COBRA Webinar – July 2026

The chemical composition and shape of prototype deep-sea nodule mining plumes

Shelby Gunnells and Dr. Jessica Fitzsimmons (Texas A&M University)

Deep-sea mining of polymetallic nodules has emerged over the last decade as one of the fastest-developing industries for acquiring critical minerals necessary for the green energy transition. Despite its rapid progression, however, the environmental impacts of nodule mining remain uncertain, particularly in the water column. In 2022, The Metals Company became the first company to execute a modern full-system deep-sea mining test that successfully lifted nodules to the sea surface, including the first to generate a midwater plume. Here, we present the observed chemical composition and three-dimensional shape of both the midwater and benthic plumes that were generated in these mining trials. We compare these chemical loadings to baseline conditions that were established in the same mining lease region prior to mining, and we consider their potential ecosystem impacts.