with a magnified inset of the blue-boxed area.

False-colored SEM image of the tardigrade after rehydration and fixation. Credit: American Chemical Society

Tardigrades (aka “water bears”) are micro-animals that can survive in the harshest conditions: extreme pressure, extreme temperature, radiation, dehydration, starvation—even exposure to the vacuum of outer space. Scientists have exploited the robustness of these creatures to demonstrate a new ice lithography technique that can be used to essentially tattoo patterns at the nanoscale on living creatures. They described their method in a paper published in the journal Nano Letters.

Creating precision patterns on living organisms is challenging because the latter require very specific conditions in order to thrive, while fabrication techniques typically require harsh environments—the use of corrosive chemicals, for instance, vacuum conditions, or high radiation. So researchers at Westlake University tested their ice lithography on tardigrades in their dehydrated state (cryptobiosis). Once cooled, the tardigrades were coated with vaporized anisole, creating an ice layer. The team used an electron beam to etch patterns in that layer. Once the creatures were warmed back up, the parts of the ice layer that had not been exposed to the beam sublimated away, and the pattern was preserved on the tardigrade’s surface, even after the creatures were rehydrated.

Granted, only about 40 percent of the tardigrade test subjects survived the full procedure, but further improvements could improve that rate significantly. Once the technique is fully developed, it could enable the fabrication of nanoscale patterns for marking living organisms, such as tracking single cells as they develop or for the creation of sophisticated biosensors.

Nano Letters, 2025. DOI: 10.1021/acs.nanolett.5c00378  (About DOIs).

Holograms that can be grabbed

A 3D car is grabbed and rotated by a user.

A 3D car is grabbed and rotated by a user. Credit: Iñigo Ezcurdia

A volumetric display consists of scattering surfaces distributed throughout the same 3D space occupied by the resulting 3D image. Volumetric images can be viewed from any angle, as they seem to float in the air, but no existing commercial prototypes let the user directly interact with the holograms—until now. There is a new kind of volumetric display called FlexiVol that allows people to interact directly with 3D graphics displayed in mid-air. Elodie Bouzbib of the Public University of Navarra presented the research at the CHI conference on Human Factors in Computing Systems in Japan this month.

The key lies in a fast oscillating sheet known as a diffuser, onto which synchronous images are projected at high speed (2,880 images per second) and at different heights; human persistence of vision ensures that these images are perceived as true 3D objects. But the diffusers are usually made of rigid materials and hence pose a safety hazard should a user try to reach through and interact directly with the hologram; safety domes are usually employed because of this.

FlexiVol replaces the rigid diffuser with elastic bands that will not permanently deform or twist, distorting the 3D display, and has a different resonant frequency from the volumetric system. The team was inspired by the taxonomy of gestures used with 2D elastic displays and touch screens: swiping, for instance, or pinching in and out to make an image larger or smaller. They tested FlexiVol with a selection of users performing three sample tasks showcasing the ability to manipulate the 3D graphics, such as “grasping a cube between the thumb and index finger to rotate it, or simulating walking legs on a surface using the index and ring fingers,” said Bouzbib.

Look ma, no spashback!

A high-speed video depicting the tests used to measure the critical angle. Credit: Thurairajah et al., 2025

Men, are you tired of urine splashback when you use the loo? Scientists at the University of Waterloo have developed the optimal design for a splash-free urinal, dubbed the Nautilus (aka the “Nauti-loo”). We first covered this unusual research back in 2022, when the researchers presented preliminary results at a fluid dynamics conference. Their final findings have now formally appeared in a paper published in PNAS Nexus.

Per the authors, the key to optimal splash-free urinal design is the angle at which the pee stream strikes the porcelain surface; get a small enough angle, and there won’t be any splashback. Instead, you get a smooth flow across the surface, preventing droplets from flying out. (And yes, there is a critical threshold at which the urine stream switches from splashing to flowing smoothly, because phase transitions are everywhere—even in our public restrooms.) It turns out that dogs have already figured out the optimal angle as they lift their legs to pee, and when the team modeled this on a computer, they pegged the optimal angle for humans at 30 degrees.

