A new study indicates that sharks are no longer present on reefs on multiple continents.
New research published in the journal Nature indicates that sharks are no longer being seen on reefs in six territories around the world – a sign of loss of ecological balance in these regions.
Conducted by a team from the Global FinPrint project, which brings together more than 120 researchers from different countries, the study sought to fill a gap in the knowledge about shark populations on Earth.
Because much of what is known about the conservation status of these animals is based on numbers from industrial fishing, the researchers investigated coastal areas, which include reef ecosystems.
The researchers installed more than 15,000 underwater cameras on 371 reefs in 58 territories to estimate the conservation status of sharks around the world.
They analyzed more than 18,000 hours of video over three years, and ended up realizing that almost no sharks were seen in 69 of the monitored reefs in six territories: Dominican Republic, French West Indies, Kenya, Vietnam, Netherlands Antilles, and Qatar.
“In these countries, only three sharks were observed during more than 800 survey hours,” said Colin Simpfendorfer, a marine biologist at James Cook University in Australia and a co-author of the study, in a statement.
However, the findings do not mean that sharks will never appear in these areas. “What it does mean is that they are ‘functionally extinct’ – they are not playing their normal role in the ecosystem,” Simpfendorfer explained.
Since they are natural predators of several marine species, sharks are essential to control animal populations in the oceans. Its absence implies a serious ecological imbalance.
Demian Chapman, a professor in the Department of Biological Sciences and Institute of Environment at Florida International University in the United States, and one of the researchers who lead Global FinPrint, believes that the cause of the disappearance of sharks on many reefs is the combination of high human population density, destructive fishing, and poor governance. But, according to him, this situation can be changed.
“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,” Chapman said.
According to the researchers, Australia, the Federated States of Micronesia and the United States are among the countries that have adopted good measures to protect shark populations, such as the ban on hunting. There may still be hope for places where sharks are disappearing.
“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,” said Jody Allen, co-founder of the Paul G. Allen Family Foundation, which supports the Global FinPrint project.