Mining deep-ocean mineral deposits: what are the ecological risks?

A key question for the future management of the oceans is whether the mineral deposits that exist on the seafloor of the deep ocean can be extracted without significant adverse effects to the environment. The potential impacts of mining are wide-ranging and will vary depending on the type of metal-rich mineral deposit being mined. There is, currently, a significant lack of information about deep-ocean ecosystems and about potential mining technologies: thus, there could be many unforeseen impacts. Here, we discuss the potential ecological impacts of deep-ocean mining and identify the key knowledge gaps to be addressed. Baseline studies must be undertaken, as well as regular monitoring of a mine area, before, during, and after mineral extraction.The attached document is the author’s submitted version of the journal article. You are advised to consult the publisher’s version if you wish to cite from it

Biophysical models of persistent connectivity and barriers on the northern Mid-Atlantic Ridge

A precautionary approach to protecting biodiversity on mid-ocean ridges, while permitting seabed mining, is to design and implement a network of areas protected from the effects of mining. Such a network should capture representative populations of vent endemic fauna within regions of connectivity and across persistent barriers, but determining where such connectivity and barriers exist is challenging. A promising approach is to use biophysical modeling to infer the spatial scale of dispersal and the positions where breaks in hydrographic connectivity occur. We use results from a deep-sea biophysical model driven by data from the global array of Argo probes for depths of 1000 m to estimate biophysical connectivity among fragmented hydrothermal vent habitats along the Mid-Atlantic Ridge, from the equator northward to the Portuguese Exclusive Economic Zone surrounding the Azores. The spatial scale of dispersal varies along the ridge axis, with median dispersal distances for planktonic larval durations (PLDs) of 75 d ranging from 67 km to 304 km. This scale of dispersal leads to considerable opportunities for connectivity through mid-water dispersal. A stable pattern of five regions of biophysical connectivity was obtained for PLDs of 100 d or more. Connectivity barriers between these regions can persist even when planktonic larval duration extends beyond 200 d. For a 50 d PLD, one connectivity barrier coincides with the region of the genetic hybrid zone for northern and southern vent mussel species at the Broken Spur vent field. Additional barriers suggest potential for genetic differentiation that so far has not been detected for any taxon. The locations of persistent zones of connectivity and barriers to dispersal suggest that there may be multiple biogeographic subunits along the northern Mid-Atlantic Ridge that should be taken into account in planning for effective environmental management of human activities

Hyperon-nucleon scattering and hyperon masses in the nuclear medium

We analyze low-energy hyperon-nucleon scattering using an effective field theory in next-to-leading order. By fitting experimental cross sections for laboratory hyperon momenta below 200 MeV/c and using information from the hypertriton we determine twelve contact-interaction coefficients. Based on these we discuss the low-density expansion of hyperon mass shifts in the nuclear medium.Comment: 10 pages, 2 figure

Characterization of methane-seep communities in a deep-sea area designated for oil and natural gas exploitation off Trinidad and Tobago

Exploration of the deep ocean (>200 m) is taking on added importance as human development encroaches. Despite increasing oil and natural gas exploration and exploitation, the deep ocean of Trinidad and Tobago is almost entirely unknown. The only scientific team to image the deep seafloor within the Trinidad and Tobago Exclusive Economic Zone was from IFREMER in the 1980s. That exploration led to the discovery of the El Pilar methane seeps and associated chemosynthetic communities on the accretionary prism to the east of Trinidad and Tobago. In 2014, the E/V Nautilus, in collaboration with local scientists, visited two previously sampled as well as two unexplored areas of the El Pilar site between 998 and 1,629 m depth using remotely operated vehicles. Eighty-three megafaunal morphospecies from extensive chemosynthetic communities surrounding active methane seepage were observed at four sites. These communities were dominated by megafaunal invertebrates including mussels (Bathymodiolus childressi), shrimp (Alvinocaris cf. muricola), Lamellibrachia sp. 2 tubeworms, and Pachycara caribbaeum. Adjacent to areas of active seepage was an ecotone of suspension feeders including Haplosclerida sponges, stylasterids and Neovermilia serpulids on authigenic carbonates. Beyond this were large Bathymodiolus shell middens. Finally there was either a zone of sparse octocorals and other non-chemosynthetic species likely benefiting from the carbonate substratum and enriched production within the seep habitat, or sedimented inactive areas. This paper highlights these ecologically significant areas and increases the knowledge of the biodiversity of the Trinidad and Tobago deep ocean. Because methane seepage and chemosynthetic communities are related to the presence of extractable oil and gas resources, development of best practices for the conservation of biodiversity in Trinidad and Tobago waters within the context of energy extraction is critical. Potential impacts on benthic communities during oil and gas activities will likely be long lasting and include physical disturbance during drilling among others. Recommendations for the stewardship of these widespread habitats include: (1) seeking international cooperation; (2) holding wider stakeholder discussions; (3) adopting stringent environmental regulations; and (4) increasing deep-sea research to gather crucial baseline data in order to conduct appropriate marine spatial planning with the creation of marine protected areas.Copyright © 2017 Amon, Gobin, Van Dover, Levin, Marsh and Raineault. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms

