One in seven deepwater sharks and rays at risk of extinction

A Bluntnose Sixgill Shark (Hexanchus griseus) off Puget Sound, United States. Photo by Greg Amptman. One in seven species of deepwater sharks and rays are threatened with extinction due to overfishing, according to a new eight-year study released today in the journal Science . Specifically, the analysis found that sharks and rays are caught as incidental bycatch in fisheries targeting more commercially valuable species. However, they are kept due to the value of their oil and meat. This, partnered with a recent global expansion in the trade of shark liver oil, have resulted in steep population declines. "About half of the world's sharks are found below 200 metres, below where the sunlight reaches into the ocean," says Nicholas Dulvy, Distinguished SFU Professor of Marine Biodiversity and Conservation.