Environmental Science Marine Mining
Andrew David Thaler
  • LAST MODIFIED: 30 November 2015
  • DOI: 10.1093/obo/9780199363445-0047


In his underwater epic 20,000 Leagues Under the Sea (1869), Jules Verne speculated that the seafloor would one day yield untold mineral resources. Although he was correct, it would be nearly a century before the first marine mines became viable commercial prospects. This nascent industry has a short but complex history, with numerous stops and starts as the value of precious metals rises and falls. The first marine mines were established in the 1960s off the coast of Namibia, where fluvial diamond deposits could be found in relatively shallow (less than 400 meters) water. These diamond mines have remained in operation into the 21st century. Even with more than fifty years of continuous production, scientific evaluations of the environmental impact of offshore diamond mining on the surrounding marine environment are scarce. This phenomenon continues through the emergence of new marine mining industries, as technology and the promise of untapped mineral resources in the high seas progresses rapidly, with comprehensive environmental impact assessments conducted often in hindsight. Valuable marine mineral resources include manganese and phosphorite nodule deposits, cobalt-rich manganese crusts, polymetallic seafloor massive sulfides, and, most recently, rare-earth element-enriched sediment. The technologies needed to develop these mineral resources present a major barrier-to-entry for marine mining institutions and represent one of the largest bottlenecks to the successful establishment of a deep-sea mining industry. To date, and with the exception of offshore diamond mines, the marine mining ventures discussed in this article have yet to demonstrate commercial sustainability. As the marine mining industry matures and the inevitability of the first deep-sea mine draws closer, the scientific understanding of these ecosystems lags behind; conservation and policy initiatives are only beginning to be put into practice.

General Overview and Overarching Policy

Understanding the environmental consequences of mining in the ocean is a discipline still largely in its infancy. The deep sea provides essential ecosystem services that may or may not be threatened by the emerging deep-sea mining industry, described in Thurber, et al. 2014. The International Seabed Authority (ISA) has jurisdiction over seafloor mineral deposits that fall outside of states’ exclusive economic zones (EEZ) and is tasked with managing those resources “for the good of mankind,” summarized by Marvasti 1989. Currently, the ISA has adopted draft policies for the exploration and exploitation of manganese nodules (Clark, et al. 2013) cobalt-rich crusts (International Seabed Authority 2012) and seafloor massive sulfides (International Seabed Authority 2010), three of the potentially most profitable mineral resources. Although the ISA lacks jurisdiction within national EEZs, many nations have adopted policies informed by ISA regulations. Even as the marine mining industry makes significant progress in exploration and technological advancement, the regulations surrounding assessing and managing the environmental impacts of deep-sea mines, in particular, lag behind, according to Van Dover 2011, and include principles such as establishing baseline diversity measurements, assessing community connectivity, and identifying adequate and appropriate set-asides. Although the first era of deep-sea mining, beginning in the 1960s and ending in the mid-1980s, was considered an economic failure, documented by Glasby 2000, the future impacts of deep-sea mining, as outlined by Glover and Smith 2003, are uncertain.

