Shark Attacks Victims and Reasons Why Attacks Occur | Sea Life, Islands and Oceania

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SHARK ATTACK VICTIMS

Traditionally most bites have been related to surfing and board sports. According to National Geographic, until fairley recently, surfers accounted for approximately half of all unprovoked shark attacks. Surfers are frequent victims because they are in the water a lot, often some distance from the shore, where sharks sometimes hunt, and their kicking and splashing at the water's surface mimics the activities of a mullet or seals or some other food item of the shark. Surfers and other board sport athletes, largely undeterred by the COVID-19 pandemic, experienced 61 percent of bites worldwide in 2020, compared with 53 percent in 2019 and 2018.

Victim Activity at Time of Encounter in 2022
Swimming/wading — 43 percent
Surfing/board sports — 35 percent
Snorkeling/free-diving — 9 percent
Other — 13 percent
[Source: Shark Files, Florida Museum of Natural History]

According to Shark Files: Breaking from recent trends, surfers and those participating in board sports accounted for less incidents (35 percent of the total cases). Swimmers and waders accounted for the majority of incidents at 43 percent. Snorkelers/free divers accounted for 9 percent, and the remainder of activities were too varied to combine. These included jumping in the water, floating on a raft, and scuba diving (13 percent).[Source: Shark Files, Florida Museum of Natural History]

In 2001, surfers were the recreational user group most often subjected to shark attacks, with 35 incidents, or 49 percent of cases. In 1998, surfers accounted for 69 percent of all shark attacks. The remaining attacks occurred equally against swimmers and divers, who accounted for 15 percent each. In the United States swimmers and waders were the most frequent victims at 46 percent, followed by surfers and windsurfers with 32 percent, divers and snorkelers at 18 percent, body surfers at 3 percent and people just entering the water at 1 percent.

See Great White Sharks, Bull Sharks, Tiger Sharks and Grey Reef Sharks.

Websites and Resources: Shark Foundation shark.swiss ; International Shark Attack Files, Florida Museum of Natural History, University of Florida floridamuseum.ufl.edu/shark-attacks ; Tracking Sharks trackingsharks.com, which records all global shark attacks; Animal Diversity Web (ADW) animaldiversity.org; National Oceanic and Atmospheric Administration (NOAA) noaa.gov; Fishbase fishbase.se ; Encyclopedia of Life eol.org ; Smithsonian Oceans Portal ocean.si.edu/ocean-life-ecosystems

Surfers and Sharks

According to Shark Files: The majority of individuals (51 percent) bitten by sharks in 2021 were surfers or boarders, who spend a significant amount of time on the water in and around surf zones. This thin strip of water, where inbound waves that may have travelled for hundreds of miles finally snag on the rising coastal seafloor and topple over, creates the perfect environment for surfers and sharks alike. [Source: Jerald Pinson, Shark Files, Florida Museum of Natural History, January 24, 2022]

Brianna Le Busque wrote in The Conversation: Surfers have a complex relationship with sharks. Many surfers, either knowingly or not, share their waves with sharks of various shapes and sizes. On rare occasions these interactions can result in bites or close calls. A highly publicised close call involved Australian surfer Mick Fanning and a white shark during the 2015 World Surf League final at Jeffreys Bay in South Africa. A video of this interaction has over 19 million views on YouTube alone. Others tune into Hollywood films such as Soul Surfer, which tells the story of surfer Bethany Hamilton who lost her arm to a tiger shark in Hawaii. [Source: Brianna Le Busque, Lecturer in Psychology, University of South Australia, The Conversation, October 31, 2022]

When shark bites occur, often surfers are involved because they are frequently in the ocean. Despite this, many surfers appear to accept these interactions as simply a part of surfing. Surfers even refer to certain sharks as “locals” at particular breaks. In many places, surfers use the term “men in grey suits” when sharks are present. Authors of a 2019 study in California explain this euphemism is used to alert surfers that sharks are present without causing anxiety or stress.

