One-Third of Sharks Could Go Extinct

Great white shark cruises underwater in search of prey. Credit: Neil Hammerschlag / www.neil4sharks.org

Atlantic blacktip sharks are known to breach out of the water while feeding, sometimes spinning a few times around their axis. The spinning breach could help the sharks vertically attack fish below as they plunge back into the water. Credit: Matthew D. Potenski, MDP Photography.

Whale sharks are the largest shark and largest fish species swimming around in the seas. Credit: Brad Norman

Whale sharks are considered filter feeders, as they filter tiny fish from the water using the fine mesh of their gill-rakers. Credit: Copyright Brad Norman

Threats to sharks are nothing new. For years, scientists have been saying that these ancient fish are in danger of going extinct as many are caught by accident, or on purpose just for their fins, and populations are decimated.

Now a new warning from the International Union for Conservation of Nature states that nearly a third of sharks and rays are threatened with extinction. The analysis of 64 species of ocean sharks and rays found 32 percent are at risk, including the great white shark.

An estimated 38 million sharks are killed for their fins each year. Sharks, meanwhile, kill very few people (despite the myth that they're very deadly).

If sharks go, the ocean food chain could crumble, experts have warned. Top predators are key to keeping populations of key species from growing too large. If sharks die off, you could have a food chain Whac-a-Mole, scientists say.

At least one exception to the dire situation: The biggest sharks of all, whale sharks, are thriving off the coast of western Australia.

• Quiz: The Dirty Jobs of Sharks