"We now know that many species of sharks and rays, not just the charismatic white sharks, face extinction across the ice-free seas of the world," Nick Dulvy, a Simon Fraser University (SFU) Canada Research Chair in Marine Biodiversity and Conservation, said in the news release. "There are no real sanctuaries for sharks where they are safe from overfishing."

A study involving 300 experts and taking place over 20 years took "distribution, catch, abundance, population trends, habitat use, life histories, threats and conservation measures" into account when looking at the conservation status of the species'.

One-hundred-and-seven species of rays and skates and 74 shark species were defined as "threatened." Only 23 percent of all the species studied were considered to be of "Least Concern."

The team found the regions where these species were most threatened were the Indo-Pacific, the Red Sea, and the Mediterranean.