The next step was to figure out a design that would offer that optimal urine stream angle for men across a wide range of heights. Instead of the usual shallow box shaped like a rectangle, they landed on the curved structure of the nautilus shell. They conducted simulated urine stream experiments with the prototypes, et voila! They didn’t observe a single droplet splashing back. By comparison, the other urinal designs produced as much as 50 times more splashback. The team did come up with a second design with the same optimal angle, dubbed the Cornucopia, but unlike the Nautilus, it does not fit a range of heights, limiting its usefulness.

PNAS Nexus, 2025. DOI: 10.1093/pnasnexus/pgaf087  (About DOIs).

Colossal baby squid

First confirmed live observation of the colossal squid in its natural habitat. Credit: Schmidt Ocean Institute

In 1925, scientists first described the colossal squid in a scientific paper, based on the discovery of arm fragments in the belly of a sperm whale. This species of squid is especially elusive because it prefers to stay in the deep ocean, although occasionally full-grown colossal squid have been found caught in trawl nets, for instance. One hundred years after its discovery, the colossal squid has now been filmed alive in its deep-ocean home environment for the first time by a team aboard Schmidt Ocean Institute’s R/V Falkor (too) in waters off the South Sandwich Islands.

Colossal squid can grow up to 23 feet long and weigh as much as 1,100 pounds and have distinctive hooks on the middle of their eight arms. Juvenile squid have transparent bodies. It was a baby squid just 30 centimeters long that the team captured on video at a depth of 1,968 feet (600 meters) during a 35-day expedition searching for new marine life; a remote submersible dubbed SuBastian took the footage. The scientists hope to eventually be able to capture an adult colossal squid on camera. The team also filmed the first confirmed living footage of a similar cephalopod species, the glacial glass squid, spotted in the Bellingshausen Sea near Antarctica in January.

Digitally unfolding a Merlin manuscript

Virtual opening of CUL’s Vanneck Merlin fragment.

In 2019, conservationists at Cambridge University discovered a fragment of an Arthurian medieval manuscript that had been repurposed as the cover of a land register document. Written between 1275 and 1315 CE, it was far too fragile to manually unfold, but the university library’s Cultural Heritage Imaging Laboratory has succeeded in digitally unfolding the fragment so that the text can be read for the first time, while keeping the original artifact intact as a testament to archival practices in 16th-century England. Their method could be used to noninvasively study fragile manuscript fragments held in other collections.

The team used a combination of CT scanning, multispectral imaging, and 3D modeling, as well as an array of mirrors, prisms, magnets, and other tools to photograph each section of the fragment. In this way they were able to reconstruct and virtually unfold the manuscript, revealing the text. Scholars had originally thought it was a text relating to Sir Gawain in Arthurian lore, but it turned out to be part of a French language sequel to the King Arthur legend called the Suite Vulgate du Merlin. There are only 40 known surviving manuscripts of this work. One section concerns Gawain’s victory over Saxon kings at the Battle of Cambenic; the other is a story of Merlin appearing in Arthur’s court disguised as a harpist on the Feast of the Assumption.

Photo of Jennifer Ouellette

Jennifer is a senior writer at Ars Technica with a particular focus on where science meets culture, covering everything from physics and related interdisciplinary topics to her favorite films and TV series. Jennifer lives in Baltimore with her spouse, physicist Sean M. Carroll, and their two cats, Ariel and Caliban.

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an-ultra-athlete-goes-head-to-head-with-the-world’s-most-formidable-sharks

An ultra-athlete goes head-to-head with the world’s most formidable sharks

Mano a sharko —

Ross Edgley faces a challenge like no other in NatGeo’s Shark vs. Ross Edgley.

Man in scuba gear on ocean floor standing next to giant hammerhead shark

Enlarge / Extreme sportsman Ross Edgley comes face to face with a great hammerhead shark in the waters of Bimini in the Bahamas.

National Geographic/Nathalie Miles

Ultra-athlete Ross Edgley is no stranger to pushing his body to extremes. He once ran a marathon while pulling a one-ton car; ran a triathlon while carrying a 100-pound tree; and climbed a 65-foot rope over and over again until he’d climbed the equivalent of Mt. Everest—all for charity. In 2016, he set the world record for the world’s longest staged sea swim around the coastline of Great Britain: 1780 miles over 157 days.

