Deep-ocean exploration using remotely operated vehicle at gas hydrate site in Krishna-Godavari basin, Bay of Bengal

摘要

Work class remotely operated vehicle (ROV) rated for 6000 m depth of operation (ROSUB 6000) has been developed at the National Institute of Ocean Technology, Chennai, for deep-ocean resource studies. This system is being developed for the exploration of deep-sea mineral deposits such as poly-metallic nodules, gas hydrates, cobalt crust and other deep-ocean scientific observations in the Indian waters. The first ROV-based deep-water scientific expedition was performed to decipher the surface expression of gas hydrate at a depth of 1017 m in the Krishna-Godavari basin, Bay of Bengal, during September 2009. High-resolution bathymetry with multibeam sonar, vertical profiles of dissolved oxygen and water temperature were also collected in real time using ROV. Live images of seafloor habitats and deep-sea organisms such as fishes, shrimp, corals, holothurians and polychaetes were recorded and identified. Probable deep-water coral reef province is being established from deep waters of the Bay of Bengal and the exploration results have brought out chemosynthetic habitat at the expedition site in Bay of Bengal.