The Joint Programming Initiative Healthy and Productive Seas and Oceans (JPI Oceans) is a coordinating and integrating platform for marine and maritime research and innovation, open to all EU Member States and Associated Countries. In 2013 the JPI Oceans Member Country representatives decided to launch a pilot action to study the long-term ecological effects of deep-sea mining. To realise this aim, the German Federal Ministry of Education and Research (BMBF) offered 118 days of on-site research on the recently inaugurated RV Sonne for two cruises in the Pacific. A group of international scientists under the lead of Matthias Haeckel (GEOMAR) and Pedro Martinez (German Centre for Marine Biodiversity Research / Senckenberg institute) subsequently developed a common scientific proposal for these cruises. For Belgium the Marine Biology Research Group of University of Gent and the Royal Belgian Institute of Natural Sciences are part of the research consortium.