Sydney: In a massive global study of the world’s reefs, scientists have found that ocean’s top predator sharks are ‘functionally extinct’ on nearly one in five of the reefs surveyed.
For the study, published in the journal Nature, the research team from James Cook University (JCU) in Australia surveyed 371 reefs in 58 countries.
The researchers found that sharks were rarely seen on close to 20 per cent of those reefs.
“This doesn’t mean there are never any sharks on these reefs, but what it does mean is that they are ‘functionally extinct’ – they are not playing their normal role in the ecosystem,” said study researcher Colin Simpfendorfer from JCU.
The findings showed that almost no sharks were detected on any of the 69 reefs of six nations: the Dominican Republic, the French West Indies, Kenya, Vietnam, the Windward Dutch Antilles, and Qatar.
“In these countries, only three sharks were observed during more than 800 survey hours,” said Simpfendorfer added.
According to the research team, it’s clear the central problem is the intersection between high human population densities, destructive fishing practices, and poor governance.
“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,” said study co-author Dr. Demian Chapman from the Florida International University.
The research team said it was encouraging that Australia was among the best nations at protecting shark populations and ensuring they played their proper role in the environment.
“We’re up there along with such nations as the Federated States of Micronesia, French Polynesia, and the US,” Chapman said.
“These nations reflect key attributes that were found to be associated with higher populations of sharks: being generally well-governed, and either banning all shark fishing or having strong, science-based management limiting how many sharks can be caught,” he added.
Jody Allen, said the study is part of a project called Global FinePrint and the results exposed a tragic loss of sharks from many of the world’s reefs but also gave some hope.
“The data collected from the first-ever worldwide survey of sharks on coral reefs can guide meaningful, long-term conservation plans for protecting the reef sharks that remain,” she said.