Monday, 22 August 2011 07:52
A fragment of a shark tooth extracted by surgeons from shark attack victim Ian Redmond is most probably from a Great White (Carcharodon carcharias). This is the opinion of South African scientists from the Kwa Zulu Natal Sharks Board whose assistance has been sought by Seychelles authorities.
They examined photographs of the victim and of the tooth fragment. Geremy Cliff from the KZN Sharks Board has said that that the fragment, although very small, suggests the shark may be a Great White. Further examination of the victim is needed because it is better to see the actual wounds rather than photographs, he said. He and Mike Anderson-Reade, also from KZN Sharks Board, are now in Seychelles.
The last confirmed sighting of a Great White in Seychelles was apparently in 1938 although most fish guide books record its occurrence in our waters. One of the densest known populations is found around Dyer Island in South Africa where scientists have been studying the species for many years
The Great White is one of only four species of sharks that have been involved in a significant number of fatal unprovoked attacks on humans. Unlike other sharks it is warm blooded. It approaches prey from below and favors murky water or situations where there is poor lighting. Attacks usually take place near the water’s surface.
Although the Great White has been implicated in fatal attacks on humans, it finds the taste unfamiliar. Humans also may not be appropriate prey because the shark's digestion is too slow to cope with high ratio of bone to muscle and fat in human beings. Great Whites usually break contact with a human after the first bite. However, one bite can tear off a 14 kilogram piece of flesh. This is usually why attacks on humans are fatal. Fatalities are usually caused by blood loss from which was the case in both attacks in the Seychelles.
More evidence is awaited. Meanwhile, Seychellois fisher Daryl Green of Praslin island who has been studying the shark attacks has predicted that the next attack will take place on 29th August and is preparing to take on the shark.
However, in the need to get the culprit we must not give carte blanche to kill endangered species such as whale sharks, turtles and dolphins that may be entangled in the nets that have been set out or otherwise killed using various means. If we start wiping out these animals we will be cutting our nose to spite our face.
"We are not out to kill endangered species, we want to find the culprit," says Green.
See Link for further behavior of Great white sharks: http://www.ucmp.berkeley.edu/vertebrates/Doug/shark.html