Sharks have long been demonised in films, but shark attacks are rare, and many species are harmless to humans. Their role as predators is essential to the equilibrium of marine ecosystems. Without sharks around to devour weak and sick fish, the populations of these fish explode and quickly exhaust their food supply, marine biologists say.

Apart from environmental consequences, the dwindling population of the Red Sea shark is simply bad for business. More than 1.2 million tourists visited Egypt's Red Sea resorts in 2001, generating nearly a billion dollars in revenue. Surveys indicate that sharks are a major attraction.

"They are essential, especially for experienced divers who come here expecting to see sharks". "Every time there is a shark sighting the divers get very excited."

It not clear why Egypt's shark populations are declining, but reports of "finning" have sent shivers through the local diving community. "If the reports are true, it will be a catastrophe," says local diver Mahmoud Ali.

The practice of finning is lucrative. The fins are highly valued in East Asian markets. Shark fin soup, a traditional delicacy, sells for something like 150 dollars a bowl. Shark meat, on the other hand, is high in uric acid and almost worthless.

"The fishermen don't have room in their boats for the shark, so they cut off its fins and throw the rest away," Ali explains.

Up to 100 million sharks are believed killed worldwide each year solely for their fins. East Asian countries account for 95 per cent of all fin imports, officially reported at 7,000 tonnes annually but believed to be much higher. Commercial fishing is banned in Egypt's Red Sea marine sanctuaries, while a governor's decree prohibits shark fishing in most remaining territorial waters.

Local authorities deny that illegal fishing is a serious problem. "There is no shark fishing in Egypt because already the population of sharks is very low," says Mahmoud Hanafy from the Egyptian Environmental Affairs Agency (EEAA). He admits that some Egyptian companies are exporting a "small number" of shark fins, but says fishing vessels are probably catching these sharks outside Egyptian waters.

"If they catch sharks in Egypt, it is just by accident," he says. "It's not commercial fishery and there is no fishing for sharks using, for example, lines with many hooks."

Dive boat captains returning from Egypt's southern Red Sea reefs suggest otherwise. One captain spoke of a long line discovered during a diving excursion in late 2001.

"We found a buoy and what we thought was a mooring line, but when we went to cut it we saw that it was a fishing line with 12 baited hooks," says Yasser El- Moafi, owner of the dive boat Royal Emperor. "On one of the hooks was a huge Mako shark."

El-Moafi has no doubt that the fishermen who placed the line were targeting sharks. "The hooks were baited with baby sharks, so definitely they were trying to catch sharks," he says. "While we were there a small boat approached, but when the fishermen saw us they ran away." Several journalists were on board the Royal Emperor at the time and this encounter was captured on film.

Dive boat operators say this was not an isolated incident. "There's finning going on in the deep south," says Amr Ali, managing director of Conquest Fleet. "You can see the shark hooks on buoys. There's tonnes of them."Ali reports shark long-liners to local authorities, but since the poachers operate hundreds of kilometres from the nearest coast guard base, he sometimes takes matters in his own hands.

"Now they run when they see us coming, because I gave a direct order to my boat crew to hit their boats," he says. "No mercy about it, we have to act." According to figures from the Food and Agriculture (FAO), Hong Kong alone imported 5,500 kg of dried shark fins from Egypt in 2000. About 75,000 sharks were slaughtered to meet the order.

Dozens of exporters openly advertise shark fins on the Internet. Minimum orders range from 100 to 1,000 kilos, according to the species and fin length. Even baby shark fins less than 15 centimetres are on offer. "It's a huge amount," says Ali. "Not all of this can be coming from outside Egyptian waters."