At one point during that swim, a basking shark appeared and swam alongside Edgley for a day and a half. That experience ignited his curiosity about sharks and eventually led to his new National Geographic documentary, Shark vs. Ross Edgleypart of four full weeks of 2024 SHARKFEST programming. Edgley matches his athletic prowess against four different species of shark. He tries to jump out of the water (polaris) like a great white shark; withstand the G forces produced by a hammerhead shark‘s fast, rapid turns; mimic the extreme fasting and feasting regimen of a migrating tiger shark; and match the swimming speed of a mako shark.

“I love this idea of having a goal and then reverse engineering and deconstructing it,” Edgley told Ars. “[Sharks are] the ultimate ocean athletes. We just had this idea: what if you’re crazy enough to try and follow in the footsteps of four amazing sharks? It’s an impossible task. You’re going to fail, you’re going to be humbled. But in the process, we could use it as a sports/shark science experiment, almost like a Trojan horse to bring science and ocean conservation to a new audience.”

And who better than Edgley to take on that impossible challenge? “The enthusiasm he brings to everything is really infectious,” marine biologist and shark expert Mike Heithaus of Florida International University told Ars. “He’s game to try anything. He’d never been in the water with sharks and we’re throwing him straight in with big tiger sharks and hammerheads. He’s loving the whole thing and just devoured all the information.”

That Edgley physique doesn’t maintain itself, so the athlete was up at 4 AM swimming laps and working out every morning before the rest of the crew had their coffee. “I’m doing bicep curls with my coffee cup and he’s doing bicep curls with the 60-pound underwater camera,” Heithaus recalled. “For the record, I got one rep in and I’m very proud of that.” Score one for the shark expert.

(Spoilers below for the various shark challenges.)

Ross vs. the great white shark

  • Ross Edgley gets some tips on how to power (polaris) his body out of the water like a white shark from synchronized swimmer Samantha Wilson

    National Geographic/Nathalie Miles

  • The Aquabatix synchronized swim team demonstrates the human equivalent to a white shark’s polaris.

    National Geographic/Nathalie Miles

  • Edgley tries out a mono fin to improve his polaris performance.

    National Geographic/Nathalie Miles

  • Edgley propelling 3/4 of his body out of the pool to mimic a white shark’s polaris movement

    National Geographic/Bobby Cross

For the first challenge, Edgley took on the great white shark, a creature he describes as a “submarine with teeth.” These sharks are ambush hunters, capable of propelling their massive bodies fully out of the water in an arching leap. That maneuver is called a polaris, and it’s essential to the great white shark’s survival. It helps that the shark has 65 percent muscle mass, particularly concentrated in the tail, as well as a light skeleton and a large liver that serves as buoyancy device.

Edgley, by comparison, is roughly 45 percent muscle mass—much higher than the average human but falling short of the great white shark. To help him try to match the great white’s powerful polaris maneuver, Edgley sought tips on biomechanics from the Aquabatix synchronized swim team, since synchronized swimmers must frequently launch their bodies fully out of the water during routines. They typically get a boost from their teammates to do so.

The team did manage to boost Edgley out of the water, but sharks don’t need a boost. Edgley opted to work with a monofin, frequently used in underwater sports like free diving or finswimming, to see what he could achieve on his own power. After a bit of practice, he succeeded in launching 75 percent of his body (compared to the shark’s 100 percent) out of the water. Verdict: Edgley is 75 percent great white shark.

Ross vs. the hammerhead shark

  • Edgley vs. a hammerhead shark. He will try to match the animal’s remarkable agility underwater.

    National Geographic/Nathalie Miles

  • A camera team films a hammerhead shark making sharp extreme turns

    National Geographic/Nathalie Miles

  • Edgley prepares to go airborne in a stunt plane to try and mimic the agility of a hammerhead shark in the water.

    National Geographic/Nathalie Miles

  • A standard roll produces 2 g’s, while pulling up is 3 g’s

    YouTube/National Geographic

  • Edgley is feeling a bit queasy.

