Study reveals facts on shark hunting behaviour


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Newspapers jumped on the chance to sensationalise a study done in America on the hunting techniques of Great white sharks.

Comparing their ability to kill with that of Hannibal Lecter and the Yorkshire Ripper, papers speculated on the ~ruthless hunting techniques of these much maligned sharks.

In actual fact, the findings by a team of researchers in America make fascinating reading. Shark predation is very difficult to study because it is rarely observed in the wild. As a result, their hunting patterns have remained much of a mystery.

This study focussed on attacks on seals in False Bay in South Africa. Using geographic profiling - a criminal investigation tool used to track and locate serial criminals- the research aimed to find a centre point for the sharks hunting techniques. This can be highly useful as most sharks are constantly swimming, and unlike other animals they do not have the equivalent of a den or nest.

White sharks hunt solitary juvenile Cape fur seals during the Southern

Hemisphere winter when light levels are low, stalking them from near the ocean floor to remain undetected, before launching a vertical attack.

This strategy maximizes a shark s chances of catching a seal unaware and thus achieving a fatal first strike.

Nearly half (48%) of all attacks are fatal and there are an average 6.7 attacks daily. Stealth and ambush are key elements in the white sharks predatory strategy.

Like most serial killers, the scientists found that great white sharks share refined hunting skills and return repeatedly to areas familiar to them. This is an area around 100m further out to sea from the seals island and is not always the area with the most prey.

This position probably represents a place where there is a balance for the individual shark between prey detection, actual capture rates and the least amount of competition with other sharks. Smaller sharks have a more dispersed attack area and a lower attack rate which suggests that sharks refine their hunting technique as they become older and more experienced.

At a time when the IUCN have just announced that over 30% of all sharks and rays are threatened with extinction, this study which increases our knowledge of these elusive creatures is extremely important.

Neil Hammerschlag from the University of Miami who was a key researcher in this study adds: Sharks are apex predators, so studies of shark hunting behaviour are important for understanding their ecology and role in structuring marine communities. Our need for more knowledge of these fascinating animals has become critical because of recent drastic declines in their populations globally.