Zoology - Shark Attacks Under

Zoology - Shark Attacks

Under the apparent stillness of even the calmest of seas, an age-old drama plays out countless times as a creature designed for locating, stalking, chasing, and then tearing into living flesh closes in on its doomed prey. Its efficient design, mouth bristling with teeth meant to sink into flesh and never let go, and its swimming speed, agility, and intelligence all but ensure hunting success. After a brief chase, hunter catches up to hunted, its jaws clamp down tightly, and it is all over: the same species of bottle nosed dolphin that humans adore captures another helpless herring in its mouth.

Dolphin, shark, and most other aquatic creatures either hunt other species for food, or they are hunted themselves. As often as not, animal species are both hunters and hunted. Human beings tend to view sharks very differently from other aquatic species, based more on the fact that we sometimes end up on their menu than on the distinction between animals that are predatory hunters and those that are not. To a herring, the common dolphin is a dreaded predatory killer; to us, it is a playfully intelligent mammal that deserves or protection. Would we feel the same way about dolphin if they were no different in personality or character but the size of a large whale who sometimes mistook human beings for tuna? Chances are we would fear dolphin attack as much as we fear shark attack and our characterization of dolphin would incorporate vocabulary like ruthless," "deadly," and "cold-blooded" (despite its mammalian nature).

Discussion and Analysis:

Like dolphin, tuna, swordfish, and many other large predatory aquatic species with which we are familiar, sharks must locate and consume other organisms to survive.

To do so, they have all evolved physiologically and behaviorally to adapt to their environment and to guarantee successful hunts often enough to survive. Unlike the other aquatic species, we fear attack from sharks disproportionately to the actual risk, simply by virtue of the fact that some of them are large enough to mistake us for their prey under the right circumstances. Our characterization of sharks as ruthless killers intent on consuming us reflects our emotional response to the concept of being eaten alive than reality (Ellis, 1989).

Contrary to assumption, sharks - even those large enough to consume us - do not actually hunt human beings. Under the right circumstances, human beings simply find themselves within the vicinity of sharks looking to feed and our awkward swimming motion just happens to mimic some of the signals of distress or injury in the shark's natural prey (Stevens, 1999). In many cases, surfers fall victim to shark attack precisely because they violate some of the basic rules of shark safety: they swim at dawn and dusk, when sharks are most likely to feed, and they dangle their limbs from the sides of a flat board at the surface, despite the fact that sharks almost always attack from the and target prey that is approximately our size and our apparent shape, especially when we lie on the surface of the water with our limbs extended into the water (Ritter, 2000).

More often than not, shark attacks on humans are cases of mistaken identity (Ritter, 2000). According to many experts, one clue to this conclusion is the frequency of initial bite that is not followed up by a full-fledged attack. It seems that this is attributable to the fact that sharks tend to test potential prey before consuming it, partly, it is thought, to protect their teeth from unnecessary loss (Perrine, 1995). The problem, from the human perspective, is that large sharks are so powerful and their teeth so sharp, that an even an exploratory test bite can prove fatal to us. In truth, large sharks tend to hunt large blubbery prey with a much higher ratio of flesh-to-bone than human beings. That is apparently why many test bites on a human result in no further attack.

In the last decade, a tourist industry has evolved in parts of the world with access to coral reefs and natural shark populations. Hand-feeding excursions allow divers, lead by more experienced professionals to encounter sharks in the wild without a high likelihood of attack. Typically, divers descend to the ocean floor where they assemble into a tight group that de-emphasizes their appearance as meal-sized organisms and merges them (from the sharks' point-of-view into a single larger organism, too large to eat. But other procedures involve much smaller groups of two or three divers to hand feed sharks, relying only on the fact that most sharks tend not to perceive humans as potential prey, unless we exhibit specific characteristics or linger at the surface in their habitat (Perrine, 1995).

On one hand, these industries illustrate how out of proportion our fears of shark attack are in comparison to the reality. On the other hand, these excursions probably increase the incidence of attacks on swimmers and surfers. While sharks do not actively hunt humans as prey, they are very susceptible to learned associations. Shark attacks have been documented to increase in areas where hand-feeding tours operate, simply because sharks in the area learn to associate the sound of boats and human activity with feeding. Once drawn to human swimmers, they may very well initiate test bites on anything in their vicinity, especially, when their expected handouts are not forthcoming (Ritter, 2000).

For the same reason, spot divers are disproportionately more likely to be attacked by sharks, because the spearing of fish triggers distress reflexes and panicked swimming to which a sharks sensory organs are finely tuned to recognize (RCSR, 2001). At the same time, the spearing also introduces blood into the environment, which sharks have evolved the ability to detect in infinitesimally small concentrations in water (RCSR, 2001).