Moving towards an operational framework for defining serious harm for management of seabed mining

Interest in deep seafloor mineral exploitation has been developing over the last few decades, and especially recently as the potential application of metals and elements in these mineral deposits has become more relevant for clean energy technology. The mineral resources located in areas beyond national jurisdiction (“the Area”) are under the regulatory control of the International Seabed Authority (ISA), which is required to protect the marine environment from the harmful effects of seabed mining activities and make recommendations to avoid serious harm to the marine environment. However, there is currently no agreed operational definition of serious harm for the Area. Noting that we neither support or disapprove of deep-sea mining, we propose a scientifically-focused risk framework approach for defining serious harm in the context of polymetallic nodule mining based on ISA documentation, as well as international and national criteria, and approaches developed for managing deep-sea resources. A three-tier “traffic light” scheme is proposed, with a threshold level between detectable (green) and significant harm (orange), and a further limit beyond which significant harm becomes serious harm (red). The green, orange and red sectors are associated with no additional management, additional management required, and stopping mining operations, respectively. We further provide illustrations of the type of criteria that could be used in defining levels of harmful effects, and further discuss aspects related to ensuring definitions and their application are fit-for-purpose. The framework proposed here provides a blueprint of an adaptive process that can be applied to the management of any mineral resource, although we focus in some specifics on polymetallic nodule mining. The work bridges the gap between earlier attempts at defining serious harm in the context of deep-sea mining and the need for a clear and consistent approach to operationalise the concept of serious harm. •Currently, no agreed operational definition of serious harm exists for deep-seabed mining.•Here, we define serious harm based on existing documentation and ecological criteria.•Three-tier traffic light scheme: detectable harm (green), significant harm (orange), serious harm (red).•The new framework provides a consistent and adaptive approach for the management of deep-seabed mining.