The University of Hawaiʻi at Mānoa’s latest study is a wake-up call for the maritime industry, revealing that deep-sea mining could disrupt the ocean’s food web in ways we’re only beginning to understand. More than half of the zooplankton in the twilight zone—those tiny but mighty building blocks of marine life—could be harmed by mining waste. That’s not just a problem for the deep; it’s a potential domino effect that could ripple up to the surface, impacting everything from tuna to seabirds to marine mammals.
Here’s the kicker: the waste from deep-sea mining doesn’t just cloud the water—it changes what’s available to eat. Michael Dowd, the study’s lead author, puts it bluntly: “When the waste released by mining activity enters the ocean, it creates water as murky as the mud-filled Mississippi River.” That murk isn’t just a visual issue; it’s a nutritional one. The particles in the mining waste dilute the natural, nutrient-rich food that zooplankton rely on, turning their meals into junk food. And when zooplankton suffer, so do the creatures that feed on them—micronekton like small fish and shrimp, which in turn support larger predators.
The study zeroed in on the Clarion-Clipperton Zone (CCZ), a vast stretch of the Pacific Ocean targeted for deep-sea mining. Researchers analyzed water samples from the 2022 mining trial and found that the discharged particles had far lower concentrations of amino acids—key nutrients—than the natural particles that sustain life in these depths. That’s a red flag for the entire food web, which relies on a delicate balance of predators and prey.
The twilight zone, where this all unfolds, is a hotspot of biodiversity. It’s home to krill, fish, squid, octopus, and gelatinous species like jellyfish and siphonophores. These creatures play a crucial role in transporting carbon to the deep ocean, a process that helps regulate the planet’s climate. If mining waste disrupts their food supply, the consequences could be far-reaching.
Jeffrey Drazen, a co-author of the study and deep-sea ecologist, underscores the broader implications: “Our research suggests that mining plumes don’t just create cloudy water—they change the quality of what’s available to eat, especially for animals that can’t easily swim away.” That’s a problem not just for marine life but for industries like Pacific tuna fisheries, which operate in the CCZ. If deep-sea mining proceeds without strong environmental safeguards, the waste could impact fish that end up on dinner plates around the world.
This study lands at a critical moment. As countries race to meet the growing demand for metals needed for electric car batteries and other low-carbon technologies, about 1.5 million square kilometers of the CCZ are already under license for deep-sea mining. The question now is whether we can balance the need for these resources with the need to protect the ocean’s fragile ecosystems.
The findings are a stark reminder that the deep sea isn’t a limitless resource. It’s a complex, interconnected system where every action has a reaction. If we’re not careful, the quest for critical minerals could come at the cost of the very ecosystems that sustain life in the ocean—and, by extension, on land. The maritime industry, policymakers, and environmental advocates need to take note. The stakes are too high to ignore.