Sharks And Mortality: How Do Sharks Die?

how do sharks die

Sharing is caring!

Sharks can be found in almost all ocean habitats, from out in the unexplored deep blue to shallow coastal waters hiding out in reefs.

With over 500 shark species ranging from big to small, these fascinating animals are predatory in many ecosystems and are vital for controlling fish populations.

Most sharks live for between 20 – 30 years, but there are some outliers such as the Greenland shark which has a conservative lifespan of 272 years.

A common question that often comes up when discussing sharks is “how do sharks die?”

In short, sharks die in a number of ways, including sickness or injury, by-catch, habitat destruction, and being eaten by other predators. The fishing industry also plays a large role in the number of shark deaths each year.

Let’s take a closer look…

What Causes Sharks To Die?

Research shows that over 100 million sharks die every single year.

This is a shocking statistic that is climbing every year and is the large part responsible for the 70% reduction in shark populations globally over the past 50 years.

Below are some of the ways that sharks die every single day:


We, humans, are incredibly destructive on planet earth, and we’re largely to blame for the drastic reduction in shark numbers we’re seeing in recent times.

Overfishing, culling, by-catch, and habitat destruction are just a few of the ways that humans kill sharks.

“Shark finning” is the act of catching sharks and removing their fins from them before throwing them back in the ocean.

This alone is responsible for the death of over 75 million sharks every year, as shark fin soup is a popular dish in parts of China, Taiwan, and Southeast Asia.

Millions more sharks die every year from being entangled in commercial fishing nets. The sad reality is that we humans are wiping out sharks at an alarming rate.

Natural causes

In modern times, natural causes are the least common cause of shark deaths as sharks rarely see their lives out to their full potential.

That said, sickness and disease do kill sharks every single year. Whilst these animals are immune to lots of diseases, they’re not immune to mother nature and ultimately meet their fate.

Bacteria, viruses, and worms target sharks and can lead to their demise.

Climate change

The impacts of climate change on marine life are immense, and sharks are no exception to the rule.

Shifts in fish populations, changes in migratory patterns as well as finding a safe place to live and reproduce are all having an effect on sharks.

Their habitats are littered with human rubbish and can become stuck in the shark’s gills causing them to suffocate.

Image: Flickr (Alpha)

Prey is becoming less available for sharks, which means they’re resulting in eating things they wouldn’t usually need to, including human trash.


Sharks are top ocean predators that are absolutely ruthless when it comes to hunting prey. There’s a good reason they have the reputation they do, as they’re quite literally built for killing.

That killing doesn’t just stop at fish, it also extends to weaker, more vulnerable sharks if the opportunity presents itself.

Sharks are scavengers, opportunistic feeders that won’t pass up on the chance of a quick meal, even if it is cannibalism.

A hungry Great white won’t hesitate to make quick work of a sick or injured shark.

Average Shark Life Expectancy

The average life expectancy for most species of sharks is between 20 – 30 years, but some species can live MUCH longer.

The Greenland shark for example can live for over 272 years, with some suggesting they may even live over 500 years.

These sharks typically live in the deep where they can are mostly unaffected by human interactions, thus allowing them to reach their full potential.

That said, even the Greenland shark isn’t safe from by-catch and many of these animals often get caught and die as a result.

Do Sharks Die Outside Of The Water?

Unlike marine mammals, sharks are fish that use their gills to breathe whilst underwater. They do not have lungs, and therefore on land would quickly die as they would be unable to breathe.

If a shark is taken out of the water it will be unable to extract oxygen. It will suffer brain damage incredibly quickly and hypoxia will begin to set in.

A human’s brain will suffer brain damage usually between four and six minutes without oxygen, and sharks will suffer a similar fate out of the water.

After a couple of minutes, the shark will be suffering from irreversible damage and ultimately die after five to seven minutes out of the water.

Do Sharks Die If They Stop Moving?

As sharks extract oxygen from the water through their gills, they are required to keep moving so that water pushes through the gills and they can take oxygen.

If some sharks stop moving, they will be unable to extract oxygen from the water and die if it does not start moving again.

This is why some shark species like Great white and Bull sharks are required to constantly stay on the move, even whilst sleeping.

They do this by sleeping in areas where there is a current so that they can rest but water is still being pushed over their gills so they can breathe.

dead shark
Image: 20Jazzfunk Stuart via Flickr

Sharks that are required to swim in order to breathe are known as “obligate ram ventilators“, but there are many other species that don’t need to move in order to breathe.

Reef sharks, lemon sharks, and sand tiger sharks are all able to sit motionless on the seafloor as they breathe by sucking in water through their mouths and forcing it over their gills.

Final Thoughts

Sharks are fascinating animals that are often top of the food chain in many ecosystems. They’re vital for the overall health of ecosystems as they play a vital role in killing off sick and injured fish.

Sadly we humans kill millions of sharks every single year through by-catch, overfishing, and shark finning.

We’re decimating shark populations globally and if we don’t see large conservation efforts in the near future many of the species we’ve come to know will likely be wiped out.

The Shark Trust are a remarkable organization that is really leading the way in shark conservation, if you have some free time I would urge you to go and check them out.

Hopefully, this post has provided a clear answer to “how do sharks die” and you now know many of the ways that these animals perish.

See you in the next one!