Distribution characteristics of seamount cobalt-rich ferromanganese crusts and the determination of the size of areas for exploration and exploitation

Abstract

In 2001, the International Seabed Authority (ISBA) initiated the consideration relating to the Regulations for Prospecting and Exploration for Hydrothermal Polymetallic Sulphides and Cobalt-rich Ferromanganese Crusts in the Area at its 7th session. Since then, the consideration of the Regulations has been mainly focused on the size of areas to be allocated for exploration and exploitation of the crusts. This paper, based on the investigation data and the analysis of the distribution characteristics of the crusts, suggests a model for determining the size of areas for exploration and exploitation of the crusts, taking into account various factors such as production scale, crust thickness and grade, mineable area proportion, recovery efficiency, exploration venture, and so on. Through the modeling, the paper suggests that the exploration area (the area covered by each application for approval of a plan of work for exploration of cobalt-rich crusts) shall be 4 856 km 2 and the exploitation area (the mine site area) shall be 1 214 km 2 , for 20 years of 1 million wet tonnes annual production.

Marine Litter Distribution and Density in European Seas, from the Shelves to Deep Basins

“…Litter levels on seamounts, banks, mounds and ocean ridges were characterised by intermediate levels when compared to other physiographic settings. They are typically located far away from coastal areas where the main anthropogenic activities include fishing [79] and seabed mining [80] , [81] . The presence of litter on these settings is of concern because they harbor Vulnerable Marine Ecosystems (VMEs) (such as cold-water corals and hydrothermal vents) that have reduced capacity to recover from disturbance events and for which conservation is a global priority [82] .…”

Deep-Sea Robotic Survey and Data Processing Methods for Regional-Scale Estimation of Manganese Crust Distribution

“…Mn-crusts, nodules, or sediment deposits, which are compiled into estimates of distribution [4], [6]. However, manual labeling is time consuming, making it difficult to scale the operations to larger regions.…”

“…The different seafloor types present in the survey area can be classified into continuous Mn-crust deposits, Mn-nodules, and sediments [6]. Examples of each type are shown in Fig.…”

“…The northwestern Pacific ocean is known to have large Mn-crust deposits spread over several hundreds of square kilometers [3]- [5]. Mn-crusts vary from 10 to 250 mm in thickness and are found between a depths of more than 800 m, with reports of Mn-crusts as deep as 5700 m. These deposits contain cobalt, nickel, platinum, and various rare-earth elements, making them a potential target for mining [6]- [9]. However, the thickness of Mn-crust varies due to slope, seawater conditions, depth, historical landslides, and sediment cover [2].…”

CenSeam, an International Program on Seamounts within the Census of Marine Life: Achievements and Lessons Learned

“…Consequently, impacts from bottom-contact fishing can be massive, and recovery times may be in the range of decades to centuries [26] . Mining for mineral deposits on seamounts presents a new, and potentially large, threat to seamount ecosystems [27] , and emphasizes a need for global, scientifically robust conservation and management planning for seamounts [28] , [29] . The increasing biological research on seamounts [30] , coupled with these growing management concerns, led to the founding of the Global Census of Marine Life on Seamounts (CenSeam) in 2005 as part of the Census of Marine Life program.…”