New research published in Nature Communications reveals that deep-sea mining for battery minerals could disrupt a crucial ocean food web, potentially impacting fish populations and the livelihoods of those who depend on them. The study highlights a significant risk: waste released from mining operations could starve tiny animals like zooplankton and other creatures that consume them, leading to cascading effects throughout the ocean ecosystem.
The Race for Deep-Sea Minerals and Growing Concerns
The push to extract minerals from the deep ocean floor is gaining momentum as demand for battery materials rises. President Trump attempted to accelerate this process by seeking to circumvent international law and grant companies permission to mine the seabed for commercial use. This effort has prompted the International Seabed Authority (ISA) to develop a “mining code” aimed at regulating deep-sea mining and protecting shared natural resources.
However, this push forward is raising significant concerns. Over 900 scientists and policy experts have called for a freeze on deep-sea exploitation, fearing “irreversible” losses of biodiversity and ecosystem function. The current study, partially funded by The Metals Company (TMC), a Canadian startup that partnered with the island nation of Nauru to initiate commercial harvesting, adds another layer of complexity to this debate.
Understanding the Threat to Zooplankton
The research focuses on the “twilight zone,” located 200 to 1,500 meters below the ocean surface—a region populated by various life forms, including zooplankton, small fish, crustaceans, micronekton, and gelatinous creatures. Zooplankton feed on organic material drifting down from above, playing a critical role in the marine food web.
The study’s authors found that waste released from mining operations into the twilight zone would inundate the area with particles of a similar size to those consumed by zooplankton. However, these particles would be significantly less nutritious – 10 to 100 times less, according to the researchers. They compared the nutritional value of the particles using amino acid concentrations and described the mining waste particles as “junk food” lacking essential organic material.
“We’re trying to go against that [rush to mine] and put the brakes on this process,” says Michael Dowd, the study’s lead author. “Those current plans are going to cause severe impacts.”
Cascading Effects Throughout the Food Web
The consequences of starving zooplankton are far-reaching. Micronekton, small organisms that consume zooplankton, would then suffer, followed by larger fish such as tuna and swordfish that rely on micronekton for food. Zooplankton also migrate to the sea surface to feed before returning to the twilight zone, playing a key role in transporting carbon deep into the sea—a process that helps regulate Earth’s climate. Releasing vast quantities of nutrient-poor particles into the twilight zone would thus disrupt multiple levels of the ocean food web.
Furthermore, the study highlights that releasing mining waste in shallower waters, closer to higher-level predators, would likely pose similar or worse risks. There’s a lack of data available about the potential impact of mining waste deeper in the water column, where new species are still being discovered and where some species from shallower depths migrate to avoid predators.
Potential Mitigation and Alternative Solutions
The researchers acknowledge that mitigating the harms of deep-sea mining could involve returning sediment waste all the way back to the seafloor, where it was initially extracted. However, this approach would likely be more complex and costly.
Beyond mitigation strategies, the study authors suggest exploring alternative solutions to reduce the demand for newly mined minerals. “We can recycle our [e-waste], we can mine our waste,” says Brian Popp, a co-author of the study. Advances in battery technology—such as alternatives to conventional rechargeable batteries—and robust e-waste recycling programs could significantly lessen the need for deep-sea mining and prevent further environmental crises.
While TMC maintains that it plans to discharge waste at a greater depth (2,000 meters), below the twilight zone studied in the paper, and that waste particles dissipate quickly, the new research underscores the urgent need for caution and a more thorough understanding of the potential ecological consequences of deep-sea mining before proceeding. This research adds to the growing body of evidence supporting the call for a pause in deep-sea exploitation and a commitment to sustainable alternatives.
Ultimately, proceeding with deep-sea mining without a complete grasp of the risks could have devastating and irreversible impacts on a vital ocean food source, threatening marine ecosystems and human livelihoods alike.