Offshore Diamond Mining

Diamonds were discovered on the Namibian coast in the early 1900s, but it was not until 1957 that the first permits for offshore diamond exploration were issued (Garnett 2002). Over the next half-century, offshore diamond mining would grow from experimental development to a dominant force in the global diamond trade, producing 800,000 carats annually, a rate that now surpasses that of terrestrial diamond mining in Namibia, according to Garnett 2002. Offshore diamond deposits are the product of fluvial processes on the west coast of southern Africa, as described by Gurney, et al. 1991. As explained in Sutherland 1982, diamonds formed in inland kimberlite formation areas carried downstream by erosion and deposited on the coast over thousands of years. As the sea level varies over time, many of these coastal deposits are now situated at depths of up to 400 meters or more (Gurney, et al. 1991), while the process of fluvial sorting acts as a filter, resulting in offshore diamond deposits yielding high-quality gemstones, which renders the process of extracting offshore diamonds commercially viable (Sutherland 1982). The technology used in offshore diamond mining has evolved significantly over the last fifty years. Heavy drills and vacuum systems gave way to crawlers and other seafloor-based machinery that isolate the production process from the large ocean swells common off the southwest African coast, as described in Garnett 2002. The current generation of crawlers uses massive suction nozzles to draw up tons of seafloor sediment per hour to be sorted aboard support vessels. When the seafloor topology is not favorable, miners can switch to large-diameter drills to conduct vertical mining operations. Mining benthic substrate significantly alters the grain size of seafloor sediment; an assessment of grain-size fractionation revealed a transition from a unimodal grain-size distribution pre-mining, to a polymodal distribution post-mining, assessed in Rogers and Li 2002. This transition alters the available habitat for benthic fauna. A meta-analysis of environmental impacts of offshore diamond mining revealed that post-mining annelid abundance in the mined region fell by 50 percent, while bivalves and gastropods increased, potentially as an opportunistic response to organic enrichment of the sediments post-mining as determined by Savage, et al. 2001. However, coastal studies of the impact of fine-grain sedimentation produced by offshore diamond mining suggested minimal impacts on Jasus lalandii, a commercially important rock lobster studied by Pulfrich, et al. 2003. Despite the age and commercial success of offshore diamond mining, few longitudinal studies of the environmental impacts of this industry have been conducted.

  • Garnett, R. H. T. 2002. Recent developments in marine diamond mining. Marine Georesources & Geotechnology 20:137–159.

    DOI: 10.1080/03608860290051840Save Citation »Export Citation »E-mail Citation »

    Although more than a decade out of date, Garnett provides the most recent comprehensive review of the state of offshore diamond mining, its history, geology, technologies involved, and an overview of the key players in the industry.

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    • Gurney, J. J., A. A. Levinson, and H. S. Smith. 1991. Marine mining of diamonds off the west coast of southern Africa. Gems and Gemology 27:206–219.

      DOI: 10.5741/GEMS.27.4.206Save Citation »Export Citation »E-mail Citation »

      This accessible overview of the state of offshore diamond mining covers a range of important topics, including the commercial viability of the industry as well as a general overview of the geologic processes that created offshore diamond deposits.

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      • Pulfrich, A., C. A. Parkins, G. M. Branch, R. H. Bustamante, and C. R. Velásquez. 2003. The effects of sediment deposits from Namibian diamond mines on intertidal and subtidal reefs and rock lobster populations. Aquatic Conservation: Marine and Freshwater Ecosystems 13:257–278.

        DOI: 10.1002/aqc.543Save Citation »Export Citation »E-mail Citation »

        This study assesses the fate of a commercially important shellfish when exposed to fine-grain sediments that are the byproduct of both onshore and offshore diamond mining, but it does not detect significant changes in rock lobster abundance as a result of mining impacts.

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        • Rogers, J., X. C. Li. 2002. Environmental impact of diamond mining on continental shelf sediments off southern Namibia. Quaternary International 92:101–112.

          DOI: 10.1016/S1040–6182(01)00118-5Save Citation »Export Citation »E-mail Citation »

          One of the few studies that examine the environmental impacts of offshore diamond mining, this assessment of how mining alters sediment composition points to the potential for significant habitat alteration following offshore diamond mining.

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          • Savage, C., J. G. Field, and R. M. Warwick. 2001. Comparative meta-analysis of the impact of offshore marine mining on macrobenthic communities versus organic pollution studies. Marine Ecology Progress Series 221:265–275.

            DOI: 10.3354/meps221265Save Citation »Export Citation »E-mail Citation »

            This meta-analysis of the available environmental impact studies concludes that significant change to the taxonomic composition of marine communities occurs following mining, but that the currently available data makes it difficult to draw broad conclusions.

