Shark attack

Shark attack
Shark attack
Classification and external resources

A sign warning about the presence of sharks off Salt Rock, South Africa.
ICD-10 W56
ICD-9 E906.3 E906.3

A shark attack is an attack on a human by a shark. Every year around 60 shark attacks are reported worldwide, although death is quite unusual. Despite the relative rarity of shark attacks, the fear of sharks is a common phenomenon, having been fueled by the occasional instances of serial attacks, such as the Jersey Shore shark attacks of 1916, and by horror fiction and films, such as the Jaws series. Almost all shark experts feel that the danger presented by sharks has been exaggerated, and even the creator of the Jaws phenomenon, the late Peter Benchley, attempted to dispel the myth of sharks being man-eating monsters in the years before his death.

Contents

Statistics

The great white shark is one of only four kinds of sharks that have been involved in a significant number of fatal unprovoked attacks on humans

In 2000, the year with the most recorded shark attacks, there were 79 shark attacks reported worldwide, 11 of them fatal.[1] In 2005 and 2006 this number decreased to 61 and 62 respectively, while the number of fatalities dropped to only four per year.[1] Of these attacks, the majority occurred in the United States (53 in 2000, 40 in 2005, and 39 in 2006).[2] The New York Times reported in July 2008 that there had been only one fatal attack in the previous year.[3] On average, there are 16 shark attacks per year in the United States with one fatality every two years.[4] Despite these reports, however, the actual number of fatal shark attacks worldwide remains uncertain. For the majority of third world coastal nations there exists no method of reporting suspected shark attacks therefore losses and fatalities at near-shore or sea there often remain unsolved or unpublicized.[citation needed][5]

The United States has had more reported shark attacks than any other country, with a total of 1,049 attacks (49 fatal) during the past 339 years (1670–2009).[6] According to the International Shark Attack File, the states in the U.S. where the most attacks have occurred in are Florida, Hawaii, California, Texas, and the Carolinas, though attacks have occurred in almost every coastal state.[6] Outside the U.S., Australia (since records started in 1791, 875 attacks of which 214 were fatal) [7] and South Africa have had the most attacks.[8]

As of 2009, the ISAF recorded a total of 2,251 attacks worldwide since 1580, with 464 attacks being fatal.[8] The location with the most recorded shark attacks is New Smyrna Beach, Florida.[9] First world nations such as the United States, Australia, both high income countries, and to some extent South Africa, an upper middle income country, facilitate more thorough documentation of shark attacks on humans than poorer coastal countries.

The Florida Museum of Natural History compares these statistics with the much higher rate of deaths from other, less feared causes. For example, an average of more than 38 people die annually from lightning strikes in coastal states, while less than 1 person per year is killed by a shark.[10][11] In comparison, 100 million sharks are killed every year by humans.[12][13][14]

Even considering only people who go to beaches, a person's chance of getting attacked by a shark is 1 in 11.5 million, and a person's chance of getting killed by a shark is less than 1 in 264.1 million.[15][16] In the United States, the annual number of people who drown is 3,306, whereas the annual number of shark fatalities is 1.[17]

Species involved in incidents

A blacktip reef shark. In rare circumstances such as bad visibility, blacktips may bite humans, mistaking them for prey. Under normal conditions, however, they are harmless and often even quite shy.

Contrary to popular belief, only a few sharks are dangerous to humans. Out of more than 360 shark species, only four have been involved in a significant number of fatal unprovoked attacks on humans: the great white, tiger, bull[18] and the oceanic whitetip.[19] These sharks, being large, powerful predators, may sometimes attack and kill people; however, they have all been filmed in open water by unprotected divers.[20][21] The 2010 French film Oceans shows footage of humans swimming next to sharks deep in the ocean. It is possible that the sharks are able to sense the presence of unnatural elements on or about the divers, such as polyurethane diving suits and air tanks, which may lead them to accept temporary outsiders as more of a curiosity than prey. Uncostumed humans, however, such as those surfboarding, light snorkeling, or swimming, present a much greater area of open meaty flesh to carnivorous shark predators. In addition the presence of even small traces of blood, recent minor abrasions, cuts, scrapes, or bruises, may convince sharks to attack a human in their environment. Some sharks such as the Hammerhead seek out prey through electromagnetic detection, an unpreventable transmission relative to natural human intervention in an oceanic environment. Most of the oceanic whitetip shark's attacks have not been recorded,[19] unlike the other three species mentioned above. Famed oceanographic researcher Jacques Cousteau described the oceanic whitetip as "the most dangerous of all sharks".[22]

