Long before Jaws took movie terror to a new and bloodcurdling level, monster sharks were whipping Sydney into whirlpools of fear and panic.

On March 12, 1922, a balmy Sunday in the Harbour City, an estimated 70,000 people lined the shores and surrounds of Coogee Beach to witness the most macabre predator hunt.

A group of New Caledonian sailors, knives clenched between their teeth, plunged into the sea on the search for the shark – or sharks – that fatally mauled two swimmers at the beach four weeks apart.

Milton Coughlan, 18, rescued a drowning man the week before a shark attacked him off the rocks by the surf club.

Another local, 21-year-old Mervyn Gannon, suffered grisly wounds when a shark launched at him in shallow water.

The incidents had newspapers debating how to end attacks. Beaches across the city were ignored by frightened swimmers, and bounties offered for any shark caught off Coogee.

Self-styled hunters patrolled in boats, the New Caledonian sailors opted for a bare-hand approach, and successful catches were proudly hung for public viewing.

There were even calls, ignored by authorities, to bomb the bay with explosives to kill any sharks in the area.

More than a century on with Australia enduring five fatal attacks this year – two of them in NSW in the past few months – sharks are back in the public eye.

WHO ARE THESE OCEAN PREDATORS?

Gavin Naylor manages the International Shark Attack database and is director of the shark research program at the University of Florida in the US.

He tells Weekend Extra: “They pre-date dinosaurs and have been around 350 to 400 million years. These are amazing, ancient animals.

“They have very few pups but are well adapted to their environment and have lasted all this time. As an evolutionary biologist I find them both mysterious and fascinating.”

Yiannis Papastamatiou is another world-renowned American researcher, a leading expert in shark behaviour at Florida International University.

“We used to think of them as mindless killing machines,” he says.

“But they have cognitive abilities beyond what we gave them credit for and they’re important components in marine ecosystems. It’s clichéd but they are genuinely misunderstood.”

He details how great whites are warm-blooded, preferring prefer cooler waters, while bull and tiger sharks are tropical and sub-tropical dwellers.

Naylor adds: “A white shark is as different to a bull shark as a kangaroo is from a dog.”

Great whites and tigers feed primarily on marine mammals such as seals and sea lions while bull sharks, despite being a factor in human attacks, are predominantly fish feeders.

Papastamatiou says research has also shown great whites are more active at dawn while the dusk period is when tiger and bull sharks are likely to be “searching for prey”.

WHAT TRIGGERS SHARKS TO ATTACK?

“Someone gets killed or bitten and everyone wants to know why,” says Papastamatiou. “The truth is, we often don’t know.”

He believes “mistaken identity” is often the root cause as a shark forages for its regular prey.

“A shark may also lash out if it sees some sudden movement,” Papastamatiou adds. “Or, in some cases, it might just investigate an object floating on the surface.”

Naylor holds a similar view saying if sharks targeted people “we’d have 10,000 bites a day” because humans are “pretty much helpless” in the water.

He also talks to the “transition” period for great white sharks when they move from feeding on fish to seals and other mammals as they reach 3 to 4 metres in length.

“It has been speculated, but not proven, that in some instances whites that have bitten humans are roughly of that size,” he adds.

“While it’s anecdotal, you could have naive animals transitioning their food source, seeing something on the surface, and mistakes happen.

“But there are still so few incidents. They could, if they wanted, go in and eat people like sausages.

“I think 90 per cent of shark bites are cases of mistaken identity. Consistent with that, 60 per cent of the about 7000 shark bites we’ve recorded in our database have occurred in low visibility water.”

Naylor does not rule out targeted attacks. He cites a case three years ago in the Red Sea where a Russian tourist was bitten by a tiger shark.

“The shark circled him, could see it wasn’t a marine mammal, then moved in,” he says. “It was on video and pretty unambiguous. This person was targeted by the shark. But that is incredibly rare.”

Dave Pearson, mauled by a shark 14 years ago on the NSW north coast and founder of the Bite Club for survivors of attacks by apex predators, is more jaundiced about the mistaken identity theory.

“We’ve had many people in our group who have been circled and circled and then attacked,” he says.

“We have cases where a shark has bitten somebody, other humans are trying to get them out of the ocean, and the shark has pushed them out of the way to get to the person they’ve already attacked.

“What I’ve learnt over the years is that sometimes we are on the shark’s menu.”

WHAT ARE THE ODDS?

Rodney Fox, 85, is a legend in shark conservation.

He survived one of the most brutal non-fatal attacks in history, needing almost 500 stitches to close wounds after a great white gored him during a spear fishing competition in South Australia in 1962.

Fox went on to invent the first shark cage for underwater viewing, establish an expedition company, work with Hollywood film directors including Steven Spielberg on Jaws, and is still collaborating on attack mitigation initiatives.

Claiming he was “left on earth to do something”, Fox has worked for years with others on developing electronic deterrent devices and wetsuits made of materials to reduce the severity of injuries from bites.

“There was a saying in the days when I was attacked that ‘the best sharks are dead sharks’,” he says. “Everybody thought ‘get rid of them they’re useless’.

“But that’s because they knew nothing about them. I didn’t hate the shark that bit me.

“I had the saying ‘we’ve got to learn to live with them not kill them from fear’.

“People who know more about them are less frightened of sharks and know that the few attacks we have don’t compare with the number of motor vehicle deaths, or even fatalities from riding horses.

“You don’t go and get rid of all the horses do you?”

Based on World Health Organisation statistics, Naylor says people are 200,000 times more likely to drown than die from a great white attack.

“Indeed, surfers are more likely to die in a car crash on the way to the beach than they are to be bitten by a shark,” he adds.

SHOULD SHARK CULLING BE INTRODUCED?

Charlie Huveneers, a world-renowned expert on shark deterrents, is a marine ecologist and professor based at Flinders University in South Australia where he researches great whites, a protected species.

He says killing sharks could reduce risk to humans if enough were removed from the oceans. But what level of culling would actually make a difference is difficult to quantify, he argues.

Huveneers refers to Hawaii where 4668 tiger sharks were killed over 17 years. The rate of shark attacks did not reduce. On shark netting, he is “neither for nor against” the practice.

His academic pursuits focus on attack prevention and providing “scientific support to help government and the public to make informed decisions”.

“My group has been testing the efficacy of shark-bite mitigation measures for 15 years ... research on electric deterrents ... and bite-resistant material,” Huveneers says.

“(But) there’s no silver bullet in terms of completely eliminating risks altogether.”

Papastamatiou is an adamant opponent to culling.

“Whether you like sharks or not culling predators is a bad idea,” he says. “Occasionally you have these tragic events but they are rare, not the norm.”