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            • Sutherland, D. G. 1982. The transport and sorting of diamonds by fluvial and marine processes. Economic Geology 77:1613–1620.

              DOI: 10.2113/gsecongeo.77.7.1613Save Citation »Export Citation »E-mail Citation »

              A geologic analysis of the process by which offshore diamond deposits are formed, this study also suggests that, due to sorting effects, offshore diamond deposits may be of higher quality than comparable onshore deposits.

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              Manganese and Phosphorite Nodules

              Manganese nodules form on the seafloor when iron and manganese hydroxides are deposited in concentric layers around a core, which can be comprised of anything from inorganic particles to diatom or radiolarian tests, described by Takematsu, et al. 1989. The chemical composition of manganese nodules varies significantly depending on region, geologic setting, and local water chemistry, but manganese nodules are often rich in nickel, copper, manganese, and cobalt, as well as rare-earth elements. These nodules are found throughout the Pacific and Antarctic Oceans in regions around the Antarctic Circumpolar Current, Southwest Pacific Basin, the Peru and Chile Basins, and regions around the Cook, Tahiti, and Tuamotu Islands, reviewed by Glasby 1976. The history of manganese nodule extraction is fraught with starts and stops, as the value of the resource rises and falls in a volatile global market. Hein, et al. 2010 describes recent technological developments that have made the prospect of exploiting seafloor manganese nodule economically viable, at least in principle. Manganese nodules are extracted from the seafloor using a variety of techniques, including continuous line buckets—8-km cables with regularly spaced collecting buckets—and more advanced hydraulic crusher/crawlers, according to the International Seabed Authority 2000. Phosphorite nodules, a related geologic phenomenon form on continental margins and seamounts, are known from both the Atlantic and Pacific Oceans. Baturin, et al. 1979 notes that these nodules are also being investigated as an exploitable resource. Researchers have only recently begun to understand the ecology of communities that thrives around manganese nodule fields. Nodules provide hard substrata for benthic marine species, which have been observed “maintaining” nodule structures by removing sedimentation from manganese nodules, thus preventing gradual burial or these slow-forming structures (Paul 1976). Mullineaux 1987 found that macrofaunal abundance at nodule fields is ten times that of background sediments, whereas infauna abundance shows a ten-fold reduction compared to background sediments. Manganese nodules brought to the surface are covered by an organic film comprised of filamentous bacteria (Burnett and Neilson 1981). In a baseline assessment of the potential impacts of crawler-style mining of manganese nodules in the Clipperton-Clarion Fracture zone, resuspension and deposition of marine sediments, as well as physical damage to the seabed, were identified as significant contributors to environmental impact (Oebius, et al. 2001).

              • Baturin, G. N., and P. L. Bezrukov. 1979. Phosphorites on the sea floor and their origin. Marine Geology 31:317–332.

                DOI: 10.1016/0025-3227(79)90040-9Save Citation »Export Citation »E-mail Citation »

                This paper provides a thorough overview of the formation, distribution, and composition of phosphorite nodules in marine systems, with several hypotheses regarding their formation.

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                • Burnett, B. R., and K. H. Neilson. 1981. Organic films and microorganisms associated with manganese nodules. Deep Sea Research Part A 28:637–645.

                  DOI: 10.1016/0198-0149(81)90124-2Save Citation »Export Citation »E-mail Citation »

                  This study assesses the microbial communities associated with manganese nodule deposits and examines the organic film of filamentous bacteria often found coating recovered nodules.

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                  • Glasby, G. P. 1976. Manganese nodules in the South Pacific: A Review. New Zealand Journal or Geology and Geophysics 19:707–736.

                    DOI: 10.1080/00288306.1976.10426315Save Citation »Export Citation »E-mail Citation »

                    Provides a comprehensive review of manganese nodule formation and geographic locations of nodule-rich regions.

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                    • Hein J. R., T. A. Conrad, and H. Staudigel. 2010. Seamount mineral deposits: A source of rare metals for high-technology industries. Oceanography 23:184–189.

