Shark attack

From Infogalactic: the planetary knowledge core
Jump to: navigation, search

<templatestyles src="Module:Hatnote/styles.css"></templatestyles>

Shark attack
Shark warning - Salt Rock South Africa.jpg
A sign warning about the presence of sharks off Salt Rock, South Africa
Classification and external resources
Specialty Lua error in Module:Wikidata at line 446: attempt to index field 'wikibase' (a nil value).
ICD-9-CM E906.3 E906.3
Patient UK Shark attack
[[[d:Lua error in Module:Wikidata at line 863: attempt to index field 'wikibase' (a nil value).|edit on Wikidata]]]

The term shark attack is used to describe an attack on a human by a shark. Every year over 70 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 a double-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

Confirmed Unprovoked Shark Attacks, 1958–2014
Region Total
Attacks
Fatal
Attacks
Last
Fatality
United States
(Excluding Hawaii)
1104 35 2013
Australia 665 232 2015
Africa 346 94 2014
Asia 129 48 2000
Hawaii 137 10 2015
Pacific Islands / Oceania
(Excluding Hawaii)
126 49 2011
South America 117 26 2013
Antilles and Bahamas 70 16 2013
Middle America 56 27 2011
Europe 51 27 1989
New Zealand 49 9 2013
Réunion Island 38 18 2015[3]
Unspecified / Open Ocean 21 7 1995
Bermuda 3 0
Total: 2,899 548 2015
Sources: Australian Shark Attack File for unprovoked attacks in Australia
International Shark Attack File for unprovoked attacks in all other regions
Last Updated: 19 February 2015

According to the International Shark Attack File (ISAF), between 1958 and 2014 there were 2,778 confirmed unprovoked shark attacks around the world, of which 497 were fatal.[4]

Although Australia is ranked the second highest in terms of global shark attacks with 664 unprovoked attacks, it is ranked the highest in terms of shark fatalities, with 232 unprovoked fatalities.[5] The highest death rate occurred in Western Australia, which has experienced 11 fatal attacks since 2000.[6] In 2000, there were 79 shark attacks reported worldwide, 11 of them fatal.[7] In 2005 and 2006 this number decreased to 61 and 62 respectively, while the number of fatalities dropped to only four per year.[7] Of these attacks, the majority occurred in the United States (53 in 2000, 40 in 2005, and 39 in 2006).[8] The New York Times reported in July 2008 that there had been only one fatal attack in the previous year.[9] On average, there are 16 shark attacks per year in the United States with one fatality every two years.[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 Unpublicised.[citation needed].[11]

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).[12] According to the ISAF, the states in the U.S. in which the most attacks have occurred are Florida, Hawaii, California, Texas, and the Carolinas, though attacks have occurred in almost every coastal state.[12] South Africa has a high number of shark attacks along with a high fatality rate of 27 percent.[13]

The location with the most recorded shark attacks is New Smyrna Beach, Florida.[14] 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.[15][16]

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.[17][18] In the United States, the annual number of people who drown is 3,306, whereas the annual number of shark fatalities is 1.[19]

Shark attacks in Western Australia

Since 2008, the Western Australian Government has been working to address the issue of human-shark interactions. There have been 10 deaths from shark attacks in Western Australia waters in the last 10 years, with seven of these in the last three and a half years. According to the Western Australian Shark Hazard Mitigation Drum Line Program (WASHMDLP, 2014)[20] following the latest fatal attack at Gracetown on 23 November 2013, the Western Australian Government have decided in the interest of the public safety to deploy a limited number of drum lines over a limited time period of the metropolitan and south west coasts. During the period the drum lines were set out 25 January – 30 April 2014 they mostly comprised by tiger sharks.

figure 1. number of animals caught on the drum lines. from Government Of Western Australia, June 2014, Western Australia Shark Hazard Mitigation Drum Line Program.

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 480 shark species, only three are responsible for two-digit numbers 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.[21][22] 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 exposed skin surface to sharks. 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".[23]

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 because of 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.[24] 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.[25] Tiger sharks may also have been involved.

