Sharks facing extinction risk: study

Washington, February 18: Sharks might soon be seen in the official list of animals at global risk of extinction, for a new esearch has shown that they are disappearing from the world's ceans.

The study has shown that many large shark species have declined by more than 50 percent due to increased demand for shark fins and meat, recreational shark fisheries, as well as tuna and wordfish fisheries, where millions of sharks are taken as catch each year.

The World Conservation Union (IUCN) assessed the global status of the sharks.

"As a result of high and mostly unrestricted fishing pressure, any sharks are now considered to be at risk of extinction," said Julia Baum, an NSERC Postdoctoral Fellow at Scripps Institution of Oceanography and a member of the IUCN's shark specialist group.

"Of particular concern is the scalloped hammerhead shark, an iconic coastal species, which will be listed on the 2008 IUCN Red list as globally 'endangered' due to overfishing and high demand or its valuable fins in the shark fin trade," Baum added.

She further said that fishing for sharks in international waters is unrestricted, and she supports a recently adopted UN esolution calling for immediate shark catch limits as well as a meaningful ban on shark finning.The research conducted by Baum and the late Ransom Myers over the past five years, demonstrated the magnitude of shark declines in the northwest Atlantic Ocean.

All species the researchers looked at had declined by over 50 per cent since the early 1970s.

For many large coastal shark species, the declines were much greater: tiger, scalloped hammerhead, bull and dusky shark opulations have all plummeted by more than 95 per cent.

Baum will speak at the American Association for the Advancement of Science (AAAS) Annual Conference in Boston, which runs from Feb 14 to 18.

She will highlight management measures required to conserve harks at an afternoon press conference on February 17.

Scientists Find 'Devil Toad' Fossil

WASHINGTON (AP) - A frog the size of a bowling ball, with heavy armor and teeth, lived among dinosaurs millions of years ago - intimidating enough that scientists who unearthed its fossils dubbed the beast Beelzebufo, or Devil Toad.

But its size - 10 pounds and 16 inches long - isn't the only curiosity. Researchers discovered the creature's bones in Madagascar. Yet it seems to be a close relative of normal-sized frogs who today live half a world away in South America, challenging assumptions about ancient geography.

The discovery, led by paleontologist David Krause at New York's Stony Brook University, was published Monday by the journal Proceedings of the National Academy of Sciences.

``This frog, if it has the same habits as its living relatives in South America, was quite voracious,'' Krause said. ``It's even conceivable that it could have taken down some hatchling dinosaurs.''

Krause began finding fragments of abnormally large frog bones in Madagascar, off the coast of Africa, in 1993. They dated back to the late Cretaceous period, roughly 70 million years ago, in an area where Krause also was finding dinosaur and crocodile fossils. But only recently did Krause's team assemble enough frog bones to piece together what the creature would have looked like, and weighed.

The largest living frog, the Goliath frog of West Africa, can reach 7 pounds. But Krause teamed with fossil frog experts from University College London to determine that Beelzebufo isn't related to other African frogs.

It seems to be a relative of South American horned frogs, known scientifically as Ceratophrys. Popular as pets, they're sometimes called pacman frogs for their huge mouths.

Like those modern frogs, Beelzebufo had a wide mouth and powerful jaws, plus teeth. Skull bones were extremely thick, with ridges and grooves characteristic of some type of armor or protective shield.

The name comes from the Greek word for devil, Beelzebub, and Latin for toad, bufo (pronounced boo-foe).

The family link raises a paleontology puzzle: Standard theory for how the continents drifted apart show what is now Madagascar would have been long separated by ocean from South America during Beelzebufo's time. And frogs can't survive long in salt water, Krause noted.

He contends the giant frog provides evidence for competing theories that some bridge still connected the land masses that late in time, perhaps via an Antarctica that was much warmer than today.