Tube worms are an integral part of the vent community food chain.

8,000 feet down, along the Galapagos Rift, Bob Ballard made a discovery that would forever change scientists' understanding of life on earth. Using the submersible Alvin to explore the Mid-Ocean Ridge, the 42,000-mile underwater mountain range that is the planet's largest geological feature, Ballard found deep vents in the seafloor. Around these vents, he was shocked to see giant white clams, a sign of life in the dark, seething-hot waters.

Further examination revealed an entire ecosystem unlike any found before - fields of giant red worms living in strange tubes, octopuses, crabs, and even fish. Rather than relying on the sun as their energy source, these vent creatures used a system of chemosynthesis, depending instead on the heat of the earth for survival. Many scientists now speculate that life on this planet may have originated in just such an environment.

ALVIN has made more deep ocean discoveries than any other sub.

For the twenty-five years since this breakthrough, researchers have carefully brought vent specimens to the surface for study, using elaborate pressurized systems to keep them alive. Today, hundreds of hydrothermal vent communities are known to exist around world. As Ballard tells Alan, this was his proudest moment of discovery.

Into the Deep...Part Three - Deep Ocean Archeology

For more on this topic, see the Web feature:
Earth on the Move