Transcript: Collapse of Sharks

For a long time, shark fishing was small scale. Fishermen would catch enough for their local markets. It's still done this way in some places -but today there is a huge international demand, especially in Japan and other parts of Asia.

In a shark net off Mexico, a Scalloped Hammerhead has met its end.

So has a Silky Shark.

And another Silky. When only a few sharks were taken at a time, their numbers could recover. When more are taken, shark populations plummet.

Rays are fished as well. Rays and Sharks are in grave trouble because, Unlike bony fish, they reach sexually maturity later and don't bear many young at a time. Their numbers can't recover quickly. Because of this, they shouldn't be viewed the same as other fish when it comes to commercial consumption. In recent years, the global shark fishing market has exploded. And one part of the shark is in great demand: its fins.

Often, sharks are taken only for their fins. In Japan, especially, they are believed by many to have medicinal value, and to work as an aphrodisiac. There is no scientific evidence to support these beliefs.

This shark was about to give birth. The death of this one female meant the death of many sharks.

These fins are the prized ingredient for soup that has sold for as much as one hundred and fifty dollars a bowl in Japan. Shark-fin soup now sells for less, becoming available for the masses.

Factory fishing ships race to meet the demand. This shark's fins are being cut off.

As a direct result of this practice, shark populations are collapsing around the world.

Only the fins have been taken, yet the sharks are then thrown back into the sea -often still alive.

But Asia is not the only offender. In the U.S. and Europe, shark cartilage pills are commonly sold as health food. Their popularity grows in spite of evidence that they are nothing more than expensive placebos.