Mostly from overfishingA new study by the Shark Specialist Group at the International Union for Conservation of Nature (IUCN) provides yet more evidence to support the urgency behind ocean conservation efforts.
"Over two decades, the authors applied the IUCN’s Red List categories and criteria to the 1,041 species at 17 workshops involving more than 300 experts. They incorporated all available information on distribution, catch, abundance, population trends, habitat use, life histories, threats and conservation measures. [...] Previous studies have documented local overfishing of some populations of sharks and rays. But this is the first one to survey their status through out coastal seas and oceans. It reveals that one-quarter (249) of 1,041 known shark, ray and chimaera species globally fall under three threatened categories on the IUCN Red List."
One-in-four. 25% That's horrible! Species that have thrived for hundreds of millions of years - almost living fossils - facing oblivion, for what? Soup?
There were 107 species of rays and 74 species of sharks that could be classified as threatened, but just 23% of species fit in the 'Least Concern' category based on the IUCN criteria.
“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,” says Nick Dulvy, a Simon Fraser University (SFU) Canada Research Chair in Marine Biodiversity and Conservation in British Columbia. “There are no real sanctuaries for sharks where they are safe from overfishing. In the most peril are the largest species of rays and sharks, especially those living in relatively shallow water that is accessible to fisheries. The combined effects of overexploitation—especially for the lucrative shark fin soup market—and habit degradation are most severe for the 90 species found in freshwater."