scholarly journals Meiofauna in a Potential Deep-Sea Mining Area—Influence of Temporal and Spatial Variability on Small-Scale Abundance Models

Diversity ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 3
Author(s):  
Katja Uhlenkott ◽  
Annemiek Vink ◽  
Thomas Kuhn ◽  
Benjamin Gillard ◽  
Pedro Martínez Arbizu
Keyword(s):  
Deep Sea ◽  
Benthic Communities ◽  
Mining Operation ◽  
Mining Area ◽  
Environmental Drivers ◽  
Small Scale ◽  
Taxon Richness ◽  
Distribution Models ◽  
Polymetallic Nodule ◽  
Meiofauna Abundance

In large areas of the Clarion Clipperton Fracture Zone (northeast Pacific), exploration of deep-sea polymetallic nodules as a potential source of high-technology metals is ongoing. Deep-sea mining may have a severe impact on the benthic communities. Here, we investigated meiofauna communities in the abyss at the scale of a prospective mining operation area. Random forest regressions were computed to spatially predict continuous layers of environmental variables as well as the distribution of meiofauna abundance across the area. Significant models could be computed for 26 sediment and polymetallic nodule parameters. Meiofauna abundance, taxon richness and diversity were also modelled, as well as abundance of the taxon Nematoda. Spatial correlation is high if the predictions of meiofauna are either based on bathymetry and backscatter or include sediment and nodule variables; Pearson’s correlation coefficient varies between 0.42 and 0.91. Comparison of differences in meiofauna abundance between different years shows that spatial patterns do change, with an elevated abundance of meiofauna in the eastern part of the study area in 2013. On the spatial scale of a potential mining operation, distribution models prove to be a useful tool to gain insight into both temporal variability and the influence of potential environmental drivers on meiofauna distribution.

scholarly journals Observations of deep-sea fishes and mobile scavengers from the abyssal DISCOL experimental mining area

2019 ◽  
Vol 16 (16) ◽  
pp. 3133-3146 ◽  
Author(s):  
Jeffrey C. Drazen ◽  
Astrid B. Leitner ◽  
Sage Morningstar ◽  
Yann Marcon ◽  
Jens Greinert ◽  
...  
Keyword(s):  
Deep Sea ◽  
Fish Community ◽  
Population Level ◽  
Mining Area ◽  
Hermit Crabs ◽  
Fish Density ◽  
Environmental Drivers ◽  
Large Contribution ◽  
Ecosystem Responses ◽  
Polymetallic Nodule

Abstract. Industrial interest in deep-sea mineral extraction began decades ago, and today it is at an all-time high, accelerated by global demand for metals. Several seafloor ecosystem disturbance experiments began in the 1970s, including the Disturbance and Recolonization experiment (DISCOL) conducted in the Peru Basin in 1989. A large seafloor disturbance was created by repeatedly ploughing the seafloor over an area of ∼10.8 km2. Though a number of studies in abyssal mining regions have evaluated megafaunal biodiversity and ecosystem responses, few have included quantitative and detailed data on fishes or scavengers despite their ecological importance as top predators. We used towed camera transects (1989–1996, 2015) and baited camera data (1989–1992) to evaluate the fish community at the DISCOL site. The abyssal fish community included 16 taxa and was dominated by Ipnops meadi. Fish density was lower in ploughed habitat at 6 months and 3 years following disturbance but thereafter increased over time. Twenty-six years after disturbance there were no differences in overall total fish densities between reference and experimental areas, but the dominant fish, I. meadi, still exhibited much lower densities in ploughed habitat, likely avoiding these areas and suggesting that the fish community remains affected after decades. At the scale of industrial mining, these results could translate to population-level effects. The scavenging community was dominated by eelpouts (Pachycara spp.), hermit crabs (Probeebei mirabilis) and shrimp. The large contribution of hermit crabs appears to be unique amongst abyssal scavenger studies worldwide. The abyssal fish community at DISCOL was similar to that in the more northerly Clarion–Clipperton Zone (CCZ), though some species have only been observed at DISCOL thus far. Also, further species-level identifications are required to refine this assessment. Additional studies across the polymetallic nodule provinces of the Pacific are required to further evaluate the environmental drivers of fish density, diversity and species biogeographies. This information will be important for the development of appropriate management plans aimed at minimizing human impact from deep-sea mining.

scholarly journals Observations of deep-sea fishes and mobile scavengers from the abyssal DISCOL experimental mining area

2019 ◽  
Author(s):  
Jeffrey C. Drazen ◽  
Astrid Leitner ◽  
Sage Morningstar ◽  
Yann Marcon ◽  
Jens Greinert ◽  
...  
Keyword(s):  
Deep Sea ◽  
Fish Community ◽  
Mining Area ◽  
Hermit Crabs ◽  
Fish Density ◽  
Environmental Drivers ◽  
Large Contribution ◽  
Ecosystem Responses ◽  
Polymetallic Nodule ◽  
Ecological Importance

