scholarly journals RV SONNE Fahrtbericht/Cruise Report SO268 - Assessing the Impacts of Nodule Mining on the Deep-sea Environment: NoduleMonitoring, Manzanillo (Mexico) – Vancouver (Canada), 17.02. – 27.05.2019

2021 ◽  
Author(s):  
Matthias Haeckel ◽  
Peter Linke
Keyword(s):  
Environmental Impacts ◽  
Deep Sea ◽  
Industrial Test ◽  
Small Scale ◽  
Second Phase ◽  
Technical Problems ◽  
Fully Integrated ◽  
Polymetallic Nodules ◽  
Clarion Clipperton Fracture Zone ◽  
Nodule Mining

Cruise SO268 is fully integrated into the second phase of the European collaborative JPI-Oceans project MiningImpact and is designed to assess the environmental impacts of deep-sea mining of polymetallic nodules in the Clarion-Clipperton Fracture Zone (CCZ). In particular, the cruise aimed at conducting an independent scientific monitoring of the first industrial test of a pre-protoype nodule collector by the Belgian company DEME-GSR. The work includes collecting the required baseline data in the designated trial and reference sites in the Belgian and German contract areas, a quantification of the spatial and temporal spread of the produced sediment plume during the trials as well as a first assessment of the generated environmental impacts. However, during SO268 Leg 1 DEME-GSR informed us that the collector trials would not take place as scheduled due to unresolvable technical problems. Thus, we adjusted our work plan accordingly by implementing our backup plan. This involved conducting a small-scale sediment plume experiment with a small chain dredge to quantify the spatial and temporal dispersal of the suspended sediment particles, their concentration in the plume as well as the spatial footprint and thickness of the deposited sediment blanket on the seabed.

Impact of simulated deep-sea polymetallic nodule mining on sediment and pore-water geochemistry in prospective mining areas in the NE Pacific Ocean

2020 ◽  
Author(s):  
Jessica Volz ◽  
Laura Haffert ◽  
Matthias Haeckel ◽  
Andrea Koschinsky ◽  
Sabine Kasten
Keyword(s):  
Steady State ◽  
Pacific Ocean ◽  
Deep Sea ◽  
Surface Sediments ◽  
Small Scale ◽  
Mining Activities ◽  
Mining Equipment ◽  
Geochemical Conditions ◽  
Polymetallic Nodules ◽  
Ne Pacific

<p>Industrial-scale harvesting of deep-sea mineral resources, such as polymetallic nodules, is likely to have severe consequences for the natural environment. However, the effects of mining activities on deep‑sea ecosystems, sediment geochemistry and element fluxes are still poorly understood. Predicting the environmental impact is challenging due to the scarcity of environmental baseline studies and the lack of mining trials with industrial mining equipment in the deep sea. Thus, currently we have to rely on small-scale disturbances simulating deep-sea mining activities as a first-order approximation to study the expected impacts on the abyssal environment and ecosystem.</p><p>We have investigated surface sediments in disturbance tracks of seven small-scale benthic impact experiments, which have been performed in four European contract areas for the exploration of polymetallic nodules in the Clarion-Clipperton Zone (CCZ) in the NE Pacific Ocean. These small-scale disturbance experiments were performed 1 day to 37 years prior to our sampling program in the German, Polish, Belgian and French contract areas using different disturbance devices, such as dredges and epibenthic sledges. We show that the depth distribution of solid-phase Mn in the upper 20 cm of the sediments in the CCZ provides a reliable tool for the determination of the disturbance depth. We found that the upper 5–15 cm of the sediments were removed during various small‑scale disturbance experiments in the different contract areas. Transient transport‑reaction modelling for the Polish and German contract areas reveals that the removal of the surface sediments is associated with the loss of reactive labile organic carbon. As a result, oxygen consumption rates decrease significantly after the removal of the surface sediments, and consequently, oxygen penetrates up to tenfold deeper into the sediments inhibiting denitrification and Mn(IV) reduction. Our model results show that the return to steady state geochemical conditions after the disturbance is controlled by diffusion until the reactive labile TOC fraction in the surface sediments is partly re‑established and the biogeochemical processes commence. While the re-establishment of bioturbation is essential, steady state geochemical conditions are ultimately controlled by the burial rate of organic matter. Hence, under current depositional conditions, new steady state geochemical conditions in the sediments of the CCZ are reached only on a millennium-scale even for these small-scale disturbances simulating deep-sea mining activities.</p>

scholarly journals Physical and hydrodynamic properties of deep sea mining-generated, abyssal sediment plumes in the Clarion Clipperton Fracture Zone (eastern-central Pacific)

