Stillness. Stillness and balance until… humans.
Deep sea environments have become specially adapted over millions of years to take advantage of the darkness and undisturbed nature of the world 3 miles deep.
But then humans, inevitably, arrived to disrupt the peace. At first, it was the low rumble of industrialisation and our ever-growing shipping lanes but now a new threat is diving down into the deep. A huge, alien contraption is preparing to drill and sieve the seabed, wreaking relentless destruction on the seabed. In doing this they will kill thousands of organisms and destroy their homes in the process. Deep sea mining.
Deep-sea mining for metals to use in the latest tech would cause ecological damage that will take at least 50 years to recover.
The deep ocean remains the most poorly explored region on earth. It was once thought to be devoid of life but, increasingly, we are learning the contrary. Scientists discover new species on every exploration, each completely unique and finely tuned to the balance of life without a light source for energy. Life down here relies, instead, on chemical sources and the flurry of organic debris from waters above. However, the uniqueness of this habitat is fast becoming its greatest threat. Organisations are planning to mine these deep-sea habitats for valuable minerals but recent research has shown that, as well as the loss of various species, this would cause ecological damage on a microbial scale that will take at least 50 years to recover from.
Some areas of the seabed are scattered with rock formations containing rare metals and minerals, such as manganese, copper and cobalt. These formations are referred to as polymetallic nodules. Metals and minerals form in layers around a core which could be anything from part of a shell to a shark’s tooth fallen to the ocean floor. Polymetallic nodules form better at depth and need to be undisturbed if they are to accumulate in vast numbers which is why the deep-sea provides such a bountiful source, particularly around hydrothermal vents.
These natural, pre-historic phenomena are thought to be the origin of life on earth and, as well as hosting an astounding array of fascinating marine life, they are a source of many metals and minerals. These are often rare and are used in many modern-day electronics, including your smartphone which contains around 62 metals. Manganese, in particular, is highly sought after as it is to play a leading role in the next generation of rechargeable batteries. There is growing talk around the use of these metals in renewable energy, though this surely goes against everything renewable energy stands for. Either way, the demand for these metals makes them valuable to manufacturers and governments all over the world as a substitute for terrestrial mining, which is recognised as an environmental threat.
Despite the drive to exploit these resources, the process is not yet economically viable as each dive costs around $12 billion. Deep sea mining is both promoted and regulated by the International Seabed Authority (ISA) so they control much of the process. The pursuit of these potato-sized, valuable rocks has been in development since the 60s at a cost of billions of dollars already. Even after 60 years the process hasn’t been made cheap enough to turn a profit but the designs and contracts have been planned. Clearly these are some valuable rocks, but so far, not valuable enough. An area in the North Pacific, known as the Clarion-Clipperton Zone is being targeted as an area of ample supply. The plans cover an area the size of Europe and a number of countries have secured a region for themselves already which makes these regions exempt from marine protection. If the venture to mine this region follows through, the economic gain could be at the cost of an ecosystem. An ecosystem the size of Europe. For a long time, little consideration was given to the ecosystem in the deep-sea mining venture because little was known about its fragility, nor it’s importance. That is changing fast.
In recent years scientists have realised the value of deep-sea marine life. For example, there are 10 times the number of fish in the deep sea, referred to as the mesopelagic layer, than at the surface. These fish play a significant role in offsetting our carbon emissions, through their daily migrations up and down through the water column and their role in the storage of carbon in the sediment. It has been estimated that without mesopelagic fish, there would be 50% more carbon in the atmosphere than we see today which would make our earth uninhabitable for humans. These fish rely on the sea-bed and organisms living there which is why the deep sea must be protected from what is being exposed as an ecologically damning activity.
Surprisingly, the effects of deep-sea mining surpass fish and even crabs. Recent research has exposed the effects of deep-sea mining on a microbial scale!
In 1989, a deep-sea mining replication experiment was carried out across an 11km2 area in the Peru basin, deep in the south Pacific Ocean. The seabed here has a particularly nutrient rich surface layer made of manganese oxide which allows for high microbial activity in this habitat, but also means it is covered with valuable polymetallic nodules. In the experiment, the seabed was repeatedly ploughed, shifting the surface layer down and bringing the less productive bottom layers upwards. In this process many polymetallic nodules were either removed or became buried, which prevents them from growing.
Published in 2020 in Science Advances, a re-visit to the site carried out by a research team led by Tobias Vonnahme in 2015, 26 years later, unveiled the long-term impacts of such destructive activity. On the surface, nodules had not recovered and the tracks from 26 years ago were still visible. They found microbial abundance and activity to still be 30% less than undisturbed areas and was made worse by a secondary disturbance. Many other processes, such as those involved in carbon storage were, too, no longer evident. This is likely due to the loss of the manganese oxide surface which could prevent the habitat’s recovery. These activities remove organisms living in the sea floor but, worse than that, they are fundamentally destroying processes that such ecosystems rely on. It is this that prevents systems from recovering for what Vonnahme and his team estimate to be at least 50 years.
Since the publication of these results, no changes have been made to the plans to mine the Clarion Clipperton Zone in the North Pacific. However, the impacts of this on the deep-sea environment will have impacts on us too. Without the deep sea to remove the carbon we relentlessly pump into the atmosphere every day of every month of every year, our climate will continue to warm. As a result, weather events will get more extreme, warm days will get hotter and sea levels will rise enough to drown out entire regions. Climatic events like these will cost billions of dollars, and many lives, every year.
Is your mobile phone worth the potential cost of an ecosystem? The cost of lives?
This is not as much the consumers fault as it is the manufacturers, the mining organisations and the system as we know it. However, if we do nothing, nothing will change. We need to put pressure on manufacturers to make space for a circular economy of these metals. We have mined enough from earth already. We have no need to spend copious amounts of money on an ecologically damaging activity that 60 years of development cannot make economically viable. It’s time we took care of what we have and recycle our old tech into the new. After all, they’re made from the same stuff.
Effects of a deep-sea mining experiment on seafloor microbial communities and functions after 26 years, Vonnahme et al. 2020. Science Advances https://advances.sciencemag.org/content/6/18/eaaz5922.abstract