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

Black December refers to at least nine shark attacks on humans causing six deaths that occurred along the coast of KwaZulu-Natal Province, South Africa, from December 18, 1957 to April 5, 1958.[26]

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, lemon, silky shark 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 Hawaii and Maui was attacked by a cookiecutter shark. The two bites, delivered about 15 seconds apart, were not immediately life-threatening.[27]

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.[28] It was the first confirmed shark attack fatality in the country since 1976.[29][30]

Types of attacks

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.[31][32] Postmortem scavenging of human remains (typically drowning victims) are also not accorded "provoked" or "unprovoked" status.[32][33] The GSAF categorizes scavenging bites on humans as "questionable incidents."[32] The most common criteria for determining "provoked" and "unprovoked" attacks are discussed below:

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

Provoked attack

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

Unprovoked attacks are initiated by the shark—they occur in a shark's natural habitat on a live human and without human provocation.[31][32] 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.[34]
  • Sneak attack – The victim will not usually see the shark, and may sustain multiple deep bites. This kind of attack is often carried out with the intention of preying upon the victim; it is extraordinarily rare for this to occur and is known to happen more often in places such as South Africa where sharks are acclimated to human presence (or, worse, have learned that human presence means food due to "chumming" to lure sharks closer to the cages) due to shark cage-diving activity. Sneak attacks are the most fatal kind of attacks and are not believed to be the result of mistaken identity.[34]
  • Bump-and-bite attack – The shark circles and bumps the victim before biting. Great whites are known to do this on occasion, referred to as a "test bite", in which the great white is attempting to identify what is being bitten. Repeated bites are not uncommon, depending on the reaction of the victim (thrashing or panicking may lead the shark to believe the victim is prey), and can be severe or fatal. Bump-and-bite attacks are not believed to be the result of mistaken identity.[34]

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.[35]

Reasons for attacks

The tiger shark is second in number of unprovoked attacks on humans.[33]

Large sharks species are apex predators in their environment,[36] and thus have little fear of any creature (other than orcas[37]) with which they cross paths. 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 the third in statistics of unprovoked attacks on humans.[33] They are found in freshwater rivers and lakes as well as the ocean.[47]

Protection by dolphins

The oceanic whitetip has made many attacks on survivors of shipwrecks or downed aircraft; these are difficult to confirm and are rarely included in shark attack indices.[33][48]

There are documented instances of bottlenose dolphins protecting humans from shark attacks, such as one attack on a surfer in northern California in August 2007[49] and one off the coast of New Zealand in 2004.[50] 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".[51] In some cases, sharks have been seen attacking, or trying to attack dolphins.[52] The presence of porpoises does not indicate the absence of sharks as both eat the same food.[53]

Media impact

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,[54] 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.[55] 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.

The Jersey Shore shark attacks of 1916 killing 4 people in the first 2 weeks of July 1916 along the New Jersey shore and Matawan Creek in New Jersey, started media attention on shark attacks in the United States of America.[56]

In 2010 nine Australian survivors of shark attacks banded together to promote a more positive view of sharks. The survivors made particular note of the role of the media in distorting the fear of sharks.[57] Films such as Jaws[58] were the cause of large-scale hunting and killing of thousands of sharks.[59] There are some television shows, such as the famous Shark Week,[60] 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.

List of notable victims

See also

References

Lua error in package.lua at line 80: module 'strict' not found.

