In one of that group's publications, the percent of ocean floor area covered by manganese nodules is shown for approximately a 2,000,000 km2 area of the Pacific Ocean between the Clarion and Clipperton fracture zones in a region centred about 2,000 km southeast of Hawaii (Schultz-Westrum, 1973). On the basis of about 1,000 sample points, including some 200 photographic stations, a map was prepared showing the percent of sea floor covered by nodules. While the percent of the ocean floor covered by nodules is an interesting statistic and is of some general value in economic considerations, it is of little help in calculating the concentration of nodules in weight per unit area of 334 ECONOMIC ASPECTS OF NODULE MINING the ocean floor, which, from an economic standpoint, is a more important statistic, unless the size distribution of the nodules is also known for the specific area. Using the coverage data given by Schultz-Westrum (1973) and, assuming an average nodule size of 4 cm and an average coverage of nodules in the area surveyed of 20%, the tonnage of nodules contained in this area can be estimated to be about 15 billion metric tons. An average coverage of 20% of 4-cm diameter nodules of bulk nodule density of 2.0 would yield a surficial concentration of nodules of about 10 kg/m2 or about 10,000 metric tons per square kilometre. In some 15 areas covering a total of about 100,000 km2, the surface coverage is indicated to be in excess of 50%. The area of which this coverage data is given is also that of relatively high-grade nodules.

2014 Report ->The sampling activities and the program of investigations were concentrated on four selected working areas (WA) within flat seafloor regions of the western and eastern parts of the German license area (Fig. 2.3). WA-1 (Fig. 2.5) is located in the north of the western area. WA-2 (Fig. 2.6) lies within the second key prospective area PA-2, which is predominantly covered with small nodules < 4 cm. This area was selected as target for further investigations in order to determine its suitability for potential future mining. Moreover, the benthic living communities and the physical and chemical environment were investigated. WA-3 (Fig. 2.7) is located within the first key prospective area PA-1 that was explored in detail during cruise MANGAN 2013 and of which a substantial part is covered with large nodules. In WA-3, we recovered and redeployed three current meter moorings, in addition to the deployment of another current meter with a longer range that was deployed for the first time. Furthermore, multicorer and epibenthic sledge samples were recovered to study potential spatial and temporal differences in the biodiversity of the "impact reference area" (WA-3) and the “preservation reference area” (WA-4; Fig. 2.8) as compared to results from 2013. The recurrent investigation of biodiversity and environmental characteristics of these two reference areas will provide the basis for a future evaluation of the disturbance of the seafloor associated with possible tests of deep-sea mining equipment in the impact reference area. Figures 2.5 to 2.8 show the locations of sampling and observation deployments to study the four working areas.

2013 Report-> The sampling activities and the program of investigations were concentrated on three selected working areas (WA) within flat seafloor regions of the eastern German license area (Fig. 2.3). WA-1 (Fig. 2.5) and WA-2 (Fig. 2.6) are located within the key prospective area that was selected as target for further investigations in order to determine its suitability for potential future mining. WA-1 is predominantly covered with large manganese nodules whereas WA-2 is mainly covered with small nodules. These two areas have been explored for nodule abundances and the metal concentrations of nodules. Moreover, the benthic living communities and the physical and chemical environment have been investigated. WA-3 (Fig. 2.7) has been selected as "preservation reference area" and is situated about 60 km to the west of the prospective area which also represents the "impact reference area". The recurrent investigation of biodiversity and environmental characteristics of these two reference areas will provide the basis for a future evaluation of the disturbance of the seafloor associated with possible tests of deep-sea mining equipment in the impact reference area. Figures 2.5 to 2.7 show the locations where the sampling and observation devices were deployed to study the three working areas.

BGR Site-> The German industry is fully dependent on the import of metals such as manganese, copper, nickel and cobalt from foreign countries. In view of strong fluctuations in commodity prices, the BGR signed a contract for the exploration of polymetallic nodules in the Central North-eastern Pacific with the International Seabed Authority (ISA) in July 2006. The aim of such exploration in the forefront of industrial exploitation is to secure the supply of the above-mentioned metals to Germany in the long run. The German license area encompasses a total of 75,000 km2, divided into two regions with 15,000 km2 in the central part and 60,000 km2 in the eastern part of the manganese nodule belt. This deep-sea area located between Hawaii and Mexico has water depths of 4000 to 6000 meters and is densely covered with polymetallic nodules, also called manganese nodules, which are about 3 to 8 centimetres in diameter. They on average contain 30% manganese and about 3% of copper, nickel and cobalt. Especially these last three metals form an important future source of raw material. Further trace metals occurring in economically significant concentrations in the nodules are titanium, molybdenum, lithium and neodymium. The manganese nodule resource in the German license area comprises ca. 900 million tons wet weight, which translates to ca. 600 million tons dry weight.

The regulations on prospecting and exploration of manganese nodules adopted by the ISA require each contractor to gather environmental baseline data during the 15 years exploration phase. Based on such data, the likely effects of possible future mining can be estimated and assessed before intervention within the deep-sea realm actually takes place. Studies of benthic species composition, population densities and connectivity form the most important component of these environmental analyses. In addition to the collection of biological data, detailed analyses of the oceanographic and sedimentological characteristics of the license area must be carried out (e.g. current strengths and directions, particle concentrations in the water column, shear strengths, composition and grain size of the sediment, seafloor topography). In order to determine the possible effects of future mining on the fauna, contractors should use the above-mentioned baseline data to define pristine areas (Preservation Reference Zones) against which impacted areas (Impact Reference Zones) can be compared. To allow for comparability, both reference zones should have similar species compositions, species densities, nodule abundances and sedimentological characteristics. As the spatial distribution of manganese nodules is not uniform throughout the area, large undisturbed zones will remain in between economically attractive areas. The recolonisation of disturbed areas could then take place from these neighbouring unaffected zones. As part of the progression of mining operations from exploration to exploitation, each contractor is obliged to submit an Environmental Impact Assessment (EIA) to the ISA before any decision on future mining can be taken. The EIA will include the results of “pilot mining tests” with a nodule collector and the associated comparison of environmental characteristics before and after the test(s). The above-mentioned provisions by the ISA have been designed to safeguard the sustainable use and the effective conservation of the deep-sea realm.