Shark fins drying on the deck of a longliner. The booming shark fin trade is killing up to 73 million sharks per year - three times more than the official catch numbers. That's according to a new study by Miami University researchers affiliated with the Pew Institute for Ocean Science. (Press release)

MSNBC reports:

Fins are the most valuable parts of a shark and are used in shark fin soup, a delicacy served at Chinese weddings and business dinners in Southeast Asia and the Pacific Rim. Sharks are often still alive when their fins are sliced off, and their bodies are thrown back into the sea.

Scientists worry that the demand for shark fins could soon outpace the abilities of sharks to reproduce. This is probably already happening for one species, the blue shark, the researchers say. Their findings suggest that the current trade in blue sharks is close to or possibly even exceeding the species' maximum yield levels.

Another recent study found that removing sharks from an ecosystem can have serious ripple effects on other species...

Without sharks, carnivorous fish that the sharks usually fed on thrived. The carnivorous fish, in turn, preyed on parrotfish that kept the corals clean.

In time, the reefs changed from one dominated by coral to one overrun by algae.

Just think about that next time you're tempted to order some shark fin soup.