Environmental Impacts & Risks of Deep-Sea Mining: Recommendations for Exploitation Regulations

After more than 20 years, mining of mineral resources, such as polymetallic nodules and massive sulfides, in the deep sea is back on the agenda of many countries and companies in their quest for metals for the energy transition and high tech products. In this course, the past 10 years have seen an immense increase of exploration licenses issued by the International Seabed Authority (ISA), which administers and controls activities at the ocean floor beyond national jurisdiction, generally termed the Area. The seven pilot investors have renewed their exploration licenses in the Clarion-Clipperton Zone (CCZ) for another five-year term, after which they will need to apply for an exploitation license (or return their contracted claim). Thus, ISA is currently developing the regulatory framework for the exploitation of seafloor mineral resources, which includes, amongst several other issues, legislation to ‘ensure effective protection of the marine environment from harmful effects’ according to UNCLOS article 145.
In order to support decision-making for ISA’s regulations, the European project ‘MiningImpact’, funded through the Joint Programming Initiative Healthy and Productive Seas and Oceans (JPIO), has carried out extensive environmental research in the eastern exploration license areas for polymetallic nodules in the CCZ. At the heart of the project were two research cruises, which established the environmental baselines in the German and Belgian license areas of the CCZ and independently monitored the first test of an industrial prototype nodule collector vehicle conducted by the Belgian company DEME-GSR. The monitoring program focused on studying the direct impacts in the trial areas and the dispersal and redeposition of the suspended sediment plume. Topics covered during the monitoring included, habitat characterization, natural variability, disturbance effects, temporal evolution, faunal communities and the development of techniques for rapid biodiversity assessment. The MiningImpact project also initiated a restoration experiment with artificial hard substrates which aims at exploring the possibility to enable and accelerate the recolonization of areas affected by mining.

This special issue presents novel scientific results of the biological, biogeochemical, geological, and oceanographic investigations carried out in the MiningImpact project (consisting of 29 research institutes and organizations from 8 European countries) that significantly improve our understanding of the abyssal ecosystem and its functions as well as the impacts of future deep-sea mining operations. Based on these results recommendations for the Mining Code of the ISA are derived and, in addition, legal and economic issues are also addressed.