5 Things You Didn’t Know Sharks Do For You

Editor’s Note: This post was updated on July 21, 2017. In honor of Shark Week 2017, which kicks off July 23 on the Discovery Channel, we’re sharing one of our most popular shark blog posts. 

shark in Fiji

Shark in Fiji. (© Photo Rodolphe Holler)

It has always struck me as odd how terrified many people are of sharks. It’s one thing if you’re a surfer or fisherman, but why would people living thousands of miles from the coast list the marine predators among their greatest fears, when statistically you are more likely to be killed by a toaster?

The annual success of “Shark Week” continues to show how fascinated and petrified we are of these creatures. If anything, sharks should be afraid of humans — many species of sharks are threatened by human activities, including overfishing and shark finning.

If sharks were to disappear, it would be bad news for all of us. Here are just a few of the reasons why.

1. Sharks keep the food web in check.

Many shark species are “apex predators,” meaning they reside at the top of the food web. These sharks keep populations of their prey in check, weeding out the weak and sick animals to keep the overall population healthy. Their disappearance can set off a chain reaction throughout the ocean — and even impact people on shore.

For example, a study in Australia found that as shark numbers declined, mid-level predators like snappers increased while herbivorous fish populations shrank. With fewer algae-eating fish around, the algae overwhelmed the reef system and limited its ability to bounce back from bleaching and other disturbances.

2. Sharks could hold cures for diseases.

It has puzzled researchers for years: Why don’t sharks get sick? (They do, of course, but not as often as other species.) Shark tissue appears to have anticoagulant and antibacterial properties. Scientists are studying it in hopes of finding treatments for a number of medical conditions, including viruses and cystic fibrosis.

snorkelers in South Africa

Snorkelers in South Africa peer into the water as they prepare to swim with sharks for the first time. (© Sijmon de Waal/Marine Photobank)

3. Sharks help keep the carbon cycle in motion.

Carbon is a critical element in the cycle of life — and a contributor to climate change. By feeding on dead matter that collects on the seafloor, scavengers like deep-sea sharks, hagfish and starfish help to move carbon through the ocean.

In addition, research has found that large marine animals such as whales and sharks sequester comparatively large amounts of carbon in their bodies. When they die naturally, they sink to the seafloor, where they are eaten by scavengers. However, when they are hunted by humans, they are removed from the ocean, disrupting the ocean’s carbon cycle.


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4. Sharks inspire smart design.

People have been practicing biomimicry — imitating nature’s designs to solve human problems — for many years. However, recent advances in technology have made it possible to go even further in pursuit of efficient design.

With a history spanning more than 400 million years, sharks can teach us a lot about speed and efficiency in the water. In fact, some researchers are now trying to make artificial shark skin that would reduce friction drag and prevent the accumulation of algae and barnacles in the water — and even prevent bacterial growth when applied to hospital surfaces.

Copying sharks could even lead to globally significant innovations. An Australian company called BioPower Systems has designed a device resembling a shark’s tail to capture wave energy from the ocean and convert it into electric power. As the world looks for clean energy alternatives to fossil fuels, use of this kind of technology could be one promising solution.

5. Sharks boost local economies.

Over the last several decades, public fascination with sharks has developed into a thriving ecotourism industry in places such as the Bahamas, South Africa and the Galápagos Islands.

According to a study published in 2013, shark tourism generates more than US$ 300 million a year and is predicted to more than double in the next 20 years. These activities — which support businesses like boat rental and diving companies — are said to provide 10,000 jobs in 29 countries. Several studies have indicated that in these places, sharks are worth much more alive than dead.

In addition to these benefits for people, it’s likely that sharks fulfill other roles in their habitats that we have yet to understand or appreciate.

Species are sometimes called the “building blocks of ecosystems,” Yet humans continue to remove these blocks without fully understanding the consequences. Up to 100 million sharks are killed every year, largely for the shark fin trade.

Think of the world’s biodiversity as a giant game of Jenga: if you keep removing blocks, eventually the whole thing will come tumbling down.

Molly Bergen is the managing editor of Human Nature. Check out the next blog in our Shark Week series.

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  1. Pingback: Whale.org | Ocean Alliance | 5 Things You Didn’t Know Sharks Do For You

  2. Chris says

    The Far East needs to get off of it’s old world views . Shark fin does nothing for you . it is a placebo . This old world is killing the animals on this planet . Enough is enough !

    1. kayla says

      yeah and if your going to just drown the animal u should go right with it because they are so beautiful and the only reason u kill them is for those chinese people noafence.

    2. jayden says

      seriously people are taking fishing way too far and if you live at least 100 meters from the ocean your more likely to be killed by a bee than a shark.BUT REALLY JUST STOP BEING AFRAID OF SHARKS YOU LIVE LIKE WHAT 300 SOMETHING MILES FROM THE OCEANS AND YOUR STILL TERRIFIED.

    3. aaliyah meadows says

      yeah I agree this has gone to far umm… hey people of the world man kind need to stop this madness because some people are just down right dirty and I my self think that they should get a second chance but they lost that because you know what the great white shark is almost exstinked wildlife experts say that they are even more endangered than the tiger shark and they are uncommon to find

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  23. Dr UN Nandakumar says

    Great. Highly informative. Quite useful for understanding ecosystem dynamics and how even sharks which may not have direct contact can influence the life of human beings . it also stress the need for their conservation &management.

    1. Bee Stannerman says

      This was highly uninformative an doesn’t really say how it affects us. How does algae overwhelming the system affect us? It doesn’t!

  24. Caroline Coogan says

    Cownose rays have finally been exonerated – there was widespread misinterpretation of those early studies on a trophic cascade and a spurious link between rays and the decline of scallop and oyster industry. More recent studies and panels of experts have worked to overturn that misconception.

    Please update this blog to reflect the latest science.



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  26. Sarah Itta says

    Hello, I am from Highland Middle School’s FIRST Robotics team. Part of our competition involves a research project. Our team has chosen to do our research project the impacts humans have on sharks. Specifically, I am interested in learning more about Shark endangerment, and I would really appreciate it if you could help me by answering some of my research questions.
    Thank you for any help you can give.

    Sarah Itta

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  28. sans says

    they need to stop killing sharks they kill more than 1 million of sharks In 1 year and sharks kill 5 humans a year how is that info for u they need to STOP NOW!

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