Elem Sci Anth ◽  
2019 ◽  
Vol 7 ◽  
Author(s):  
Benjamin Gillard ◽  
Kaveh Purkiani ◽  
Damianos Chatzievangelou ◽  
Annemiek Vink ◽  
Morten H. Iversen ◽  
...  
Keyword(s):  
Fracture Zone ◽  
Deep Sea ◽  
Transport Model ◽  
Dry Weight ◽  
In Situ Tests ◽  
Central Pacific ◽  
Polymetallic Nodule ◽  
Clipperton Fracture Zone ◽  
Clarion Clipperton Fracture Zone ◽  
Nodule Mining

The anthropogenic impact of polymetallic nodule harvesting in the Clarion-Clipperton Fracture Zone is expected to strongly affect the benthic ecosystem. To predict the long-term, industrial-scale impact of nodule mining on the deep-sea environment and to improve the reliability of the sediment plume model, information about the specific characteristics of deep-sea particles is needed. Discharge simulations of mining-related fine-grained (median diameter ≈ 20 μm) sediment plumes at concentrations of 35–500 mg L–1 (dry weight) showed a propensity for rapid flocculation within 10 to 135 min, resulting in the formation of large aggregates up to 1100 μm in diameter. The results indicated that the discharge of elevated plume concentrations (500 mg L–1) under an increased shear rate (G ≥ 2.4 s–1) would result in improved efficiency of sediment flocculation. Furthermore, particle transport model results suggested that even under typical deep-sea flow conditions (G ≈ 0.1 s–1), rapid deposition of particles could be expected, which would restrict heavy sediment blanketing (several centimeters) to a smaller fall-out area near the source, unless subsequent flow events resuspended the sediments. Planning for in situ tests of these model projections is underway.

scholarly journals Microbial communities associated with sediments and polymetallic nodules of the Peru Basin

2020 ◽  
Author(s):  
Massimiliano Molari ◽  
Felix Janssen ◽  
Tobias Vonnahme ◽  
Frank Wenzhöfer ◽  
Antje Boetius
Keyword(s):  
Community Composition ◽  
Deep Sea ◽  
Microbial Community Composition ◽  
Rrna Gene ◽  
Operational Taxonomic Units ◽  
Polymetallic Nodules ◽  
Relevant Role ◽  
Bacterial And Archaeal Communities ◽  
Clarion Clipperton Fracture Zone ◽  
And Function

Abstract. Industrial-scale mining of deep-sea polymetallic nodules will need to remove nodules in large areas of the seafloor. The regrowth of the nodules by metal precipitation is estimated to take millions of years. Thus for future mining impact studies, it is crucial to understand the role of nodules in shaping microbial diversity and function in deep-sea environments. Here we investigated microbial community composition based on 16S rRNA gene sequences retrieved from sediments and nodules of the Peru Basin (> 4100 m water depth). The nodule field of the Peru Basin showed a typical deep-sea microbiome, with dominance of the classes Gammaproteobacteria, Alphaproteobacteria, Deltaproteobacteria, and Acidimicrobiia. Nodules and sediments host distinct bacterial and archaeal communities, with nodules showing lower diversity and a higher proportion of sequences related to potential metal-cycling bacteria (i.e. Magnetospiraceae, Hyphomicrobiaceae), bacterial and archaeal nitrifiers (i.e. AqS1, unclassified Nitrosomonadaceae, Nitrosopumilus, Nitrospina, Nitrospira), and bacterial sequences found in ocean crust, nodules, hydrothermal deposits and sessile fauna. Sediment and nodule communities overall shared a low proportion of Operational Taxonomic Units (OTU; 21 % for Bacteria and 19 % for Archaea). Our results show that nodules represent a specific ecological niche (i.e. hard substrate, high metal concentrations and sessile fauna), with a potentially relevant role in organic carbon degradation. Differences in nodule community composition (e.g. Mn-cycling bacteria, nitrifiers) between the Clarion-Clipperton Fracture Zone (CCZ) and the Peru Basin suggest that changes in environmental setting (i.e. sedimentation rates) play also a significant role in structuring the nodule microbiome.

scholarly journals From principles to practice: a spatial approach to systematic conservation planning in the deep sea

