Governing the Deep Sea: Legal, Technological, and Environmental Challenges in the Exploitation of Polymetallic Nodules under the UNCLOS/ISA Regime

Abstract

The commercial exploitation of polymetallic nodules in the International Seabed Area poses governance challenges under international law. This article examines the adequacy of the normative framework established by the United Nations Convention on the Law of the Sea (UNCLOS), as administered by the International Seabed Authority (ISA), amid pressure driven by geopolitical competition and unilateral state action. Four dimensions are evaluated: gaps in the draft Mining Code, assessed through Part II of the ISA's 30th Session (July 2025); Sponsoring State responsibility when authorising contractors with prior risk records; emerging extraction and mitigation technologies (including artificial intelligence, autonomous underwater vehicles, satellite monitoring, digital twins, and high-resolution sonar) and their capacity to minimise environmental impacts; and the geopolitical rupture generated by the April 2025 United States Executive Order to expedite seabed mining permits in the international Area. Findings demonstrate that, absent binding exploitation regulations and mandatory application of best available technologies verified by independent third parties, environmental risks and legal uncertainties regarding State responsibility remain unacceptably high. The governance trajectory is not merely incomplete; it is structurally incapable of ensuring environmental protection under commercial pressure. A precautionary pause is warranted until law, science, and technology converge to deliver a protective governance framework.