Surfer Psychology and Sharks

Brianna Le Busque wrote in The Conversation: A new study published in Marine Policy surveyed 391 surfers across 24 different countries (predominantly the United States). The study found 60 percent of surfers are not afraid of sharks despite 52 percent having seen sharks while surfing. And 17 percent said either they or someone they knew had been bitten by a shark. This study of the complex but little-researched relationship between surfers and sharks offers interesting insight into the perception of risk. [Source: Brianna Le Busque, Lecturer in Psychology, University of South Australia, The Conversation, October 31, 2022]

In general, most people have no direct experience with sharks, yet overestimate the chance of encountering one and have a strong fear of them. Many surfers have had direct encounters with sharks but perceive the risk to be low and aren’t afraid of them. In fact, 44 percent of surfers said they would still go into the water if a shark was sighted.

The psychology of cognitive heuristics – or shortcuts in thinking – can help us explain why surfers aren’t afraid of sharks. The behavioural psychology principle of operant conditioning explains how consequences influence behaviours. For surfers who have encountered a shark but have not been bitten or had a close call, this behaviour of surfing with sharks (and not being afraid) is being reinforced.

Perhaps this lower level of fear is influenced by a consistent personality trait. Research has found people high in sensation-seeking, which is the tendency for people to pursue thrill-seeking experiences, view the risks of sharks as lower. It is plausible that many surfers are high on sensation-seeking, which may help explain why they perceive the risk of sharks to be low. Post-rationalisation, or choice-support bias, is the tendency for people to ascribe positive attributes to a decision they have made, essentially to justify the decision. Surfers may downplay their fear of sharks to rationalise their decision to continue to surf, as their desire to surf is greater than their perceived risk of a shark bite.

Shark Attacks and Spearfishing

A number of spearfishermen have been bitten and even killed by shark but often they don’t appear in statistics because the attacks are regarded as provoked. The following is one such case. “Police originally said Sheldon Jee, a 21-year-old dive instructor, was presumed to have fallen victim to a shark while scuba diving off Sodwana Bay on South Africa's northeast coast. His severed left hand was all that was found. But his diving school said he had been spear fishing at the time. They think he was attacked by a 13-foot tiger shark far from the dive sites of Sodwana. [Source: Ed Stoddard, IOL, November 29, 2003]

"Scuba divers usually don't get attacked. The shark recognizes them as non-food because of their odd shape such as the tank. The bubbles may also bother them," said Phil Heemstra, a marine biologist with the South African Institute for Aquatic Biodiversity. Spear fishing is a different matter: "Spear fishermen sometimes pass out from holding their breath, and he may have blacked out and then been taken by a shark. "They (sharks) also pick up the vibrations and blood from the speared fish and that gets them excited and puts them in feeding mode,"

Heemstra said. Debby Oscroft, who works for Jee's diving school Coral Divers, said: "Sheldon was spear fishing when he went missing and he was in deep water hundreds of meters out from the reefs where people scuba dive. "The divers who searched for him came across a four-meter tiger shark in the area where he went missing. It was so big that a search plane also saw it from the air," she told Reuters.

Reasons for Shark Attacks

shark attack image from 1874

Shark attacks have risen somewhat in recent years in part because many more people are taking to the water for recreation and staying in the water for longer periods of time. Burgess said the increase was partly a result of increased intrusions on shark habitat by a worldwide population that spends more time in the water. Attacks are basically an odds game based on how many hours you are in the water," Burgess said. "Some of these attacks are beginning to pop up in far-flung corners of the Earth as tourists can afford to vacation in areas they wouldn't normally have gone to in the past...Unfortunately, lots of these tourists gleefully enter waters that natives — who learn over the years where to swim and not to swim — might choose not to go into.” [Source: UPI]

Sometimes it seems like attacks are increasing because more attacks are being reported. On reports that have come in from places like Kiribati, the Galapagos, Fiji and Reunion Island in the Indian Ocean, Burgess said many victims help the International Shark Attack File by looking for information on shark attacks on the Internet and finding the file's Web site. He said they often e-mail their experiences.

