NARD Diving MedicineDiving MD

Bites And Lacerations

All creatures of the sea, like man, eat to survive. However unlike man they do not kill for sport, but of the need to live. Traumatic injuries caused by marine creatures should be handled as any other traumatic injury. Bites and lacerations come from a variety of marine life. Some are venomous, others are not.

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. It does not matter if the attacking shark was a Squalus or Carcharhinus all inflict major trauma. 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. The fatality rate from shark bite is about 87% worldwide.

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 the 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 it 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.

Shark bites occur frequently in murky water. They are attracted by lights, noise, or splashing, and smell. For theses reasons surface swimming should be kept to a minimum, in shark waters. Research shows that colors attract sharks more than dark objects, it is better for divers to wear dark colors. Blood in the water can attract sharks from long distances to a location. They can sense blood in the water in concentrations as little as 4 parts per million. Bleeding into the water by a diver or swimmer may not go unnoticed. Women who are menstruating are recommended to wear tampons. As to any evidence that the menstrual cycle can increase the hazard of shark attack is inconclusive. It is believed that sharks are only attracted by fresh blood.

When a shark is sighted the diver or swimmer, he should make slow movements, remaining still until the shark leaves is best. 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. A diver may be better off descending to the bottom if possible for protection in rocks, or on the seabed. Always keep the shark in sight.

Shark bites are always severe, with an extremely high rate of fatality and loss of limb. Control bleeding in water if necessary. The massive tissue loss that is present can result in rapid bleeding out of the victim. Treatment is prompt control of bleeding. 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.

Often other animals are mistaken for sharks such, as dolphins and porpoises. Manta rays are also mistaken for sharks because they swim close to the surface and their wing tips break the surface looking like two sharks.

Barracudas are sleek swift swimmers that rarely attack people unless provoked. They are very fast swimmers capable of striking rapidly and fiercely. Barracudas are attracted to anything that enters the water and are particularly curious about bright objects. Their bite can be severe and straight or V-shaped. They often follow swimmers and divers but rarely attack.

Moray eels like most other marine life attacks only when threatened. Sometimes they bite without releasing and their jaws. Divers come in contact with them poking their hands into holes and crevices. Do not put your hands in any holes.

When in the water and predators are in the area use slow purposeful movements, and when approached remain still. Often times sharks can be pushed away. Attempting to kill a predator fish can make them more dangerous. Dark clothing and equipment is preferable over brightly colored. Do not swim with open wounds. Use extreme care when reaching into holes.

MARINE MAMMALS: On the Pacific coast are Sea Lions, very similar to dogs in attitudes. They are normally harmless, but during breeding season they can easily be irritated. Swimmers and divers who attempt to handel seals may get bit. The bites should be treated as dog bites. First priority is to control bleeding. Orca, or Killer Whales are found all over the world. They have a reputation of fearlessness and intelligence close to man. They have been known to attack polar bears on ice flows and to take seals off of beaches. They have no natural enemies. It is recommended that when encountered divers should get out of the water. However there are very few if any documented cases of a killer whale attacking man. There are two schools of thought to this, one no one would survive if attacked to tell about it. The other is that Orca is so intelligent that he respects life and will not attack unless hungry or attacked.
TURTLES: Although each variety of turtle found are nonaggressive, they will bite when molested. The bite can be painful and significantly large, the snapping variety have been known to break arms and amputate fingers. Their bite are strictly traumatic and nonvenomous, although eating some turtles can be toxic and fatal. Treatment of turtle bites should be handled as any other traumatic wound. There is no specific treatment.

Signs and Symptoms
Falling Blood Pressure (due to blood loss or venom)
Fever and/or Chills
Rapid or slow pulse
Headache
Nausea
Dizziness
Delirium
Shortness of Breath
Death - sometimes quickly

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