Study Reveals that Deep-Sea Mining Harms Over a Third of Seabed Animals

Fri Dec 05 2025 18:59:39 GMT+0200 (Eastern European Standard Time)

A new study conducted by scientists from leading institutions found that deep-sea mining operations significantly reduce animal populations and biodiversity on the seabed.

Machines mining for minerals in the deep ocean have been found to cause substantial ecological damage, with a study revealing that the number of animals living in the disturbed areas decreased by 37%. The research, which identified over 4,000 unique species in a remote Pacific area, has raised alarms over the environmental impact of proposed deep-sea mining operations, crucial for future green technologies.

Machines mining minerals in the deep ocean have been found to cause significant damage to life on the seabed, scientists carrying out the largest study of its kind say.

The number of animals found in the tracks of the vehicles was reduced by 37% compared to untouched areas, according to the scientists.

The researchers discovered more than 4,000 animals, 90% of which were new species, living on the seafloor in a remote area of the Pacific Ocean.

Vast amounts of critical minerals needed for green technologies could be locked in the deep ocean, but deep sea mining in international waters is very controversial and currently not permitted until more is known about the environmental impacts.

The research by scientists at the Natural History Museum in London, the UK National Oceanography Centre, and the University of Gothenburg was conducted at the request of deep sea mining company The Metals Company.

The scientists said their work was independent and that the company was able to view the results before publication but was not allowed to alter them.

The team compared biodiversity two years before and two months after the test mining that drove machines for 80km on the seafloor.

They looked specifically at animals 0.3mm – 2cm in size, such as worms, sea spiders, snails, and clams.

In the tracks of the vehicle, the number of animals fell by 37% and the diversity of species by 32%.

The machine removes about the top five centimeters of sediment. That's where most of the animals live. So obviously, if you're removing the sediment, you're removing the animals in it too, lead author Eva Stewart, PhD student at the Natural History Museum and the University of Southampton, told BBC News.

Even if they are not killed by the machine, pollution from the mining operations could slowly kill some less resilient species, said Dr. Guadalupe Bribiesca-Contreras from the National Oceanography Centre.

A few of the animals could have moved away, but whether or not they come back after disturbance is a different question, she added. However, in the areas near the vehicle tracks, where clouds of sediment landed, the abundance of animals did not decrease.

We were expecting possibly a bit more impact, but [we didn't] see much, just a shift in which species were dominant over others, Dr. Adrian Glover, research scientist at the Natural History Museum, told BBC News.

A spokesperson for The Metals Company expressed encouragement, stating that past activist concerns about widespread impact were unfounded and that biodiversity impacts were limited to mined areas. Experts, however, caution against large-scale commercial mining due to the significant impacts observed even during tests.

The latest research took place in the Clarion-Clipperton Zone, a vast area of the Pacific Ocean estimated to hold over 21bn tonnes of valuable polymetallic nodules. The minerals are crucial for renewable energy technologies aimed at combating climate change.

As the world’s demand for these minerals continues to rise, the debate over deep-sea mining intensifies, with many advocating for more environmentally friendly methods or a complete ban.

The research is published in the scientific journal Nature Ecology and Evolution.

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