Figure F7. Cell density data from ODP sediment cores. Solid circles are data from ODP Leg 201 (D’Hondt, Jørgensen, Miller, et al., 2003) and dotted region shows 2-σ envelope around global compilation of previously censused ODP sites (Parkes et al., 1994). It is not clear whether this trend will be continued into basement, or if populations will be greater or less than projected, particularly within narrow zones that carry most of the hydrothermal flow. Long-term monitoring and sampling within CORK observatories will provide the best opportunity to address this uncertainty.