Abstract. Industrial interest in deep-sea mineral extraction began decades ago and today it is at an all-time high, accelerated by global demand for metals. Several seafloor ecosystem disturbance experiments were performed beginning in the 1970’s, including the DISturbance and reCOLonization experiment (DISCOL) conducted in the Peru Basin in 1989. A large seafloor disturbance was created by repeatedly plowing the seafloor over an area of ~ 10.8 km2. Though a number of studies in abyssal mining regions have evaluated megafaunal biodiversity and ecosystem responses, few have included quantitative and detailed data on fishes or scavengers despite their ecological importance as top predators. We used towed camera transects and baited camera data to evaluate the fish community at the DISCOL site. The abyssal fish community was relatively diverse with 16 taxa dominated by Ipnops meadi. Fish density was lower in ploughed habitat during the several years following disturbance but thereafter increased over time in part due to changes in regional environmental conditions. 26 years post disturbance there were no differences in overall total fish densities between reference and experimental areas, but the dominant fish, I. meadi, still exhibited much lower densities in ploughed habitat suggesting only partial fish community recovery. The scavenging community was dominated by eelpouts (Pachycara spp), hermit crabs (Probeebei mirabilis) and shrimp. The large contribution of hermit crabs appears unique amongst abyssal scavenger studies worldwide. The abyssal fish community at DISCOL was similar to that in the more northerly Clarion Clipperton Zone, though some species have only been observed at DISCOL thus far. Also, further species level identifications are required to refine this assessment. Additional studies across the polymetallic nodule provinces of the Pacific are required to further evaluate the environmental drivers of fish density and diversity and species biogeographies, which will be important for the development of appropriate management plans aimed at minimizing human impact from deep-sea mining.

scholarly journals The importance of different spatial scales in determining structural and functional characteristics of deep-sea infauna communities

2013 ◽  
Vol 10 (7) ◽  
pp. 4547-4563 ◽  
Author(s):  
J. Ingels ◽  
A. Vanreusel
Keyword(s):  
Functional Diversity ◽  
Deep Sea ◽  
Spatial Ecology ◽  
Spatial Scales ◽  
Benthic Communities ◽  
Standing Stock ◽  
Terrestrial Ecosystems ◽  
Small Scale ◽  
Functional Characteristics ◽  
Sampling Locations

Abstract. The urge to understand spatial distributions of species and communities and their causative processes has continuously instigated the development and testing of conceptual models in spatial ecology. For the deep sea, there is evidence that structural and functional characteristics of benthic communities are regulated by a multitude of biotic and environmental processes that act in concert on different spatial scales, but the spatial patterns are poorly understood compared to those for terrestrial ecosystems. Deep-sea studies generally focus on very limited scale ranges, thereby impairing our understanding of which spatial scales and associated processes are most important in driving structural and functional diversity of communities. Here, we used an extensive integrated dataset of free-living nematodes from deep-sea sediments to unravel the importance of different spatial scales in determining benthic infauna communities. Multiple-factor multivariate permutational analyses were performed on different sets of community descriptors (structure, structural and functional diversity, standing stock). The different spatial scales investigated cover two margins in the northeast Atlantic, several submarine canyons/channel/slope areas, a bathymetrical range of 700–4300 m, different sampling locations at each station, and vertical sediment profiles. The results indicated that the most important spatial scale for structural and functional diversity and standing stock variability is the smallest one; infauna communities changed substantially more with differences between sediment depth layers than with differences associated to larger geographical or bathymetrical scales. Community structure differences were greatest between stations at both margins. Important regulating ecosystem processes and the scale on which they occur are discussed. The results imply that, if we are to improve our understanding of ecosystem patterns of deep-sea infauna and the relevant processes driving their structure, structural and functional diversity, and standing stock, we must pay particular attention to the small-scale heterogeneity or patchiness and the causative mechanisms acting on that scale.

scholarly journals Simulated mining-related sedimentation impacts on the deep-sea macrofauna of the Chatham Rise, New Zealand

2021 ◽  
Author(s):  
Campbell Murray
Keyword(s):  
Community Structure ◽  
New Zealand ◽  
Deep Sea ◽  
Benthic Communities ◽  
Sampling Period ◽  
Mining Area ◽  
Warning Sign ◽  
Disturbed Areas ◽  
One Year ◽  
The Impact

