Why sharks matter to ocean ecosystems: an expert explains

This article is brought to you thanks to the collaboration of The European Sting with the World Economic Forum.

Author: Johnny Wood, Senior Writer, Formative Content

• Shark attacks on humans are rare, according to a shark expert.
• Overfishing is causing many shark populations to decline and driving some to the point of extinction.
• Improved marine management is a key component of protecting endangered species.

In 1975, the fictional beach town of Amity and cinema audiences the world over were terrorized by a tactically astute great white shark. While films like JAWS often do well at the box office, their legacy is to cast the planet’s shark species as dangerous predators that prey on humans.

This image is highly misleading, says Andy Cornish, leader of the World Wildlife Fund’s ‘Sharks: Restoring the Balance’ conservation programme.

Sharks evolved more than 400 million years ago and continue to thrive. These ancient creatures have outlived the dinosaurs and play a key role in maintaining marine ecosystems. Human activity poses a much greater danger to sharks than they do to us, and it is pushing more species towards the endangered list – or extinction.

A case of mistaken identity

“Whenever I’m asked about the number of shark-related human deaths, people are surprised how few there are compared to other predators. Lions and tigers each kill about 100 people annually, hippos kill 500, crocodiles 1,000, and yearly snake-related deaths are estimated at between 20,000 and 50,000,” Cornish says.

“On average sharks kill six people annually. Not 6,000, not 600, not 60, but six. Yet shark sightings and attacks make front-page news, while deadly snake bites seldom make news headlines,” he adds.

Around 507 species of sharks are recorded, and only 11 of those are known to have ever caused human fatalities – less than 2% of the total.

“Sharks don’t deliberately attack people to eat them. Occasionally some species bite, either because they feel threatened or they’re hungry and are not sure whether humans are edible. So they bite as a way of testing,” Cornish explains.

Even when fatalities do happen, generally it’s a case of mistaken identity. Sharks very rarely eat their human prey, instead they typically swim away.

Why should I care if sharks are endangered?

With 500 plus species, sharks don’t just dwell in the ocean, they help shape it. https://www.youtube.com/embed/nic4JKD88Kg?enablejsapi=1&wmode=transparent

“The ocean’s upper surface receives the most sunlight, which enables phytoplankton – the engines of marine ecosystems – to thrive, but these shallow waters are nutrient poor,” says Cornish. “When sharks, rays and marine mammals like whales dive to feed on animals in deeper waters, they return carrying essential nutrients, which they excrete and help make shallower waters more productive.”

Creatures that perform these vertical migrations also help mix the different ocean layers, dragging up nutrient-rich water from the depths and helping to oxygenate and expand the most productive top layer.

Research shows that Tiger sharks also help mitigate climate change. Dugongs – a type of sea cow – and turtles graze on seagrass, which is more efficient at sequestering carbon than rain forests. In the absence of Tiger sharks that feed on these creatures, they overgraze, but with a shark predator around, the Dugongs and turtles don’t stay long in one place, which prevents overgrazing and promotes carbon storage.

Overfishing, overfishing, overfishing

While sharks make a significant contribution to healthy oceans, human activity is diminishing their numbers.

“There are three main threats to the planet’s shark populations: Overfishing, overfishing and overfishing. It’s estimated that around 100 million sharks are caught every year, which is a mind-boggling number,” says Cornish.

Overfishing happens at every level, from low-scale inshore fishing to industrial tuna vessels far out at sea. And it’s a myth that most sharks are caught as bycatch. Sharks are deliberately targeted, not only for their fins used in shark fin soup but also for their meat, which has increased in value recently, and their liver oil.

Research published in Nature shows oceanic shark and ray abundance has declined 71% since 1970 due to an 18-fold increase in relative fishing pressure.

More than a third of all shark and ray species could face extinction, according to the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services.

What can be done to help shark populations recover?

There are a number of measures that can help preserve shark species, many of which centre around more effective marine management.

