Back in 1870 when French author Jules Verne penned what was to become arguably his best known science fiction work he probably never envisioned that a mere 100 years later humans would be contemplating undersea mining! However, even though the mid 1900's discovery of mineral rich nodules on the seabed was tempting, land-based deposits of these minerals were more readily available and easily accessed. Thus, plans for harvesting them from the oceans' floors were shelved.
Fast-forward 50 years and, as land-based deposits begin to run dry, venturing under water to get these minerals has again become hot news. Thus figuring out how modern seabed mining methods will impact deep-sea ecosystems has now become a priority.
Twenty Thousand Leagues Under The Sea
In the meantime….
…. the world continues to need minerals that are increasingly harder to find, access, or ethically and sustainably dig up. For instance, over half the world's cobalt is supplied by a country whose mining practises are questionable at best. These types of issues can cause repercussions all the way along the supply chain as more and more companies get on board sustainable and ethical sourcing and production objectives. Various other significant sources of these essential minerals are in politically unstable regions of the world and so on. All of which makes getting them from the sea floor instead an attractive option.
A veritable treasure trove?
At the centre of current interest in deep-sea mining are 10 million year old polymetallic or manganese nodules that contain a range of minerals but most importantly, commercial quantities of cobalt, copper, manganese, and nickel. The nodules have formed as metals suspended in the ocean waters around vents in the sea floor precipitated out and aggregated around objects like small rocks and shells.
The nodules are predominantly found at depths of 4000 to 6500 metres on the abyssal plains. There are 2 main zones of commercial interest – the Clarion Clipperton Fracture Zone (CCZ) between the USA's west coast and Hawaii, and the Central Indian Ocean Basin. Current estimates for the CCZ are that the nodules there (covering around 9 million square kilometres of sea floor) contain 3 times more nickel and 6 times more cobalt than the sum total of all known land-based reserves of these minerals. Plus a lot of manganese and copper as well.
Two other zones of commercial significance are the Penrhyn Basin just off the Cook Islands and the Peru Basin situated in the southeast Pacific. The Clarion Clipperton Zone, Central Indian Ocean Basin, and Peru Basin are all located in international waters, which bring them under the jurisdiction of the International Seabed Authority (ISA). This is an intergovernmental body set up by the United Nations in 1994 to regulate deep-sea mining activities, notably around environmental issues. It's headquartered in Kingston, Jamaica. The Penrhyn Basin and various other smaller deposits closer to land generally fall within the jurisdiction of the country within whose exclusive economic zone (EEZ) it falls.
However, as previous mentioned, the potential biological and environmental impacts of deep-sea mining still pose more questions than have yet been answered. Significantly, scientists do know it takes around a million years for a nodule to grow just a few millimetres. And that it takes at least one thousand years to accumulate 1 millimetre of sediment on the deep ocean floor.
A big part of the problem is that current deep sea mining methods to harvest the mineral rich polymetallic nodules will disturb at least the top 10 centimetres of the sediment in which these nodules are lying. Further, it's calculated that some 120 square kilometres of seabed are likely to be 'mined' annually. If there are any ecosystems within these disturbed sediments it's going to take them a very (very) long time to recover.
Existing technology for collecting the nodules is via a vacuum like piece of equipment called, appropriately, a 'collector vehicle'. The vehicle, attached to a processing ship via hoses and pipes, is dropped into the water. When it reaches the ocean bed, it sifts through the top layers of sediment to collect the nodules. This creates a cloud of disturbed sediment (collector plume) that is then carried away and dispersed by the prevailing ocean currents. The nodules and any sediment sucked up with them are pumped back to the ship where further sorting separates out the nodules. The sediment is then returned to the ocean, creating a second 'discharge' plume.
Where, and how fast, the ocean currents subsequently disperse these sediment plumes is the subject of ongoing research by scientists at MIT's Environmental Dynamics Lab (END). Questions they require answers for include how will the sediments impact other ecosystems as they float through the water and as they drop back to the sea floor in other areas? Will the clouds of drifting sediment impact/choke the similarly floating food chains of various deep-sea marine creatures? Will the sediment bury other organisms on the sea floor when it eventually lands? All these and many other questions remain to be answered before deep-sea mining can comfortably be allowed to commence on a commercial scale.
Is deep sea mining really a good idea?
Many would suggest that it's probably not, or at least not just yet! This 'wait awhile' concept is in many ways a departure from history for mining. Once upon a time it was usually 'in like Flynn' as soon as the technology was available. Any potential environmental or health concerns were 'sorted' as and when they happened. If you did dare to raise questions, you were likely to be pegged as someone who simply wanted to impede progress and more often than not you'd find yourself flicked aside like a bothersome gnat.
Today, miners face a considerably different scenario. Today environmental, health, and safety issues caused by careless mining activities are headline news, and a major concern for a huge number of people. Thus we've gone from asking whether an ESIA (environmental and social impact assessment) 'should' be done as part of a project's pre-planning stages, to asking 'how' do we do one most effectively so as to ensure we can get permission to proceed.
Then there's that increasingly important social licence to operate; failure to obtain or maintain one of these has put many a spoke in many a mining project's wheels. Indeed, this 'licence' is now considered so important it's topped the list of major concerns for business executives for the second year running in Ernst and Young's Top 10 Business Risks and Opportunities 2020 report. The subject of obtaining a social licence also reveals another problem with the whole concept of deep-sea mining, one that goes beyond the already considerable environmental concerns.
A looming concern with deep-sea mining
Western societies are increasingly discovering that the world's oceans and their seabeds are an integral part of a whole traditional belief system for many indigenous peoples who consider all components of the environment to be intrinsically linked. Their world is viewed as a series of interdependent connections between themselves (beings), nature, and the guardian spirits who look after the various elements of nature. Thus, disturbing or destroying any part of the environment guarded by these spirits dramatically upsets the spiritual cosmos, with corresponding repercussions on the rest of the universe, and on the fundamental well being of life within that environment. In other words, to desecrate any one part is to desecrate the whole. These beliefs fly directly in the face of 'traditional' western concepts that tend to think of these watery oceanic environments as separate entities to dry land and therefore peripheral to human activities, particularly the deep sea environments.
Nautilus Mining found out the hard way though just how significant the ocean and ocean floor are to indigenous communities when their long-held licence to begin the first commercial deep-sea mining operation off the coast of Papua New Guinea (within that country's EEZ) met with an immovable object. Namely the objections of local indigenous communities who have long-held traditional and spiritual connections with the area, including the ocean floor that was to be mined!
As history records, the affected communities in the region took the PNG government, Nautilus, and their deep-sea mining plans to court, and won. In this instance, the defendants made the case that because they are so spiritually and physically connected with their environment, including the bits under water, removing pieces of it would be like removing pieces of themselves.
So it looks like those 10 million old 'gemstones' currently lying on the seabeds of the world's oceans are safe for at least a few years yet. And who knows – by the time scientists are ready to give it a green light those alternative energy storage solutions may be a commercial reality.