This article focuses on the recent progress in implementing robotics for making deep-sea mining ecologically sustainable.
Slow-growing polymetallic nodules found on the seabed contain precious minerals, such as manganese, pictured above. Image Credit: V.Gordeev/Shutterstock.om
The world is continuously evolving technologically, marked by scientific progress that fuels innovation across diverse sectors. Deep-sea mining is a process that is progressing rapidly owing to advances in scientific instruments. The deep-sea ecosystem holds a treasure of valuable minerals and substances, ranging from polymetallic nodules and hydrothermal vents to cobalt-rich ferromanganese crusts and rare earth elements. However, recent focus is on making the process of deep-sea mining sustainable and environmentally viable.
A Brief Overview of Deep Sea Mining
Deep-sea mining involves exploring the seabed or the ocean floor at significant depths to extract rare and highly valuable minerals, including cobalt, gold, and nickel. These minerals are not abundant and essential for manufacturing modern-day user products, such as rechargeable batteries and smartphones.
Research published in Environmental Law Review has identified three major deep-sea mining areas. The first area comprises abyssal plains or deep-water plains, which make up the seafloor where slow-growing polymetallic nodules, roughly resembling potatoes in shape and size, contain precious minerals like copper, manganese, nickel, and cobalt, the essential materials for modern battery technology.
The second significant region encompasses the metal-rich crust enveloping seamounts that rise thousands of meters above the abyssal plains.
Hydrothermal vents are among the highly explored areas during deep-sea bed mining. These vents emit superheated water with volcanic ridges. In these vents, mineral deposits rich in copper, lead, zinc, gold, and silver are found, making them a critical focus for mining exploration.
The deep-sea beds encompassing polymetallic nodules, hydrothermal vents, cobalt-rich ferromanganese crusts, and rare earth elements are being studied thoroughly for extraction. These resources are progressively gaining paramount importance for various industrial and technological applications.
Deep-Sea Mining: A Major Hazard to Marine Life
The deep sea represents the Earth's largest habitat, supporting an extensive range of unique species and ecosystems, making it a home of remarkable biodiversity. Research studies indicate that polymetallic nodules and sediments in this environment contribute significantly to habitat heterogeneity, a driving force behind deep-sea biodiversity.
During the exploration and drilling process, polymetallic nodules are almost destroyed. This damage can change the ocean's geochemical composition and result in numerous organisms' displacement from their habitats. Such massive changes in the ecosystem threaten the balance of deep-sea ecological systems.
The impacts of deep-sea mining extend beyond the immediate extraction of minerals. Discharged dredging spoils, marine litter, and the release of cooling or ballast waters by marine vessels associated with mining activities all adversely affect ocean ecosystems. The mining process itself also has the potential to release naturally occurring toxic compounds found on the ocean floor, further threatening the delicate balance of marine environments.
These cumulative impacts highlight the importance of carefully assessing and mitigating the environmental consequences of deep-sea mining operations. A sustainable approach leading to advancements in deep-sea mining is essential to aiding the efficient extraction of minerals and poses no significant dangers to living organisms.
Hurdles in Sustainable Deep Sea Mining Practices
Nature Communications has thoroughly reviewed the challenges the deep-sea mining industry faces in adopting a sustainable approach. Deep-seabed mining provides many challenges, with environmental uncertainties, vulnerabilities, and expenses ranking among the most prominent.
The vast remoteness of deep ocean locations and harsh operational conditions, such as high pressure, low temperatures, and darkness, necessitates using costly and highly specialized equipment. Consequently, these factors have led to limited exploration and scientific research in this domain.
Cobalt-rich crusts on seamounts represent one of the least explored habitat types, and consequently, their biodiversity remains poorly characterized. The absence of comprehensive disturbance studies conducted at realistic scales, both in terms of space and time, means that the exact intensity, duration, and consequences of the impacts associated with commercial mining remain largely unknown.
If deep-seabed mining continues to advance, adopting a precautionary and adaptive approach is imperative. This approach should prioritize integrating new knowledge and aim to prevent and minimize harm to habitats, communities, and overall ecosystem functionality.