                      DOI: 10.5670/oceanog.2010.70Save Citation »Export Citation »E-mail Citation »

                      This general interest review in the society journal Oceanography explores the economic prospects of several seafloor mineral deposits. Although the paper looks specifically at deposits found on seamounts, the information is generalizable to many marine deposits.

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                      • International Seabed Authority. 2000. Polymetallic nodules. In International Seabed Authority.

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                        This summary document from the ISA covers the fundamental principles behind manganese nodule formation and covers the technologies used in the extraction and processing of nodule resources.

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                        • Mullineaux, L. S. 1987. Organisms living on manganese nodules and crusts: Distribution and abundance at three North Pacific sites. Deep Sea Research Part A 34:165–184.

                          DOI: 10.1016/0198-0149(87)90080-XSave Citation »Export Citation »E-mail Citation »

                          One of the earliest and most thorough studies of the abundance and composition of organisms associated with deep-sea manganese nodule deposits, with a focus on comparative community composition at neighboring background sites.

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                          • Oebius, H. U., H. J. Becker, S. Rolinski, and J. A. Jonkowski. 2001. Parametrization and evaluation of marine environmental impacts produced by deep-sea manganese nodule mining. Deep Sea Research Part II 48:3453–3467.

                            DOI: 10.1016/S0967-0645(01)00052-2Save Citation »Export Citation »E-mail Citation »

                            Among the first critical assessments of the potential environmental damage caused by the most recent form of deep-sea manganese nodule mining using a crawler-and-riser system.

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                            • Paul, A. Z. 1976. Deep-sea bottom photographs show that benthic organisms remove sediment cover from manganese nodules. Nature 263:50–51.

                              DOI: 10.1038/263050a0Save Citation »Export Citation »E-mail Citation »

                              Although brief, this is one of the first studies documenting biological processes at manganese nodule fields.

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                              • Takematsu, N., Y. Sato, and S. Okabe. 1989. Factors controlling the chemical composition of marine manganese nodules and crusts: A review and synthesis. Marine Chemistry 26:41–56.

                                DOI: 10.1016/0304-4203(89)90063-7Save Citation »Export Citation »E-mail Citation »

                                This review provides a comprehensive overview of the chemical and geologic processes that regulate manganese nodule formation in marine systems.

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                                Cobalt-Rich Crusts

                                Cobalt-rich ferromanganese crusts are found around seamounts, submerged ridges, and other raised structures on the seafloor and are among the slowest-forming geological structures in the world, described in Manheim 1986. Cobalt-rich crusts are formed through the oxidation of iron and manganese, and they occur throughout the Pacific, particularly near volcanic islands and coral atolls (Hein, et al. 1992), at depths from 400 to 4,000 meters according to the International Seabed Authority 2008, and in smaller deposits in the Atlantic and Indian Oceans. These crusts are rich in cobalt, platinum, and manganese, as well as nickel, copper, molybdenum, yttrium, tellurium, and rare-earth elements; however, unlike manganese nodules, they can be found in much shallower regions, allowing for easier exploitation. Because much of late-phase cobalt-rich crust formation is regulated by biogeochemical processes, these crusts can act as hotspots for microbial diversity, although the actual microbial communities that occur on crusts remains poorly characterized, as explained in Huo, et al. 2015. Microbial communities on cobalt-rich crusts tend to have a higher bacterial diversity compared to archaeal diversity, demonstrated by Liao, et al. 2011. Because cobalt-rich crusts are often associated with seamounts, they tend to host large assemblages of benthic macrofauna, particularly invertebrates; these assemblages are often compositionally different from those in regions where cobalt-rich crusts are not found, as summarized by Schlacher, et al. 2014.

                                • Hein, J. R., M. S. Morrison, and L. M. Gein. 1992. Central Pacific Basin cobalt-rich ferromanganese crusts: Historical perspective and regional variability. In Geology and offshore mineral resources of the central Pacific basin. Edited by B. H. Keating and B. R. Bolton, 261–283. Earth Science Series 14. New York: Springer-Verlag.

