Sharks rarely attack humans, even though we’re slower than fish and seals. But when attacks happen, they can be very bad. Why do sharks attack people?
Case Study: Hannah Mighall’s Shark Attack
Hannah, 13, was surfing with her cousin in Tasmania. The water was clear and the beach quiet. Suddenly, the water got dark below her. She lifted her feet, thinking it might be seaweed. But then something grabbed her leg.
The water around Mighall exploded as a five-metre-long great white shark latched onto her right leg
Mighall said, “It felt gentle at first. Then I was in the water.”
But others saw it differently. A huge shark grabbed her leg. It lifted her up and shook her. Then it went underwater.
“It took me a moment to know it was a shark,” she said. “I came up and saw my leg in its mouth. I saw its teeth, gums, and nose. I thought I was dreaming.”
Mighall’s cousin, Syb, was nearby. He swam over and hit the shark’s head. The shark let go of Mighall and went for her surfboard instead. The board was tied to her leg.
The shark pulled Mighall under again. When she came up, her board was badly bitten.
Mundy put Mighall on his back and swam to shore. Earlier, Mighall had practiced rescues. Now it was real.
The shark came with us all the way up to the beach
Hannah Mighall
Immediate Aftermath and Rescue
“The shark followed us,” said Mighall. “A wave came, and Syb said we must catch it. It saved us. The shark came with us to the beach.”
A doctor and nurse on the beach helped Mighall until an ambulance came.
Ten years later, Mighall has scars on her leg. Her right leg is weaker. She needs help to start her dirt bike.
Statistics on Shark Attacks
About 83 people were attacked by sharks worldwide in 2009. This number has stayed about the same for years. In 2023, there were 69 unprovoked attacks and 22 provoked ones. Fourteen people died, with 10 deaths from unprovoked attacks.
Shark attacks are rising in some places. The eastern US and southern Australia have seen almost twice as many attacks in the last 20 years. Hawaii has also seen more attacks. Why is this happening?
Why Do Sharks Attack Humans?
Gavin Naylor, who studies sharks, says, “More shark bites happen when there are more people and sharks in the water together.”
This makes sense. In southern Australia and the eastern US, many people swim in the ocean. In Australia, there are also more fur seals now. Great white sharks like to eat these seals.
In Cape Cod, Massachusetts, seal numbers have grown since 1972. This brings more great white sharks to hunt them in summer.
Sadly, in 2019, someone died from a shark attack there for the first time in 82 years. Many beaches have closed due to shark sightings.
In 2022, New York had eight shark bites, more than ever before. Young sand tiger sharks now live in a bay near New York. These sharks may come close to shore for food, meeting more swimmers.
We are like helpless little sausages floating around in the water
Gavin Naylor
Shark Behavior and Human Interaction
Scientists say sharks don’t hunt humans on purpose. Great white sharks in the North Atlantic move south in winter. Some swim far out to sea for months.
“We’re like helpless sausages in the water,” says Naylor. But sharks usually ignore people. “If people knew how often they swim near sharks, they’d be surprised.”
Naylor thinks there are more shark attacks than reported. Most reports come from rich countries with lots of news. Attacks in remote places might not be reported.
In 2022, there were 57 unprovoked shark attacks. This is lower than usual and matches the lowest number in 10 years. Different groups report different numbers of deaths from these attacks.
In 2023, between 10 and 13 people died from unprovoked shark attacks, depending on the source.
In early 2024, there were eight unprovoked attacks, with two in Hawaii.
On June 24, 2024, Tamayo Perry, a surfer and actor, died after a shark attack in Hawaii. Perry was also a lifeguard and was surfing near Laie when it happened.
Hawaii had eight shark attacks in 2023, more than usual. One was deadly. Experts are watching Hawaii closely.
Florida has the most shark bites worldwide. In 2023, it had 16 bites, which was 44% of US bites and 23% of world bites.
Over time, shark attacks have increased. This may be because more people swim where sharks live, and more attacks are reported online.
Shark bites have varied recently. There were 57 in 2020, 73 in 2021, and 98 in 2015.
Many kinds of sharks bite humans. The main three are great white, tiger, and bull sharks. Great whites are very different from the other two.
Blake Chapman, who studies sharks, says, “There are 530 types of sharks. They’re all very different.”
Chapman wrote a book about shark attacks. She explains that different sharks have different senses, behaviors, and homes.
For example, bull sharks hunt in shallow, muddy water. They use smell and can sense tiny electric fields from their prey, rather than relying on sight.