2013 ◽  
Vol 280 (1773) ◽  
pp. 20131684 ◽  
Author(s):  
L. M. Wedding ◽  
A. M. Friedlander ◽  
J. N. Kittinger ◽  
L. Watling ◽  
S. D. Gaines ◽  
...  
Keyword(s):  
Conservation Planning ◽  
Deep Sea ◽  
Planning Process ◽  
Systematic Conservation Planning ◽  
Economic Interests ◽  
Socioeconomic Impacts ◽  
Ocean Management ◽  
International Seabed Authority ◽  
Clarion Clipperton Fracture Zone ◽  
Nodule Mining

Increases in the demand and price for industrial metals, combined with advances in technological capabilities have now made deep-sea mining more feasible and economically viable. In order to balance economic interests with the conservation of abyssal plain ecosystems, it is becoming increasingly important to develop a systematic approach to spatial management and zoning of the deep sea. Here, we describe an expert-driven systematic conservation planning process applied to inform science-based recommendations to the International Seabed Authority for a system of deep-sea marine protected areas (MPAs) to safeguard biodiversity and ecosystem function in an abyssal Pacific region targeted for nodule mining (e.g. the Clarion–Clipperton fracture zone, CCZ). Our use of geospatial analysis and expert opinion in forming the recommendations allowed us to stratify the proposed network by biophysical gradients, maximize the number of biologically unique seamounts within each subregion, and minimize socioeconomic impacts. The resulting proposal for an MPA network (nine replicate 400 × 400 km MPAs) covers 24% (1 440 000 km 2 ) of the total CCZ planning region and serves as example of swift and pre-emptive conservation planning across an unprecedented area in the deep sea. As pressure from resource extraction increases in the future, the scientific guiding principles outlined in this research can serve as a basis for collaborative international approaches to ocean management.

scholarly journals Impact of small-scale disturbances on geochemical conditions, biogeochemical processes and element fluxes in surface sediments of the eastern Clarion–Clipperton Zone, Pacific Ocean

2020 ◽  
Vol 17 (4) ◽  
pp. 1113-1131 ◽  
Author(s):  
Jessica B. Volz ◽  
Laura Haffert ◽  
Matthias Haeckel ◽  
Andrea Koschinsky ◽  
Sabine Kasten
Keyword(s):  
Steady State ◽  
Environmental Impact ◽  
Deep Sea ◽  
Surface Sediments ◽  
Small Scale ◽  
Mining Activities ◽  
Biogeochemical Processes ◽  
Geochemical Conditions ◽  
Element Fluxes ◽  
Polymetallic Nodules

Abstract. The thriving interest in harvesting deep-sea mineral resources, such as polymetallic nodules, calls for environmental impact studies and, ultimately, for regulations for environmental protection. Industrial-scale deep-sea mining of polymetallic nodules most likely has severe consequences for the natural environment. However, the effects of mining activities on deep-sea ecosystems, sediment geochemistry and element fluxes are still poorly understood. Predicting the environmental impact is challenging due to the scarcity of environmental baseline studies as well as the lack of mining trials with industrial mining equipment in the deep sea. Thus, currently we have to rely on small-scale disturbances simulating deep-sea mining activities as a first-order approximation to study the expected impacts on the abyssal environment. Here, we investigate surface sediments in disturbance tracks of seven small-scale benthic impact experiments, which have been performed in four European contract areas for the exploration of polymetallic nodules in the Clarion–Clipperton Zone (CCZ) in the NE Pacific. These small-scale disturbance experiments were performed 1 d to 37 years prior to our sampling program in the German, Polish, Belgian and French contract areas using different disturbance devices. We show that the depth distribution of solid-phase Mn in the upper 20 cm of the sediments in the CCZ provides a reliable tool for the determination of the disturbance depth, which has been proposed in a previous study from the SE Pacific (Paul et al., 2018). We found that the upper 5–15 cm of the sediments was removed during various small-scale disturbance experiments in the different exploration contract areas. Transient transport-reaction modeling for the Polish and German contract areas reveals that the removal of the surface sediments is associated with the loss of the reactive labile total organic carbon (TOC) fraction. As a result, oxygen consumption rates decrease significantly after the removal of the surface sediments, and, consequently, oxygen penetrates up to 10-fold deeper into the sediments, inhibiting denitrification and Mn(IV) reduction. Our model results show that the return to steady-state geochemical conditions after the disturbance is controlled by diffusion until the reactive labile TOC fraction in the surface sediments is partly re-established and the biogeochemical processes commence. While the re-establishment of bioturbation is essential, steady-state geochemical conditions are ultimately controlled by the delivery rate of organic matter to the seafloor. Hence, under current depositional conditions, new steady-state geochemical conditions in the sediments of the CCZ are reached only on a millennium scale even for these small-scale disturbances simulating deep-sea mining activities.

