In "Into the Deep," Bob Ballard regales Alan with stories of his voyages to the bottom of the sea. In 1977, Ballard was exploring the Galapagos Rift in the Pacific Ocean with the submersible ALVIN when he made one of the most important discoveries in modern biology— hydrothermal vent communities.

The Galapagos vents were found to support an astonishing array of animal life, in spite of the enormous pressure, total darkness and magma-heated solutions churning up from these fissures in the seafloor. What did these animals eat? Biologists puzzled over this mystery until water samples revealed the presence of chemosynthetic microbes, bacteria that transform chemicals discharged from the vent into usable energy. These bacteria then serve as the bottom of the food chain for the rest of the vent community, just as photosynthetic plants do on the sunlit surface.

A Senior Researcher in the Department of Biology, Carl O. Wirsen (above/right) has worked at the Woods Hole Oceanographic Institution (WHOI) in Woods Hole, MA since 1968. A microbiologist specializing in the physiology and ecology of marine bacteria, Wirsen became intrigued by deep-sea bacteria in 1968, after the submersible ALVIN broke free from its support cables and sank, unmanned, in 5,000 feet of water. When the craft was recovered, biologists were struck by the conditions inside the sub.
- - - - - - - - - - - -

WIRSEN: When the sub was recovered after ten months on the bottom, the seawater soaked lunches were in a remarkable state of preservation. Bologna sandwiches were not spoiled and the meat was still pink. The apples tasted salty, but were still quite fresh. All this left us scratching our heads. It was a perfect experiment. The lunches had just been sitting in an open leather satchel inside the sub, protected from all the little scavenging animals, but free for microbes to act. We jokingly asked if we could sink another submersible and maybe repeat the experiment but the Navy wasn't too thrilled about that!

	Giant tube worms thrive in the vent environment, reaching sizes up to four feet long.

This accident got me involved with studying the microbes of the deep sea, which is the largest biosphere on Earth, comprising 80 percent of the living space on Earth. What microorganisms are there? How are they reacting/adapting to pressure? To the near freezing temperature? What are the factors that limit life? I consider myself a classical microbiologist. I like to isolate and culture microorganisms, study their physiology and look at how environmental factors affect them. With this approach, we can answer a lot of questions. I very much like the hands-on part of doing research, so I jumped at that opportunity to work at Woods Hole and I've been here almost 34 years now.
- - - - - - - - - - - -
5 pages: | 1 | 2 | 3 | 4 | 5 |

Photos: Woods Hole Oceanographic Institute (WHOI)