Dec. 16, 1998 to Jan. 21, 1999 The goals of this expedition were twofold: To collect the suite of microbes and invertebrate organisms associated with hydrothermal vents along the southern East Pacific Rise. To sample vent fluids for analyses of the water chemistry and hydrothermal plume dynamics. Sponsors for this series of dives included: The National Science Foundation (NSF), which funded 14 dives for the biological team headed by R.C. Vrijenhoek and R.A. Lutz. The National Oceanographic and Atmospheric Administration (NOAA), which funded 10 dives for the geological team headed by J. Lupton. Chief Scientists: Robert C. Vrijenhoek Monterey Bay Aquarium Research Institute 7700 Sandholdt Road P.O. Box 628 Moss Landing, CA 95039-0628 John Lupton NOAA/PMEL Hatfield Marine Sciences Center Newport, OR