There is treasure beyond imagination in the ocean depths: life forms, unique systems, and structures vital to sustaining Earth and the people on it. But buried within are monetary riches too – minerals that can be sold to industry. Companies want to extract them for profit, but they can’t be removed painlessly. The price will be the destruction of the deep. We have a choice to make about what we value more.
About the deep sea
The deep sea is one of the most remote, diverse, and mysterious places on Earth. Its dark, cold depths lie 200 metres to 11 kilometres beneath the ocean surface, and its rich ecosystems help make the planet habitable for humankind.
But life here is also extremely fragile. Scientists are only just beginning to uncover the secrets of the deep, but they do know that many of the creatures here are slow to reproduce and exquisitely adapted to a slow-changing environment. Human disturbance can have a devastating effect.
Why the deep sea is important?
The deep sea is vital to our climate systems. It helps drive the global currents that keep temperatures and weather regulated. It stores massive amounts of carbon that might otherwise contribute to global heating. The deep seabed supports some of the most unique ecosystems on the planet.
Scientists believe these may be as diverse as the world’s richest tropical rainforests and are excited that discoveries about life here are providing new routes for medicine and clues about the beginnings of life on Earth. The test being used to diagnose COVID-19 was developed using an enzyme isolated from a microbe found in deep sea hydrothermal vents.
The threat from mining
Among the riches of the seabed, deeply embedded into its ecosystems, are minerals – copper, cobalt, nickel, manganese, and silver. Their potential industrial value means that prospectors are keen to extract them, so a new, highly speculative, deep-sea mining industry is growing. Three types of mining are planned: sucking up polymetallic nodules from the abyssal plains; stripping cobalt crusts from seamounts; and pulverizing unique hydrothermal vents to extract polymetallic sulfide.
There is a real possibility that mining on of the sea floor will be permitted very soon, with initial exploratory licences being issued over an area of 1.3 million square km. The area affected could be far larger than that. And there are unknown consequences for deep-sea ecosystems and wider ocean systems.
What the scientists say
Many scientists believe that deep-sea mining will cause so much damage that ecosystems and biodiversity will not recover – at least for many thousands of years. Species may be driven to extinction. Mining will generate huge plumes of sediment and toxic wastewater, possibly spreading thousands of kilometres beyond the mining site.
What effect will this have on filter feeders, or creatures that find each other using bioluminescence? Will the noise of mining make it harder for animals to find prey using sound? What will happen to the remarkable creatures that rely on the nodules, seamounts, and vents as their home? Many scientists do not think that it is possible to mine the deep without causing irreparable damage and loss.
How deep-sea mining is progressing
Many mining companies are now exploring potential deep-sea sites using advanced robotics. They are working hard to convince politicians and the public of the potential benefits of deep-sea mining, downplaying the effects on the ocean and its creatures. A few countries actively support exploration because they believe it may bring them economic benefits.
But one Pacific country, Papua New Guinea, has already lost tens of millions of US dollars of its investment and its government now wants a moratorium (official global delay) on deep-sea mining. Opposition from scientists and many civil society organizations is growing. They say the impacts are poorly understood and the consequences unacceptable. They are also asking questions about the effectiveness of the international bodies that are supposed to be protecting the deep sea.
Why deep-sea mining is unnecessary
Companies and some governments say that we need to harvest metals from the deep. They say that land-based mining isn’t producing enough of the metals such as cobalt, nickel and copper that we need to move to cleaner energy sources. But this isn’t true. New, better and more sustainable solutions are being developed all the time and we can start with better design and recycling of the metals already available.
Through innovation, sustainable consumption and production, reuse, recycling and transforming economies we can make better choices about what we use and how we use it. At a time when we are witnessing how humanity can suffer if we do not respect nature, the risks posed by deep-sea mining seem greater than ever.