Overall sharks attack are declining despite the fact that more people than ever are swimming in the sea. The number of fatal attack in the 20th century has dropped as result of advances in beach safety, medical treatment and public awareness of shark habits. Burgess said that some scientists believe that overfishing of sharks could be a factor. The drop could also be due to changing weather patterns or variations in currents, which could affect the number of fish available for sharks to feed on close to shore. There could also be fewer people in the water for sharks to bump into. "If there is a downturn in the economy, you're going to get (fewer) tourists going to the beaches and therefore less time spent in the water," Burgess told Reuters.

Small sharks — ones that are two meters or less in size — typically eat relatively small prey like small fish, shrimp, rays and octopus and don't normally go after large prey items. Burgess told the Huffington Post the “teeth are not designed evolutionarily for tearing, but rather for grabbing and swallowing whole." When these sharks feed in the murky surf zone where the jostling of waves and currents forces them to rely on quick grabs to feed, a flailing leg or arm of a bather frolicking in the surf can be mistaken for the animal's normal prey. [Source: Huffington Post October 31, 2011]

The teeth of white sharks, tiger sharks and bull sharks are designed for shearing and who normally go after large prey item can in some cases see humans as simply representing an appropriate sized and perhaps appropriately behaviored image of the normal prey item." The silhouette of surfer in a black wetsuit paddling on the surface can resemble a seal, for example. "You can't dismiss all bull shark and white shark attacks on humans as cases of mistaken identity; a human simply looks like something worthy of a trial."

Conditions for Shark Attacks

Updated June 2023

Shark attacks often occur in murky, turbulent water. The shallow water and turbulent waves in surf zones where attacks often take place kick up sediment that make it hard for sharks to sight their prey. Naylor said: “About 60 percent of all bites we record are in low visibility water.” "I think one of the interesting factors when it comes to shark bites is that a lot of bites take place because sharks are not seeing clearly what they're biting," said Stephen Kajiura of FAU Biological Sciences.

According to Shark Files: A feeding shark in this habitat must make quick decisions and rapid movements to capture its traditional food items. When these difficult physical conditions are considered in conjunction with provocative human appearance and activities associated with aquatic recreation (splashing, shiny jewelry, contrasting colored swimsuits, contrasting tanning, especially involving the soles of the feet), it is not surprising that sharks might occasionally misinterpret a human for its normal prey. We suspect that, upon biting, the shark quickly realizes that the human is a foreign object, or that it is too large, and immediately releases the victim and does not return. Some of these attacks could also be related to social behaviors unrelated to feeding, such as dominance behaviors seen in many land animals. Injuries to “hit and run” victims are usually confined to relatively small lacerations, often on the leg below the knee, and are seldom life-threatening. [Source: International Shark Attack Files, Florida Museum of Natural History]

“Bump and bite” attacks and “sneak” attacks, while less common, result in greater injuries and most fatalities. These types of attack usually involve divers or swimmers in somewhat deeper waters, but occur in nearshore shallows in some areas of the world. “Bump and bite” attacks are characterized by the shark initially circling and often bumping the victim prior to the actual attack. “Sneak” attacks differ in having the strike occur without warning.

In both cases, unlike the pattern for “hit and run” attacks, repeat attacks are not uncommon and multiple or sustained bites are the norm. Injuries incurred during this type of attack are usually quite severe, frequently resulting in death. We believe these types of attack are the result of feeding or antagonistic behaviors rather than being cases of mistaken identity. Most shark attacks involving sea disasters, e.g. plane and ship accidents, probably involve “bump and bite” and “sneak” attacks. We know less about the offending parties in “hit and run” cases since the shark is seldom observed, but it is safe to assume that a large suite of species might be involved.

Why Shark Attacks Are More Common in the Atlantic than the Pacific

According to National Geographic Within the continental United States, more shark-human incidents occurred in the Atlantic Ocean—only four attacks were reported in the Pacific (three from Hawaii) compared to 27 in the Atlantic. The reasons for the difference may be complicated, but Naylor said it is most likely due to the prevalence of shark species on the two coasts, and the strength and body sizes of those species. [Source: Jenny Howard, National Geographic, July 3, 2019]

In the Pacific, larger shark species—white, tiger, and bull sharks—were implicated in the reported incidents. In Hawaii, attacks by tiger sharks are the most common, whereas in California, white sharks (also known as great white and white pointer) are most likely to be involved. Globally, these species are involved in the majority of fatal attacks, contributing to their negative reputation in the media. These species tend to be territorial and if they do attack people, they may be sending a warning: get out of my space.

