Shark attack

From Wikipedia, the free encyclopedia
Jump to: navigation, search
For the film, see Shark Attack (film).
Shark attack
Classification and external resources
Shark warning - Salt Rock South Africa.jpg
A sign warning about the presence of sharks off Salt Rock, South Africa
ICD-9 E906.3 E906.3

A shark attack is an attack on a human by a shark. Every year around 75 shark attacks are reported worldwide. Despite their relative rarity, many people fear shark attacks after occasional serial attacks, such as the Jersey Shore shark attacks of 1916, and horror fiction and films such as the Jaws series. Out of more than 480 shark species, only three are responsible for two-digit number of fatal unprovoked attacks on humans: the great white, tiger and bull;[1] however, the oceanic whitetip has probably killed many more castaways, not recorded in the statistics.[2]

Statistics[edit]

Confirmed Unprovoked Shark Attacks, 1580–2013
Region Total
Attacks
Fatal
Attacks
Last
Fatality
United States
(Excluding Hawaii)
1055 36 2012
Australia 652 184 2014
Africa 339 93 2013
Asia 129 48 2000
Hawaii 129 10 2013
Pacific Islands / Oceania
(Excluding Hawaii)
126 49 2011
South America 117 26 2013
Antilles and Bahamas 70 16 2013
Middle America 57 27 2011
Europe 49 27 1989
New Zealand 49 9 2013
Réunion Island 33 17 2013
Unspecified / Open Ocean 21 7 1995
Bermuda 3 0
Total: 2,881 569 2014
Sources: Australian Shark Attack File for unprovoked attacks in Australia
International Shark Attack File for unprovoked attacks in all other regions
Last Updated: 10 September 2014

According to the International Shark Attack File (ISAF), between 1580 and 2013 there were 2,667 confirmed unprovoked shark attacks around the world, of which 495 were fatal.[3]

Although Australia is ranked the second highest in terms of global shark attacks with 652 unprovoked attacks, it is ranked the highest in terms of shark fatalities, with 184 unprovoked fatalities.[4] The highest death rate occurred in Western Australia, which has experienced 11 fatal attacks since 2000.[5] In 2000, there were 79 shark attacks reported worldwide, 11 of them fatal.[6] In 2005 and 2006 this number decreased to 61 and 62 respectively, while the number of fatalities dropped to only four per year.[6] Of these attacks, the majority occurred in the United States (53 in 2000, 40 in 2005, and 39 in 2006).[7] The New York Times reported in July 2008 that there had been only one fatal attack in the previous year.[8] On average, there are 16 shark attacks per year in the United States with one fatality every two years.[9] Since 1950, there have been four reports of sharks being discovered in swimming pools.[10] 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].[11]

Australia has the highest number of fatal shark attacks in the world with Western Australia recently becoming the deadliest place in the world for shark attacks, which has also prompted a shark cull by state authorities (later scrapped due to public outrage).[12] However, less than one in every three million scuba dives in Western Australia result in a fatal shark attack.[13] Australia and South Africa's fatality rate for shark attacks is approximately 30 percent. The United States has the highest reported number of shark attacks but has the lowest fatality rate with around 4 percent of those attacked dying. The United States has had a total of 1,085 attacks (44 fatal) during the past 342 years (1670–2012).[14] According to the ISAF, 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.[14] South Africa has a high number of shark attacks along with a high fatality rate of 27 percent.[15]

The location with the most recorded shark attacks is New Smyrna Beach, Florida.[16] Developed 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.[17][18]

Even considering only people who go to beaches, a person's chance of getting attacked by a shark in the United States 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.[19][20] In the United States, the annual number of people who drown is 3,306, whereas the annual number of shark fatalities is 1.[21] In New York alone people are bitten 10 times more each year by other people than worldwide by sharks.[22]

Species involved in incidents[edit]

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 480 shark species, only three are responsible for two-digit number of fatal unprovoked attacks on humans: the great white, tiger and bull;[1] however, the oceanic whitetip has probably killed many more castaways, not recorded in the statistics.[2] These sharks, being large, powerful predators, may sometimes attack and kill people; however, they have all been filmed in open water by unprotected divers.[23][24] The 2010 French film Oceans shows footage of humans swimming next to sharks 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. Sharks seek out prey through electroreception, sensing the electric fields that are generated by all animals due to the activity of their nerves and muscles.

