A research ship dropped a steel box into water so deep that sunlight stopped existing thousands of meters above it somewhere between Honolulu and the middle of nowhere. The crew bided their time. Manganese nodules, those odd, potato-shaped rocks that have become the focus of a small, well-funded industry that is betting on the seafloor as the next great frontier for cobalt, nickel, and copper, were supposed to be inside the box when it came back up. The box was filled with sediment instead. Only sediment. Not the haul that everyone had secretly hoped for.
The goal of that late-2025 expedition, which was headed by USGS Research Oceanographer Kira Mizell and included researchers from the U.S. Bureau of Ocean Energy Management, Scripps, Japan’s JAMSTEC, and the University of Hawaii at Mānoa, was to fill in one of the biggest gaps on the global seabed map.
Science had hardly touched the abyssal plains far offshore the Hawaiian Islands. Nodules were anticipated by the team. They anticipated a dense, unusual deep-sea fauna similar to that found in the more thoroughly researched Clarion-Clipperton Zone. They didn’t receive either. Mizell stated, “We actually didn’t find any nodules,” and there’s something almost subdued about that acknowledgement—the kind of statement that seems modest until you sit with it.
Up until now, it had been assumed that the patterns seen in the CCZ would more or less predictably spread into neighboring areas. Models stated as much. Perhaps not, according to the latest data. The team was surprised by the heterogeneity of the sediments. The biological density was not as high as anticipated. Although none of this is dramatic in the sense of a movie, it raises unsettling questions about how much we truly know for a sector whose entire business case depends on extrapolating from one zone to another.
At about the same time, another piece of work was, in a sense, arriving in a completely different room within the same building. In a study published in Nature Communications, a team led by UH Mānoa oceanography graduate student Michael Dowd, along with co-authors Erica Goetze, Jeffrey Drazen, Brian Popp, and Angelicque White, examined what happens when mining waste is dumped back into the ocean’s midwater “twilight zone”—that peculiar layer between 200 and 1,500 meters where krill, small fish, squid, and gelatinous creatures form a food web that most people will never see but quietly rely on. The figures were startling. In the discharge zone, 53% of zooplankton and 60% of micronekton would be impacted. According to Dowd, the waste dilutes the real food these animals eat and makes the water as murky as the Mississippi.
It’s like adding empty calories to a system that has been operating on a carefully calibrated diet for hundreds of years, according to Drazen’s phrasing, which stuck with me. There is no decoration in the twilight zone. Every night, those animals migrate vertically, bringing carbon down into the deep ocean to feed the tuna that eventually find their way onto dinner plates in Tokyo and Los Angeles. Currently, mining licenses cover about 1.5 million square kilometers of the CCZ. There are currently no regulations controlling the discharge of waste.
As I watch this develop, I get the impression that two findings are coming together to form an unsettling picture. The suggested solutions for mineral extraction from the deep ocean are more disruptive than the industry has been prepared to admit, and the deep ocean is less predictable than the models proposed. Regulations that will influence the coming decades are currently being considered by NOAA and the International Seabed Authority. To be honest, it’s still unclear if they will stop long enough to consider what the Hawaii teams just mentioned.
