Steve Connor: Bite marks key to identifying species responsible for death

One of the first tasks of the experts sent into Sharm el-Sheikh will be to identify the species of shark responsible for the attacks on tourists, which led to the death of an elderly German woman.

Reports have suggested that the killer may have been an oceanic whitetip but the specialists in shark attacks will want a positive identification, possibly from studying the bite marks or teeth left in the flesh of its victims. "Sometimes sharks leave teeth behind because they are growing new ones and the older ones are easily dislodged in an attack. If teeth are left that will give a 100 per cent positive identification," said Bethan Gillett of the Florida Museum of Natural History in Gainsville. "We can also look at the bite marks because that gives us some idea of the morphology of the teeth, which can also lead to a positive identification. Different sharks have different teeth morphology," Ms Gillett said.

Oceanic whitetips, a tropical and subtropical species, are not known to be aggressive to humans unless provoked, according to Ali Hood, the director of conservation at the Shark Alliance, a charity aimed at preserving shark numbers.

"Thousands of divers have dived with them and photographed them without being attacked. For sharks to behave in this way there must be a causal factor, and the Egyptians are doing the right thing by trying to assess what this factor is," Ms Hood said.

One report suggested that a ship carrying livestock had jettisoned the carcasses of dead animals, while other reports said that some illegal fishing boats had dumped dead bycatch close to shore. Either activity could have brought the sharks closer to the beach and then into contact with humans.