To make it worse, it is nearly impossible for a non-specialist to emerge with an informed opinion after wading through a muddy quagmire of half-truths in magazines, newspapers, websites and TV documentaries. How can one separate scientific fact from falsehood? Fear of the unknown lies at the heart of the issues, and surfers should arm themselves with the truth about the creatures they share the line-up with.
In 2004, there were 560 drownings in South Africa. That’s 25 times more fatalities in one year than deaths by white sharks in 83 years. Between 1922 and 2005, 91 people were bitten by great whites, of which 22 were fatal. Surfers accounted for 43 percent.
Yes, white shark bites have increased over this time. Between 1951 and 1970, there were six bites per decade. Between 1991 and 2000 this increased to 22 bites. However, so has the number of people using our oceans, an exponential increase that increases the likelihood of shark encounters.
Why white sharks bite people is the million-dollar question. But I am afraid that there is unlikely to be a definitive answer. Incidences are too infrequent and variables too numerous to postulate an iron-clad mathematical correlation. Despite this uncertainty, there are several theories that at least shed light on shark incidents.
White sharks have roamed the oceans for millions of years. They have evolved their hunting behaviour in parallel with their prey: seals, dolphins and tuna. Humans are relative newcomers to the planet. Only in the last 50 years have we begun to spend extended periods of time in the sea. White sharks do not consider us an integralpart of their diet. There is only one confirmed account, and a handful of unconfirmed stories, that white sharks actually consumed a person.
Humans send out a different ‘sense signature’ to fish or seals. White sharks detect sense signatures from far away. However, perhaps when visibility is marginal, or when surf causes background noise and other prey is in the vicinity, a white shark’s hunting instinct may be triggered. But taste buds lining its mouth will signal that it has made a mistake. A full bite can snap a person in half, but in most cases people only sustain minor tissue damage suggesting that the shark has not delivered a full bite. Some white shark bites can be linked to curiosity.
Sharks don’t have hands or paws to investigate with. Unable to satisfy their curiosity with other senses, they will explore by mouthing or biting objects. Injuries are minor because sharks use minimal force. Bites can also have social or defensive reasons – white sharks sometimes communicate by biting. While not territorial, white sharks defend their personal space. When two white sharks meet, one will give way to the dominant individual. If neither backs off, displays of parallel swimming and jaw gaping follow. If this fails then one of the sharks, presumably the more dominant one, will bite or rake its teeth on the other’s body. It is plausible that a white shark will treat a human like another shark if there is no response to their body language (withdrawing).
Shark bites are such a rare phenomenon that there is no need to eradicate sharks to surf safely. Neither does one have to stop surfing to be safe. The relative success of humans compared to other species on this planet is largely attributable to our ability to logically process information and make rational and practical decisions. By using this ability wisely and by following a few basic rules (see Precautions on page 120) it is possible to the risk to close to zero, and make the oceans a safer place for humans and sharks.
Since they are often the apex, or top, predators in their ecosystems, the depletion or removal of sharks is likely to affect marine ecosystems and the abundance of other fish species in ways that cannot currently be predicted. Many marine experts believe that sharks are vital in maintaining marine biodiversity, and concern has been raised that some species may become extinct before their ecological role is fully understood.
– sharklife.co.za
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