Watson and the Shark by J.S. Copley, based on an attack on a swimmer in Havana in 1749

Modern day statistics show the oceanic whitetip shark as being seldom involved in unprovoked attacks. However, there have been a number of attacks involving this species, particularly during World War I and World War II. The oceanic whitetip lives in the open sea and rarely shows up near coasts, where most recorded incidents occur. During the world wars many ship and aircraft disasters happened in the open ocean, and due to its former abundance the oceanic whitetip was often the first species on site when such a disaster happened.

Infamous examples of oceanic whitetip attacks include the sinking of the Nova Scotia, a steamship carrying 1000 people, that was sunk near South Africa by a German submarine in World War II. Only 192 people survived, with many deaths attributed to the oceanic whitetip shark.[23] The same species is probably responsible for many of the of the 60–80 or more shark casualties following the torpedoing of the USS Indianapolis on 30 July 1945;[24] tiger sharks may also have been involved.

Incidents involving the oceanic whitetip total in the thousands worldwide[25]

In addition to the four species responsible for a significant number of fatal attacks on humans, a number of other species have attacked humans without being provoked, and have on extremely rare occasions been responsible for a human death. This group includes the shortfin mako, hammerhead, Galapagos, gray reef, blacktip reef, lemon, silky, and blue sharks.[18] These sharks are also large, powerful predators which can be provoked simply by being in the water at the wrong time and place, but they are normally considered less dangerous to humans than the previous group.

A few other shark species do attack people every year, producing wounds that can potentially kill, but this occurs either specifically because they have been provoked, or through mistaken identity due to water conditions or the like.

In the evening of 16 March 2009 a new addition was made to the list of sharks known to attack human beings. In a painful but not directly life threatening incident a long distance swimmer crossing the Alenuihaha Channel between the islands of Hawai‘i and Maui was attacked by a cookiecutter shark. The 2 bites, delivered about 15 seconds apart were not immediately life threatening.[26]

Types of attacks

Scientists have defined two types of shark attacks, one of which has three subcategories:[27]

  • Provoked attack – the human touches the shark, pokes it, teases it, or otherwise aggravates/provokes it in some way.
  • Unprovoked attack [28]
    • Hit-and-run attack – Usually non-fatal, the shark bites and then leaves; most victims do not see the shark.
    • Sneak attack – Victim will not usually see the shark, and they may receive repeated deep bites. This is the most fatal kind of shark attack.
    • Bump-and-bite attack – The shark bumps before biting and then normally swims away.

An incident occurred in 2011 when a 3-metre long great white shark jumped onto a 7-person research vessel off Seal Island, South Africa. The crew were undertaking a population study using sardines as bait, and the incident was judged to be an accident.[29]

Reasons for attacks

While one should be very cautious with great white sharks, they do not target humans as prey.

Large sharks species are apex predators in their environment,[30] and thus have little fear of any creature they cross paths with. Like most sophisticated hunters, they are curious when they encounter something unusual in their territories. Lacking any limbs with sensitive digits such as hands or feet, the only way they can explore an object or organism is to bite it; these bites are known as exploratory bites.[31] Generally, shark bites are exploratory, and the animal will swim away after one bite.[31] For example, exploratory bites on surfers are thought to be caused by the shark mistaking the surfer for the shape of prey.[32] Nonetheless, a single bite can grievously injure a human if the animal involved is a powerful predator like a great white or tiger shark.[33]

