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Article for: The Davis Enterprise
Date: March 14, 2003
Author: Leslie Madsen
Contact: Tom Wickersham

What creature is more than three meters long, gutless, mouthless, and thrives in a toxic environment?

The fantastic animal described is the tube worm, which lives in the thermal vents in the deep ocean. The worms' ecology will be just one of the topics discussed by Dr. Alissa Arp at Explorit Science Center's next Cutting Edge of Science Lecture. On Tuesday, Arp will give a talk titled "Life in Toxic Deep Sea Vents, Seeps, and Local Mudflats" at the Davis Branch Library.

Arp is a professor of biology and director of the Romberg Tiburon Center for Environmental Studies at San Francisco State University. Her research in ecological physiology takes her to environments as different as northern California's coastal mudflats and deep-sea hydrothermal vents.

Arp was studying midwater ocean environments as a graduate student in the late 1970s when hydrothermal vents were first discovered.

"It was a big deal, new discovery, new life forms, all new habitats," Arp said.

Arp explained that a hydrothermal vent is a place on the bottom of the ocean where volcanic activity releases unusual chemicals into the water. When fissures open in the seafloor, seawater comes into contact with the hot magma of the earth's interior. The water is heated and forcibly ejected back up through the seafloor.

Early in her career, Arp decided she had to see the vents for herself. Arp said she is glad she managed to join in vent research when it first began. The result of those studies is among some of her most exciting research, she explained.

"I was there on the ground floor," she said, "and together with my advisor at the time was able to describe how they transport the hydrogen sulfides through them to the bacteria that need it for metabolism."

The tube worms receive some nourishment by absorbing nutrients from the water with their tentacles. However, most of the worms' nutrition comes from symbiotic bacteria that dwell inside the worm, in a specialized organ that replaces a gut. These bacteria are able to oxidize the hydrogen sulfide that is plentiful in the vent environment. The bacteria get energy from oxidizing the hydrogen sulfide, and the process creates larger organic molecules that nourish the tube worms.

The adaptations that animals exhibit in these environments," Arp explained, "tend to teach us about life itself-how animals evolve, how they deal with challenges, how they respond to geology, to toxicity. Those kinds of lessons can be translated to other kinds of situations."

In addition to showing slides of the tube worms and research submarines, Arp will discuss the invertebrate animals that live in hydrocarbon seeps and estuarine mud. Like hydrocarbon vents, these environments feature abundant hydrogen sulfide, and the animals that live in them exhibit sophisticated adaptations that allow them to flourish in the toxic habitats.

Arp's eight deep-sea dives, 22 oceanographic expeditions, and routine publication in major scientific journals qualify her as a world authority on these extreme physiological adaptations. In addition to receiving international attention from fellow scientists, Arp has made headlines in both the national and international popular press.

Despite her status as a scientist, Arp still finds time to teach, and she takes special pride in mentoring her students and in demystifying science for girls and young women. Arp herself did not decide to become a scientist until she took science classes in college, and she said she wants to let other people know that, despite popular depictions of young scientific geniuses, it is never too late to start studying science.

"You don't have to know you're a scientist the day you're born," she said.

Arp's talk begins at 7:30 p.m. in the library at 315 E. 14th Street. For more information, call 756-0191.

Explorit's Cutting Edge of Science Lecture Series is sponsored by Novozymes Biotech and is hosted by the Davis Branch Library.

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Explorit Science Center is at 3141 5th Street in East Davis. The current exhibition is "Written in Stone: The Story of Sand, Soil and Rocks," which continues through Apr. 5. Public hours are Saturday from 11 a.m. to 4:30 p.m., Sunday from 1 to 4:30 p.m., and Tuesday through Friday from 2 to 4:30 p.m. For more information, visit www.explorit.org or call Explorit at (530) 756-0191.