Role of Robotics in Deep-Sea Mining
Robotics has emerged as a game-changing technology in deep-sea mining, particularly in its crucial role during the initial phases of resource exploration and mapping.
Underwater robots play an important role in deep-sea mining. As per an article published in Emerald Insight, remotely operated vehicles (ROVs) are underwater robots with tethered connections, extensively employed in deep-sea mining operations. They are powered and controlled through a physical link from the surface, managed by ship operators.
ROVs, equipped with robotic arms and specialized tools, can meticulously gather samples from the ocean floor. This automation guarantees the precision of sample collection, lowering the risk of contamination and minimizing waste.
The latest state-of-the-art perspective on deep-sea mining has been presented in the International Journal of Mining Science and Technology. The article states that various companies utilize auxiliary cutters (AC) and bulk cutters (BC).
In deep seabed mining operations, the AC is typically deployed for preliminary tasks, addressing intricate terrains, and establishing functional workspaces for other machinery.
On the other hand, the BC is a sizable track-mounted cutting machine designed to efficiently cut and grind large pieces, ensuring an effective and practical cutting process. Previously, conventional methods led to a loss of minerals and resource wastage.
A collecting robot is employed to manage the processed fragments, a substantial robotic vehicle capable of suctioning mineral fragments, seawater, and mud through an internal pump. Subsequently, the collected mineral material is transported through pipes into the riser and lifting system without material loss.
For polymetallic nodules, robotics has advanced to such an extent that a specialized subsea mining vehicle (SMV) is employed.
Operating at seabed depths averaging 6000 meters and facing water pressures of 60 MPa, the submersible mining vehicle (SMV) works in a challenging deep-sea environment characterized by high pressure, permeation pressure, and intricate submarine topography.
The SMV's capabilities extend beyond efficient mineral collection on the obstacle-laden, thin, soft seabed while following predetermined routes. It also excels in maintaining stability and controllability under these demanding conditions.
During the early 1980s, towed SMVs were frequently used in deep-sea mining trials, proving their technical feasibility. However, controlling towed SMVs was challenging, leading to their replacement by the self-propelled walking mode.
How Robotics Technology is Increasing Deep-Sea Mining Sustainability
Companies and governments worldwide are introducing sustainable techniques for deep-sea mining, including using robots.
A European Union-funded project titled ROBUST is helping to develop autonomous robots for deep-sea mining.
Researchers stated in their article published in IEEE that an autonomous underwater vehicle is an effective and environmentally non-intrusive system for mapping, surveying, and analysis designed to minimize its impact on the environment. Initially, the autonomous underwater vehicle examines the designated area of interest to identify a sub-area with the highest likelihood of containing a manganese nodule field.
Upon detecting a potential nodule, the vehicle descends and lands on the seafloor, enabling a specialized sensor attached to the manipulator's end-effector to conduct the nodule analysis. This approach ensures no unnecessary demolition or drilling, preserving the seabed environment.
A startup, Impossible Metals, completed the trial of its first autonomous underwater vehicle (AUV) ‘Eureka 1’. The robotics fleet is currently under development, employing advanced "pick and place" technology driven by artificial intelligence to carefully harvest nodules one by one.
This approach is aimed at minimizing disturbances to the sediment and seafloor ecosystems.
Image-sensing technology identifies the presence of megafauna on the nodules, ensuring that those nodules remain untouched to safeguard nodule-dependent fauna and their habitats.
Recent Technological Advances in Deep-Sea Mining
Concerning the development of modern robotics and new systems, deep-sea mining has taken a massive step forward. As per the latest article in the International Journal of Coal Science & Technology, developing novel monitoring techniques for efficiently monitoring deep seabed mining activities has been a critical focus.
A novel system has recently been tested to monitor real-time alterations in the physical and chemical characteristics of seawater and seabed boundary layers. This system measures parameters such as temperature, salinity, and pressure.
Monitoring of marine subsidence often relies on microelectromechanical systems (MEMS) accelerometers and inclinometers. A device utilizing MEMS sensors and microcontrollers for tracking changes in seafloor topography within underwater autonomous vehicles has recently been integrated. This will reduce costs and ensure the safety of microorganisms by reducing extra equipment and pollution.
