SHARKS ask anyone about dangerous fish and they always bring up sharks. The word strikes fear in the hearts of many men. In a few cases it is true, in most it is not. Sharks are unpredictable, scavengers, continuously on the hunt for food, when they take a bite, there is massive tissue loss from a crescent shaped wound. There is always severe primary shock. Shark attacks on swimmers are infrequent. Some researchers state the odds of getting attacked by a shark are the same as getting hit by lighting.
All shark bites are created equal, it is only the size that varies. The rule of thumb concerning shark bites is "the bigger the shark the bigger the bite". A small 2 foot surf shark can make a bite the size of a hamburger.
All sharks have common characteristics and range in size from 1 foot to over 25 feet long. They have an extremely large mouth, with multiple rows of sharp teeth and extremely powerful jaw muscles. When a shark bites, it hangs on with a characteristic shaking of the head, side to side, crushing bone and ripping soft tissue. A single bite may be immediately fatal.
Pre-attack behavior by most sharks is moderately predictable. They start by swimming with an exaggerated motion, and their pectoral fins point down instead of out. Swimming in decreasing size circles around its intended prey. As a rule divers should believe an attack may be imminent if a shark assumes an unnatural posture. Sharks have attacked without any pre-attack behavior.
Sharks will follow schools of fish and fishing boats. They most often feed at dusk and dawn, but will feed anytime. After dark, they have a tendency to move toward shore. Since most fish are more active at night sharks generally feed at night. They first locate their pray by smell or sound. They will investigate large objects in the water, but will not always attack. They rarely jump out of the water as the movies imply, but the Great White will more often than any other.
When a shark is sighted by diver or swimmer, he should make slow movements, remaining still until the shark leaves, or slowly swim towards shore, always facing the shark. A diver may be better off descending to the bottom if possible for protection in rocks, or on the seabed. This is due to sharks preferring the surface over the deep. Always keep the shark in sight. Attempting to kill a shark is usually more dangerous than effective. If attacked, try to beat away the shark by hitting to the eyes, gills or underside. Hitting the "nose" may be hard, being that a shark thrust up his jaw when biting. Sometimes a shark can be moved or shoved away.
Treatment is prompt control of blood lose. Control of hemorrhage by arterial tourniquet proximal to the wound has priority in the ABC's. The wound should be packed, and wrapped with elastic bandages. Lay victim down and place in shock position. Start two large bore IV's, wide open, for fluid replacement. A plasma expander IV must be given in at least two sites and whole blood must be given as soon as possible. Bites also may cause bone fractures. Any shark bite to a limb should be splinted as if it were fractured. Use MAST as needed and transport to the nearest trauma center by quickest means. Use a helicopter if available. If a limb is severed and retrievable, wrap it in bandages and put on ice, then transport with the victim. Definitive surgical treatment is the only therapy that will help the patient. Prehospital and E.R. care should only be directed toward getting the victim to surgery as soon as possible.
Shark Attack Victims
There are approximily 100 shark attacks worldwide annually. That is reported shark attacks and it must be noted not all shark attacks are reported. Many resort areas are sometimes made to keep shark attacks quiet due to bad publicity which is bad for trade. Historically the death rate has been much higher than today, but due to the advent of water rescue teams and advances in emergency services and improved medical treatment, the chances of death haas been greatly decreased. Even though the death rate has decreased the actual numbers of shark attacks has been going up. This is thought to be due to the increasing numbers of water activities. North America Accounts for 27.78% of all shark attacks world wide.
Most attacks occur in near shore waters, typically inshore of a sandbar or between sandbars where sharks feed and can become trapped at low tide. Areas with steep dropoffs are also likely attack sites. Sharks congregate there because their natural food items also congregate in these areas.
Slash Shark Wounds
There are three major kinds of unprovoked shark attacks. By far the most common are "hit and run" attacks. These typically occur in the surf zone with swimmers and surfers the normal targets. The victim seldom sees his attacker and the shark does not return after inflicting a single bite or slash wound. In most instances, these probably are cases of mistaken identity that occur under conditions of poor water visibility and a harsh physical environment (breaking surf and strong wash/current conditions). 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.
International Shark Attack File Statistics of Shark Attacks
"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 near shore 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 occurs 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. Most shark attacks involving sea disasters, e.g. plane and ship accidents, probably involve "bump and bite" and "sneak" attacks.
Size Does Matter
Almost Any Large Shark, Roughly Six Feet or
These species have been repetitively implicated as the primary "Bump and Bite" and "Sneak"Attackers (in no particular order) All are worldwide in distribution, reach large sizes, and consume large prey items such as marine mammals, sea turtles, and fishes as normal elements of their diets.
Great White Shark (Carcharodon carcharias)
Tiger Shark (Galeocerdo cuvier)
Bull Shark (Carcharhinus leucas)
Great Hammerhead (Sphyrna mokarran)
Mako (Isurus oxyrhynchus)
Whitetip (Carcharhinus longimanus)
Galapagos (Carcharhinus galapagensis)
Reef Sharks (such as the Caribbean reef shark, Carcharhinus perezi)
There is less known about the "Hit and Run" cases since the shark is seldom seen, however it is assumed that a large number of species are involved. Evidence from Florida and Texas where several of these type attacks occur per year, suggests that the Blacktip (Carcharhinus limbatus) and Blacknose (Carcharhinus acronotus) sharks are the major culprits in the Gulf region.
Graphs are From The International Shark Attack File Statistics of Shark Attacks on Divers
Data shows that the majority of shark attacks on divers are not fatal. This does not mean that divers should be less careful in the water, but it does support the idea that sharks are not hunting humans for food. Fatal attacks are usually the result of significant blood loss and stress. One theory suggests that sharks will bite their prey to make sure it is edible before eating it. Once this 'prey' item is identified as an unnatural source of food, the shark will swim away to find more suitable food elsewhere.
Shark Attack On Diver
Use this data with CAUTION, remembering that scientific and media coverage of shark attack during the early part of this century was far less inclusive than that of today. Data indicates an overall increase in the numbers of reported shark attacks over the last century. This apparent trend is thought to be a reflection of increased numbers of people utilizing the ocean, and increased media coverage over the last century.
This data list the various diving activities divers were participating in at the time of attack. As the data depict, snorkelers are attacked the most. This is most likely due to the fact that more people snorkel than SCUBA dive worldwide.
Activities of Others in the Area of Unprovoked Attacks
(N=120 of at least one of the activities going on; individuals may be represented in more than one category)
|Splashing or Horseplay||
|Being Unusually Loud||
|Thrashing or Flailing||
As you can see, many of the attacks on divers occurred less than one hour after entering the water. This is mostly due to the fact that divers do not spend as long in the water compared to other water activities. The next graphs depict the activities of divers being struck less than an hour after entry into the water and more than an hour after entry into the water
These are the relative percentages of divers who participate in the listed activities who were attacked less than an hour after entry into the water.
Nearly all shark attacks occur between 8:00 AM and 6:00 PM and during the weekend, NOT because of the shark's daily activity cycles, but because these are the times of the day when people are in the water.
Remember these graphs reflects the behavior patterns of people. NOT the shark's daily activity cycles, because these are the times of the day when divers go out in the water.
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