Most of the oceanic whitetip shark's attacks have not been recorded,[2] unlike the other three species mentioned above. Famed oceanographic researcher Jacques Cousteau described the oceanic whitetip as "the most dangerous of all sharks".[25]

Watson and the Shark by J.S. Copley, based on the attack on Brook Watson in Havana Harbor 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 British steamship carrying 1,000 people, that was sunk on 28 November 1942 near South Africa by a German submarine in World War II. Only 192 people survived, with many deaths attributed to the oceanic whitetip shark.[26] The same species is probably responsible for many of the 60–80 or more shark casualties following the torpedoing of the USS Indianapolis on 30 July 1945.[27] Tiger sharks may also have been involved.

Signs warning of shark attacks at Boa Viagem Beach in Recife, Brazil

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.[1] 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.[28]

A great white shark is believed to be responsible for an attack on a swimmer at Muriwai Beach in Auckland, New Zealand in February 2013.[29] It was the first confirmed shark attack fatality in the country since 1976.[30][31]

Types of attacks[edit]

Shark attack indices use different criteria to determine if an attack was "provoked" or "unprovoked." When considered from the shark's point of view, attacks on humans who are perceived as a threat to the shark or a competitor to its food source are all "provoked" attacks. Neither the International Shark Attack File (ISAF) nor the Global Shark Attack File (GSAF) accord casualties of air/sea disasters "provoked" or "unprovoked" status; these incidents are considered to be a separate category.[32][33] Postmortem scavenging of human remains (typically drowning victims) are also not accorded "provoked" or "unprovoked" status.[33][34] The GSAF categorizes scavenging bites on humans as "questionable incidents."[33] The most common criteria for determining "provoked" and "unprovoked" attacks are discussed below:

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

Provoked attack[edit]

Provoked attacks occur when a human touches a shark, pokes it, teases it, spears, hooks, or nets it, or otherwise aggravates/provokes it in a certain manner. Incidents that occur outside of a shark's natural habitat, e.g., aquariums and research holding-pens, are considered provoked, as are all incidents involving captured sharks. Sometimes humans inadvertently "provoke" an attack, such as when a surfer accidentally hits a shark with a surf board.

Unprovoked attack[edit]

Unprovoked attacks are initiated by the shark—they occur in a shark's natural habitat on a live human and without human provocation.[32][33] There are three subcategories of unprovoked attack:

  • Hit-and-run attack – Usually non-fatal, the shark bites and then leaves; most victims do not see the shark. This is the most common type of attack and typically occurs in the surf zone or in murky water. Most hit-and-run attacks are believed to be the result of mistaken identity.[35]
  • Sneak attack – The victim will not usually see the shark, and may sustain multiple deep bites. This is the most fatal kind of attack and is not believed to be the result of mistaken identity.[35]
  • Bump-and-bite attack – The shark circles and bumps the victim before biting. Repeated bites are not uncommon and can be severe or fatal. Bump-and-bite attacks are not believed to be the result of mistaken identity.[35]

An incident occurred in 2011 when a 3-meter 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.[36]

Reasons for attacks[edit]

After the great white, the tiger shark is the species involved in the most unprovoked attacks on humans.[34]

Large sharks species are apex predators in their environment,[37] 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.[38] Generally, shark bites are exploratory, and the animal will swim away after one bite.[38] For example, exploratory bites on surfers are thought to be caused by the shark mistaking the surfer for the shape of prey.[39] Nonetheless, a single bite can grievously injure a human if the animal involved is a powerful predator like a great white or tiger shark.[40]

Despite a few rare exceptions,[41][42] 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.[39]

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.[43] Shark attacks may also occur due to territorial reasons or as dominance over another shark species, resulting in an attack.[44]

Sharks are equipped with sensory organs called the Ampullae of Lorenzini that detect the electricity generated by muscle movement;[45] 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.[44]

George H. 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".[46]

The bull shark is responsible for the most unprovoked attacks on humans.[34] Bull sharks can be found in the ocean and in freshwater rivers and lakes.[47]

Protection by dolphins[edit]

Many attacks have occurred on survivors of shipwrecks or downed aircraft by the oceanic whitetip; these attacks are difficult to confirm and are rarely included in shark attack indices.[34][47]

There are documented instances of dolphins protecting humans from shark attacks, such as one attack on a surfer in northern California in August 2007[48] and one off the coast of New Zealand in 2004.[49] 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".[50] In some cases, sharks have been seen attacking, or trying to attack dolphins.[51] The presence of porpoises does not indicate the absence of sharks as both eat the same food.[52]

Media impacts[edit]

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,[53] 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.[54] 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[55] were the cause of large-scale hunting and killing of thousands of sharks.[56] There are some television shows, such as the famous Shark Week,[57] 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. In that regard, given that statistics show drowning is a more common form of death for recreational water users than shark attack, it can be claimed that by doing so sharks actually save the lives of humans who might otherwise drown.