Shark Conservation and Human Impact
There is some evidence that shark teeth may also function as mechanosensory structures to help the animals learn more about what they are biting
Great white sharks hunt in clear water and use their eyes more. Shark teeth may also help them feel what they’re biting.
Chapman thinks there are many reasons why shark attacks have increased:
- More people live near coasts
- Shark habitats are being destroyed
- Water quality is changing
- Climate change affects where sharks and their food live
Safety Tips for Avoiding Shark Attacks
Other factors matter too. For example, in Hawaii, some sharks bite more on dark nights.
In 1992, many shark bites happened in Recife, Brazil. This was new. Chapman thinks building a port there may have forced sharks to move to new areas to find food.
Réunion Island has had more shark attacks recently. Since 2011, 11 people have died. Many survivors lose limbs. Most attacks happen in murky water with big waves.
Naylor thinks most shark bites are mistakes. Sharks might mistake a foot for a fish. Big sharks like tigers or great whites can cause fatal bites.
Great whites often attack from below with a big bite. They might wait for prey to die before eating.
Greg Skomal studies great whites. Once, a shark jumped at him while he was on a boat. He says, “It showed me how a seal feels.”
Skomal thinks some attacks might happen when a shark is very focused on hunting and a person is in the wrong place.
For each shark attack, there are also stories of people safely getting close to sharks. Ocean Ramsey swam next to a huge great white shark in Hawaii. This made news all over the world.
Skomal and his team are using new tags that show what sharks do every second. These give them much more detailed information.
It is like they are in a heightened predatory state where their senses lock onto any kind of stimuli
– Greg Skomal
Skomal hopes these tags will help explain shark behavior and breeding. This might also help us understand why sharks attack humans.
Psychological and Economic Impact of Shark Attacks
Some researchers use detective-like methods to study attacks. They use DNA and bite marks to identify shark species. They also study videos of attacks to understand what happened.
In South Africa, shark watchers found that great whites are seen more when:
- Water is warmer than 14°C
- During a new moon
- In the afternoon
But other research says great whites hunt better at night during a full moon.
Some think young great white sharks might attack humans while learning to hunt, like young lions do.
But shark attacks are still very rare:
- In Australia, about 0.5 to 0.8 attacks happen per million people
- In the US, it’s even less, between 0.08 to 0.2 attacks per million people
These numbers show how uncommon shark attacks really are.
In Australia the rate of shark attacks is in the order of 0.5 attacks per million people, while in the US it is less than 0.2 attacks per million
These numbers don’t show how few people actually swim where dangerous sharks live. But even these low numbers don’t stop people from fearing sharks.
Chapman says, “Fear helped us survive. We learn to fear things from stories, even without seeing them.”
Worrying about shark attacks makes us forget that we’re the real danger to sharks. Overfishing and climate change have greatly reduced shark numbers. In Australia, shark numbers may have dropped by 75-92%.
To stay safe from sharks:
- Swim in groups
- Stay close to shore
- Wear dark clothes
- Don’t wear jewelry
If attacked, some say to hit the shark’s gills or eyes. But remember, shark attacks are very rare.
Some products claim to keep sharks away using electric signals. But research shows these don’t always work well.
Some areas have tried to protect swimmers:
Shark nets were used, but they harm other sea life, Now, they’re testing “smart drum lines” in western Australia
- These use baited hooks
- When a shark bites, it sends an alert
- Teams then catch the shark, tag it, and move it somewhere safer
These methods try to keep people safe while also protecting sharks and other sea creatures.
The harm caused by shark attacks can extend far beyond their immediate victims
In Cape Town, they’re testing an electromagnetic cable to keep sharks away from swimmers. Scientists are also trying an electromagnetic barrier instead of shark nets. These new methods could help a lot.
Shark attacks hurt more than just the victim. Dave Pearson, who started a support group for shark attack survivors, says attacks affect whole communities. Pearson was bitten by a shark while surfing and almost lost his arm. He says after his attack, many of his friends stopped swimming for a long time. Fear of sharks can spread fast in a community.
Pearson visited Ballina, Australia, where shark attacks hurt the town’s business. Coffee shops and surf shops lost customers.
In Reunion, swimming bans due to sharks have hurt tourism.
Hannah Mighall, who survived a shark attack, doesn’t want sharks killed. But the attack changed her life. She tried surfing again but lost her love for it. Now she’s scared of the sea and has nightmares about sharks.
Pearson says many victims struggle to recover mentally. He needed a psychiatrist’s help after his attack.
Mighall keeps her bitten surfboard as a reminder. She says if you’re scared of sharks, you can always stay out of the water.