    YouTube/National Geographic

Next up: Edgley pitted himself against the remarkable underwater agility of a hammerhead shark. Hammerheads are known for being able to swim fast and turn on a dime, thanks to a flexible skeleton that enables them to bend and contort their bodies nearly in half. They’re able to withstand some impressive G forces (up to 3 G’s) in the process. According to Heithaus, these sharks feed on other rays and other sharks, so they need to be built for speed and agility—hence their ability to accelerate and turn rapidly.

The NatGeo crew captured impressive underwater footage of the hammerheads in action, including Edgley meeting a 14.7 hammerhead named “Queenie”—one of the largest great hammerheads that visits Bimini in the Bahamas during the winter. That footage also includes shots of divers feeding fish to some of the hammerheads by hand. “They know every shark by name and the sharks know the feeders,” said Heithaus. “So you can safely get close to these big amazing creatures.”

For years, scientists had wondered about the purpose of the distinctive hammer-shaped head. It may help them scan a larger area of the ocean floor while hunting. Like all sharks, hammerheads have sensory pores called ampullae of Lorenzini that allow them to detect electrical signals and hence possible prey. The hammer-shaped head distributes those pores over a wider span.

But according to Heithaus, the hammer shape also operates a bit like the big broad flap of an airplane wing, resulting in excellent hydrodynamics. Moving at high speeds, “You can just tilt the head a tiny bit and bank a huge degree,” he said. “So if a ray turns 180 degrees to escape, the hammerhead can track with it. Other species would take a wider turn and fall behind.”

The airplane wing analogy gave Edgley an idea for how he could mimic the tight turns and high G forces of a hammerhead shark: take a flight in a small stunt plane. The catch: Edgley is not a fan of flying. And as he’d feared, he became horribly airsick during the challenge, even puking into a little airbag at one point. “It looks so cool in the clip,” he said. “But at the time, I was in a world of trouble.” Pilot Mark Greenfield finally cut the experiment short when he determined that Edgley was too sick to continue. Verdict: Edgley is 0 percent hammerhead shark.

Ross vs. the tiger shark

  • Shark expert Mike Heithaus holds a gelatin shark “lolliop” while Edgley flexes.

    National Geographic/Nathalie Miles

  • Edgley and Heithaus underwater with a tiger shark, tempting it with a gelatin lollipop.

    National Geographic/Nathalie Miles

  • Success! A tiger shark takes a nice big bite.

    National Geographic/Nathalie Miles

  • Edgley flexes with the giant gelatin lollipop with a large bite taken out of it by a tiger shark

    National Geographic/Nathalie Miles

  • Edgley gets his weight and body volume measured in the “Bodpod” before his tiger shark challenge.

    National Geographic/Bobby Cross

  • Edgley fasted and exercised for 24 hours to mimic a tiger shark on a migration route. He dropped 14 pounds.

    National Geographic/Nathalie Miles

  • After all that fasting and exercise, Edgley then gorged himself for 24 hours to put the weight back on. He gained 22 pounds.

    National Geographic/Nathalie Miles

The third challenge was trying to match the fortitude of a migrating tiger shark as it makes its way over thousands of miles without food, only feasting at journey’s end.  “I was trying to understand the psychology of a tiger shark because there’s just nothing for them to eat [on the journey],” said Ross. And once they arrive at their destination, “they can chow down on entire whale carcasses and eat just about anything. That idea of feast and famine is something we humans used to do all the time. We live quite comfortably now so we’ve lost touch with that.”

The first step was to figure out just how many calories a migrating tiger shark can consume in a single bite. Heithaus has been part of SHARKFEST for several years now and recalled one throwback show, Sharks vs. Dolphins, in which he tried to determine which species of of shark were attacking dolphins, and just how big those sharks might be. He hit upon the idea of making a dolphin shape out of gelatin—essentially the same stuff FIU’s forensic department uses for ballistic tests—and asked his forensic colleagues to make one for him, since the material has the same weight and density of dolphin blubber.

For the Edgley documentary, they made a large gelatin lollipop the same density as whale blubber, and he and Edgley dove down and managed to get an 11-foot tiger shark to take a big 6.2-pound bite out of it. We know how many calories are in whale blubber so Heithaus was able to deduce from that how many calories per bite a tiger shark consumed (6.2 pounds of whale meet is equivalent to about 25,000 calories).