External links

  1. 1.0 1.1 1.2 ISAF Statistics on Attacking Species of Shark
  2. 2.0 2.1 2.2 Lua error in package.lua at line 80: module 'strict' not found.
  3. http://www.lemonde.fr/planete/article/2015/04/12/un-adolescent-tue-par-un-requin-a-la-reunion_4614491_3244.html
  4. Lua error in package.lua at line 80: module 'strict' not found.
  5. Lua error in package.lua at line 80: module 'strict' not found.
  6. Lua error in package.lua at line 80: module 'strict' not found.
  7. 7.0 7.1 Lua error in package.lua at line 80: module 'strict' not found.
  8. Lua error in package.lua at line 80: module 'strict' not found.
  9. Lua error in package.lua at line 80: module 'strict' not found.
  10. Lua error in package.lua at line 80: module 'strict' not found.
  11. Lua error in package.lua at line 80: module 'strict' not found.
  12. 12.0 12.1 Lua error in package.lua at line 80: module 'strict' not found.
  13. Lua error in package.lua at line 80: module 'strict' not found.
  14. Lua error in package.lua at line 80: module 'strict' not found.
  15. Lua error in package.lua at line 80: module 'strict' not found.
  16. Florida Museum of Natural History, University of Florida. A Comparison with the Number of Lightning Fatalities in Coastal United States: 1959–2006
  17. Lua error in package.lua at line 80: module 'strict' not found.
  18. Lua error in package.lua at line 80: module 'strict' not found.
  19. Lua error in package.lua at line 80: module 'strict' not found.
  20. Lua error in package.lua at line 80: module 'strict' not found.
  21. Lua error in package.lua at line 80: module 'strict' not found.
  22. The 1992 Cageless shark-diving expedition by Ron and Valerie Taylor.
  23. Lua error in package.lua at line 80: module 'strict' not found.
  24. 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.
  25. Lua error in package.lua at line 80: module 'strict' not found.
  26. National Geographic: South Africa Rethinks Use of Shark Nets
  27. University of Florida News New study documents first cookiecutter shark attack on a live human
  28. Lua error in package.lua at line 80: module 'strict' not found.
  29. Lua error in package.lua at line 80: module 'strict' not found.
  30. Lua error in package.lua at line 80: module 'strict' not found.
  31. 31.0 31.1 Lua error in package.lua at line 80: module 'strict' not found.
  32. 32.0 32.1 32.2 32.3 Lua error in package.lua at line 80: module 'strict' not found.
  33. 33.0 33.1 33.2 33.3 Lua error in package.lua at line 80: module 'strict' not found.
  34. 34.0 34.1 34.2 Lua error in package.lua at line 80: module 'strict' not found.
  35. Lua error in package.lua at line 80: module 'strict' not found.
  36. Lua error in package.lua at line 80: module 'strict' not found.
  37. Lua error in package.lua at line 80: module 'strict' not found.
  38. 38.0 38.1 Lua error in package.lua at line 80: module 'strict' not found.
  39. 39.0 39.1 Lua error in package.lua at line 80: module 'strict' not found.
  40. Lua error in package.lua at line 80: module 'strict' not found.
  41. Lua error in package.lua at line 80: module 'strict' not found.
  42. Lua error in package.lua at line 80: module 'strict' not found.
  43. Lua error in package.lua at line 80: module 'strict' not found.
  44. 44.0 44.1 Lua error in package.lua at line 80: module 'strict' not found.
  45. Lua error in package.lua at line 80: module 'strict' not found.
  46. Lua error in package.lua at line 80: module 'strict' not found.
  47. Lua error in package.lua at line 80: module 'strict' not found.
  48. Lua error in package.lua at line 80: module 'strict' not found.
  49. Lua error in package.lua at line 80: module 'strict' not found.
  50. Lua error in package.lua at line 80: module 'strict' not found.
  51. Lua error in package.lua at line 80: module 'strict' not found.
  52. http://www.abcactionnews.com/news/local/story/Rehabilitated-dolphin-dies-after-shark-attack/Os5uEUUiFU2NukbdnqiZXQ.cspx
  53. Lua error in package.lua at line 80: module 'strict' not found.
  54. Lua error in package.lua at line 80: module 'strict' not found.
  55. Lua error in package.lua at line 80: module 'strict' not found.
  56. Lua error in package.lua at line 80: module 'strict' not found.
  57. attack survivors unite to save sharks, Australian Geographic, 14 September 2010
  58. Lua error in Module:WikidataCheck at line 28: attempt to index field 'wikibase' (a nil value). Jaws at IMDb
  59. Lua error in package.lua at line 80: module 'strict' not found.
  60. Lua error in package.lua at line 80: module 'strict' not found.