Despite a few rare exceptions,[34][35] it has been concluded that feeding is not a reason sharks attack humans. In fact, humans don't provide enough high-fat meat for sharks, which need a lot of energy to power their large, muscular bodies".[32]

Sharks normally make one swift attack and then retreat to wait for the victim to die or exhaust itself before returning to feed. This protects the shark from injury from a wounded and aggressive target; however, it also allows humans time to get out of the water and survive.[36] Shark attacks may also occur due to territorial reasons or as dominance over another shark species, resulting in an attack.[37]

Sharks are equipped with sensory organs called the Ampullae of Lorenzini that detect the electricity generated by muscle movement;[38] another theory is that the shark's electrical receptors, which pick up movement, pick up the signals like those emitted by wounded fish from someone who is fishing or spearfishing, and thus attack the person by mistake.[37]

George Burgess, director of the International Shark Attack File, said the following regarding why people are attacked: "Attacks are basically an odds game based on how many hours you are in the water".[39]

Prevention

While there is no way to completely eliminate the possibility of a shark attack when one is in the water, one may take precautions such as:[40]

  • avoiding the water at dawn, dusk, or night, when sharks tend to feed;
  • avoiding areas where sharks generally locate themselves, such as murky waters and steep drop-offs
  • avoiding swimming alone, always being near a group of people, and if possible, avoiding being at the edge of the group;
  • refraining from excess splashing or movement;
  • preventing pets from entering the water;
  • avoiding shiny jewelry, tan lines and bright clothing, all of which can attract sharks;
  • avoiding entering water if bleeding from an open wound or if menstruating;
  • avoiding areas where prey animals of sharks live, for instance seals;
  • avoiding areas where the remains of fish have been discarded into the water, such as near fishermen cleaning their catch.
  • sharks attack at 2-3 feet of water so remember to stay closer than that in shark infested waters.

Dolphins' protection

There are many documented instances of dolphins protecting humans from shark attacks, such as one attack on a surfer in northern California in August 2007[41] and one off the coast of New Zealand in 2004.[42] Typically, dolphins form a ring around humans who are injured.[41] There is no accepted explanation for this behavior; as mentioned in the Journal of Zoology, "The importance of interactions between sharks and cetaceans has been a subject of much conjecture, but few studies have addressed these interactions".[43] In some cases, sharks have been seen attacking, or trying to attack dolphins.[44] The presence of porpoises does not indicate the absence of sharks as both eat the same food.[45]

Media impacts

The effect the media has on the population's view of shark attacks has generally been negative. Using such theories as the cultivation theory and the effects of "mean world syndrome",[46] it is simple to see how such media as television and movies can quickly affect a person’s view. Starting with the effects generated from news broadcasts, a shark attack is quickly broadcast across the country, particularly if fatal, even though more people die from random occurrences such as lightning strikes than from a shark attack.[47] This will bring the fear of a shark attack to life as it becomes a reality for many that hear of a particular incident. This heightened state of unnecessary fear is accredited to the sometimes negative portrayal of sharks through television and motion pictures. Films such as Jaws [48] were the cause of large scale hunting and killing of thousands of sharks. There are some television shows, such as the famous Shark Week,[49] that are dedicated to the preservation of these animals. They are able to prove through scientific studies that sharks are not interested in attacking humans and generally mistake humans as prey. It is however, a mixture of these media exposures that keep many people out of the water for fear of a shark attack.

See also

References

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  2. ^ "ISAF Statistics for the USA Locations with the Highest Shark Attack Activity Since 1999". Flmnh.ufl.edu. 2010-05-03. http://www.flmnh.ufl.edu/fish/sharks/statistics/statsus.htm. Retrieved 2010-09-23. 
  3. ^ Tierney, John (2008-07-29). "10 Things to Scratch From Your Worry List". The New York Times. http://www.nytimes.com/2008/07/29/science/29tier.html?scp=1&sq=shark+attack&st=nyt. Retrieved 2010-09-19. 
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