Shark Week: Why we have to save the ocean’s greatest predators

Melissa Cristina Márquez

What comes to mind when you think of sharks? Is it shark attacks? The thriller film, Jaws? If your answer is yes, think again. In honor of the 34th annual Shark Week, find out how top predators are critical to ocean survival and why these majestic creatures are in need of our protection.

Image © Andy Mann

Melissa Cristina Márquez

Image © Andy Mann

Just because you’re one of the most imposing creatures in the ocean doesn’t mean life is easy for you.

In the vast, interconnected food chain of approximately 300,000 marine species we have discovered so far, the apex predators, also known as “top predators,” are some of those most in need of our help today.

These animals are larger and faster than most of their competition, with few, if any, daring to call them prey, and they include the likes of sharks, orcas, polar bears, leopard seals, and sea lions. Orcas are arguably the ocean’s ultimate predator, hunting everything from great white sharks to other whales. Recently, a pod of orcas was even seen working together to capture an adult blue whale, a species that is up to 100 feet (30 meters) long.

Among the mightiest and, I would argue, the most charismatic animals on Earth, the ocean’s greatest predators fascinate and inspire, and are a quintessential representation of biodiversity. Yet being at the pinnacle of the food chain is no guarantee of survival.

Orcas · Pixaterra Photography

What, or who, threatens these top predators?

You might have already guessed: it’s us. Habitat destruction, declining prey populations, pollution, and climate change have combined to inflict great losses on these species. Not only are many of these mighty animals susceptible to human impacts, but their young can also take decades to mature, making their populations slow to recover and therefore vulnerable to continued exploitation despite their high-ranking ecosystem status — male white sharks only reach maturity at 26 years, and the females aren’t ready to carry pups until they are even older at 33 years old.

Climate change and its worrying effects on predator populations are only just beginning to be explored. Just last month, in a first-of-its-kind study, scientists found that little bull shark pups, known for head-butting prey with their blunt snouts before devouring it, rely heavily on nutrients from the green-blue water of salt marsh to survive and thrive. Salt marsh is a type of coastal wetland in grave danger from the climate crisis and estimates show that we’ve already lost 50% worldwide, as people have “reclaimed” these ecosystems for agriculture or coastal development. As a result, these pudgy little bull sharks are facing shrunken and impacted habitats during their formative years.

Despite their ecological, economic, and cultural significance, predators are among the most heavily persecuted animals on the planet, due to conflict with humans and their assets. Overfishing in the past 50 years has led to the high likelihood that some shark species could disappear from the ocean altogether; their populations fell sharply by over 70% from 1970 to 2018.

Bull shark at Pinnacles reef, Mozambique · Fiona Ayerst

A perfect match between predator and ecosystem

While the motivation to remove the ocean’s predators is easy to understand — they hunt economically important prey, can kill or injure people, and are generally perceived as a threat to human safety — we often forget that these animals provide fundamental ecosystem services such as disease regulation, biodiversity maintenance, and carbon capture and storage. Research indicates that our inability to live alongside these predators is not only putting their survival at risk but also doing untold damage to the environment.

For example, exploding populations of herbivorous marine animals that graze on algae or seagrass meadows can drastically reduce seagrasses’ remarkable ability to store carbon. As predators, sharks have the power to limit unsustainable growth of these grazing populations, thus allowing ecosystems such as seagrass beds to grow and flourish. Through modifying the habitats of these ocean predators or outright killing them, we are greatly compromising the ecosystems that they help to keep in balance. In turn, this is causing problems that have severe consequences for humans and other marine life, such as fewer healthy fish populations and a reduction in the ocean’s ability to absorb carbon and fight climate change. 

The question many people are asking is how can we act now to save these predators?

Leopard seal in Antarctica · Stanislav Photography

It’s up to us

Human tolerance of these species is the major issue. Most would now agree that ocean predators have an intrinsic right to exist and that instead of killing them, we should take steps to reduce human-wildlife conflict and coexist. So what does this look like?

Interventions that champion living with these animals and lead to sustainable management include non-lethal predator removal or relocation — for example, using acoustic deterrent devices to keep ocean predators away from people’s homes or economically important prey. This year researchers tracked the movements of three shark species near the U.S. city of Miami and discovered that, contrary to predictions, sharks were often to be found exploring nearby urban coastlines. While it’s rare for sharks to attack humans, more detailed zoning of areas close to the shore, to better reflect sharks’ range, could reduce the chances of a negative encounter for swimmers and other water users and promote human-shark coexistence. And together, we can call on governments to end the unsustainable fishing policies and cruel hunting practices that are responsible for the continued persecution and eradication of predators from our planet.

As a marine biologist who works with sharks and other oceanic predators, I haven’t emerged from my dives unscathed: I was once bitten by a saltwater crocodile. Yet I want to share a positive message of how we can all change the narrative and help conserve these beautiful and important creatures. While some may still believe the world is a scary place with a bunch of predators running around, trust me... the world would be even scarier without these predators.

Polar bear in the Arctic Ocean, Svalbard · Andy Mann

How you can help

1

Sign and share petitions urging world leaders to take action to save the ocean’s predators. More than 160,000 people have signed petitions here on Only One to protect sharks in New Zealand and Costa Rica, and we need your help to keep building momentum.

2

Support nonprofit organizations that protect wildlife in the ocean. Through a monthly subscription to Only One, you can grow your own ocean forests and reefs, helping to save the countless creatures that call these habitats home. In just one month, you can plant up to 100 mangrove trees and 6 super corals at our planting sites around the world.

3

When you hear someone say that the ocean’s predators are nothing more than killing machines, if you feel comfortable to do so, why not share the knowledge you’ve gained from this article and encourage them to challenge their perception? Spreading awareness is a powerful way to create ripples of change!

Contributors
Melissa Cristina Márquez
Marine Biologist & Conservationist
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