Source: Nature: "The Secret World of Sharks and Rays"
Major corporate support for the Nature collection was provided by Canon U.S.A. and SC Johnson. Additional support was provided by the Corporation for Public Broadcasting and the nation’s public television stations.
The highly sophisticated sensory system of sharks allows them to locate their prey with remarkable accuracy. Their speed, agility and acute sensory ability leave few predators able or willing to compete with sharks for a potential meal. In this video segment from Nature, sharks sense and pursue a fisherman's catch.
Transcript (Document)
Sharks and their biological cousins, the rays, are among the highest-profile denizens of the deep. But sharks are not the solitary killing machines that popular movies and the press might have us believe. In their marine environment, sharks coexist with numerous other species - many of whom flock to be near the sharks, rather than running from them in fear. In many of these cases, the interaction between two different species mutually benefits each species. But humans, too, have become an increasingly important player in the lives of sharks - and as they are increasingly hunted for their fins, sharks are actually becoming more endangered than they are dangerous. The impact on the marine ecosystem that would result from the disappearance of sharks would be devastating, but there is still time to save these magnificent creatures, and the ecosystems that depend on their existence.
Fishermen know all too well how sharks will seize the moment and with it, their catch.
A struggling fish is a magnet to sharks" Sharks have highly remarkable senses that can hear, feel, and smell prey from long distances with shocking accuracy.
The fishermen move on, but there's no escape" What's worse, fishermen have unwittingly trained sharks to follow in their wake by tossing fish scraps overboard.
To fishermen, sharks are not just mindless eating machines, but clever hunters.