What makes sharks attack people

I thought I was having a nightmare and kept trying to blink my eyes open. The shark that attacked Hannah Mighall took an enormous bite out of her surfboard before it allowed her to bob back to the surface Credit: Malcolm Mighall.

The shark pulled away from him and as it went underwater it let go of Mighall, lunging instead for her surfboard that was still attached by a rope to her leg. With the board in its mouth, the shark pulled Mighall underwater for a second time. Moments later she popped back up to the surface with her damaged board. The animal had bitten clean through the fibreglass and foam.

Mundy grabbed hold of his cousin, put her on his back and paddled frantically for the shore. Now she was doing it for real.

The shark came with us all the way up to the beach as there is a deep gutter running up to it. We could see its fin as it surfed in on the same wave. Luckily for Mighall, among the few people on the beach who witnessed what had happened that day were a doctor and a nurse. They gave her vital first aid while waiting for an ambulance to arrive. Her right leg is noticeably weaker than her left — so much so that she has to lift it with her hands when she wants to kick-start the dirt bike she rides occasionally.

Great white sharks typically attack their prey from below with great speed, delivering a single devastating bite Credit: Getty Images. Mighall was one of roughly 83 people around the world to be attacked unprovoked by sharks in It is a figure that has remained around the same level over the past decade.

The average number of unprovoked attacks between , for example, was But recent research indicates that shark attacks in some parts of the world appear to be on the rise. The eastern US and southern Australia have seen shark attack rates almost double in the past 20 years , while Hawaii has also seen a sharp increase. But why? This seems like an obvious point, but when you look closer at where attacks are taking place there are some clues as to what might be going on. The large human populations along the southern coast of Australia and the eastern coast of the US mean large numbers of people enjoying the water.

But southern Australia has also seen rising numbers of fur seals along its coastline, the favourite prey of great white sharks in the region. The resurgence in seal populations on Cape Cod on the east coast of the US has led to rising numbers of great white sharks in areas popular with people Credit: Getty Images. This has led to increased numbers of great whites in the area too during the warm summer months as they look to feast on the seals that pull themselves out to bask on the beaches.

Sadly, last autumn, Massachusetts suffered its first fatal shark attack in 82 years and growing numbers of shark sightings have led to a string of beach closures.

But there is no real evidence that sharks are actively hunting humans, according to the scientists who study them. Great whites in the North Atlantic, for example, show seasonal movement patterns, migrating thousands of miles to warmer waters further south during the winter months. Some mature adults will venture out into the open ocean for months at a time , covering tens of thousands of miles and diving to depths of 1,m as they seek prey. But despite being potentially such an easy meal, sharks are really not that interested in hunting humans.

I think if people knew how frequently they were in water with sharks, they would probably be surprised. However, Naylor believes that the official statistics on shark attacks are probably an underestimate. Most reports come from highly developed countries with large populations and highly active news media.

Attacks on remote islands or in less developed communities probably go unreported. It's trying to use what we know about shark visual systems to come up with shark deterrents. As part of this research, we're putting lights on the bottom of seal decoys to try and stop white sharks attacking those decoys, with a view to putting lights on surfboards and other water craft.

In reality, the risks of a shark attack are extremely low. There are lots of other activities that are far higher risk — including drowning or having a car accident on the way to the beach. People should continue doing what they love and accept that any time you go in the ocean, there's a certain risk of misadventure. Please explain: Why do sharks attack humans?

Faculty of Science and Engineering. Our Stories. There are three major kinds of unprovoked shark attacks. These typically occur in the surf zone with swimmers and surfers the normal targets. The victim seldom sees its attacker and the shark does not return after inflicting a single bite or slash wound. A feeding shark in this habitat must make quick decisions and rapid movements to capture its traditional food items.

When these difficult physical conditions are considered in conjunction with provocative human appearance and activities associated with aquatic recreation splashing, shiny jewelry, contrasting colored swimsuits, contrasting tanning, especially involving the soles of the feet , it is not surprising that sharks might occasionally misinterpret a human for its normal prey.

We suspect that, upon biting, the shark quickly realizes that the human is a foreign object, or that it is too large, and immediately releases the victim and does not return.

Using detailed shark neuroscience data, the researchers applied filters to the video footage to simulate the way a juvenile white shark would process shapes and movements. Macquarie University previously found incidents of sharks biting humans have risen over the past two decades , with surfers likely having a higher risk because they spend more time in the ocean than swimmers. The findings, the researchers said, will help understand why shark bites occur and how they can be prevented.