Time-series chemical and temperature habitat characterization of diffuse flow hydrothermal sites at 9 super(o)50'N East Pacific Rise

The spatial and temporal distributions of hydrothermal vent organisms are considered to be controlled by a combination of chemical and biological interactions. However, the degree of habitat specificity imposed by fluid chemistry on hydrothermal vent-endemic siboglinid tubeworms Tevnia jerichonana and Riftia pachyptila, as well as the mussel Bathymodiolus thermophilus, remains largely unknown. A comparison of time-series sulfide and temperature data reveals that T. jerichonana primarily inhabit higher temperatures and sulfide concentrations, that B. thermophilus primarily inhabit lower temperatures and sulfide concentrations, and that R. pachyptila habitats overlap the range of temperature and sulfide concentrations observed. Based on these data in combination with previous laboratory studies, we speculate on potential in situ uptake rates of oxygen and sulfide by R. pachyptila. These estimates suggest that R. pachyptila potentially experiences both oxygen and sulfide limitations. The mean uptake rates for areas inhabited by R. pachyptila are favorable for R. pachyptila, while those inhabited by B. thermophilus and T. jerichonana appear to be sulfide and oxygen limited, respectively.