Polymetallic nodule deposits and sediments rich of metals in the deep ocean represent the major world reserves of metals. The areas likely to be affected by deep-sea mining would range from the seafloor (due to the sediment cloud created by the movement of the miner while collecting the nodules), to the water column (due to discharge of the unwanted debris and spillage during lifting) and the surface (due to at-sea processing and transportation). Up to the present it has only been possible to study the effects of small-scale, short-term mining and the first more ambitious research programmes on the impact of deep sea mining are just starting (e.g. the FP7-MIDAS programme, http://eu-midas.net/, and the JPI-Oceans Pilot Action “EcoMining”).
BRIDGES will provide the detailed requirements and potential uses and users for subsea mining and raw materials extraction and prospecting, providing safer and more environmentally sound subsea operations. Use in prospecting by imaging, necessary baseline studies, operational monitoring during extraction, crushing and waste (tailings and gray rock) placements on the sea floor will be explored. Measurement scenarios with hybrid propulsion at the bottom are particularly focused on turbidity, particle counter technologies, video imaging and acoustic active sensors for sea-bed properties.