Great white swims into shark heaven in South Australia
Nick Squires in Sydney
It was the closest thing to shark heaven. A four-metre-long great white shark managed to find its way into an experimental fish farm off the coast of South Australia packed with more than 300 tuna.
But after marauding around the enclosure for six days, feasting on the prized fish, fishermen and scientists decided enough was enough. Yesterday, a team of experts, including shark wrangler and animal behaviouralist Ian Gordon, from Sydney, managed to coax the enormous female shark out of the 30-metre-wide pen by cutting a hole in the side of the enclosure.
The drama began last Thursday, when the shark somehow managed to get into the tuna cage. Scientists could find no trace of a hole made by the 700kg shark and believe it may have jumped into the pen in pursuit of a seal, which then either was eaten or managed to escape.
The tuna pen is protected by a 2.4-metre-high electric fence, but great white sharks have been known to jump as high as 2 1/2 metres out of the water.
The cage, located off the coast of Port Lincoln, west of Adelaide, is part of a research programme underpinning the area's multimillion-dollar tuna farm industry.
The mission was carried out by a team of eight, including three divers working underwater outside the pen.
Anthony Cheshire, chief aquatic scientist with the South Australian Research Development Institute, said: 'The final strategy was to create a funnel out from the side of the cage. As the shark swam around the circumference of the pen, it found itself in the funnel, which took it straight to an access gate, and it swam free of its own accord.'
He said the team had originally planned to try to lasso the great white by its tail and drag it out of the enclosure, but the idea was quickly shelved.
'It has been done with smaller sharks in the past, but Ian [Gordon] took one look at this one and saw it was twice as big as anything that had been lassoed before,' he said.
'It was not really a practicable solution for a shark that big.'
The scientists were keen to attach a tracking device to the shark to provide data on its future movements, but the attempt failed.
After nearly a week in the cage, the shark swam away from the cage none the worse for wear for its ordeal, Mr Cheshire said.
The toll taken on the tuna was less than originally feared, with only one or two apparently snatched by the shark and at least two escaping through the funnel.
'When the shark swam to the surface, the tuna swam to the bottom of the net and vice versa,' Mr Cheshire said.