SCIENCE AND THE SEA 



SHARKS 



The history of attacks by sharks dates back to the beginning of 

 written records. Displayed on the side of a vase, that is believed to 

 have been painted approximately 725 B. C, are drawings of a sailor 

 being devoured by a shark-like fish. 



Shortly after the New World was discovered, the Spaniards 

 began to call the shark tiburon. While sailing with Vasco de Gama 

 around Africa. Antonio Pigafetta wrote that "the tiburon have teeth 

 of a terrible kind and eat people when they find them in the sea". 



Pliny the Elder knew of the shark and referred to him as the 

 dog fish. The word shark made its debut to our vocabulary in the 

 middle of the sixteenth century when an English sea captain placed 

 one on exhibit in London. Although not known for sure, it is gen- 

 erally believed that English sailors picked up the German word 

 scharke. meaning villain. At any rate, the word seems to apply 

 quite well, for the shark is truely a villain. 



Considerable controversy still apparently exists among mariners 

 as well as some ichthyologists regarding shark attacks. Prior to 

 World War II there was very little accurate information available 

 on the subject of sharks. Some of our survival manuals flatly stated 

 that sharks were cowards and would not attack an uninjured man. 

 Authenticated reports and observations made during the war, how- 

 ever, proved beyond doubt that some sharks will attack. 



Further, the insurance offered by shark repellent isn't too 

 promising- Some articles refer to it as absolute protection while 

 others imply it is rather useless. The truth, however, is somewhere 

 between these two extremes. The present day shark repellent 

 consists of a packet of copper acetate and nigrosine dye. But, it 

 has been demonstrated to have no inhibiting effect on the behavior 

 of the species of sharks that inhabit the Caribbean Sea and Pacific 

 Ocean. Therefore, the safest solution against shark attack is to 

 get in one of the available life craft as soon as possible. 



A survivor of a Pacific Ocean aircraft ditching, in which sharks 

 killed two men, said that using the repellent was "like feeding them 

 orange juice." Shark repellent loses effectiveness with age and 

 should be in powder form. When it has hydrolyzed into cake form, 

 it will not release the chemicals intended to provide the protection. 

 Although not 100 per cent effective, repellent is the only weapon 

 we currently have against hungry sharks. Hence, one should keep 

 his repellent fresh and his powder dry. 



Other than repellent, there are other measures one may take to 

 enhance his safety. 



While in the water: 



1. Keep a sharp lookout for sharks. 



2. Stay quiet and conserve as much energy as possible. 



3. If swimming is required, do so with strong regular strokes 

 Frantic irregular movements should be avoided. 



4. When threatened by a shark, try feinting toward it. With 

 some luck, it may scare him off. 



5. Loud noises have also been successful. With the hand cupped, 

 regularly slap the water surface. Another method reported 

 to frighten away sharks is to put one's head under water and 

 shout. One of the earliest accounts of this procedure working 

 was of three survivors from a German submarine sunk off 

 the west coast of Africa in 1943. They were attacked and 

 bitten by sharks, but by submerging their heads below the 

 surface of the water and "roaring", they succeeded in 

 frightening the sharks away. 



6. Do not swim directly away from a shark, but rather face him 

 and try to outmaneuver him. 



7. If a group of survivors are threatened, form a circle, facing 

 outward, and around any previously injured men. 



8. As a last resort, use your knife in self defense. 



While aboard a life craft; 



\. When sharks are known to be nearby, do not fish. 



2. Do not clean any previously caught fish nor throw any waste 

 overboard while sharks are in the vicinity. 



3. If a firearm has been salvaged, shoot to kill. Shots close 

 enough to the water to produce heavy concussion may ward 

 off further attacks. 



4. Before going into the water, check for sharks under the 

 life craft. 



5. If a shark threatens your raft, try jabbing his gills, snout, or 

 eyes, with anything available. 



6. Any burials at sea should be conducted at night. 



The likelihood of shark attack is a very real concern to any 

 mariner who finds himself in the water following a marine disaster. 

 For there is no longer any question that sharks will attack and that 

 a grave danger exists to anyone exposed to them. 



By and large, when sharks are successful in their attack they 

 leave no evidence. Consequently, the number of missing swimmers 

 who may have succumbed to them cannot even be estimated. 



To make a bad situation worse, sharks are found in all oceans 

 and seas of the world. They may even ascend river mouths. AH 

 have voracious appetites. They are guided to their food by scent, 

 sound, and sight. Further, they frequently travel in packs and feed 

 at all hours of the day and night. 



A shark's sense of smell is developed quite highly and it is gen- 

 erally believed that the presence of blood in the water tends to excite 

 them. They are also very sensitive to sound vibrations transmitted 

 through the water. Underwater explosions are known to draw them 

 in search for food. Abnormal impulses, as those of a hooked fish, 

 a dying animal, or a poorly-coordinated swimmer will draw sharks 

 from a much greater distance than the scent of blood. This is the 

 reason a swimmer should swim with powerful and even strokes. 



It has been the general belief of many mariners that a shark 

 must turn on its side or back to bite. This is not quite true, for 

 though a shark may turn partially on his side, he doesn't have to. 

 When a shark lunges forward in attack, he invariably arrives mouth 

 first, with the entire front end displayed as mouth. It is possible 

 for him to bite a man from most any position. 



Sharks may hunt for food and attack singly. The majority of 

 survival accounts mention the presence of more than one. This is 

 because once a shark finds a victim he is almost immediately joined 

 by others in the same proximity. 



A most inconceivable aspect of a shark bite is the high percent- 

 age of survivors that have been bitten who reported feeling no pain 

 from the bite at the time. 



Two conclusions may be drawn concerning tiburon: One can 

 never be certain what he will do, and the more we learn about him, 

 the less we find we really know. 



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