Offshore Seafloor 303 Japan trench, Izu-Ogasawara trench

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Characteristics References

These waters are characterized by a lengthy submarine trench ecosystem reaching depths of 6000 m or more, connecting the Kuril trench, the Japan Trench with the Izu-Ogasawara Trench. The deepest depth in the Japan Trench is 8020m . These trenches also mark the boundary where the Pacific Plate sinks under other plates (Japan Oceanographic Data Center, 1985). In the trenches numerous unique species that have evolved independently have been discovered, since there is no interaction with other waters (Shiroyama, personal communication). These waters also include seamounts such as the Erimo Seamount, the Takuyo-Daiichi Seamount, and the Daiichi-Kashima Seamount, which is sinking into the trench floor (Japan Oceanographic Data Center, 1985). At the Daiichi-Kashima Seamount Calyptogena phaseoliformis has been confirmed to live at the base of the seamount, at depths of 5640–5695 m (Fujikura et al, 2008).