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Where there are groups of seals, there are sharks. Massachusetts Office of Energy and Environment, CC BY-NC

White shark populations are growing. Here’s why that’s good news

When bald eagle populations rebounded, people rejoiced. When alligators came back from the brink of extinction, most of us agreed it was a good thing. But tell people how happy you are that the great white shark population is on the rise, and you won’t find many who will join in the celebration.

It’s understandable. We have an inherent and sensible fear of predators that can eat us as we enjoy a summer swim, and the recent attacks by other shark species in the Carolinas have been frightening and traumatic. And many people this week have watched the video of a professional surfer fend off an attack from a white shark. But in the balance, healthy shark populations are part of a healthy ocean, and we depend on a healthy ocean for our very lives.

Pro surfer Mick Fanning escapes a shark encounter earlier this week.

The world’s oceans provide humankind with critical sources of food. They help regulate the Earth’s climate and remove carbon dioxide from the atmosphere. Even those of us who live thousands of miles from the coast are very much in the oceans’ debt for many of the comforts and conveniences of our existence.

Sharks – occupying the top of the marine food chain as they do – are a visible sign of the how our seas are faring. We don’t know what would happen to the oceans without them, but we know this: removing apex predators – or any species – from the web of life can have consequences that are just as problematic for people as the “problem” species was.

Sharks on rebound

Like it or not, sharks are part of a balanced ocean ecosystem. After a decline of up to 90% for some species in the United States, they are beginning a gradual rise toward the numbers of a century ago.

That suggests some of the damage we’ve done to the oceans has been reversed, and that’s something to celebrate.

I have no wish to minimize or make light of the trauma suffered by shark-attack victims and their families, which includes eight people in North Carolina this year. Quite the reverse: I hope civic leaders and beachgoers will take these events seriously, because they’re going to happen more often.

The Atlantic White Shark Conservancy tags sharks off the coast of Cape Cod last summer.

It won’t be a rapid change. Sharks take eight or more years to reach reproductive age, and their gestation periods can be as long as 18 months, with a year or two between pregnancies, so we won’t be seeing a shark baby boom.

If it seems that they’re turning up in ever greater numbers, it’s because incidents are more visible now: there are more of us and we’re all ready with our smartphones, capturing and sharing footage whenever someone yells “Shark!”

While the white shark population rise won’t be rapid, it will be noticeable. These will be numbers few of us have seen in our lifetimes.

We can trace it back to another success story. With the passage of the Marine Mammal Protection Act in 1972, seal and sea lion populations began to rebuild along the West Coast. White sharks eat seals and sea lions, and having more of their favorite food available enabled them to make a comeback, too.

Now we’re seeing seals returning to parts of the Northeast where they haven’t been for nearly a century. We can expect that white sharks won’t be far behind.

Learning how to coexist

As seals and sharks return to their former numbers and territories, we will need to make adjustments.

We have protected these animals from being killed, but now we have to relearn how to live alongside them. Marine mammals will reclaim beaches that we’ve become accustomed to using, and sharks will follow to prey on them.

Because these changes will happen gradually, there’s no need to be caught unaware. We know it’s going to happen; we need to start planning how we’re going to deal with this at a community and personal level.

We can take steps to coexist safely with sharks. Additional beach safety personnel can help spot sharks near swimming areas. Guidelines about swimming a safe distance from seal colonies and fishing areas where sharks may be found could help.

There’s even talk of deploying drones to keep a lookout for sharks. We also need to be prepared to cede some beaches back to the species that once dominated them.

Beachgoers keep a white shark on Cape Cod alive before it’s captured and put back into the ocean.

Changes in our behavior will help, but a change in our mindset is also in order. We’re going to have to accept that when we swim in the ocean, we enter a world that is not our own, one where we have no guarantee of safety. We already know there’s a risk of drowning, even for strong swimmers, and we accept this risk when we go into the ocean. The risk of shark attack is – and will remain – much lower.

There is, in fact, some evidence that attitudes are starting to change. Earlier this month, beachgoers in Cape Cod kept a beached white shark alive long enough for volunteers and researchers to release it back into the sea, whereas in previous years it might have been deliberately killed or left to die.

Education and warnings, such as this one in California, can help. Gino Zahnd/flickr, CC BY-NC-ND

A growing white shark population is a success story where few are found. It’s like money in the bank for a sound ecosystem. For decades, most of us didn’t give sharks a second thought, but now we will have to. That’s part of the give-and-take in any relationship.

Think of it as a compromise that keeps the marriage between us and the natural world going.

If we can make some adjustments in our thinking and behavior, we can minimize conflicts between sharks and people. They may be the ones blessed with the teeth, but we’re the ones blessed with the brains.

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