This sharp sense of smell, however, is not the only sense that helps them. .
Sharks also have very good sight and are extremely sensitive to light when it comes to sight. Some sharks can see in total darkness. They have shields for their eyes called a nictitating membrane, for protection. Sharks also have what is known as "tapetum", which allows sharks to see in total darkness (Hall 42). Sharks, because of their sensitivity to light, are attracted to bright reflective colors, which may include sports apparel, or gear design. This is some times the reason for shark attacks. .
Even though sharks do not have ears, they do have good hearing. "They can hear low-frequency sounds up to a half-mile away. Internal ears work with the shark's lateral line to pinpoint the location of the sound" (Hall 42). Sharks have things called "receptors" on the top of their heads, which assist the sharks with their hearing. .
Sharks also have a very good sense of touch and taste, which is probably why they know when a diver has food and when he does not. Sharks also have electro-sensitivity, where they can detect minute levels of electricity. This is how they detect a fish in distress. All of these senses allow for the shark to be what you could say a "hunting machine" (emphasis added). .
So, why is that people fear sharks so much? George Burgess, the Director of the International Shark Attack File at the University of Florida, summed up the feeling of many by reminding swimmers, "Say the word shark and the first image people come up with is Jaws. Shark attack could be the most feared natural danger to man--ahead of hurricanes and earthquakes (website)." Shark attack rate is rising each year. Burgess says this is due to the rising number of bathers each year, but the percentage of attacks leading to fatalities is dropping. Burgess says it's because the medical equipment was poor back then. Today we know more about sharks and what precautions to take.
