How deep sea mining could threaten a vital source of food in the oceans

The race to extract battery metals from the ocean floor would create a new waste stream that could deprive marine life of a critical food source, according to new research. Published research Today in the magazine Nature Communications. This could have far-reaching impacts across the ocean, potentially affecting larger fish like tuna that people depend on for food and livelihoods.

These results come at a time when President Donald Trump is trying to do just that Circumventing international law And giving companies Allow commercial deep sea miningThis has not yet happened anywhere in the world. the The first company to apply To obtain an international mining permit from the Trump administration, it has already funded this study. And you probably didn’t expect the results of this research to raise another warning sign about deep-sea mining.

The study authors found that if mining operations release waste into the ocean’s “twilight zone,” about 200 to 1,500 meters below sea level, it could starve tiny animals called zooplankton and other organisms that eat them. This could have serious repercussions down the road Food webs That links predators and their prey, prompting scientists to say that more research is still needed on how to avoid potential dangers.

“We’re trying to go against that and stop the process,” says Michael Dodd, lead author of the study and a graduate student in oceanography at the University of Hawaii at Mānoa College of Ocean and Earth Sciences and Technology. “We don’t have the science to fully conclude what the best option is.” “These current plans will cause serious impacts.”

The Trump administration has set its sights on rock-like polymetallic nodules on the seafloor rich in nickel, cobalt and manganese, which could be used to manufacture rechargeable lithium-ion batteries. A Canadian startup called The Metals Company (TMC) calls these nodules “batteries in a rock” and sparked the deep-sea mining craze several years ago when In partnership with the island nation of Nauru To start harvesting those minerals commercially. These efforts prompted the International Seabed Authority (ISA) to begin developing “Mining symbol“To regulate deep sea mining and protect natural resources is considered”The common heritage of humanity“.

Meanwhile, more than 900 oceanographers and policy experts have called for a freeze on deep-sea exploitation in public waters. statement Which says mining can lead to “a loss of biodiversity and ecosystem functioning that is irreversible over multi-generational timescales.”

This year, the mineral company and the Trump administration decided to move forward rather than wait for the SEC to finalize its mining rule. Trump I fell that Executive order To accelerate seabed mining in US and international waters, and soon TMC Applied To obtain a permit under this process. Critics say that these moves violate international law, and this is what the Secretary General of the International Atomic Energy Agency, Letizia Reyes de Carvalho, did. He said This unilateral action to clear deep-sea mines “sets a dangerous precedent that could destabilize the entire global ocean governance system.”

The new research adds to those calls for caution. The mining process involves transporting the nodules along with seawater and sediment through pipes to a ship where the precious metals can be separated and collected. The remaining waste is pumped back into the ocean, but where exactly it will be buried in the vast abyss is still a big question.

the The twilight zone One option suggested by the industry is an intermediate depth of water, where sunlight disappears and is replaced by the dim light of luminous organisms. It is an area teeming with life, including small fish, crustaceans, and gelatinous creatures called… com.micronekton and Zooplankton They eat. Zooplankton devour particles of dead organic matter that drift into the twilight zone. The main problem with releasing waste plumes here is that they would flood the area with similarly sized sediment particles that could replace the zooplankton’s food source with a less nutritious alternative.

Researchers from the University of Hawaii at Manoa collected samples of water and particles before and during a small-scale test mining operation conducted in the Pacific Ocean in 2022. By comparing the concentrations of amino acids in the particles, a measure of their nutritional value, they found that particles from the waste plume were 10 to 100 times less nutritious. Dodd describes it as “fast food with almost no organic ingredients.”

“This will cause a bottom-up effect, where these zooplankton will initially starve, and can cause microorganism starvation and even starvation,” he says. Whales and large fish such as tuna and swordfish dive into the twilight zone to eat micronekton. Zooplankton also migrate toward the sea surface at night to feed before returning to the mid-ocean waters. They become food for other animals at varying depths in the process, and rituals also play a major role in transporting carbon to the depths of the sea to regulate Earth’s climate. For all these reasons, flooding the twilight zone with unwanted particles from mining waste is likely to have cascading effects on life throughout the depths of the ocean.

The paper suggests that releasing that waste into shallow waters, home to predators higher up the food chain, would likely pose similar or worse risks. There is little data available to understand what the effect might be deeper in the water column than the twilight zone, where scientists are still discovering New types Some species migrate from shallow depths to avoid predators. If companies are intent on deep-sea mining before they fully understand the risks, they may be able to mitigate some of the damage by returning sediment waste all the way to the seafloor where it was drilled. This is potentially a more complex and expensive endeavor than launching at shallower depths, which has scientists concerned about the impact cutting corners could have on marine life.

The study authors say Edge that although they received funding from the company, they retained the independence to publish their findings without Metals influencing their work.

The minerals company said in an email to Edge It plans to discharge the waste to a depth of 2,000 metres, below the twilight zone studied in the paper, “on the advice of the authors”. She claims that waste particles dissipate quickly, and that there are fewer zooplankton at that depth anyway. “Concern about midwater impacts is understandable, but the data has moved on, and so should the conversation,” Michael Clarke, TMC’s environmental director, said in an email.

Advances in battery technology and e-waste recycling could also reduce the need for mining. Automakers including Tesla, BYD and Ford They turned to alternatives to traditional rechargeable batteries that would eliminate or reduce the need for nickel and cobalt. Creating a more robust recycling infrastructure could also help ensure that electric vehicles and renewable energy sources such as wind and solar, which need rechargeable batteries, do not cause new environmental crises.

“We can recycle (electronic waste), and we can extract our waste,” says Brian Pope, co-author of the study and a professor in the UH Manoa School of Ocean and Earth Sciences and Technology. “We don’t need to dig deep to power the green revolution.”