First ever global survey of reef sharks reveals widespread decline

Results shows reef sharks are functionally extinct on many coral reefs, but Australian populations are among the healthiest.

A landmark new study published today in Nature by Global FinPrint reveals sharks are virtually absent on many of the world’s coral reefs. Sharks were not observed on nearly 20 percent of the 371 reefs surveyed in 58 countries, indicating a widespread decline that has largely gone undocumented until this global survey.

Fortunately, Australia is a country where shark populations on coral reefs are still largely intact. The most common shark species observed were grey reef, whitetip reef and blacktip reef sharks.

Dr Mark Meekan, from the Australian Institute of Marine Science in Perth and Principal Investigator for the Global FinPrint project in the Indian Ocean region said good management plays a key role in determining the status of reef sharks.

“Our survey not only reveals the plight of sharks on coral reefs, which is in many cases very worrying, it also reveals how control of shark fishing can make effective conservation gains,” Dr Meekan said.

Australia was one of several nations where the study revealed that shark conservation on coral reefs is working. Other nations include the Bahamas, the Federated States of Micronesia, French Polynesia, the Maldives, and the United States.

Dr Meekan said reef sharks play an important role maintaining a healthy ecosystem.

“Sharks are important for the ecology of coral reefs, particularly at a time when they are facing so many other threats from climate change. But few people realise that reef sharks are also an important part of the economies of many small island nations around the world because they are a key attraction for reef tourism.

“Rebuilding shark numbers isn’t just good sense ecologically – it also makes good sense economically,” Dr Meekan said.

AIMS scientist Dr Michelle Heupel, and Global FinPrint Principal Investigator in the Western Pacific, said this world first study relied on cooperation and collaboration of colleagues in many nations and territories across the globe.

“Hundreds of scientists, researchers, and conservationists captured and analysed more than 15,000 hours of video from surveys of 371 reefs in 58 countries, states and territories around the world over four years.

“We hope these findings will help countries continue to maintain shark populations or make management changes to improve their status,” she said.

Funded by the Paul G. Allen Family Foundation, the Global FinPrint’s survey data were generated from baited remote underwater video systems (BRUVS) consisting of an underwater video camera attached to a bait bag containing a small amount of fish. Coral reef ecosystems were surveyed with BRUVS in four key geographic regions: The Indo-Pacific, Pacific, the Western Atlantic and the Western Indian Ocean.

As well as AIMS, other coordinating organisations working on the project came from Florida International University, Curtin University, Dalhousie University, and James Cook University.

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