Sharks are top predators of the ocean, but they are struggling hard to survive. Human greed causes 100 to 150 millions of them to die every year, according to the World Wide Fund for Nature (WWF) and Sharkproject International, a global initiative working on shark and marine protection.

These fearsome animals take many years to mature and don't reproduce often. This had never been a problem for them - until human beings' demand for their body parts skyrocketed. Some sharks get their fins cut off for an expensive Asian soup, while others are killed for their meat. More and more often, sharks also die as bycatch. The population cannot recover at the same rate as it declines.

Scientists and conservationists want to help, but facts and data are hard to come by.

To tackle that issue, the Global FinPrint project has emerged, aiming to shed some light on our massive, mysterious oceans. Researchers from an international team have mounted cameras which are called baited remote underwater videos (BRUV) on over four-hundred reefs worldwide, particularly in regions where little is known about shark populations, like the Indo-Pacific, the tropical western Atlantic, the waters off the coast of southern and eastern Africa and around some Indian Ocean Islands.

By 2018, the world should be able to know more about how many and what kinds of sharks there are, as well as their role in coral reef ecosystems.

Similar projects at a local scale have been carried out before, but this project, which has been launched in June 2015, is the first-ever attempt at a "global shark census."

Project remains controversial

The data will help conservation actions, the project promises. BRUVs should be a reliable, time- and cost-effective method for studying underwater species.

Project leader Demian Chapman of Stony Brook University of New York told AFP that Global FinPrint "will help us better understand one of ocean's great mysteries," namely, what will happen to the marine ecosystems when sharks are removed.

The idea has even convinced Vulcan Inc., Microsoft co-founder Paul. G. Allen's company, to fund the project with a total of four million dollars.

Despite the support the project has received so far, some experts are criticizing its feasibility, since baits on the sites have to be refilled on a daily basis, while camera batteries have to be changed regularly.

"The effort required is immense," says Gerhard Wegner, president of Sharkproject International. "However, we are just going to get a small part of the larger picture."

"One can identify sharks based on their dorsal fins, but it requires a very comprehensive database," he adds. "Besides, we don't even know if the underwater cameras will always be able to take snaps of the fins."

"It is just in my and some of my colleagues' opinion a little like blowing the research funds."

Shark matters

But Wegner agrees that actions have to be taken against the population's decline. As a top predator, sharks play a key row in maintaining the food chain by eating other predators and sea creatures, preventing them from over-flourishing. By taking away the top predators, humans are changing the ecosystem.

"It leads to the result that fish almost do not exist in many areas anymore. Instead of that, we have plenty of jelly fish," says Wagner. "There are so many that we can even see them from space, since there were no sharks to eat them up.

"We are in the middle of the process. Experts estimate that if we continue to treat the ocean in the way we do now, it will be dead in no later than 50 years' time."

"The only way to protect sharks is not banning the catch, but setting up the monitoring of marine sanctuaries."