Cornish says there are three important ways we can limit the damage of overfishing to sharks. “Firstly, to set and police catch limits for those species still caught in reasonable numbers,” he says. “Secondly, more endangered species need to be put on protected lists, but we also need to safeguard their critical habitats.

“And finally, we need to find ways that commonly-used fishing equipment can be adapted to still catch the target species, but harm fewer sharks, rays and other unintended marine life.”

What’s the World Economic Forum doing about the ocean?

Our ocean covers 70% of the world’s surface and accounts for 80% of the planet’s biodiversity. We can’t have a healthy future without a healthy ocean – but it’s more vulnerable than ever because of climate change and pollution.

Tackling the grave threats to our ocean means working with leaders across sectors, from business to government to academia.

The World Economic Forum, in collaboration with the World Resources Institute, convenes the Friends of Ocean Action, a coalition of leaders working together to protect the seas. From a programme with the Indonesian government to cut plastic waste entering the sea to a global plan to track illegal fishing, the Friends are pushing for new solutions. https://platform.twitter.com/embed/Tweet.html?dnt=false&embedId=twitter-widget-0&features=eyJ0ZndfZXhwZXJpbWVudHNfY29va2llX2V4cGlyYXRpb24iOnsiYnVja2V0IjoxMjA5NjAwLCJ2ZXJzaW9uIjpudWxsfSwidGZ3X2hvcml6b25fdHdlZXRfZW1iZWRfOTU1NSI6eyJidWNrZXQiOiJodGUiLCJ2ZXJzaW9uIjpudWxsfX0%3D&frame=false&hideCard=false&hideThread=false&id=1372898575710101506&lang=en&origin=https%3A%2F%2Fwww.weforum.org%2Fagenda%2F2021%2F07%2Fsharks-overfishing-ocean-ecosystems-endangered%2F&sessionId=f6507fb508286e2bcfca07d3547bc4b76febd862&theme=light&widgetsVersion=82e1070%3A1619632193066&width=550px

Climate change is an inextricable part of the threat to our oceans, with rising temperatures and acidification disrupting fragile ecosystems. The Forum runs a number of initiatives to support the shift to a low-carbon economy, including hosting the Alliance of CEO Climate Leaders, who have cut emissions in their companies by 9%.

Is your organization interested in working with the World Economic Forum? Find out more here.

Moves to incentivize the fishing industry to act could be part of the solution. The growth of shark and ray tourism – where visitors travel to see charismatic species like great whites, hammerheads and manta rays in their natural habitat – has the potential to boost local economies and provide new job opportunities for fishermen and others, for example.

A broad plan is needed to recover the planet’s shark populations. Currently, there is no international consensus on the plight of sharks and little urgency about the need to stop species from going extinct.

AI and drones protecting sharks

Conservationists in California have introduced the latest digital technology in their efforts to save the great white shark from extinction. Drones patrol popular surfing areas scanning the sea for signs of sharks that could pose a danger to humans. AI scans the drone footage to give a positive identification. The system can warn surfers of the presence of sharks – and keep the sharks safe from the frequently fatal consequences of an encounter with humans.

The project is part of the World Economic Forum’s Uplink initiative which connects entrepreneurs with experts and investors looking to scale up solutions to help meet the UN’s Sustainable Development Goals. Goal 14 aims to protect life below water and preserve the health of ocean ecosystems.

What can I do to get involved?

Organizations that support and protect sharks like the World Wildlife Fund, welcome support for their work from people like you.

“Try to educate yourself about the issues, get involved and let your voice be heard,” Cornish advises. “Governments typically don’t prioritize issues unless they feel a significant number of people care about them. So it’s important that people speak up about sharks.”

“The vast majority of shark products are from fisheries that are not sustainable and the products are not traceable. Say no to shark products. Don’t buy fins or shark meat, but also boycott health supplements containing squalene – a compound found in shark liver oil – or sharks’ teeth sold as holiday souvenirs in some countries,” he adds.

We can all play our part in protecting sharks so they continue to thrive for another 400 million years.