Shark attacks this year are way above the numbers in any recent period. What's going on, and should we be afraid?

You might not be familiar with the word, but you probably know the feeling. And with a spate of attacks in Australia this year, the fear of sharks is very much on the mind as beachgoers venture back into the water for summer.

The six fatal encounters in 2020 came after no fatal attacks last year, and just one in 2018.

One of them was in WA in January, when experienced diver Gary Johnson, 57, was taken near Cull Island, close to West Beach in Esperance.

Less than two weeks ago popular surfer Nick Slater, who was raised in Newcastle, was bitten on the Gold Coast and died despite frantic efforts to save him.

Before that, there had been three fatal attacks in a month, from the NSW mid-north coast to Fraser Island.

Then there are some wild stories of survival. In Tasmania, 10-year-old Lucas Arnott was pulled from a boat by a great white shark while fishing off Stanley in July. His dad saved him, leaping into the water at the shark, which left Lucas and swam away.

A month later, environmental scientist Chantelle Doyle, 35, was attacked while surfing at Shelly Beach near Port Macquarie. Her partner Mark Rapley jumped on the juvenile great white's back and punched it in the eyes until it let her go. (The couple has since responded by starting a crowdfunding campaign to save sharks and protect our oceans).

Closer to home, Dunsborough surfer Phil Mummert was attacked by a white shark on July 31 but survived.

And reports of sightings in Mandurah seem to be increasing.

So what hope do any of us have of adopting the surfer's mindset of casual mindfulness when it comes to one of the ocean's apex predators? And do beaches have adequate patrols and safety measures?

Experts such as Rob Townsend from Sydney's SeaLife aquarium say the chance of being bitten by a shark is miniscule. "Logically, there's no reason to be scared of sharks," he said.

"They kill far less people than just about anything else. Even though people are saying we've got this increase in shark attacks ... the numbers are so low to begin with.

"If the road toll went up by three people in a year no-one would even mention it."

But facts don't always trump fears - particularly when it comes to a large unseen animal that could eat you, and when it seems shark encounters have been on the rise.

So a fear of sharks is not irrational, marine scientist and author Dr Blake Chapman said, as they are "difficult" - and often unseen.

"A fear of sharks isn't something we're born with, but it is a really easily acquired fear," Dr Chapman said.

"This stems way back to our earliest ancestors, who learnt to fear a wide variety of biological factors - including predators.

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"While fear means that the risk is over-perceived from a statistical standpoint, and so often seems irrational, fear is something that has protected humans over their evolution."

We would hope 2020 is an anomaly. Sydney's Taronga Zoo keeps track of shark attacks each year, and 2020 has had 16 unprovoked attacks, five fatal. Of the three classed as provoked - this can include fishing - one was fatal.

But a 2011 paper published by the CSIRO found shark attacks had risen from an average of 6.5 incidents per year in 2000, to 15 per year by 2010. This year we've had 19.

Some - especially commercial fishers - say it's because protection has helped the shark population grow.

But research led by University of Wollongong senior lecturer Dr Leah Gibbs found no evidence of increasing shark numbers.

In fact, the UOW team's analysis of the NSW shark meshing program found numbers of target sharks - white, tiger and whalers - caught in nets had declined steadily since the 1950s. But concluding a population shift is not simple.

"Identifying the number of sharks in the ocean is extraordinarily difficult," Dr Gibbs said. "So working out if numbers are rising is very challenging."

The researchers found shark bites per capita had substantially declined since mid-last century.

But the most significant factor in increased shark encounters was the increase in population, and the boom in people visiting beaches - along with different water activities, such as spearfishing, putting people right in the shark's habitat. Warming seas also expanded bull shark habitat beyond the tropics.

Rob Townsend and Dr Gibbs both pointed to increasing numbers of whales moving up and down the coast as a possible reason sharks may be more prevalent, drawn to the mammals's path for easy food when one dies.

Mr Townsend said sharks were always around, and mostly stayed away.

"Yes they are a large predator and occasionally they decide to munch on people," he said.

"But every day a shark will swim by close to people [and] decide to avoid them. We need to be aware that when we enter the water we enter it on the shark's terms.

"We don't go to Africa and jump out of the safari jeep and go running around with the lions, but essentially that's what we're doing every weekend - and it's only that the sharks are more well-behaved than lions."

Fans of shark nets point to the fact that there's only been one fatal attack at a netted beach in NSW since meshing started in 1937.

But Dr Gibbs said this simply reflected the fact that nets are installed at patrolled beaches - so it may well be patrols - spotters - that are keeping people safe. The nets, her team found, were therefore ineffective and killed too many other species.

She said a "patchwork approach" was needed, which would include ocean surveillance, drones, improved and extended beach patrols, and repellent technology.

In particular, Dr Gibbs said beach patrols should be funded to expand significantly, in recognition of their role in spotting sharks.

"It's reasonable to have a fear of sharks," she said. "But that doesn't mean we need to get rid of them all. It means we need to think carefully about how we live with them.

"We all want to keep people safe. I think most people actually want to keep sharks safe - and we can do both.

"There's a whole range of strategies that are being developed around the world right now to do both of those things ... and I think we should be adopting the best of these strategies right here."