Known as the most ferocious of sharks from its depiction in the movie "Jaws," the great white shark may actually be a hunter of the ambush type, according to a study by Yuki Watanabe, associate professor at the National Institute of Polar Research, and other researchers.
The study marked the first time that small instruments were installed on a great white shark to record their behavior in detail. The paper was published in the Journal of Experimental Biology.
The survey was conducted between 2014 and 2016 in waters around the Neptune Islands in southern Australia. The islands are inhabited by fur seals that attract large numbers of great white sharks.
The researchers found that the sharks swam around the island at about 3-5 kilometers per hour, about the speed at which people walk. The speed was about half as fast as what they had predicted based on the body weight and temperature of great white sharks.
On the other hand, when targeting fur seals entering the water, the sharks reached hunting speeds of up to 25 kilometers per hour.
The researchers postulate that -- despite their high level of physical prowess -- great white sharks often swim slowly to save energy as part of a "sit-and-wait" strategy in which they watch for opportunities to catch prey.
The researchers attached devices with multiple sensors to the dorsal fins of eight great white sharks that they lured to their ship with food. They set the devices to automatically disconnect after one or two days, and then collected them using radio waves. The data offered a detailed look at the behavior of the sharks.
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