3,000-Year-Old shark attack victim in Peru, from New Scientist

Smaller shark species contribute more attacks to the Atlantic Ocean tally. Currents in the Atlantic Ocean, like the Gulf Stream, can push warmer water closer to shore—with bait fish. These bait fish attract sharks, like blacktips, closer to shore. The one exception to the Atlantic trend, says Naylor, is Massachusetts, where a few more attacks popped up in the last few years as the white shark population has rebounded since the Marine Mammal Protection Act in 1972 brought back their prey—seals.

Another factor in the distribution of shark incidents may be water temperature. Catherine Macdonald, a shark expert and director of the Field School in Miami, Florida, says more attacks do tend to occur in warmer waters, because more people spend more time playing or swimming in those waters, increasing the chances of bumping into a shark. Overall, “there is a strong correlation with people in the water and time in the water and the chance that they will encounter sharks or really any marine life,” she said.Most victims of attacks are swimmers or surfers. That also explains why more shark incidents tend to occur in warm months, because that’s when more people pursue those activities.

People Survive Shark Attacks Because Shark’s Don’t Like Their Taste?

Konstantin Zgurovsky, the marine program coordinator for the Russian branch of the World Wildlife Fund, told the New York Times that one reason many shark attack victims survive is that sharks actually find the taste of humans off-putting. “A big enough shark can instantly rip off a limb, but as soon as it tastes the meat and realizes that it is not right, it will immediately leave it behind,” Dr. Astakhov said. “Victims are often injured, but not killed.”

Because humans are about the same size or larger than most sharks and because humans are larger than normal shark prey, sharks generally swim around to check humans out but leave them alone, and swim away after a while. Studies have shown that sharks respond much more strongly to the blood of fish than they do to human blood.

Man Last Seen in a Beach Buggy Found in a Shark's Stomach

Postmortem shark wounds illustration from an attack in 1980 in Chile

In February 2023, The Telegraph reported: Diego Barria, 32, a father-of-three, was last seen riding his Yamaha Raptor off-road buggy along a stretch of coastline in the southern province of Chubut in Argentina. He then disappeared. His wife, Virginia, posted desperate messages on her Facebook page, appealing for him to get in touch. Two days later, his damaged all-terrain vehicle and his helmet were found on a beach near Rocas Coloradas, a protected area of lagoons, dunes and coloured rock formations. [Source: Nick Squires, The Telegraph, February 28, 2023]

At the weekend, two local men went fishing and hauled three sharks out of the sea. When they cut them open to clean them and prepare them for eating, they found human remains. A tattoo depicting a rose was still visible on the arm of the body which matched a tattoo that Mr Barria had, allowing for him to be identified. The remains were recognised by Mr Barria’s relatives “due to a tattoo that appeared in one of those remains.”

It is thought that Mr Barria, who was keen on fishing and other outdoor pursuits, had an accident on his quadbike, was knocked out, and was then dragged out to sea – there was a strong tidal surge on the day he disappeared. He would have then been easy prey for the sharks, which were around 1.5 meters long. It is probable that Mr Barria “had an accident and was dragged” out to sea, according to Cristian Ansaldo, a police officer from the nearby town of Comodoro Rivadavia. He said there had been a strong tidal surge on the weekend Mr Barria had disappeared. That theory was backed up by Jose Mazzei, a civil protection official, who told Argentinian media that Mr Barria was probably unconscious on the beach when he was dragged out to sea by a high tide.

Image Sources: National Oceanic and Atmospheric Administration (NOAA); Wikimedia Commons, International Shark Attack File, South African Shark Spotters, Australia First Aid, Natal government, Queensland government, New South Wales government and West Australia government

Text Sources: Shark Files, Florida Museum of Natural History, Global Shark Attack File (GSAF), National Geographic, New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Natural History magazine, Discover magazine, The New Yorker, Time, Newsweek, Reuters, AP, AFP, Lonely Planet Guides and various books and other publications.

Last Updated June 2023