A growing attraction over the past several years in one of Africa's biggest tourist destinations, Cape Town, has been underwater dives with sharks, with operators clouding waters with a bloody mixture called "chum" to attract the predators.

Many marine experts doubt if chumming changes the behaviour of sharks in the region, which include great white sharks as long as mini-buses that weigh upwards of four tonnes.

But the practice has rattled surfers, swimmers and kayakers, especially after a suspected great white shark ripped the leg off of David Lilienfeld, 20, last week, killing the champion body-boarder. .

Data shows since 2000 there have been 10 shark attacks around Cape Town's coast, five of them fatal, including Lilienfeld.

"This is an animal that kills people when it comes into confrontation with people. So let's not make them aggressive. Let's not dangle bait in front of them and stuff like that," Cas Collier, a former big wave world champion, said at Surfer's Corner, Muizenberg beach in the bay.

Sharks are drawn to the area to feed on the large number of seals at Seal Island, a rocky outcrop in the middle of False Bay. Once hunted for sport trophies, great whites have been a protected species in South African waters since 1991.

"It goes without saying that chumming in False Bay must be banned until we have a better understanding of shark behaviour and the potential for habituation," said surfer John Gasson in a published letter.

NO LINK

But for many of those who work with or study these graceful creatures, the emotion evoked in attacks clouds judgement.

"There is no link between chumming and shark attacks. Every time this happens you get paranoia," Leonard Compagno, a shark expert who helped design the mechanical shark in the blockbuster movie "Jaws", told Reuters.

Research in Australia, however, suggests prolonged chumming can affect shark behaviour around people to associate humans with food.

Every time an attack occurs, fingers are pointed at the small shark cage diving industry, centred in False Bay and Gansbaai, where the famous "shark alley" is found.

"Shark attacks are a very emotional thing and people are looking to blame somebody, and as shark operators we are easy targets," said Rob Lawrence, owner of African Shark Eco-Charters.

He says there is already a natural chum line in False Bay because of sewer outlets and gutted fish tossed overboard by boats.

Contributing about 30 million rand (4 million) to Cape Town's coffers each year, the shark cage industry is highly regulated - only three permit holders are allowed to chum in a restricted area around Seal Island.

"I think overfishing of small fish and rays has caused great whites to search wider for food and with increased people in the water, there are more chances of encounters," said fellow permit holder, Chris Fallows, a wildlife photographer and conservationist.

BEACH OF FEAR

Fish Hoek beach, a popular family beach has become a reflection of the anxiety. The beach's championship life-saving team does not swim in the water to practice and makes use of kayaks when venturing into the ocean, such is the fear of the great white menace.

"At the moment because of the sharks people don't come here and don't swim and that's a real shame," said Mike Schilperaart, spokesman for Fish Hoek Surf Lifesaving Club.

The club, which spent more than 100,000 rand on shark shields that are placed in the water and emit an electronic pulse to deter sharks, is hoping the city would soon erect a shark exclusion net as an additional barrier.

"People can see the net and they will feel much safer in the net," Schilperaart added.

(Editing by Jon Herskovitz and Paul Casciato)

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