More Shadows Attack 47 



demolished by careful Shark Research Panel investigations. Dr. Schultz 

 reports: "Our records indicate that of 68 individuals who have gone to 

 the aid of a victim of shark attack, 12, or 17.7 per cent, have been 

 attacked. Hence, anyone going to the aid of a person being attacked is 

 definitely placing himself in a dangerous situation." 



Are there no clues to what causes an attack? Is there no theory that 

 will stand up under scientific scrutiny? 



Two factors that trigger attacks seem to be established beyond 

 question: 



Blood, even greatly diluted and in small quantities, definitely attracts 

 sharks. So does vomit, offal, garbage, and carrion. 



The behavior of an injured or inexperienced swimmer— irregular, 

 frantic motions, panic— can set off a kind of signal that may embolden 

 an approaching shark to attack. The behavior of the swimmer may sug- 

 gest to the shark that something wounded is in the water and this attracts 

 the shark just as would a fish \\Tithing on a hook. 



Perhaps the very chemistry of the body sets oflF this signal. When 

 the senses of the human body detect a threat— such as a loitering shark— 

 what is usually called "fear" manifests itself in a series of swift, involun- 

 tary activities within the body. Epinephrine (also know as adrenalin) is 

 secreted by the adrenal gland to step up the heart beat and raise the blood 

 pressure, thus increasing the flow of blood to muscles the body may 

 have to use to fight the threat its senses have detected. The blood vessels 

 of the stomach, the intestines, and other internal organs suddenly con- 

 strict to lessen the flow of blood so that more will be available to the 

 muscles. The liver pulses with new, fear-inspired activity, converting 

 glycogen into sugar to provide more fuel for the muscles. The pupils 

 of the eyes dilate to increase the field of vision. The body trembles. 

 Goose pimples erupt on the flesh. Cold perspiration breaks out on the 

 brow. The body seems coated with cold sweat. The mouth goes dry. 

 These manifestations of fear occur because the body's chemical ma- 

 chinery is unbalancing the normal, orderly functions as it works at full 

 throttle, preparing for an emergency. The body may emit a subtle 

 (chemical) "aura" of fear. And it ?nay be this which lures the shark on 

 some occasions. 



The list of conditions that may bring about a shark attack is 

 seemingly endless: refuse strewn into the sea from sewers, abattoirs, 

 and factories . . . the shark-trailed schools of migrating fish . . . sea- 

 quakes and storms that disrupt the delicate balance of marine ecology, 

 sending sharks foraging for new feeding grounds, perhaps closer to 

 shore— and swimmers! Anything unusual, such as the impact of a plane 

 plunging into the sea or the mass of sounds transmitted through the 

 sea when a ship sinks, appears to attract sharks, and may trigger attacks. 



