Assessing the temporal scale of deep-sea mining impacts on sediment biogeochemistry
<p>Deep-sea mining for polymetallic nodules is expected to have severe environmental impacts because not only nodules but also benthic fauna and the upper reactive sediment layer are removed through the mining operation and blanketed by resettling material from the suspended sediment plume. Th...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2020-05-01
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| Series: | Biogeosciences |
| Online Access: | https://www.biogeosciences.net/17/2767/2020/bg-17-2767-2020.pdf |
| _version_ | 1819043371357831168 |
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| author | L. Haffert M. Haeckel H. de Stigter F. Janssen F. Janssen |
| author_facet | L. Haffert M. Haeckel H. de Stigter F. Janssen F. Janssen |
| author_sort | L. Haffert |
| collection | DOAJ |
| description | <p>Deep-sea mining for polymetallic nodules is expected to have
severe environmental impacts because not only nodules but also benthic
fauna and the upper reactive sediment layer are removed through the mining
operation and blanketed by resettling material from the suspended sediment
plume. This study aims to provide a holistic assessment of the
biogeochemical recovery after a disturbance event by applying prognostic
simulations based on an updated diagenetic background model and validated against novel data on microbiological processes. It was found that the recovery strongly
depends on the impact type; complete removal of the reactive surface
sediment reduces benthic release of nutrients over centuries, while
geochemical processes after resuspension and mixing of the surface sediment
are near the pre-impact state 1 year after the disturbance. Furthermore, the
geochemical impact in the DISturbance and reCOLonization (DISCOL) experiment area would be mitigated to some degree by a
clay-bound Fe(II)-reaction layer, impeding the downward diffusion of oxygen,
thus stabilizing the redox zonation of the sediment during transient
post-impact recovery. The interdisciplinary (geochemical, numerical and
biological) approach highlights the closely linked nature of benthic
ecosystem functions, e.g. through bioturbation, microbial biomass and
nutrient fluxes, which is also of great importance for the system recovery.
It is, however, important to note that the nodule ecosystem may never
recover to the pre-impact state without the essential hard substrate and will
instead be dominated by different faunal communities, functions and
services.</p> |
| first_indexed | 2024-12-21T09:55:43Z |
| format | Article |
| id | doaj.art-704a3f931a5d482ebf15800b5df6d85d |
| institution | Directory Open Access Journal |
| issn | 1726-4170 1726-4189 |
| language | English |
| last_indexed | 2024-12-21T09:55:43Z |
| publishDate | 2020-05-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Biogeosciences |
| spelling | doaj.art-704a3f931a5d482ebf15800b5df6d85d2022-12-21T19:08:04ZengCopernicus PublicationsBiogeosciences1726-41701726-41892020-05-01172767278910.5194/bg-17-2767-2020Assessing the temporal scale of deep-sea mining impacts on sediment biogeochemistryL. Haffert0M. Haeckel1H. de Stigter2F. Janssen3F. Janssen4GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstrasse 1–3, 24148 Kiel, GermanyGEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstrasse 1–3, 24148 Kiel, GermanyNIOZ – Royal Netherlands Institute for Sea Research, Department of Ocean Systems, and Utrecht University, P.O. Box 59, 1790 AB Den Burg, Texel, the NetherlandsHGF MPG Joint Research Group for Deep-Sea Ecology and Technology, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, GermanyMax Planck Institute for Marine Microbiology, Celsiusstrasse 1, 28359 Bremen, Germany<p>Deep-sea mining for polymetallic nodules is expected to have severe environmental impacts because not only nodules but also benthic fauna and the upper reactive sediment layer are removed through the mining operation and blanketed by resettling material from the suspended sediment plume. This study aims to provide a holistic assessment of the biogeochemical recovery after a disturbance event by applying prognostic simulations based on an updated diagenetic background model and validated against novel data on microbiological processes. It was found that the recovery strongly depends on the impact type; complete removal of the reactive surface sediment reduces benthic release of nutrients over centuries, while geochemical processes after resuspension and mixing of the surface sediment are near the pre-impact state 1 year after the disturbance. Furthermore, the geochemical impact in the DISturbance and reCOLonization (DISCOL) experiment area would be mitigated to some degree by a clay-bound Fe(II)-reaction layer, impeding the downward diffusion of oxygen, thus stabilizing the redox zonation of the sediment during transient post-impact recovery. The interdisciplinary (geochemical, numerical and biological) approach highlights the closely linked nature of benthic ecosystem functions, e.g. through bioturbation, microbial biomass and nutrient fluxes, which is also of great importance for the system recovery. It is, however, important to note that the nodule ecosystem may never recover to the pre-impact state without the essential hard substrate and will instead be dominated by different faunal communities, functions and services.</p>https://www.biogeosciences.net/17/2767/2020/bg-17-2767-2020.pdf |
| spellingShingle | L. Haffert M. Haeckel H. de Stigter F. Janssen F. Janssen Assessing the temporal scale of deep-sea mining impacts on sediment biogeochemistry Biogeosciences |
| title | Assessing the temporal scale of deep-sea mining impacts on sediment biogeochemistry |
| title_full | Assessing the temporal scale of deep-sea mining impacts on sediment biogeochemistry |
| title_fullStr | Assessing the temporal scale of deep-sea mining impacts on sediment biogeochemistry |
| title_full_unstemmed | Assessing the temporal scale of deep-sea mining impacts on sediment biogeochemistry |
| title_short | Assessing the temporal scale of deep-sea mining impacts on sediment biogeochemistry |
| title_sort | assessing the temporal scale of deep sea mining impacts on sediment biogeochemistry |
| url | https://www.biogeosciences.net/17/2767/2020/bg-17-2767-2020.pdf |
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