For more than ten years, the International bottom Authority has been developing a mining code for the deep bottom. When that code was not finished in July 2025, negotiators were sent back to their hotels without reaching an agreement, and a new round of negotiations was set for 2026. In the meanwhile, The Metals Company plans to begin nodule extraction in the Clarion-Clipperton Zone by late 2027 and has published a commercial pre-feasibility study. One of the most significant silences in contemporary environmental governance is the gap between those two timelines, and Duke researchers have been at the forefront of the scientific community’s efforts to make that silence audible.
The fundamental issue, as documented for years by Cindy Van Dover’s lab at Duke’s Marine Geospatial Ecology Lab, is that the regulations being drafted for deep-sea mining are outpacing the science on which they are meant to be based. One of the leading experts on hydrothermal vent ecosystems and deep-sea ecology, Van Dover has been personally advising ISA politicians while also disseminating studies that demonstrate how little is truly known about the animals that would be impacted by extraction.
For areas that have been “largely unexplored and uncharacterized,” according to Duke’s published analysis, the ISA’s Regional Environmental Management Planning process—the framework intended to direct where mining is authorized and where it isn’t—is in progress.” Plans are being developed for undescribed habitats.
There is more to the knowledge gap than just species listings. It includes the mining process’s actual physical behavior. Sediment plumes are clouds of disturbed material that rise from the seafloor and drift as a result of heavy collector vehicles scraping polymetallic nodules off the abyssal plain. Local current patterns at depth have a significant impact on how far the plumes go, how long they stay in the water column, and which creatures they suffocate. In the majority of the target zones, those current patterns are poorly mapped.
After the nodules are separated, return water—the slurry pumped back down from the surface ship—carries a unique set of unknowns. Research analyzing comparable effluent from previous ocean drilling operations discovered effects on microbial communities that extended farther than the models had projected. This is significant because the models now in use for evaluating environmental risk in mining evaluations are predicated on hypotheses that are not yet sufficiently supported by field evidence to be thoroughly tested.
The loss of biodiversity receives more attention than the additional dimension that carbon adds. The Clarion-Clipperton Zone’s nodule fields store carbon in a comparatively stable state because they are situated above sediments that have collected organic matter over geological ages. Commercial disturbances to that substrate, such as collector machines running nonstop over thousands of square kilometers for years, run the danger of releasing stored carbon back into the water column. It’s really uncertain how much and if it ever makes it to the atmosphere. It is evident that the environmental impact models that mining firms use to claim their operations are manageable do not incorporate this process.
