Decades of deep sea mining research show threat to seafloor creatures

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There's increasing interest in deep-sea mining, but the impacts that this will have on the animals that live in the depths isn't fully understood. A new review led by our scientists is giving us our first insight into how this industry might affect some of the remotest environments in the world.

In recent decades, commercial interest has turned to the deep sea.

Lying at the bottom of the ocean and surrounding deep-sea vents is thought to be a wealth of minerals that include critical metals. Numerous countries and companies now want to mine these regions.

But the deep sea is also home to a myriad of incredible species found nowhere else on Earth. Many people are deeply concerned that mining will irrevocably damage this ecosystem and put these animals at risk.

A new review has now gone through more than 50 years of scientific papers and data to see if a clearer picture can be formed as to what any impacts might be. The results are mixed.

The analysis shows that the visible impacts on some deep-sea environments, such as the abyssal plains, could last decades. However, we still don't have enough data to understand the impacts on other key regions, such as around hydrothermal vents. When it comes to the animals that live down there, similar questions remain.

Professor Adrian Glover is one of our deep-sea researchers and led this latest review.

"It is surprising that such a major environmental issue has not yet been comprehensively reviewed in the scientific literature," says Glover.

"Over the course of two years we reviewed more than 200 published and unpublished reports on the environmental impacts of deep-sea mining with a focus on studies of the baseline biodiversity in the regions targeted, and experimental work that measured the actual impacts of mining tests."

While mining will inevitably lead to a loss of biodiversity in the immediate region affected, the recovery of the two environments significantly differs. There's evidence, for example, that the abyssal plains could recover to a certain extent, but the picture is less clear for the vents.

The review has been published in the journal Current Biology.

Interest in the deep

The deep sea covers more than 50% of Earth's surface, making it the largest and yet least known environment on the planet.

This vast area is dominated by the abyssal plains. These are huge, silty regions that stretch uninterrupted for thousands of kilometers across the ocean floor. Usually found at least 3,000 meters below the surface, they experience huge amounts of pressure, perpetual darkness and near-freezing temperatures.

Yet despite this, the deep sea is teeming with life. The abyssal plains are home to countless species of polychaete worms, crustaceans, echinoderms and sponges. Many of these species haven't been described by scientists yet.

But the abyssal plains aren't the only environment down there. Dotted across the sea floor, towering hydrothermal vents rise from the depths. These vents spew geothermally heated water, which powers an extraordinarily rich ecosystem filled with tube worms, crabs, shrimps and snails.

However, these regions are also covered in economically valuable minerals. The abyssal plains are littered with what are called polymetallic nodules, while the vents are encrusted with cobalt, gold and copper. For decades this has made them a target for mining companies, as these minerals may help the world transition to a greener, more sustainable technology.

Opponents to mining have argued that these regions are so sensitive and pristine that any industrial activity will damage the ecosystems beyond repair. But the reality is we simply know so little about what the impacts could be that it's hard to come down on one side or the other.

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In a bid to address this knowledge gap, Glover has worked with colleagues to compile and study everything that's known to date about these impacts. The team found that while some effects are known for nodule mining on the abyssal plains, almost nothing is known about the impacts of mining on deep-sea vents.

"An important distinction we highlight is the difference between mining polymetallic nodules, hydrothermal vents and seamounts," explains Glover. "These systems could not be more different.

"Active vents and seamounts host extraordinary ecosystems rich in unique species, and it is clear that major disturbance at these sites would not be scientifically compatible with policy on biodiversity that almost all nations have already agreed to.

"For nodule mining, some simple scientific steps would help to resolve the risk of biodiversity loss, which is still mostly unknown. For example, supported by our scientific community, the regulator has already set up a protected area system that covers 30% of the main targeted region."

Debates continue as to whether or not governmental bodies should allow mining to occur in these regions, which are often outside of international jurisdiction. But what's clear is we need more studies, such as this one, to fully understand and mitigate the risks of industrial activity. Glover and his lab are continuing the work to find out exactly what lives in the deep sea and how it could be impacted by us.

Publication details

Adrian G. Glover et al, The environmental impacts of deep-sea mining, Current Biology (2026). DOI: 10.1016/j.cub.2026.03.014

Journal information: Current Biology

Key concepts

mining and quarryingcritical mineralsmineral depositsbenthic ecosystemsExtreme EnvironmentsHydrothermal Vents

Provided by Natural History Museum

This story is republished courtesy of Natural History Museum. Read the original story here