Examination of the Relinquishment Process in Deep-Sea Mining: Impacts on Conservation and Potential Improvements

Abstract

Deep-sea mining on the international seabed has caused a debate between the potential benefits of critical mineral resources and environmental impacts. Deep-sea mining exploration contracts include relinquishment, which requires contractors to release portions of their exploration lease area over time. Other than the required relinquishment percentage, there are no specific guidelines for this process. This master project is the study of deep-sea mining exploration lease areas and relinquishments, to examine the option of including ecological values in the decision-making process in the future with the goal of improving efforts for conservation. Through qualitative and statistical analysis, we revealed that polymetallic sulfide mining contractors have relinquished very few of the known active and inactive vent sites. Seamounts in the Northwest Pacific with exploration contracts showed higher coral habitat suitability than those without contracts, based on existing habitat models, but comparisons between relinquished and kept areas showed no consistent relationship with habitat suitability. Surprisingly, in cobalt-rich crust leases, the average perimeter length of lease areas increased after relinquishment. Overall, relinquishment decisions made by mining contractors without considering ecosystems do not make the best use of the seabed for the dual goals of mineral use and conservation.