Cosputtered composition-spread reproducibility established by high-throughput x-ray fluorescence

We describe the characterization of sputtered yttria-zirconia composition spread thin films by x-ray fluorescence (XRF). We also discuss our automated analysis of the XRF data, which was collected in a high throughput experiment at the Cornell High Energy Synchrotron Source. The results indicate that both the composition reproducibility of the library deposition and the composition measurements have a precision of better than 1 atomic percent

Cosputtered composition-spread reproducibility established by high-throughput x-ray fluorescence

We describe the characterization of sputtered yttria-zirconia composition spread thin films by x-ray fluorescence (XRF). We also discuss our automated analysis of the XRF data, which was collected in a high throughput experiment at the Cornell High Energy Synchrotron Source. The results indicate that both the composition reproducibility of the library deposition and the composition measurements have a precision of better than 1 atomic percent

Getter sputtering system for high-throughput fabrication of composition spreads

We describe a sputtering system that can deposit composition spreads in an effectively UHV environment but which does not require the high-throughput paradigm to be compromised by a long pump down each time a target is changed. The system deploys four magnetron sputter guns in a cryoshroud (getter sputtering) which allows elements such as Ti and Zr to be deposited with minimal contamination by oxygen or other reactive background gases. The system also relies on custom substrate heaters to give rapid heating and cool down. The effectiveness of the gettering technique is evaluated, and example results obtained for catalytic activity of a pseudoternary composition spread are presented

Getter sputtering system for high-throughput fabrication of composition spreads

We describe a sputtering system that can deposit composition spreads in an effectively UHV environment but which does not require the high-throughput paradigm to be compromised by a long pump down each time a target is changed. The system deploys four magnetron sputter guns in a cryoshroud (getter sputtering) which allows elements such as Ti and Zr to be deposited with minimal contamination by oxygen or other reactive background gases. The system also relies on custom substrate heaters to give rapid heating and cool down. The effectiveness of the gettering technique is evaluated, and example results obtained for catalytic activity of a pseudoternary composition spread are presented

Research is needed to inform environmental management of hydrothermally inactive and extinct polymetallic sulfide (PMS) deposits

Polymetallic sulfide (PMS) deposits produced at hydrothermal vents in the deep sea are of potential interest to miners. Hydrothermally active sulfide ecosystems are valued for the extraordinary chemosynthetic communities that they support. Many countries, including Canada, Portugal, and the United States, protect vent ecosystems in their Exclusive Economic Zones. When hydrothermal activity ceases temporarily (dormancy) or permanently (extinction), the habitat and associated ecosystem change dramatically. Until recently, so-called "inactive sulfide" habitats, either dormant or extinct, received little attention from biologists. However, the need for environmental management of deep-sea mining places new imperatives for building scientific understanding of the structure and function of inactive PMS deposits. This paper calls for actions of the scientific community and the emergent seabed mining industry to i) undertake fundamental ecological descriptions and study of ecosystem functions and services associated with hydrothermally inactive PMS deposits, ii) evaluate potential environmental risks to ecosystems of inactive PMS deposits through research, and iii) identify environmental management needs that may enable mining of inactive PMS deposits. Mining of some extinct PMS deposits may have reduced environmental risk compared to other seabed mining activities, but this must be validated through scientific research on a case-by-case basis.FCT: IF/00029/2014/CP1230/CT0002/ UID/05634/2020/ CEECIND005262017/ UID/MAR/00350/2019; Direcao-Geral de Politica do Mar (DGPM) Mining2/2017/005/ Mining2/2017/001info:eu-repo/semantics/publishedVersio