Regulatory Considerations for Deep Sea Mining
The International Seabed Authority (ISA) is the primary regulatory body dealing with the development of regulations, mining rules and standard procedures governing seabed mineral resources.
It has issued contracts that allow the parties to explore an area of deep-sea bed in excess of 1.2 million km2. The present situation of deep-sea mining regulatory policies by the ISA has been analyzed thoroughly in the latest article published in Marine Policy.
The ISA has been working constantly on the Mining Code, a regulatory framework to standardize and oversee deep-sea mining activities. It is a comprehensive set of guidelines, principles and protocols that must be followed by any party involved in deep-sea mining.
After the development of the Mining Code, ISA started developing a specific set of principles for exploitation practices. Until 2023, the ISA has taken various crucial steps in the progression of these exploitation regulations. A major one is the development of Deep-Data, an internet-based repository for deep-mining data.
The study of deep-sea mining has a rich history. However, significant restrictions and limitations persist in its industrial exploitation, primarily stemming from the lack of comprehensive environmental baseline and monitoring data.
The utilization of robotics has improved the deep-sea mining industry. With the fabrication of modern and better sensors and advanced hardware, robotics will continue to increase the revenue generated by the deep-sea mining industry.
Continue Reading: Using Digital Twins for 3D Visualization of Deep-Sea Mining Operations
References and Further Reading
Cordis European Commission, 2022. A high-tech robotic diver analyses the Earth’s mineral riches on the ocean floor. [Online] Available at: https://cordis.europa.eu/article/id/413476-a-high-tech-robotic-diver-analyses-the-earth-s-mineral-riches-on-the-ocean-floor [Accessed 11 September 2023].
Impossible Metals, 2023. NODULE HARVESTING. [Online] Available at: https://impossiblemetals.com/technology/robotic-collection-system/ [Accessed 10 September 2023].
The London School of Economics and Political Sciences (LSE), 2023. What is deep-sea mining and how is it connected to the net zero transition?. [Online] Available at: https://www.lse.ac.uk/granthaminstitute/explainers/what-is-deep-sea-mining-and-how-is-it-connected-to-the-net-zero-transition/ [Accessed 9 September 2023].
Fast Company. (2022). This massive robot is designed to harvest EV metals from the ocean. But can it be done sustainably? [Online] Available at: https://www.fastcompany.com/90822101/massive-robot-ev-metals-ocean-sustainably
Sartore, C. et. al. (2019). Autonomous deep sea mining exploration: the EU ROBUST project control framework. In OCEANS 2019-Marseille (pp. 1-8). IEEE. Available at: https://www.doi.org/10.1109/OCEANSE.2019.8867075
Levin, L. et. al. (2020). Challenges to the sustainability of deep-seabed mining. Nature Sustainability, 3(10), 784-794. Available at: https://doi.org/10.1038/s41893-020-0558-x
Farran, S. (2022). Deep-sea mining and the potential environmental cost of ‘going green’in the Pacific. Environmental Law Review, 24(3), 173-190. Available at: https://www.doi.org/10.1177/14614529221114947
Robert, B. (2015) Underwater robots: a review of technologies and applications. Industrial Robot: An International Journal, Vol. 42 (3). Available at: http://dx.doi.org/10.1108/IR-01-2015-0010
Liu, Z. et. al. (2023). Deep-sea rock mechanics and mining technology: State of the art and perspectives. International Journal of Mining Science and Technology. Available at: https://doi.org/10.1016/j.ijmst.2023.07.007
Guo, X. et. al. (2023). Deep seabed mining: Frontiers in engineering geology and environment. International Journal of Coal Science & Technology, 10(1), 23. Available at: https://doi.org/10.1007/s40789-023-00580-x
Blanchard, C. et. al. (2023). The current status of deep-sea mining governance at the International Seabed Authority. Marine Policy, 147, 105396. Available at: https://doi.org/10.1016/j.marpol.2022.105396