Such field work also lets him gather ever mire specimens of shark bites from a range of species for his research. “The great thing about SHARKFEST is that you’re seeing new, cutting-edge science that may or may not work,” said Heithaus. “But that’s what science is about: trying things and advancing our knowledge even if it doesn’t work al the time, and then sharing that information and excitement with the public.”

Then it was time for Edgley to make like a migrating shark and embark on a carefully designed famine-and-feast regime. First, his weight and body volume were measured in a “Bodpod”: 190.8 pounds and 140.8 pints. Then Edgley fasted and exercised almost continuously for 24 hours with a mix of weight training, running, swimming, sitting in the sauna, and climate chamber cycling. (He did sleep for a few hours.)  He dropped 14 pounds and lost twelve pints, ending up at a weight of 177 pounds and a volume of 128.7 pints. Instead of food, what he craved most at the end was water. “When you are in a completely deprived state, you find out what your body actually needs, not what it wants,” said Edgley.

After slaking his thirst, it was time to gorge. Over the next 24 hours, Edgley consumed an eye-popping 35,103 calories in carefully controlled servings. It’s quite the menu: Haribo mix, six liters of Lucozade, a Hulk smoothie, pizza, five slices of lemon blueberry cheesecake, five slices of chocolate mint cheesecake, fish and chips, burgers and fries, two cinnamon loaves, four tubs of Ben & Jerry’s ice cream, two full English breakfasts, five liters of custard, four mars bars, and four mass gainer shakes.

When his weight and volume were measured one last time in the Bodpod, Edgley had regained a whopping 22 pounds for a final weight of 199 pounds. “I wish I had Ross’s ability to eat that much and remain at 0 percent body fat,” said Heithaus. Verdict: Edgley is 28 percent tiger shark.

Ross vs. the mako shark

  • In 2018, Edgely set the world record for longest assisted sea swim.

    National Geographic/Nathalie Miles

  • Edgley tries to match the speed of a mako shark in the waters of the Menai Strait in Wales.

    National Geographic/Nathalie Miles

Finally, Edgley pitted himself against the mighty mako shark. Mako sharks are the speediest sharks in the ocean, capable of swimming at speeds up to 43 MPH. Edgley is a long-distance swimmer, not a sprinter, so he threw himself into training at Loughborough University with British Olympians coaching him. He fell far short of a mako shark’s top speed. The shape of the human body is simply much less hydrodynamic than that of a shark. He realized that despite his best efforts, “I was making up hundredths of a second, which is huge in sprinting,” he said. “That could be the difference between a gold medal at the Paris Olympics and not. But I needed to make up many kilometers per hour.”

So Edgley decided to “think like a shark” and employ a shark-like strategy of riding the ocean currents to increase his speed. He ditched the pool and headed to the Menai Strait in Wales for some open water swimming. Ultimately he was able to hit 10.24 MPH—double what an Olympic swimmer could manage in a pool, but just 25 percent of a mako shark’s top speed. And he managed with the help or a team of 20-30 people dropping him into the fastest tide possible. “A mako shark would’ve just gone, ‘This is a Monday morning, this isn’t an event for me, I’m off,'” said Edgley. Verdict: Edgley is 24 percent mako shark

When the results of all four challenges were combined, Edgley came out at 32 percent overall, or nearly one-third shark. While Edgley confessed to being humbled by his limitations, “I don’t think there’s anyone else out there who could do so as well across the board in comparison,” said Heithaus.

The ultimate goal of Shark vs. Ross Edgley—and indeed all of the SHARKFEST programming—is to help shift public perceptions of sharks. “The great Sir David Attenborough said that the problems facing us in terms of conservation is as much a communication issue as a scientific one,” Edgley said. “The only way we can combat that is by educating people.”

Shark populations have declined sharply by 70 percent or more over the last 50 years. “It’s really critical that we protect and restore these populations,” Heithaus said. Tiger sharks, for instance, eat big grazers like turtles and sea cows, and thus protect the sea grass. (Among other benefits, the sea grass sequesters carbon dioxide.) Sharks are also quite sophisticated in their behavior. “Some have social connections with other sharks, although not to the same extent as dolphins,” said Heithaus. “They’re more than just loners, and they may have personalities. We see some sharks that are more bold, and others that are more shy. There’s a lot more to sharks than we would have thought.”