scholarly journals Impact of small-scale disturbances on geochemical conditions, biogeochemical processes and element fluxes in surface sediments of the eastern Clarion-Clipperton Zone, Pacific Ocean

2019 ◽  
Author(s):  
Jessica B. Volz ◽  
Laura Haffert ◽  
Matthias Haeckel ◽  
Andrea Koschinsky ◽  
Sabine Kasten
Keyword(s):  
Environmental Impact ◽  
Deep Sea ◽  
Surface Sediments ◽  
Small Scale ◽  
Mining Activities ◽  
Biogeochemical Processes ◽  
Mining Equipment ◽  
Transport Reaction ◽  
Element Fluxes ◽  
Polymetallic Nodules

Abstract. The thriving interest in harvesting deep-sea mineral resources, such as polymetallic nodules, calls for environmental impact studies, and ultimately, for regulations for environmental protection. Industrial-scale deep-sea mining of polymetallic nodules most likely has severe consequences for the natural environment. However, the effects of mining activities on deep-sea ecosystems, sediment geochemistry and element fluxes are still poorly conceived. Predicting the environmental impact is challenging due to the scarcity of environmental baseline studies as well as the lack of mining trials with industrial mining equipment in the deep sea. Thus, currently we have to rely on small-scale disturbances simulating deep-sea mining activities as a first-order approximation to study the expected impacts on the abyssal environment. Here, we investigate surface sediments in disturbance tracks of seven small-scale benthic impact experiments, which have been performed in four European contract areas for the exploration of polymetallic nodules in the Clarion-Clipperton Zone (CCZ). These small-scale disturbance experiments were performed 1 day to 37 years prior to our sampling program in the German, Polish, Belgian and French contract areas using different disturbance devices. We show that the depth distribution of solid-phase Mn in the upper 20 cm of the sediments in the CCZ provides a reliable tool for the determination of the disturbance depth, which has been proposed in a previous study (Paul et al., 2018). We found that the upper 5–15 cm of the sediments were removed during various small-scale disturbance experiments in the different exploration contract areas. Transient transport-reaction modelling for the Polish and German contract areas reveals that the removal of the surface sediments is associated with the loss of reactive labile organic carbon. As a result, oxygen consumption rates decrease significantly after the removal of the surface sediments, and consequently, oxygen penetrates up to tenfold deeper into the sediments inhibiting denitrification and Mn(IV) reduction. Our model results show that the post-disturbance geochemical re-equilibration is controlled by diffusion until the reactive labile TOC fraction in the surface sediments is partly re-established and the biogeochemical processes commence. While the re-establishment of bioturbation is essential, the geochemical re-equilibration of the sediments is ultimately controlled by the burial rates of organic matter. Hence, under current depositional conditions, the new geochemical equilibrium in the sediments of the CCZ is reached only on a millennia scale even for these small-scale disturbances simulating deep-sea mining activities.

scholarly journals Extent of impact of deep-sea nodule mining midwater plumes is influenced by sediment loading, turbulence and thresholds

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Carlos Muñoz-Royo ◽  
Thomas Peacock ◽  
Matthew H. Alford ◽  
Jerome A. Smith ◽  
Arnaud Le Boyer ◽  
...  
Keyword(s):  
Fracture Zone ◽  
Deep Sea ◽  
Environmental Concern ◽  
Field Studies ◽  
Research Activity ◽  
Polymetallic Nodule ◽  
Commercial Scale ◽  
Clipperton Fracture Zone ◽  
Clarion Clipperton Fracture Zone ◽  
Nodule Mining

AbstractDeep-sea polymetallic nodule mining research activity has substantially increased in recent years, but the expected level of environmental impact is still being established. One environmental concern is the discharge of a sediment plume into the midwater column. We performed a dedicated field study using sediment from the Clarion Clipperton Fracture Zone. The plume was monitored and tracked using both established and novel instrumentation, including acoustic and turbulence measurements. Our field studies reveal that modeling can reliably predict the properties of a midwater plume in the vicinity of the discharge and that sediment aggregation effects are not significant. The plume model is used to drive a numerical simulation of a commercial-scale operation in the Clarion Clipperton Fracture Zone. Key takeaways are that the scale of impact of the plume is notably influenced by the values of environmentally acceptable threshold levels, the quantity of discharged sediment, and the turbulent diffusivity in the Clarion Clipperton Fracture Zone.

Sign in / Sign up

Export Citation Format

Share Document