Download 25 Percent Of Sharks And Rays Risk Extinction

Ancient And Vulnerable: 25 Percent Of
Sharks And Rays Risk Extinction
There are more than a thousand species of sharks and rays in the world, and nearly a
quarter of them are threatened with extinction, according to a new study. That means
these ancient types of fish are among the most endangered animals in the world.
This word comes from a Swiss-based group called the International Union for the
Conservation of Nature (IUCN), which maintains the so-called Red List of species threatened
with extinction.
The group has been worried about sharks, rays and related species for more than 20 years.
IUCN scientists have finally calculated the risk to these species and published their results in
the online journal eLife.
"It's quite bad, I'm sorry to say," says Sonja Fordham, who helps run the IUCN shark
assessment.
It's not news that many species of shark are in trouble. But the 25 percent risk of extinction
is a surprisingly large number, Fordham says, adding that "the rays are actually worse off
than the sharks."
A smalltooth sawfish at the Sydney Aquarium, Darling Harbour, Sydney, Australia.
Holiday Point/Flickr
Rays include mantas and skates, but also fish that look more like sharks — such as the
sawfish, which has a snout shaped like a double-sided saw.
Fordham, who is president of Shark Advocates International, says sawfish are the most
endangered of all. Some 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.
"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 sharklike rays — species like
sawfishes and wedgefishes and guitarfishes," Fordham says.
Rays also are often inadvertently snagged as bycatch. The common skate, for instance, is
(ironically, considering it's name) now extinct in some European waters — wiped out by
fishermen angling for other species.
When Fordham and her colleagues dug into the data from catch reports from various
fisheries, they discovered that more rays have been fished out of the water than sharks,
though rays don't get as much attention.
"They tend to be a little underappreciated," Fordham says.
The scale of the problem is breathtaking to Boris Worm, who was not involved in the IUCN
study. He's a marine ecologist at Dalhousie University in Halifax, Nova Scotia, and a leading
shark researcher.
A fisherman shoves overboard bycatch — mostly little skate, American lobster and yellowtail flounder —
along New England's Stellwagen Bank.
"It's shocking to me," Worm says, that 25 percent of sharks and rays are endangered.
Information about these species has been hard to come by, he says, though he and others
have been scouring global fishing records to get a sense of the problem's magnitude.
"We estimated that globally we are catching at least 100 million sharks a year," he says.
"That's 11,000 each hour, every day, 365 days a year. So that's a lot of sharks."
Worm estimates that each year, overall, 6 to 8 percent of the global population of sharks
and rays gets caught. And the fish simply can't reproduce fast enough to keep pace.
These species evolved before the dinosaurs were on Earth, 400 million years ago. "They're
like a version 1.0 model of a fish, if you will," Worm says. "They grow very slowly and the
populations are depleted very quickly."
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 headed toward oblivion.