Environmental and industry leaders from countries around the south Pacific met this week to discuss the pros and cons of the emerging deep sea mining industry. The deep sea is home to a variety of mineral formations including manganese nodules, seafloor massive sulfides, and cobalt rich crusts.
Each type of formation contains different types of valuable metals (gold, silver, nickel, cobalt, tellurium, and manganese) and is a component of the ecosystem of a variety of unique sea life including giant tube worms, iron-plated scaly foot snails, and a host of blind crustaceans and fish.
Researchers have known for a while that in some parts of the ocean, the deep sea floor is heavily littered with lumps of manganese and more recently, gold and other precious metals have been discovered near hydrothermal vents. What has changed, however, is that rising metal prices and improved technology make deep sea mining economically feasible – even if it’s practical feasibility is completely unproven at this point.
The Environmental Debate: Pros and Cons
The sentiments of environmentalists and research scientists toward deep sea mining range from cautious to outraged. Mining on land has a bad environmental track record, to say the least, so the idea of reducing terrestrial mining and supplementing the industry with deep sea mining has a certain appeal. However, a frightening concept for some is how little we know about deep sea ecosystems and how much information could potentially be lost as a result of damage caused by deep sea mining. The organisms living near these mineral deposits and sea vents, some as deep as 4000 meters below the surface of the ocean, display a myriad of specialized adaptations that allow them to live entirely without sunlight, at extreme pressure, and at temperatures that can vary from a few degrees Celsius to up to 400°C over as small a distance as an inch. New and exciting discoveries about the organisms that live at deep sea vents continue to be made and there is concern that both known and undiscovered organisms may be negatively impacted by deep sea mining.
Benefits to Local Economies
Many Pacific Island Countries (PIC) see deep sea mining as a source of income that has the potential to improve the education, health, and wealth of populations that often have limited natural resources. The economies of many PICs depend on royalties charged to foreign fishing fleets. Also, some have healthy, but generally small, eco-tourism industries. Many PICs, though, have not been able to raise development levels to the basic levels (known as the Millennium Development Goals). Deep sea mining could possibly offer Pacific Island Countries the economic potential to do so by providing a new tax base. In some cases, like Nauru and Papua New Guinea, Pacific Island Countries have even taken ownership stakes in deep sea mining companies.
Nautilus Minerals Paves the Way
Australian-based Nautilus Minerals is poised to be the first company to begin commercial mining for seafloor massive sulfides (SMS) near the hydrothermal vents of the Solwara system, in the Bismark Sea off of Papua New Guinea (PNG).
Because SMS deposits contain as much as 5 times the amount of copper and gold as the richest terrestrial deposits, Nautilus expects to be able to extract as much as $300 million of metals from only 0.1 km² of sea bottom. This high concentration of minerals over a small area means that environmental impacts are calculated to be much less than those from land-based mines. For instance, in deep sea mining, ore is brought to the surface as a mix of ore and seawater. The high concentration of copper and gold in the ore means that mining companies like Nautilus will try to keep as much of the solid material as possible, with the separated seawater being returned back to the deep sea (i.e. back to where it came from). In contrast, some terrestrial mines in PNG have permits to discharge tailings to the deep sea, allowing them to discharge a slurry of fine particles and water into the deep ocean. Over the 3-year life of the Solwara 1 project, Nautilus predicts that they will produce the same amount of deep sea discharge as 2 days of operation from a land-based gold mine that currently discharges tailings to the deep sea.
The company also is going to great lengths to minimize surface water pollution, returning sea water remaining after the ore extraction process directly to the seafloor. Over the course of its work, Nautilus expects to spend as much as 5% of gross income on environmental mitigation and monitoring – not including the research the company has already supported by hosting deep sea biologists on their exploratory cruises.
Of course, mining (like many other industries) is about the bottom line and it is not yet clear whether Nautilus’ environmentally conscious approach will prove profitable or if it will be mirrored by other deep see mining companies to come in the future. Only time, trial, and error will tell. As I proposed in my presentation to the High Level Briefing On the Status of Deep Sea Minerals in the Pacific (http://www.sopac.org/sopac/docs/director/Circular0211.pdf): we need to think, act, and then think again when it comes to analyzing, monitoring, and designing deep sea mining.