This project addresses pattems of biodiversity and convergence at deep-sea hydrothermal vents using fauna associated with mussel beds for comparisons at various spatial, temporal and contextual scales, including: i) within a vent field, ii) annually at a single vent field over three years, iii) among vent fields of different ages on a ridge segment, iv) among segments of different spreading rates on a single ridge system, and v) between ridge systems in different ocean basins. Biodiversity contrasts at these scales repeatedly arise in discussions of vent ecology and deep-sea ecology, but to date there is no quantitative information to allow comparisons. This research will develop from an ongoing comparison of biodiversity at Lucky Strike mussel beds on the Mid-Atlantic Ridge and an intertidal mussel bed on the south central Alaskan coast. An intensive field program is designed to sample a variety of mussel bed sites on the East Pacific Rise and Mid-Atlantic Ridge. The field programs are envisioned primarily as add-ons to programs developed by other scientists. All cruises and sampling involve the use of the Alvin. Dive sites for comparative biodiversity studies are hoped to include 11 N, 9N and 17S on the East Pacific Rise (i.e., two "fast' and "superfast" spreading segments) and Menez Gwen, Lucky Strike, and Snake Pit on the Mid-Atlantic Ridge. Vent ecosystems on oceanic spreading centers provide extreme examples of fragmented metapopulations on a global scale. Patterns of diversity and convergence in these communities will provide fundamental insights into regional-scale control of community structure.
