It is believed the shark was attracted to the area by a six-metre whale seen earlier near City Beach, close to Perth.
One witness talked of seeing the shark swimming near the whale, with both heading north.
"First of all, I saw the whale, and then I could see something following it," the witness said.
"And then people were saying: ‘What’s pursuing it?’. And yeah, then it was clear, it was a shark."
The 16-feet-long female dubbed “Joan of Shark,” while estimated weighing 1.6 tons, is the largest shark to be electronically tagged in Australia, the Telegraph reported.
That electronic tag, detected by a satellite monitoring system, is what warned nearby residents to stay out of the water while a team of researchers, shockingly, went straight in.
The head and gills of the ”1.5m long juvenile shark” were tightly entangled in industrial strength elastic cord. The shark was “facing a slow and painful death, with the cord continually tightening as the young animal grew in size.” Although, they knew that the mission could be dangerous, the team was determined to carry out the intervention as quickly as possible.
New figures show that three quarters of the sharks caught by Western Australia’s shark baiting were undersize. All the more reason to halt the program, writes Elizabeth Claire Alberts - and to end similar programs elsewhere in Australia
It was a Jackass-style stunt that nearly turned around and bit Australian adrenalin junkie Shaun Harrington – or rather mauled him.
Harrington, 27, and fellow forever-clowning twin brother Dean decided to go “cage diving” with sharks off the Gold Coast, which is Australia’s answer to Miami, last weekend for an extreme video shoot for their surfing and fishing clothing label, fittingly called The Mad Hueys.
But the cage wasn’t the jaws-proof reinforced steel type typically used by shark divers – it was a flimsy $50 bird cage Shaun planned to put on his head.
An Australian surfer says he felt something hit his hand - but was totally unaware of the gravity of the moment.
After six fatal shark attacks since 2011, officials in Western Australia are biting back.
"Where shark numbers are reduced we see a fundamental change in the structure of food chains on reefs," said Meekan.
"We see increasing numbers of mid-level predators such as snappers, and a reduction in the numbers of herbivores such as parrot fishes.
"The parrot fishes are very important because they eat the algae that would otherwise overwhelm young corals on reefs recovering from natural disturbances."
A spate of fatal shark attacks in [Western Australia] has led to calls for drastic action. But what’s behind the attacks?