TMC Subsidiaries Submit Massive Deep-Sea Dataset to Public Database

16 April 2026

Earlier submissions included over 12, 000 seafloor images taken using Remotely Operated Vehicles which resulted in the identification of over 30,000 megafauna. (Image credit: TMC)

TMC the metals company Inc. (TMC), a leading developer of the world’s largest resource of critical metals essential to energy, defense, manufacturing and infrastructure, announced that its subsidiaries, Nauru Ocean Resources Inc. (NORI) and Tonga Offshore Mining Ltd. (TOML), have submitted comprehensive data from almost a decade of deep-sea exploration to DeepData, an open database of contractor data managed by the International Seabed Authority (ISA).

The submission—spanning 2013–2022 and comprising an unparalleled collection of biological and geochemical samples from across the eastern Clarion Clipperton Zone (CCZ)—builds on a decade of research by NORI and TOML to characterize the polymetallic nodule resource and surrounding marine environment, from the ocean surface through the water column to abyssal sediments more than 4,000 meters deep. The data will be made publicly available through open repositories, including DeepData and UNESCO’s Ocean Biodiversity Information System (OBIS), as part of the Company’s commitment to advancing scientific understanding of the deep ocean. With this submission, TMC’s subsidiaries have contributed roughly one-third of all CCZ data in DeepData. The data will also be published to the OBIS-ISA node, where TMC subsidiary data already account for 54% of all biological records—a share expected to increase significantly following publication of this batch. TMC’s dataset is generating significant interest among researchers, with the full OBIS dataset downloaded almost ten thousand times to date and individual taxa downloads totaling more than half a billion.

Scientists prepare to launch a CTD rosette which gathers key data on water temperature, salinity, density and turbidity and can be used to measure suspended sediment and model the propagation of sound. (Image credit: TMC)

TMC Environmental Manager, Dr. Michael Clarke, commented: “After more than a decade of research, 27 expeditions, rigorously monitored pilot mining tests, tens of thousands of biological records, and hundreds of thousands of seafloor images, we’ve built one of the most comprehensive deep-sea environmental datasets ever assembled. Backed by over $250 million in investment, our findings don’t stand in isolation—they corroborate decades of prior research, including NOAA’s DOMES program,” he said, referring to the US National Oceanic and Atmospheric Administration’s Deep Ocean Mining Environmental Study program conducted in the 1970s.

With the extensive Environmental Impact Assessment now complete, the Company has begun sharing key takeaways from this comprehensive body of work through a series of videos documenting how its data addresses environmental concerns and how innovation has reduced the impact footprint of its collection system compared to legacy technology.

Environmental Concerns – What Does the Data Tell Us?

Innovation at Depth

Data from NORI and TOML’s offshore campaigns have supported 37 peer-reviewed publications by independent scientists from leading marine research institutions, all of whom retain full freedom to publish. Recent papers include those demonstrating that both biodiversity and sediment plume impacts are confined to the directly mined area. With more than a petabyte of data collected, the Company expects this body of work to expand significantly in the coming years. To date, nearly 200,000 scientific papers have been published on polymetallic nodules globally, including more than 50,000 focused on the eastern CCZ.

Multi-core samplers provide a clear snapshot of the sediment-seawater interface and were used to collect eDNA from sediment and nodule communities—an approach standard in the deep-sea but rarely applied in terrestrial mining impact assessments. (Image credit: TMC)

Dr. Clarke added: “Activists often repeat the refrain that ‘we don’t know enough’—but that narrative doesn’t hold up against the evidence. The Environmental Impact Assessments produced for the CCZ are, in aggregate, the most extensive ever conducted for any mining project anywhere in the world. That record demands recognition—and it demands that the bar for ‘enough’ be set not by the absence of all uncertainty, but by the presence of sufficient knowledge to manage risk responsibly, with adaptive mechanisms firmly in place. As with any resource project, the science is not perfect, and we will continue to learn and adapt after production begins. But it is, by any reasonable measure, more than sufficient to begin monitored commercial operations. The conclusion has been consistent for more than 50 years: with the right safeguards and monitoring, the environmental impacts of nodule collection can be effectively managed.”

In January, TMC announced that it had submitted the first-ever consolidated application under NOAA’s modernized regulatory framework, a permitting pathway that is anticipated to reduce permitting timelines and is available to applicants with sufficient environmental and technical knowledge. NOAA later confirmed substantial compliance of this application on March 9, and the Company expects the final granting of the commercial recovery permit within the next 12 months.