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                                  This chapter provides a comprehensive overview of the history and geology of cobalt-rich ferromanganese crusts. It is a valuable resource for students looking for a comprehensive introduction to the field.

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                                  • Huo Y., Cheng H., A. F. Post, et al. 2015. Ecological functions of uncultured microorganisms in the cobalt-rich ferromanganese crust of a seamount in the central Pacific are elucidated by fosmid sequencing. Acta Oceanologica Sinica 34:92–113.

                                    DOI: 10.1007/s13131-015-0650-7Save Citation »Export Citation »E-mail Citation »

                                    This recent paper attempts to unravel the ecological role of the microbial community on cobalt-rich ferromanganese crusts in the Pacific. They demonstrate the prevalence of horizontal gene transfer within these communities.

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                                    • International Seabed Authority. 2008. Cobalt-rich crusts. In International Seabed Authority.

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                                      This brochure, produced by the ISA, provides a general overview of cobalt-rich crusts.

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                                      • Liao L., Xu X., Jiang X., et al. 2011. Microbial diversity in deep-sea sediment from the cobalt-rich crust deposit region in the Pacific Ocean. Microbial Ecology 78:565–585.

                                        DOI: 10.1111/j.1574-6941.2011.01186.xSave Citation »Export Citation »E-mail Citation »

                                        This paper is the first attempt to characterize the diversity of the microbial community at cobalt-rich ferromanganese crusts.

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                                        • Manheim, F. T. 1986. Marine cobalt resources. Science 232:600–608.

                                          DOI: 10.1126/science.232.4750.600Save Citation »Export Citation »E-mail Citation »

                                          The paper reviews the state of knowledge regarding the distribution and formation of cobalt crusts as well as providing context for both extraction and environmental monitoring.

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                                          • Schlacher T. A., A. R. Baco, A. A. Rowden, et al. 2014. Seamount benthos in a cobalt-rich crust region of the central Pacific: Conservation challenges for future seabed mining. Diversity and Distributions 20:491–502.

                                            DOI: 10.1111/ddi.12142Save Citation »Export Citation »E-mail Citation »

                                            One of the few comprehensive assessments of the benthic diversity associated with cobalt-rich crusts, this is a valuable resource for students looking for an overview of the conservation issues surrounding cobalt-rich crusts.

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                                            Seafloor Massive Sulphides

                                            Seafloor massive sulphides (SMS), ore deposits created by hydrothermal vent-activity, are among the most promising prospects for deep-sea mineral exploitation. Currently numerous entities, both state and private industry, have established leases in both the high seas and within national boundaries. Technological development has been rapid, and it is likely that the first deep-sea SMS mine will begin operation by the end of the 2010s. Unlike most other marine mining operations, there is a significant and growing body of literature looking at the potential environmental impact of these projects. Internationally, governing bodies have invested significant effort into establishing best-practice guidelines, while regional efforts have produced environmental impact statements and baseline ecologic and biodiversity surveys in anticipation of future impacts.

