Coupled temporal changes in water chemistry and biological community structure at newly-formed hydrothermal vents on the EPR crest This is a study of the coupled evolution of fluid chemistry and biological community structure on a fine scale (9 degree 49.6' - 9 degree 50.6'N) with the abundant diffuse flow which supports complex animal communities as the principal focus. The work is coupled with a funded biology program on the East Pacific Rise between 9-10 N to study the coevolution of the chemistry and biological communities in newly formed hydrothermal systems. The Alvin program in April 1991 documented to within days the occurence of a seafloor volcanic eruption. In 1992 Alvin dives to this site documented significant changes in both the chemistry of the vents and the biological communities surrounding them. As this is the only portion of the mid-ocean ridge system defining "time zero" for an eruptive event and the formation of a new hydrothermal system, this site offers an unprecedented opportunity to follow temporal changes in vent chemistry and associated biological community structure.