See also[edit]

References[edit]

  1. ^ a b c ISAF Statistics on Attacking Species of Shark
  2. ^ a b c Edmonds, Molly. "HowStuffWorks "Dangerous Shark 4: Oceanic Whitetip Shark"". Animals.howstuffworks.com. Retrieved 23 September 2010. 
  3. ^ "World's Confirmed Unprovoked Shark Attacks". International Shark Attack File. 11 February 2013. Retrieved 17 February 2014. 
  4. ^ "Latest Figures". Taronga Conservation Society Australia. 10 September 2014. Retrieved 10 September 2014. 
  5. ^ "Fatal shark attacks in wa since 2000". Perth Now. 23 Nov 2013. Retrieved 10 Sep 2014. 
  6. ^ a b "ISAF Statistics for the Top Ten Worldwide Locations with the Highest Shark Attack Activity (1999–2009)". Florida Museum of Natural History Flmnh.ufl.edu. 25 March 2010. Retrieved 23 September 2010. 
  7. ^ "ISAF Statistics for the USA Locations with the Highest Shark Attack Activity Since 1999". Flmnh.ufl.edu. 3 May 2010. Retrieved 23 September 2010. 
  8. ^ Tierney, John (29 July 2008). "10 Things to Scratch From Your Worry List". The New York Times. Retrieved 19 September 2010. 
  9. ^ "Shark Facts: Attack Stats, Record Swims, More". News.nationalgeographic.com. 28 October 2010. Retrieved 17 August 2012. 
  10. ^ Baldridge, H. David (1978). Shark Attack. New York: Berkely Pub Group. 
  11. ^ "Sharks". Rescuediver.org. Retrieved 23 September 2010. 
  12. ^ "WA 'deadiest' for shark attacks – The West Australian". Au.news.yahoo.com. 1 April 2012. Retrieved 17 August 2012. 
  13. ^ Buzzacott, Peter (2005). "An estimate of the risk of fatal shark attack whilst diving in Western Australia.". Journal of the South Pacific Underwater Medicine Society 35 (2). Retrieved 6 April 2013. 
  14. ^ a b "Map of United States (incl. Hawaii) Confirmed Unprovoked Shark Attacks". Flmnh.ufl.edu. 26 August 2010. Retrieved 16 February 2012. 
  15. ^ "Map of World's Confirmed Unprovoked Shark Attacks". Flmnh.ufl.edu. 6 January 2011. Retrieved 25 November 2011. 
  16. ^ Regenold, Stephen (21 April 2008). "North America's top shark-attack beaches". USA Today. Retrieved 9 April 2010. 
  17. ^ "The Relative Risk of Shark Attacks to Humans". Flmnh.ufl.edu. Retrieved 23 September 2010. 
  18. ^ Florida Museum of Natural History, University of Florida. A Comparison with the Number of Lightning Fatalities in Coastal United States: 1959–2006
  19. ^ "Year 2000 USA Beach Injuries and Fatalities Compared To Shark Attacks and Fatalities". Flmnh.ufl.edu. Retrieved 23 September 2010. 
  20. ^ "Attack Stats | Oceana – Protecting the World’s Oceans". Oceana.org. Retrieved 23 September 2010. 
  21. ^ "A Comparison of Shark Attack and Bicycle-Related Fatalities 1990–2005". Flmnh.ufl.edu. Retrieved 23 September 2010. 
  22. ^ "Shark Accidents". Shark Foundation. 
  23. ^ "Hawaiian newspaper article". Honoluluadvertiser.com. Retrieved 23 September 2010. 
  24. ^ The 1992 Cageless shark-diving expedition by Ron and Valerie Taylor.
  25. ^ Cousteau, Jacques-Yves & Cousteau, Philippe (1970). The Shark: Splendid Savage of the Sea. Doubleday & Company, Inc. 
  26. ^ Bass, A.J., J.D. D'Aubrey & N. Kistnasamy. 1973. "Sharks of the east coast of southern Africa. 1. The genus Carcharhinus (Carcharhinidae)." Invest. Rep. Oceanogr. Res. Inst., Durban, no. 33, 168 pp.
  27. ^ Martin, R. Aidan. "Elasmo Research". ReefQuest. Retrieved 6 February 2006. 
  28. ^ University of Florida News New study documents first cookiecutter shark attack on a live human
  29. ^ "Muriwai shark most likely a great white". 3 News NZ. 28 February 2013. 
  30. ^ "Sharks and rays". Te Ara, the Encyclopedia of New Zealand. 27 February 2013. 
