Neue von der Industrie unterstützte Forschung zeigt, wie Abfälle aus dem Tiefseebergbau weitreichende Auswirkungen auf Fische und ihre Nahrung haben könnten | Abflüsse aus dem Tiefseebergbau können die Nahrungsnetze im Mittelwasser stören

Article details:

>The race to mine battery minerals from the ocean floor would create a new stream of waste that could rob sea life of a critical food source, according to new research published today in the journal Nature Communications. That could have far-reaching effects across the ocean, potentially reaching larger fish like tuna that people depend on for food and livelihoods.
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>The findings come as President Donald Trump attempts to circumvent international law and give companies permission to mine the deep sea commercially, which has yet to happen anywhere in the world. The first company to apply for an international mining permit from the Trump administration actually funded this study. It might not have anticipated that the results of that research would raise another warning flag about deep-sea mining.
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>The study authors found that if mining operations release waste into the ocean’s “twilight zone,” about 200 to 1,500 meters below the surface of the sea, it could starve tiny animals called zooplankton and other creatures that eat them. That could have serious ramifications along entire food webs that connect predators and their prey, leading the scientists to argue there still needs to be more research into how to avoid potential risks.
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>“We’re trying to go against that [rush to mine] and put the brakes on this process. We don’t have the science to fully conclude what’s the best option,” says Michael Dowd, lead author of the study and an oceanography graduate student in the University of Hawai‘i at Mānoa School of Ocean and Earth Science and Technology. “Those current plans are going to cause severe impacts.”
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>This year, The Metals Company and the Trump administration decided to move ahead rather than wait for the ISA to finalize its mining code. Trump signed an executive order to fast-track seabed mining in US and international waters, and TMC soon applied for a permit under that process. Critics say these moves violate international law, and ISA secretary-general Leticia Reis de Carvalho has said that unilateral action to mine the deep sea “sets a dangerous precedent that could destabilize the entire system of global ocean governance.”
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>The new research adds to those calls for caution. The mining process involves transporting nodules along with seawater and sediments via pipe up to a ship where the valuable metals can be separated and collected. The leftover waste is pumped back into the ocean, but where exactly to dump it in the vast abyss is still a big question.
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>The twilight zone is one option that industry has proposed, considered a midwater depth — where sunlight disappears and is replaced by the dim light of bioluminescent organisms. It’s an area that’s busy with life, including small fish, crustaceans, and gelatinous creatures called micronekton and the zooplankton they eat. The zooplankton gobble up particles from dead organic material that drifts down into the twilight zone. A major problem with releasing plumes of waste here is that it would inundate the zone with similarly sized sediment particles that could replace the zooplankton’s food source with a less nutritious alternative.
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>The researchers from the University of Hawai‘i at Mānoa collected water and particle samples before and during a small-scale test mining operation TMC conducted in the Pacific Ocean in 2022. By comparing concentrations of amino acids in the particles, a measure of their nutritional value, they found that the particles from the waste plume were 10 to 100 times less nutritious. Dowd describes it as “junk food that has almost no organic material to it.”
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>“This will cause this bottom-up impact where first, these zooplankton will starve, and it can cause the micronekton and up to starve,” he says. Whales and bigger fish like tuna and swordfish dive down to the twilight zone to eat micronekton. Zooplankton also migrate up toward the sea surface nightly to feed before returning to the ocean’s midwater. They become food for other animals at varying depths in that process, and the ritual also plays a key role in transporting carbon deep into the sea to regulate Earth’s climate. For all these reasons, flooding the twilight zone with junk particles from mining waste is likely to have cascading effects on life at all depths of the ocean.
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>Releasing that waste in shallower waters, home to predators higher up on the food chain, is likely to pose similar or worse risks, the research paper notes. There’s little data available to understand what the impact might be further down in the water column than the twilight zone, where scientists are still discovering new species and where some species from shallower depths will migrate to avoid predators. If companies are hell-bent on mining the deep sea before even fully understanding the risks, they might be able to mitigate some harms by returning sediment waste all the way back down to the seafloor where they dug it up. This is likely a more complicated and costly endeavor than releasing it at shallower depths, however — and that has scientists concerned about the impact that cutting corners could have on sea life.

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Journal link:
[Deep-sea mining discharge can disrupt midwater food webs](https://www.nature.com/articles/s41467-025-65411-w)

Research abstract:

>The Clarion-Clipperton Zone contains extensive beds of polymetallic nodules on the abyssal seafloor, with vast areas (~1.5 million km2) under license for deep-sea mining. Mining companies have proposed discharging excess waste generated during nodule extraction in the lower mesopelagic and upper bathypelagic zones, which are home to a unique faunal community including zooplankton and micronekton. Here, using compound-specific isotope analysis of amino acids, we find that natural background particles larger than 6 µm form the base of the food web, but will be diluted by the same sized, nutritionally deficient mining-associated particles. Given that 53% of zooplankton taxa are particle feeders and 60% of micronekton taxa are zooplanktivores at proposed discharge depths, there is significant potential for food-web disruption. Therefore, we show that a midwater mining plume could trigger bottom-up ecosystem impacts with potentially severe consequences for the faunal community, extending beyond zooplankton and micronekton to nekton, including large marine predators.

My daughter is studying to be a marine biologist. Her teacher routinely gives them a talk on why deep sea mining is so bad and likely to kill off/pollute fish populations. It is a horrible money grab by some very unscrupulous people.

>if mining operations release waste into the ocean’s “twilight zone,” about 200 to 1,500 meters below the surface of the sea, it could starve tiny animals called zooplankton and other creatures that eat them.

A big if. You can google the schematics for nodule collection devices if you want to find out where the extra sediment will released. Hint – it’s not in the twilight zone

[https://deepseamining.ac/deep_sea_mining_equipment#gsc.tab=0](https://deepseamining.ac/deep_sea_mining_equipment#gsc.tab=0)

The article even addresses this, although OP obviously did not quote that part:

>The Metals Company said in an email to *The Verge* that it plans to discharge waste at a depth of 2,000 meters, below the twilight zone studied in the paper, “based on the authors’ advice.”

Will this negatively affect the abyssal ecosystem? Unfortunately, yes. It’s a lot less ecologically problematic than terrestrial mining though, and if we want to move away from fossil fuel, we’ll need to get these minerals from somewhere. Pick your poison