RENEE MONTAGNE, HOST:
A change in subject now: Let's talk sharks, the kind in the sea. Of the thousand-plus species of sharks and rays in the world, a new study finds nearly a quarter are threatened with extinction, making these ancient fish among the most endangered animals in the world. NPR's Richard Harris reports on the latest assessment of these feared, yet vulnerable creatures.
RICHARD HARRIS, BYLINE: A group called the International Union for the Conservation of Nature maintains the so-called Red List of species threatened with extinction. They've been worried about sharks, rays and related species for more than 20 years. And the IUCN has finally totaled up the risk to these species, and published the results in the online journal eLife.
SONJA FORDHAM: It's quite bad, I'm sorry to say.
HARRIS: Sonja Fordham, who helps run the assessment, says it's not news that a lot of shark species were in trouble, but 25 percent of species at risk of extinction? That's a big number.
FORDHAM: And of those, the rays are actually worse off than the sharks.
HARRIS: Rays include mantas and skates, but also fish that look more like sharks, such as the sawfish, with a snout that looks like a double-sided saw.
FORDHAM: So, the sawfishes are the most endangered of the group, by far.
HARRIS: Fordham, who is president of Shark Advocates International, says some sawfish populations have already been driven to extinction. They're critically endangered elsewhere because they live along fragile coastlines, and because they're a prize catch for the Asian market.
FORDHAM: People know about the global trade in shark fins, but few know that some of the most valuable fins that are used in shark fin soup come from the shark-like rays, species like sawfishes and wedgefishes and guitarfishes.
HARRIS: Rays are also often snagged by fishermen actually trying to catch other species. For instance, the ironically named common skate is now extinct in some European waters because it was wiped out by fishermen angling for other species. When Fordham and her colleagues dug into the fisheries' catch data, they discovered that more rays had been fished out of the water than sharks.
FORDHAM: They're also not getting much conservation attention. They tend to be a little underappreciated.
HARRIS: The scale of the problem is breathtaking to Boris Worm, who was not involved in the IUCN study, but who has been studying the plight of sharks and related species at Dalhousie University in Canada.
BORIS WORM: It's shocking to me, one in four sharks and rays.
HARRIS: One reason he's surprised is information about these species is often hard to come by. Worm's group has been scouring global fishing records to get a sense of the magnitude of the problem.
WORM: We estimated that, globally, we're catching at least 100 million sharks a year. That's 11,000 each hour, every day, 365 days a year. So that's a lot of sharks.
HARRIS: Overall, he estimates that 6 to 8 percent of the global population of sharks and rays gets caught each year. And they simply can't reproduce fast enough to keep pace. These species evolved before the dinosaurs were on Earth 400 million years ago.
WORM: And they're like a, you know, version-one model of a fish, if you will. So, they have an extremely slow life history. They grow very slowly, and their populations are depleted very quickly.
HARRIS: The good news is that there are a few conservation success stories for certain species of sharks. Sonja Fordham says the challenge now is to spread those practices around the world and to include many more species that are currently heading toward oblivion. Richard Harris, NPR News.