Activities of deep-sea mining will indisputably affect the status of the environment by disturbing the seafloor and the overlying water column. The habitats of unique benthic and pelagic communities may be affected depending on the technologies used as well as on the size of the area impacted directly by mining and indirectly by the dispersion of sediment plumes and mining debris. The JPI Oceans Pilot Action "Ecological Aspects of Deep-Sea Mining" assesses the ecological impacts which could arise from commercial mining activities in the deep-sea. Core of the project are three expeditions visiting several nodule license areas and a protected area in the Clarion Clipperton Zone (CCZ) as well as the disturbance and recolonization experiment (DISCOL) in the Peru Basin, which was conducted 26 years ago. Germany will substatially support the project and the further development of guidelines and standards for deep sea exploitation.