To cull or be killed?

Jake Heron was preparing to catch the last wave of the day when the ocean's most feared predator struck without warning. Erupting from the water beside him, the great white shark bit deep into his right arm and leg and knocked him off his surfboard.

'Terror is the only word I can think of to describe it,' Heron, a 40-year-old lobster fisherman, said. 'I was punching and kicking and screaming for help. Its dorsal fin was right in front of my face.' The 4-metre-long shark was turning for another attack when a lucky wave propelled Heron and the remains of his mangled surfboard into shore. He was rushed to hospital and received more than 60 stitches.

Heron's ordeal last month earned him membership to one of the world's most exclusive clubs - those who have been attacked by a great white and been lucky enough to survive.

But it has also prompted an impassioned debate in Australia over whether the great white shark - Carcharodon carcharias - should be culled. There have been five shark attacks in Australia since December, two of them fatal - significantly more than the national average of one a year. Surfers and fishermen claim that great white numbers have increased dramatically in the past decade after the species was granted protection from hunting.

They also say the sharks are being lured closer to shore by a booming tuna fishing industry, which has developed in the past decade and is now worth millions of dollars a year.

Tens of thousands of tuna caught in the wild are fattened in offshore cages before being exported to Japan, where they are served in restaurants as premium-quality sushi and sashimi. Critics say raw pilchards tossed into the pens, and the blood and guts which spill into the water when the tuna are slaughtered, are an irresistible attraction for great whites, which can grow up to 7 metres long and weigh 2.5 tonnes.

Nowhere is the controversy more acute than in Port Lincoln, the centre of the tuna industry, on the southern tip of South Australia's rugged Eyre Peninsula.

The rocky reefs, deserted bays and crumbling limestone islands which stretch for hundreds of kilometres along the Great Australian Bight, to the west of the town, provide the perfect habitat for seals and sea lions and the sharks which hunt them.

Overlooking the deep blue waters of Boston Bay, Port Lincoln, is the Antipodean counterpart to Amity Island, the fictional New England beach resort caught up in shark attack hysteria in the 1975 blockbuster Jaws. Underwater footage of great whites used in the film was filmed at Dangerous Reef, a few kilometres up the coast.

Heron was attacked as he surfed in a picturesque cove south of the town. In 2000 two surfers were killed within 48 hours at similar surf spots along South Australia's remote and sparsely populated coast.

There was another close shave last weekend when surfer Josh Berris, 26, desperately fought for his life after being attacked off the coast of Kangaroo Island, southeast of Port Lincoln. He survived by ramming his surfboard into the shark's mouth.

'Numbers are up five- to seven-fold compared with 10 years ago,' remarked Heron, who is slowly recovering from his wounds.

'The tuna industry is teaching sharks to interact with boats and people.'

Anti-shark sentiment is running high in Port Lincoln where swimming, surfing, diving and boating are a way of life.

'To have so many attacks in such a short period of time is unheard of,' said Nick Porter, who runs a surf shop on the esplanade.

'I would say 90 per cent of surfers would be in favour of a cull.'

Gig Bailey, a prawn trawlerman who has lived in Port Lincoln for 40 years, said: 'We've seen a lot more sharks in the last 10 years, no doubt about it. I used to swim a lot but I'm much warier now.'

The tuna industry denies that its offshore farms have increased the number of great whites or led indirectly to attacks.

Port Lincoln's tuna 'barons', who have become millionaires from the prized fish, say the tuna pens act as a magnet for sharks which would be in the area anyway, rather than luring more animals from the open ocean. 'Shark sightings are up because there are so many more fishermen out on the water - there are more pairs of eyes looking out for them,' said Robbie Staunton, a tuna company manager whose office overlooks Port Lincoln's busy marina. 'The town was known for its white pointers [great whites] well before the tuna industry started up.'

The two sides are deadlocked because the great white's range is so vast that scientists have no idea whether their population has risen or dropped in the past decade.

'From our limited observations, there's no general trend either up or down,' said Barry Bruce, a government scientist who is one of the country's foremost shark authorities. 'You can't make any intelligent judgments about there being a link between tuna fishing and shark attacks.'

Experts argue that the number of shark attacks has increased because more and more Australians have moved to the coast in search of a better lifestyle.

Four million Australians, a fifth of the country's population, now live in rural coastal areas outside the big cities - more than double the proportion 25 years ago. Another million are expected to join them in the next decade. They have been dubbed 'Seachangers', after a popular television drama which documented the phenomenon. Having secured their own little piece of paradise they spend their time swimming, surfing and sailing - presenting the great white with far more targets than before.

The rush to the 'sea-burbs' is happening from Queensland in the north of the counry, right round the coast to New South Wales, Victoria and South Australia, and across the continent in Western Australia.

'The number of people with four-wheel-drives who can access remote beaches has increased dramatically,' said Peter Davis, Port Lincoln's mayor and a former shark fisherman.

'But we need to keep all this in perspective - you're more likely to die of a bee sting or a lightning strike than a shark attack.'

Such assurances fail to convince many in Port Lincoln, where the fear of great whites has bred something close to a siege mentality. 'There are way too many of them,' said Renee Smith, 18, a waitress at a cafe overlooking the turquoise shallows of Boston Bay. 'There'll be another fatal attack this [Australian] summer. I'd put money on it.'