This Study Says Sharks Are 'Functionally Extinct' In 20% Of The World's Coral Reefs

Bad news just keeps on coming. Who knows where the stop button is? Because this feels like somebody pressed the 'Ruin Planet Earth' button and then locked it and threw the key away.

This time, the concern is sharks. According to a new global study authored by a Dalhousie University professor, sharks are 'functionally extinct' in nearly 20 per cent of the world's coral reefs. This has raised many concerns about what it might mean for the coastal ecosystems which are an integral part of this planet.

"That was surprising. We expect, as a condition without humans, that there should be sharks on every reef in the world. To find 20 per cent of the reefs that we surveyed didn't have sharks is very concerning", said Aaron MacNeil, the lead author of the study, which was published Wednesday in the journal Nature.

Also read: Believe It Or Not, This Shark Took Down A Whale About Thrice Its Size

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MacNeil is a biology professor at Dalhousie University, and said that the study was inspired by initial research from Ransom Myers and Julia Baum at Dalhousie about 20 years ago. Their work showed a decline in open-ocean shark populations.

Ever since then, not much research was done on the same in other regions until now. The first of its kind global study was launched in 2015 by the Paul G. Allen Family Foundation and a team of researchers were brought in under an initiative called Global FinPrint. The team studied 371 reefs in 58 countries.

Coral reefs were monitored in the western Atlantic, the western Indian Ocean, the Indo-Pacific and the Pacific. This was done in order to determine how reef sharks impact the ecosystems.

Baited remote underwater video cameras were used by researchers to record sharks and other sea life on coral reefs. Around 30 to 100 cameras were set up on each reef which recorded one hour of footage each. More than 15,000 hours of video was captured over a period of over four years.

Also read: Strange New Species Of Sharks Discovered In Australia, Uses Fins To 'Walk'

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The research discovered that there are no sharks in reefs of the Dominican Republic, the French West Indies and Windward Dutch Antilles in the Caribbean, and in Kenya, Vietnam and Qatar.

The study said among those nations, only three reef sharks were observed during more than 800 survey hours.

"These nations are places where we're saying reef sharks are essentially functionally absent from the ecosystem. They play no role in the ecosystem and they're functionally extinct," MacNeil said.

He also said that the loss of reef sharks has been brought on by high population densities near coastal areas, lack of shark fishing regulations, and overfishing and the destructive practices that come with it.

But MacNeil said the research also identified nearly 20 nations where reef shark populations are doing well, such as in Australia, the Bahamas, French Polynesia, the Maldives and the United States.

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"Our results show that reef sharks can, under the right conditions, live alongside people and thrive just fine," said Demian Chapman, one of the lead researchers on the study.

Chapman is a biology professor at Florida International University and believes that as much these problems are brought on by people, they are also solved by them.

He said there are ways in which countries can help:

1. Establishing shark sanctuaries where commercial shark fishing and trade is banned.

2. Mandating catch limits on shark fishing so ecosystems can replenish.

3. Closing large, designated areas of water where all fishing is banned to promote ecosystem growth.

4. Prohibiting or redesigning shark fishing gillnets and longlines, which can inadvertently capture other marine life in their path.

Also read: Giant Bird Flying With Shark-Like Fish Is Making People Hunt For Answers

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He added, "The Global FinPrint results show this portfolio of approaches, and countries can actually grab from whichever ones suit best their local communities so that they can have benefits for both the reef sharks and the people that live alongside them."

He also said, "We're really, really hopeful. We're going to continue our work with governments to put these policies in place to restore and better protect reef sharks all over the world."