First we heard that elephants could be gone within 12 years. Then we learned the Western Black Rhino has been declared extinct. And now here’s some more disheartening news: within decades a quarter of the world’s sharks and rays could be gone.
The saga of a world that will be far different future generations continues:
A quarter of the world’s sharks and rays are probably threatened with extinction, according to the most extensive assessment of the marine species.
Thresher sharks, sawfishes and angel sharks are the most threatened families, according to a study by the International Union for the Conservation of Nature, which publishes the Red List of endangered species. A total of 25 species had the highest risk level and were deemed “critically endangered.”
“Our analysis shows that sharks and their relatives are facing an alarmingly elevated risk of extinction,” Nick Dulvy, a researcher at Simon Fraser University in British Columbia, Canada, and co-chair of the IUCN’s Shark Specialist Group, said in an e-mailed statement. “In greatest peril are the largest species of rays and sharks, especially those living in shallow water that is accessible to fisheries.”
The main culprit? You guessed it: mankind:
Overfishing is the main threat faced by the species, with much of the sharks and rays caught unintentionally, according to the union. Intentional killing of the creatures due to the perceived danger they bring, and the global market for shark fins used in soup are other factors, it said.
The researchers examined 1,041 species of rays, sharks and so called chimera that are closely-related. They determined 25 are critically endangered, 43 are endangered and 113 are vulnerable to extinction. Almost half of the species — 487 — had insufficient data to determine a category.
By applying the findings for the data-sufficient fish to the less-studied ones, the researchers said that 249 species, or 24 percent of the total, are likely to be threatened in one form or another.
So it’s another case of something that could be preventable:
Previous studies have documented local overfishing of some populations of sharks and rays. But this is the first 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.
“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 Dulvy. “There are no real sanctuaries for sharks where they are safe from overfishing.”
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.
Sharks and rays are at substantially higher risk of extinction than many other animals and have the lowest percentage of species considered safe. Using the IUCN Red List, the authors classified 107 species of rays (including skates) and 74 species of sharks as threatened. Just 23 percent of species were labeled as being Least Concern.
Will they be with us throughout the 21st century — or be gone by the 22nd?
graphics via shutterstock.com
Joe Gandelman is a former fulltime journalist who freelanced in India, Spain, Bangladesh and Cypress writing for publications such as the Christian Science Monitor and Newsweek. He also did radio reports from Madrid for NPR’s All Things Considered. He has worked on two U.S. newspapers and quit the news biz in 1990 to go into entertainment. He also has written for The Week and several online publications, did a column for Cagle Cartoons Syndicate and has appeared on CNN.