Shark dive at dive site known a "Tiki", features Gray reef sharks (Carcharhinus amblyrhynchos), highlighted by streaks of sunlight.  These majestic animals are frequent visitors to the reefs of Moorea.

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Shark dive at dive site known a "Tiki", features Gray reef sharks (Carcharhinus amblyrhynchos), highlighted by streaks of sunlight. These majestic animals are frequent visitors to the reefs of Moorea.

Photo by: Stephen Frink

Stephen Frink

Sharks are Nearly Extinct in the World's Reefs

By: Lucy Sherriff

Sharks are “too rare to fulfill their normal role in the ecosystem” according to a new study, and have become “functionally extinct” in one of five of the world’s coral reefs.

August 19, 2020

The study, conducted by Global FinPrint and published in the scientific journal Nature, surveyed 371 reefs in 58 countries.

Sharks were not found on 19% of the reefs, which indicated a “widespread decline that has gone undocumented on this scale until now”, Global FinPrint, a collaboration started by marine biologists Mike Heithaus and Demian Chapman, said.

Global Check-Up

The Dominican Republic, Kenya, Vietnam, Qatar, and the French West Indies are just some of the regions that are essentially devoid of sharks. In 800 hours of observing those nations, just three sharks were spotted.

The group focused on reef sharks, because they are easier to spot than the species in the high seas.

Humpback snapper (Lutjanus gibbus) break formation to make way for a Silvertip shark (Carcharhinus albimarginatus).

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Humpback snapper (Lutjanus gibbus) break formation to make way for a Silvertip shark (Carcharhinus albimarginatus).

Photo by: Stephen Frink

Stephen Frink

Destructive fishing practices, as a result of dense populations and poor management, were attributed to being one of the main factors involved in species loss.

"Although our study shows substantial negative human impacts on reef shark populations, it's clear the central problem exists in the intersection between high human population densities, destructive fishing practices, and poor governance," according to Demian Chapman, Global FinPrint co-lead and associate professor in the Department of Biological Sciences and Institute of Environment at Florida International University. "We found that robust shark populations can exist alongside people when those people have the will, the means, and a plan to take conservation action."

The research started in 2015, using underwater video cameras strapped to 1.5-meter-long poles, which had been baited and placed in reef ecosystems across the Western Atlantic, Western Indian Ocean, Indo-Pacific, and Pacific regions.

The Proof is in The Pictures

More than 15,000 hours of video footage was captured over the study period, which lasted for four years. More than 700 students helped out review the footage but Heithaus’ mother studied the most - 1,721 hours worth.

"These nations are seeing more sharks in their waters because they have demonstrated good governance on this issue," Aaron MacNeil, lead author of the Global FinPrint study and associate professor at Dalhousie University, said. "From restricting certain gear types and setting catch limits, to national-scale bans on catches and trade, we now have a clear picture of what can be done to limit catches of reef sharks throughout the tropics."

More About Sharks

There's Still A Lot You Don't Know About Sharks 12 Videos

From fintastic facts to jawsome discoveries, this is everything you need to know about the apex predators you know and love, sharks.

This is What is Killing Sharks

Despite sharks sitting at the top of their food chain as an apex predator, they are an endangered species as a result of human activities.

Sharks are especially vulnerable to overfishing as they grow so gradually and don’t have many offspring, and demand for shark fins has grown.

“This study is a tour de force,” Nick Dulvy, a conservation biologist at Simon Fraser University, told Science.

“We really need to substantively move toward conservation and recovery in the next decade, or else we’re going to be in real trouble.”

Next Up

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Shark Week: The Podcast - How Many Sharks Are Yet to Be Discovered?

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Shark Week: The Podcast - Undiscovered Sharks and the State of the Ocean

Luke Tipple invites “The Lost Shark Guy,” Dr. Dave Ebert, who is personally responsible for finding dozens of shark species that were either previously unknown to science or thought to be extinct. He and Luke discuss why shark populations are a direct indicator of how healthy the ocean is, how to find undiscovered sharks, and why diversity in sharks is essential for marine life.

Shark Week: The Podcast - How To Have A Career in Shark Science

Shark Week’s Luke Tipple tackles the question “How can I work with sharks?” alongside two experts in the field – and their answers are not always the obvious ones. Luke is joined first by Kelly Link, Associate Curator of the Georgia Aquarium who talks about what it’s like to be an aquarist, how it differs from field work, and how to get yourself noticed. The second guest is Dr. Neil Hammerschlag who goes into detail on what it takes to become a prominent scientist, and what other paths you can take if a PhD isn’t for you. And at the end, researcher Sierra stops by to tell us about the world’s smallest shark.

Shark Week: The Podcast - Why is Tagging Baby Great White Sharks So Important?

Luke Tipple speaks with Dr. Riley Elliott, a marine biologist from New Zealand who recently tagged baby great white sharks, which are rarely seen in the wild. They talk about how climate change is affecting shark pupping grounds, why fishers are wrong to think there are “too many sharks,” and about Dr. Elliott’s Great White App, which allows users to track great white sharks in the ocean.

Shark Week: The Podcast - Superstar Kesha Lifts the Gag Order on Saving Sharks

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