Reef sharks are threatened with extinction worldwide due to overfishing, according to a study published on Thursday that highlights previously underestimated risks to these sharks, AFP reported.

Blue sharkPhoto: www.greatwhitesean.com / CATERS NEWS / Caters News / Profimedia

The authors of the study say that such an extinction would have a major impact on humans because of the role the species plays in regulating marine ecosystems. Reef sharks maintain a delicate balance in the food chain that millions of people depend on.

The research, published in the journal Science, is the result of a worldwide collaboration that began in 2015 as part of the Global FinPrint project, which collected more than 22,000 hours of video footage of reefs in Africa, the Middle East, Asia, Oceania and the Americas.

Using a computer model, a team of about a hundred scientists from around the world estimated that populations of the five most common reef shark species were 60 to 70 percent lower than they would be in the absence of external human pressure.

In addition, sharks were absent from 14% of reefs where they were previously observed.

Lead researcher Colin Simfendorfer of James Cook University and the University of Tasmania in Australia explained to AFP that prior to this study, there had been little concern about the fate of the reef shark, unlike that of its older cousins.

“But when we sat down and looked at the overall results, it was pretty impressive,” the scientist said.

The results of the study should help update the red list of the International Union for Conservation of Nature (IUCN) in the next year or two. Therefore, the new species should be classified as “endangered”, which is an important step to take measures to protect them.

According to Colin Simfendorfer, the main reason for this decline is overfishing, which targets both sharks for fins and meat, as well as bycatch.

In terms of impact, the loss of these sharks will have a ripple effect through the food chain. The number of predators they feed on will increase, but the next level will decrease, and so on, causing unpredictable disruptions that will threaten global food security.