  31. ^ "Swimmer dies after shark attack". 3 News NZ. 27 February 2013. 
  32. ^ a b Burgess, George H.. "ISAF 2011 Worldwide Shark Attack Summary". Global Shark Attack File. Retrieved 26 June 2012. 
  33. ^ a b c d "Incident Log". Global Shark Attack File. Retrieved 26 June 2012. 
  34. ^ a b c d "ISAF Statistics on Attacking Species of Shark". Global Shark Attack File. 30 January 2012. Retrieved 26 June 2012. 
  35. ^ a b c Burgess, George H.. "How, When, & Where Sharks Attack". International Shark Attack File. Retrieved 26 June 2012. 
  36. ^ Rice, Xan (19 July 2011). "Great white shark jumps from sea into research boat". The Guardian (London: Guardian Media Group). Retrieved 20 July 2011. "Marine researchers in South Africa had a narrow escape after a three-metre-long great white shark breached the surface of the sea and leaped into their boat, becoming trapped on deck for more than an hour. [...] Enrico Gennari, an expert on great white sharks, [...] said it was almost certainly an accident rather than an attack on the boat." 
  37. ^ "Apex Predators Program". Na.nefsc.noaa.gov. Retrieved 23 September 2010. 
  38. ^ a b "What To Expect On Your Great White Shark Diving Tour". Romow.com. 7 August 2009. Retrieved 23 September 2010. 
  39. ^ a b Grabianowski, Ed. "HowStuffWorks "How Shark Attacks Work"". Adventure.howstuffworks.com. Retrieved 23 September 2010. 
  40. ^ Grabianowski, Ed. "HowStuffWorks "Shark Attack Damage"". Adventure.howstuffworks.com. Retrieved 23 September 2010. 
  41. ^ "Shark attack tears teenager in two". Daily Mail (London). 2 May 2007. 
  42. ^ Shears, Richard (28 December 2008). "Shark spotted with the body of a man in its jaws as witnesses look on in horror". Daily Mail (London). 
  43. ^ "Great White Shark". Extremescience.com. Retrieved 23 September 2010. 
  44. ^ a b Grabianowski, Ed. "HowStuffWorks "Shark Sensory System"". Adventure.howstuffworks.com. Retrieved 23 September 2010. 
  45. ^ "Ampullae of Lorenzini". Marinebiodiversity.ca. Retrieved 23 September 2010. 
  46. ^ "Shark attacks at record high". BBC News. 9 February 2001. Retrieved 6 April 2010. 
  47. ^ a b Curtis, Tobey. "Bull shark". Florida Museum of Natural History, University of Florida. Retrieved 26 June 2012. 
  48. ^ Celizic, Mike (8 November 2007). "Dolphins rescue surfer from shark - TODAY People - People: Tales of survival - TODAYshow.com". MSNBC. Retrieved 23 September 2010. 
  49. ^ Mercer, Phil (23 November 2004). "Dolphins prevent NZ shark attack". BBC News. Retrieved 6 April 2010. 
  50. ^ "Predator–prey and competitive interactions between sharks (order Selachii) and dolphins (suborder Odontoceti): a review – Heithaus – 2006 – Journal of Zoology – Wiley Online Library". .interscience.wiley.com. 28 February 2006. Retrieved 23 September 2010. 
  51. ^ http://www.abcactionnews.com/news/local/story/Rehabilitated-dolphin-dies-after-shark-attack/Os5uEUUiFU2NukbdnqiZXQ.cspx
  52. ^ "North Carolina Sea Grant – Coastwatch Articles". Ncseagrant.org. Retrieved 23 September 2010. 
  53. ^ "Cultivation Theory". Utwente.nl. 7 September 2010. Retrieved 17 August 2012. 
  54. ^ "FLMNH Ichthyology Department: The Relative Risk of Shark Attacks". Flmnh.ufl.edu. 18 July 2003. Retrieved 17 August 2012. 
  55. ^ Jaws at the Internet Movie Database
  56. ^ Choi, Charles Q. "How 'Jaws' Forever Changed Our View of Great White Sharks". Web. Live Science. Retrieved 29 August 2013. 
  57. ^ "Shark Week : Discovery Channel". Dsc.discovery.com. Retrieved 17 August 2012. 

External links[edit]