Oceanic sharks and rays have declined by over 70%
|"Great Hammerhead Shark Swimming" by Skylar L. Primm|
The risk of extinction to marine species is primarily caused by overfishing, but it has been difficult to measure the decline of individual species. Although reductions in oceanic and coastal shark and ray populations in different regions of the world have previously been documented, a global analysis has not been available.
|The Whitetip reef shark (Triaenodon obesus).Photo by Jan Derk|