                                            General Overview

                                            Seafloor massive sulphides are formed concurrently with the formation of hydrothermal vents. Seawater, heated by proximity to a magma body, is forced upward through stockworks in the seafloor and contacts cold seawater, described in You and Bickle 1998. This causes heavy metals and other minerals to precipitate out of seawater and creates an ore body on the seafloor, reviewed in Hannington, et al. 2011. This ore body is rich in heavy metals such as copper, gold, and silver, summarized by Herzig and Hannington 1995. Due to the way SMS deposits form, there is minimal overburden, potentially making mining much more efficient, as explained in Hoagland, et al. 2010. Seafloor massive sulphides are not formed in all hydrothermal systems and appear to be much more common and ore-rich when associated with western Pacific back-arc basin spreading centers. However, prospects are currently being explored in all world oceans and up to 20 percent of all known hydrothermal vent systems fall within the boundaries of an ISA-issued exploration lease for SMS mining (reviewed in Beaulieu, et al. 2013). The environmental consequences of mining SMS deposits are highly dependent on the hydrothermal vent system. Hydrothermal vents are extremely dynamic ecosystems, and communities that form around vents on fast and ultra-fast spreading centers experience frequent disturbance, while vents on slow and ultra-slow spreading centers can persist for centuries (Van Dover 2010). Some prospects only include inactive vents, which, though no longer hosting iconic hydrothermal vent fauna, nevertheless support endemic communities that differ significantly from the surrounding seafloor. Although natural disturbance and recovery has been occasionally observed (for example, in Shank, et al. 1998), there is currently no in situ observation of vent recovery following anthropogenic disturbance.

                                            • Beaulieu, S. E., E. T. Baker, C. R. German, and A. Maffei. 2013. An authoritative global database for active submarine hydrothermal vent fields. Geochemistry, Geophysics, Geosystems 14:4892–4905.

                                              DOI: 10.1002/2013GC004998Save Citation »Export Citation »E-mail Citation »

                                              This meta-analysis covers all known hydrothermal vent systems in the InterRidge database and, among other variables, evaluates their proximity to current mining exploration leases.

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                                              • Boschen, R. E., A. A. Rowden, M. R. Clark, J. P. A. Gardner. 2013. Mining of deep-sea seafloor massive sulfides: A review of the deposits, their benthic communities, impacts from mining, regulatory frameworks and management strategies. Ocean and Coastal Management 84:54–67.

                                                DOI: 10.1016/j.ocecoaman.2013.07.005Save Citation »Export Citation »E-mail Citation »

                                                This is an essential, comprehensive review of the geology, ecology, and policy surrounding the mining of seafloor massive sulphides covering both management and potential mitigation strategies.

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                                                • Hannington, M., J. Jamieson, T. Monecke, S. Petersen, and S. Beaulieu. 2011. The abundance of seafloor massive sulfide deposits. Geology 39:1155–1158.

                                                  DOI: 10.1130/G32468.1Save Citation »Export Citation »E-mail Citation »

                                                  This paper evaluates the distribution of known seafloor massive sulphides and places them in the context of their mineral resources.

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                                                  • Herzig, P. M., and M. D. Hannington. 1995. Polymetallic massive sulfides at the modern seafloor: A review. Ore Geology Reviews 10:95–115.

                                                    DOI: 10.1016/0169-1368(95)00009-7Save Citation »Export Citation »E-mail Citation »

                                                    This review paper provides a comprehensive look at seafloor massive sulphides, how they form, where they are located, and what their mineral and heavy metal composition is, and also discusses the viability of seafloor mining.

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                                                    • Hoagland, P., S. Beaulieu, M. A. Tivey, et al. 2010. Deep-sea mining of seafloor massive sulfides. Marine Policy 34:728–732.

                                                      DOI: 10.1016/j.marpol.2009.12.001Save Citation »Export Citation »E-mail Citation »

                                                      This policy paper reviews the emergence of the deep-sea seafloor massive sulphides mining industry and proposes ways in which scientists can engage in the exploration process to facilitate environmentally responsible development.

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                                                      • Shank, T. M., D. J. Fornari, K. L. Von Damm, et al. 1998. Temporal and spatial patterns of biological community development at nascent deep-sea hydrothermal vents (9°50′N, East Pacific Rise). Deep Sea Research Part II 45:465–515.

                                                        DOI: 10.1016/S0967-0645(97)00089-1Save Citation »Export Citation »E-mail Citation »

                                                        This paper is the first to investigate a hydrothermal vent field following a catastrophic disturbance via volcanic eruption. As such, it is one of the few studies to look directly at the recovery of hydrothermal vents following a disturbance.

