There is increasing interest in the profusion of living resources dwelling on and in the ocean floor, from scientific interest in what is there and why life is so diverse, to interest in the potential for commercial exploitation. Although recent estimates of the number of species on the deep ocean floor (10–100 million) remain the subject of intense debate, even the lower estimates are hundreds of times higher than older projections and reflect clear recognition that the deep-sea benthos is far more diverse than expected (Grassle and Maciolek, 1992; May, 1992; Poore and Wilson, 1993; National Research Council, 1995). These findings have challenged current perceptions and theories about how species diversity is produced and maintained, because the deep sea was perceived as having relatively few environmental barriers, usually considered important for the evolution of new species. The genetic and chemical diversity of these organisms also means that they have great potential commercial value. For example, bacteria living near thermal vents on the ocean floor have yielded the second generation of heat-stable enzymes for use in amplifying small quantities of DNA from clinical, environmental and forensic samples, with potentially great economic value (National Science and Technology Council, 1995). In the ocean, these vents are found primarily in the deep sea-bed areas beyond the jurisdiction of coastal states (Glowka, 1995).