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Deep Ocean Mining: Dawning Of New and Reborn Industries
Scotiabank Marine Geology Research Lab
University of Toronto,
President, Marine Mining Consultants
The vast majority of our minerals are mined from the one-quarter of our planet that is ice-free land. Both the shallow continental margins and the ocean basins, which, with seas, constitute 71 percent of the surface of Earth, harbor mineral resources whose economic potential, especially those in the deep basins, we are only beginning to appreciate.
Marine mining is not new. For more than 100 years, there has been recovery of gold, heavy minerals containing tin, titanium, zirconium and others, and aggregates from beaches and contiguous shallow waters. Present-day recovery of gem-quality diamonds from the shallow seabed off the Atlantic coast of southern Africa is a multibillion-dollar industry utilizing advanced marine technologies.
In deeper water, the Chatham Rock Phosphate Ltd. (Wellington, New Zealand) is planning to dredge phosphate nodules on the Chatham Rise off the east coast of New Zealand's South Island at 450 meters depth. Phosphate is an essential ingredient of fertilizers that are important to the country's agrarian economy.
In even deeper waters, the robotic mining of seafloor massive sulfides (SMS) of copper, zinc, lead, silver and gold is anticipated to commence soon at 1,600 meters depth in the Manus Basin of the Bismarck Sea offshore eastern Papua New Guinea by Nautilus Minerals Inc. (Toronto, Canada). Neptune Minerals (St. Petersburg, Florida) is actively exploring the seabed of the Solomon Islands. Diamond Fields International Ltd. (Vancouver, Canada) and Manafa International Trade Co. of Saudi Arabia have a license to mine metalliferous muds at 2,000 meters depth in the Atlantis II Deep, a submarine basin in the Red Sea. The International Seabed Authority, whose jurisdiction covers international waters, has issued exploration permits for SMS in the Atlantic Ocean to Russia and France, and in the Indian Ocean to China and Korea.
At around 5,000 meters depth on the abyssal plains, manganese nodules, with their concentrations of nickel, copper, cobalt and manganese, are receiving renewed attention after a failed mining attempt in the 1970s and 1980s. The claim areas issued to countries by the International Seabed Authority are in the Clarion-Clipperton Zone between Hawaii and Mexico, and in the Indian Ocean. A significant development in unlocking the value of nodules for countries that do not have the wherewithal to explore and mine is the partnering of island nations with industry (Tonga with Nautilus Minerals) or with foundations (Nauru with the Nauru Education and Training Foundation and the Nauru Health and Environment Foundation the Republic of Nauru, which own Nauru Ocean Resources Inc.).
As with any new, large projects, there are important environmental issues. Deep excavations and large piles of broken rock that characterize mining sites on land are not a problem with ocean mining—the deposits are exposed on the seafloor with little or no sediment cover. The main issue for phosphates, sulfides and nodules is biological. In the case of sulfides, exotic colonies of animals proliferate in the warmer areas of hot springs that form the ores. These animals are likely to be destroyed during mining unless a solution can be found for their preservation, such as creating refuges. For phosphate and nodules, sediment plumes wafting down current from the mining machines may smother the gills of filter-feeding animals.
Unquestionably as well, there are technological challenges facing deep-ocean miners. The oil industry led the way into the offshore in the mid-20th century. Today, about one-third of world petroleum production comes from this source and is growing as technology allows for increasingly deeper installations. The mining industry can capitalize on offshore oil's experience. As land-based mineral resources become more difficult and expensive to find and recover, resulting in higher prices pushed by increasing demand, marine mining becomes even more attractive. Ocean mining will not replace mines on land but will be an additional source of raw materials needed by the global economy.