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                                                        • Van Dover, C. L. 2010. Mining seafloor massive sulphides and biodiversity: What is at risk? ICES Journal of Marine Science 68:341–348.

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                                                          This position paper takes a comprehensive look at the risk associated with mining seafloor massive sulphides and the potential effects that such a disturbance might have on hydrothermal vent ecosystems.

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                                                          • You, C.-F., and M. J. Bickle. 1998. Evolution of an active sea-floor massive sulphide deposit. Nature 394:668–671.

                                                            DOI: 10.1038/29279Save Citation »Export Citation »E-mail Citation »

                                                            This papers covers the geologic origins and formation of seafloor massive sulphides and discusses how geology influences the age and distribution of SMS systems.

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                                                            Solwara 1

                                                            Located in the Manus Basin, within the territorial waters of Papua New Guinea, Solwara 1 is slated to become the first deep-sea mine to begin production, as described in the environmental impact assessment by Coffey Natural Systems 2008. Solwara 1 will be mined using a trio of benthic crawlers in combination with a riser-and-lift system that will bring ore to the surface for processing. Numerous studies have been undertaken to characterize the ecology, diversity, and distribution of hydrothermal vent communities at Solwara 1, a nearby set-aside site, and a remote site, examined in detail in a series of papers by Thaler, et al. 2011; Plouviez, et al. 2013; and Thaler, et al. 2014. The general community structure was assessed at active and inactive vent sites in the region, and a series of population studies assessed the extent of connectivity among sites in the Manus Basin and between the sites in the Manus Basin and other western Pacific back-arc basins, described in Erickson, et al. 2009 and Collins, et al. 2012. Although these studies are only a first step, they represent the most comprehensive investigation into the environmental consequences of deep-sea mining available as of the mid-2010s.

                                                            • Coffey Natural Systems. 2008. Environmental Impact Statement: Nautilus Minerals Niugini Limited, Solwara 1 Project. Brisbane, Australia.

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                                                              The environmental impact assessment for the Solwara 1 mining prospect covers the geology, oceanography, and ecology of Solwara 1, as well as the proposed mining process.

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                                                              • Collins, P. C., R. Kennedy, and C. L. Van Dover. 2012. A biological survey method applied to seafloor massive sulphides (SMS) with contagiously distributed hydrothermal-vent fauna. Marine Ecology Progress Series 452:89–107.

                                                                DOI: 10.3354/meps09646Save Citation »Export Citation »E-mail Citation »

                                                                This paper lays out a comprehensive approach for conducting biological surveys at seafloor massive sulphides where future mining may occur and establishes best-practices for developing consistent ecologic baselines.

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                                                                • Erickson, K. L., S. Macko, and C. L. Van Dover. 2009. Evidence for a chemoautotrophically based food web at inactive hydrothermal vents (Manus Basin). Deep Sea Research Part II 56.19–20: 1577–1585.

                                                                  DOI: 10.1016/j.dsr2.2009.05.002Save Citation »Export Citation »E-mail Citation »

                                                                  This paper examines the community structure and diversity of species found at inactive hydrothermal vent sites in the Manus Basin and suggests that chemoautotrophy still plays a dominant role in the ecosystem.

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                                                                  • Plouviez, S., T. F. Schultz, G. McGinnis, H. Minshall, M. Rudder, and C. L. Van Dover. 2013. Genetic diversity of hydrothermal-vent barnacles in Manus Basin. Deep Sea Research Part I 82:73–79.

                                                                    DOI: 10.1016/j.dsr.2013.08.004Save Citation »Export Citation »E-mail Citation »

                                                                    This paper examines the population structure and connectivity of two barnacle species that occur at Solwara 1, throughout the Manus Basin, and across the southwestern Pacific.

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                                                                    • Thaler, A. D., S. Plouviez, W. Saleu, et al. 2014. Comparative population structure of two deep-sea hydrothermal-vent-associated decapods (Chorocaris sp. 2 and Munidopsis lauensis) from southwestern Pacific back-arc basins. PloS One 9:e101345.

