Great Whites shake loner tag

White sharks are forming communities to feed on baby seals in the Great Australian Bight, which is at odds to their reputation of being solitary creatures.

The mass sightings raise questions about the behaviour of the huge predators as they have not been observed with regular companions over long periods in the past.

The study examining the behaviour of the white sharks found them gathering near South Australia’s Neptune Islands in large numbers.

The Neptunes are a group of four islands off the coast of South Australia and are a popular spot for white shark sightings.

Flinders University Associate Professor Charlie Huveneers was part of the team observing white sharks’ behaviour in the area between 2010 and 2014.

To make the findings, Assoc Prof Huveneers and others from Flinders University and the Fox Shark Research Foundation, both in South Australia, collaborated with Macquarie University and French government organisation CNRS to identify 282 individual white sharks through photo-identification over four and a half years.

Assoc Prof Huveneers said while the research did not indicate white sharks were hunting in packs, their co-occurrences appeared to be more than chance. But more research was needed to understand why the sharks behaved in this way.

“Although white sharks aggregate at the study site (Neptune Islands Group Marine Park) all year around, the same individuals do not remain at the Neptune Islands throughout the year,” Huveneers said.

“Different sharks come at different times of the year. For example, some sharks are sighted at the Neptune Islands during summer, while other sharks are mostly sighted in winter. Interestingly, some sharks tend to be observed together more regularly that you’d expect by chance.”

White sharks are also known as great white sharks or white pointers. According to National Geographic, great whites are the largest predatory fish on earth growing to an average of 4.5 meters.

Network analysis of the 101 most frequent individuals showed that these sharks formed four communities made of 25 individuals each.

Assoc Professor Huveneers said many of the sharks were seen in close proximity to…