Shark’s are being unfairly maligned, which has resulted in the generally wrong view that they are apex predators always ready to take a bite out of humans, say researchers in French Polynesia.
Blanket classification of shark bites as ‘attacks’ is misleading and sensationalist, says a team from French Polynesia’s Centre de Recherches Insulaires et Observatoire de l’Environnement (CRIOBE). Understanding why sharks bite is the key to living with these ancient predators, shark specialist and CRIOBE Principal Investigator Professor Eric Clua told Cosmos.
Sharks rarely bite humans. Around 100 bites are reported each year, of which only about 10% are fatal. Understandably, it’s the attacks leading to death or serious injury that grab headlines.
The problem lies in the classification of the rest of the bites, usually included with the fatalities in databases such as the Global Shark Attack File. ‘GSAF’ doesn’t consider the possibility that many of these may not actually have been ‘attacks’.
“It is a very anthropocentric view, showing no understanding of sharks’ intrinsic behaviour,” Clua says. No room is left for bites resulting from competition, territoriality or, as CRIOBE researchers now suggest, self-defence.
The CRIOBE researchers explored the ‘bite‘ versus ‘attack’ question using the GSAF. The database documents around 7000 bites since 1863, classified as ‘provoked’ or ‘unprovoked’, and involving boats and air and sea disasters.
Focusing on ‘provoked’ incidents involving people being near the animals, lead author, Clua and his team found that 322 of those bites could have been the sharks defending themselves.
“We show that defensive bites on humans – a reaction to initial human aggression – are a reality and that the animal should not be considered responsible or at fault when they occur,” says Clua. “These bites are simply a manifestation of survival instinct, and the responsibility for the incident needs to be reversed.”
Associate Professor, Chris Pepin-Neff of the Department of Social and Political Sciences at the University of Sydney agrees. “The phrase “shark attack” tells a one-dimensional story of shark behaviour, which is often misleading.”
“Thirty-eight percent of reported shark attacks have no injury – so I think shark ‘attack’ is probably not the classification if there was no injury,” Pepin-Neff says.
“When I told John West about this, he changed the name of the Australian Shark Attack File to the Shark Incident Database. And I spoke with folks at the State of California as well which has changed the state classification to “shark incident” and reports that 30% of reported shark attacks also had no injury in the State.”
Defensive bites might happen when humans harass, stand on or try to grab or spear them. There are typically no warning signs, says Clua. These bites might be repeated, and leave superficial, non-lethal wounds. Dogs, bears and cassowaries will do the same thing. Predation bites remove tissue, he adds.
Standing on a shark like a wobbegong in a rock pool could result in a defensive bite, he says, as could grabbing the tail of a stranded shark to guide it back to the ocean.
In both cases the human is seen as the aggressor by the shark, says Clua. Harassing a shark while on an underwater scooter could have the same result, but in this case Clua calls it an ‘anti-predation’ bite. No contact, but the shark may see the human as a potential predator.
Lemon sharks can be very territorial. Clua told Cosmos of a case where a young surfer was on his board in a new surfing spot through a passage from where he’d been surfing for the previous five years. He was bitten on the legs by the shark. This was reported as an unprovoked attack, but, Clua says, was probably a territorial defence.
Personality plays a role, too. “I am fully convinced that shark’s personality plays a critical role in triggering the bite, much more than environmental factors like water turbidity, moonlight, or this kind of thing.”
“Do not interact physically with a shark, even if it appears harmless or is in distress. It may at any moment consider this to be an aggression and react accordingly,” Clua cautioned. “These are potentially dangerous animals, and not touching them is not only wise, but also a sign of the respect we owe them.
“We need to consider the not very intuitive idea that they are very cautious towards humans and are generally afraid of them,” Clua says.
“The sharks’ disproportionate reaction probably is the immediate mobilisation of their survival instinct. It is highly improbable that they would integrate revenge into their behaviour and remain above all pragmatic about their survival.”
The research is published in Frontiers in Conservation Science.
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