Great white shark a threat or threatened?

For many, sharks embody the soulless predator -- silent, vicious, merciless. And for local residents, the danger can be personal -- Volusia County's beaches see more shark bites than anywhere else.

In the world's oceans, a far destructive force is at work. Sharks, once secure in their position as a sea's top predator, are now dying at the rate of more than 100 million a year. International fisheries experts predict that by 2017, nearly 20 once-thriving species will be extinct.

A study of sharks living in the western North Atlantic Ocean (the area that includes Florida's coast) found that over 15 years, populations for all shark species except one (mako sharks) have declined by more than 60 percent.

What's threatening the sea's ultimate threat? People are. The main threats to sharks are all human. Commercial fishing takes a tremendous toll, both intentionally -- sharks caught, stripped of their fins and tossed back to die -- or inadvertently -- sharks snared by fishermen angling for other species.

The rising toll shifts the symbolism of the shark -- to represent the ruthless predation of man. The same careless, profit-driven practices that kill sharks wreak havoc among countless other species, destroying the sustainability of fish populations.

Scientists identify many species of shark as "keystone" to marine ecosystems, meaning that a reduction in their numbers has wide-ranging consequence for other ocean life. Yet to date, only a few species have won protection through international preservation compacts, and U.S. laws do little to stop the carnage of sharks caught accidentally. Meanwhile, international fishing fleets continue to haul in sharks at a tremendous rate.

The United States can take the lead on this issue by toughening its own laws, and pushing for tighter controls on commercial fishing worldwide.

The alternative -- watching shark populations dwindle, with the knowledge that world fish populations are likewise diminishing -- is far worse than a frightening Sunday matinee of "Jaws."