People who hear about Edgley’s basking shark encounter invariably assume he’d been in danger. However, “We were friends. I’m not on its menu,” Edgley said. “There are so many different species.” He likened it to being chased by a dog. People might assume it was a rottweiler giving chase, when in fact the basking shark is the equivalent of a poodle. “Hopefully what people take away from this is moving from a fear and misunderstanding of sharks to respect and admiration,” Edgley said. “That’ll make the RAF fighter pilot plane worth it.”

And he’s game to take on even more shark challenges in the future. There are a lot more shark species out there, after all, just waiting to go head-to-head with a human ultra-athlete.

Shark vs. Ross Edgley premieres on Sunday, June 30, 2024, on Disney+.

trailer for Shark vs. Ross Edgley.

An ultra-athlete goes head-to-head with the world’s most formidable sharks Read More »

a-scientific-mission-to-save-the-sharks

A scientific mission to save the sharks

A scientific mission to save the sharks

A hammerhead shark less than one meter long swims frantically in a plastic container aboard a boat in the Sanquianga National Natural Park, off Colombia’s Pacific coast. It is a delicate female Sphyrna corona, the world’s smallest hammerhead species, and goes by the local name cornuda amarilla—yellow hammerhead—because of the color of its fins and the edges of its splendid curved head, which is full of sensors to perceive the movement of its prey.

Marine biologist Diego Cardeñosa of Florida International University, along with local fishermen, has just captured the shark and implanted it with an acoustic marker before quickly returning it to the murky waters. A series of receivers will help to track its movements for a year, to map the coordinates of its habitat—valuable information for its protection.

That hammerhead is far from the only shark species that keeps the Colombian biologist busy. Cardeñosa’s mission is to build scientific knowledge to support shark conservation, either by locating the areas where the creatures live or by identifying, with genetic tests, the species that are traded in the world’s main shark markets.

Sharks are under threat for several reasons. The demand for their fins to supply the mainly Asian market (see box) is a very lucrative business: Between 2012 and 2019, it generated $1.5 billion. This, plus their inclusion in bycatch—fish caught unintentionally in the fishing industry—as well as the growing market for shark meat, leads to the death of millions every year. In 2019 alone the estimated total killed was at least 80 million sharks, 25 million of which were endangered species. In fact, in the Hong Kong market alone, a major trading spot for shark fins, two-thirds of the shark species sold there are at risk of extinction, according to a 2022 study led by Cardeñosa and molecular ecologist Demian Chapman, director of the shark and ray conservation program at Mote Marine Laboratory in Sarasota, Florida.

Sharks continue to face a complicated future despite decades of legislation designed to protect them. In 2000, the US Congress passed the Shark Finning Prohibition Act, and in 2011 the Shark Conservation Act. These laws require that sharks brought ashore by fishermen have all their fins naturally attached and aim to end the practice of stripping the creatures of their fins and returning them, mutilated, to the water to die on the seafloor. Ninety-four other countries have implemented similar regulations.

Perhaps the main political and diplomatic tool for shark conservation is in the hands of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), composed of 183 member countries plus the European Union. The treaty offers three degrees of protection, or appendices, to more than 40,000 species of animals and plants, imposing prohibitions and restrictions on their trade according to their threat status.

Sharks were included in CITES Appendix II—which includes species that are not endangered but could become so if trade is not controlled—in February 2003, with the addition of two species: the basking shark (Cetorhinus maximus) and the whale shark (Rhincodon typus). Following that, the list of protected species grew to 12 and then increased significantly in November 2023 with the inclusion of 60 more species of sharks in CITES Appendix II.

But do these tools actually protect sharks? To seek out answers, over the past decade researchers have worked to develop tests that can easily identify which species of sharks are being traded—and determine whether protected species continue to be exploited. They have also focused on studying shark populations around the world in order to provide information for the establishment of protected areas that can help safeguard these animals.

A scientific mission to save the sharks Read More »