                                                                      DOI: 10.1371/journal.pone.0101345Save Citation »Export Citation »E-mail Citation »

                                                                      This paper examines the population structure and connectivity of two arthropod species that occur at Solwara 1, throughout the Manus Basin, and across the southwestern Pacific.

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                                                                      • Thaler, A. D., K. Zelnio, W. Saleu, et al. 2011. The spatial scale of genetic subdivision in populations of Ifremeria nautilei, a hydrothermal-vent gastropod from the southwest Pacific. BMC Evolutionary Biology 11:372.

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                                                                        This paper examines the population structure and connectivity of a foundational, habitat-building snail species that occurs at Solwara 1, throughout the Manus Basin, and across the southwestern Pacific.

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                                                                        A significant body of policy has developed around mining seafloor massive sulphides, both nationally and internationally. The ISA has stringent requirements for maintaining a mining lease and establishing environmental baselines and establishing appropriate set-asides prior to the commencement of mining operations, according to the International Seabed Authority 2010. Even so, many experts believe that current policies are not adequate, and states pursuing nationalized mining operations within their own territorial waters are exempt from international regulations (Van Dover 2011). One promising proposal is the establishment of networks of chemosynthetic ecosystem reserves to act as buffers against mining impacts, described by Van Dover, et al. 2012, whereas others explore the potential for environmental restoration following mining events, as in Van Dover, et al. 2014. As the first deep-sea mine has yet to commence production, the future of deep-sea mining of seafloor massive sulphides and the potential environmental consequences remain uncertain, although Collins, et al. 2013 has proposed an effective model for establishing environmental baselines for mining operations at SMS deposits.

                                                                        Rare-Earth Element-Enriched Sediment

                                                                        The extraction of rare-earth elements (REE) directly from deep-sea sediment is among the most recent developments in the marine mining industry, having only recently been proposed as a possible source of mineral resources, as explained in Kato, et al. 2011. In some particularly rich regions, one square kilometer of seafloor sediment could meet one-fifth of the world’s current rare-earth element demand. Originally identified from the Pacific, similar deposits have also been found in the Indian Ocean (Yasukawa, et al. 2014). Deposits can form in situ as suspended rare-earth elements come out of solution in seawater or can be formed as rare-earth elements are transported by terrestrial river systems. As of the early 21st century, there are no studies regarding the environmental consequences of extracting rare-earth elements from the seafloor. Further confounding the situation, future increases in demand for rare-earth elements will be significantly influenced by the development and demand for renewable energy and sustainable technology such as wind turbines, solar panels, and electric vehicles, reviewed by Alonso, et al. 2012.

                                                                        • Alonso, E., A. M. Sherman, T. J. Wallington, et al. 2012. Evaluating rare-earth element availability: A case with revolutionary demand from clean technologies. Environmental Science and Technology 46:3406–3414.

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                                                                          This review covers the anticipated increased demand for rare-earth elements as driven by alternative energy and green technology development and concludes a significant increase in REE need.

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                                                                          • Kato, Y., K. Fujinaga, K. Nakamura, et al. 2011. Deep-sea mud in the Pacific Ocean as a potential resource for rare-earth elements. Nature Geoscience 4:535–539.

                                                                            DOI: 10.1038/ngeo1185Save Citation »Export Citation »E-mail Citation »

                                                                            This paper is the first to present a case for mining rare-earth elements directly from deep-sea sediments.

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                                                                            • Yasukawa, K., H. Liu, K. Fujinaga, et al. 2014. Geochemistry and mineralogy of REY-rich mud in the eastern-Indian Ocean. Journal of Asian Earth Sciences 93:25–36.

                                                                              DOI: 10.1016/j.jseaes.2014.07.005Save Citation »Export Citation »E-mail Citation »

                                                                              This paper assesses potential rare-earth element enriched sediment from the Indian Ocean.

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