<p>With the possibility of deep-sea mining of marine mineral resources occurring in the near future, it is necessary to understand the potential impacts that mining may have on benthic communities. Previous simulated mining experiments have observed direct impacts of deep-sea mining (e.g., faunal mortality); however, indirect impacts of sedimentation were not understood. In New Zealand, there has been interest in mining the seabed of the Chatham Rise, but mining consents have been refused, partly due to the uncertainties of sedimentation impacts on benthic communities. A disturbance experiment conducted in 2019 on the Rise used a modified agricultural plough designed to create a sediment cloud that could result from mining. This disturbance was used to assess the resilience of benthic communities to sedimentation in a proposed future mining area. Macrofaunal and sediment samples were collected with a multicorer before, immediately after and one year after disturbance to assess the impact on the community and its ability to recover. Samplingevents took place in disturbed (physically run over by the plough and subjected to sedimentation) and undisturbed areas (subjected to sedimentation only) at each sampling period. Macrofaunal abundance significantly decreased in disturbed areas after disturbancebut not in undisturbed areas. However, community structure changed in both areas after disturbance; in disturbed areas this was mostly driven by changes in numerically dominant fauna, but in undisturbed areas by the more sensitive fauna which may provide an early warning sign for further changes under increased sedimentation. One year after disturbance, community structure had recovered in both areas. Abundance-based community structure correlated most strongly with C:N molar ratios in the sediment which increased after disturbance. Ecosystem function was measured by sediment community oxygen consumption (SCOC) which increased similarly in both disturbed and undisturbed areas after disturbance; SCOC may be a more sensitive measure than community structure in assessing sedimentation impacts. No correlations were found between SCOC and macrofaunal abundance, biomass, diversity or bacterial abundance. The results of this research are useful for managing the impacts of industries where sedimentation is an issue, such as for bottom trawl fisheries and deep-sea mining. The results highlight the importance of leaving unmined patches of seabed adjacent to or within mined areas, to aid the recovery of macrofaunal communities subjected to mining disturbance.</p>

scholarly journals Arctic benthic diversity research with PANABIO: scale, sharing, and modelling

2018 ◽  
Author(s):  
Dieter Piepenburg ◽  
Jan Holstein ◽  
Paul Kloss ◽  
Thomas Brey ◽  
Casper Kraan
Keyword(s):  
Sea Ice ◽  
Benthic Communities ◽  
Public Information ◽  
Environmental Drivers ◽  
Ecosystem Functions ◽  
Marine Biota ◽  
Distribution Models ◽  
Ice Dynamics ◽  
Environmental Forcing ◽  
Sea Ice Dynamics

Arctic marine biota areaffected profoundly and at large scales by accelerating environmental change, such as ocean warming and sea-ice decline. Moreover, increasing human activities add further cumulative pressures. Substantial shifts in ecosystem functions and services,including biodiversity, are expected. Tounderstand, predict, and mitigate the profound ecologicalconsequences of such shifts, it is critical to identify and analyzetherelationships between environmental drivers and ecosystem functionsata range of scales (local, regional, and pan-Arctic). We address this challenge by means of apan-Arctic knowledge system on benthicbiota(PANABIO). Underpinned by international efforts to combine data and expertise, PANABIO integrates quality-controlled and geo-referenceddata on benthiccommunities in a public information system. The system allows for (a) providingecological baseline-data to gauge ecosystem changes, (b) analysingcoupling mechanisms between environmental drivers and ecosystemfunctions/services on regional and pan-Arctic scales, (c) developing futureecosystem scenarios in response to external forcing, and (d) creating onlinestakeholder-orientedvisualization and analysis tools. The talk will demonstrate the huge up-scaling of benthic data with PANABIO, our achievements to support data-sharing, as well as first results of community-level distribution models to discern benthic communities in relation to multiple-factor environmental forcing, including sea-ice dynamics.

scholarly journals The importance of different spatial scales in determining structure and function of deep-sea infauna communities

2013 ◽  
Vol 10 (1) ◽  
pp. 195-232 ◽  
Author(s):  
J. Ingels ◽  
A. Vanreusel
Keyword(s):  
Spatial Scale ◽  
Deep Sea ◽  
Spatial Ecology ◽  
Spatial Scales ◽  
Benthic Communities ◽  
Standing Stock ◽  
Small Scale ◽  
Sampling Locations ◽  
And Function ◽  
Structure Diversity

Abstract. The urge to understand spatial distributions of species and communities and their causative processes has continuously instigated the development and testing of conceptual models in spatial ecology. For the deep-sea, there is evidence that structure, diversity and function of benthic communities are regulated by a multitude of biotic and environmental processes that act in concert on different spatial scales, but the spatial patterns are poorly understood compared to those for other ecosystems. Deep-sea studies generally focus on very limited scale-ranges, thereby impairing our understanding of which spatial scales and associated processes are most important in driving diversity and ecosystem function of communities. Here, we used an extensive integrated dataset of free-living nematodes from deep-sea sediments to unravel which spatial scale is most important in determining benthic infauna communities. Multiple-factor multivariate permutational analyses were performed on different sets of community descriptors (structure, diversity, function, standing stock). The different spatial scales investigated cover two margins in the Northeast Atlantic, several submarine canyons/channel/slope areas, a bathymetrical range of 700–4300 m (represents different stations, 5–50 km apart), different sampling locations at each station (replication distances, 1–200 m), and vertical sediment profiles (cm layers). The results indicated that the most important spatial scale for diversity, functional and standing stock variability is the smallest one; infauna communities changed substantially more with differences between sediment depth layers than with differences associated to larger geographical or bathymetrical scales. Community structure differences were largest between stations at both margins. Important regulating ecosystem processes and the scale on which they occur are discussed. The results imply that, if we are to improve our understanding of ecosystem patterns of deep-sea infauna and the relevant processes driving their structure, diversity, function and standing stock, we must pay particular attention to the small-scale heterogeneity or patchiness and the causative mechanisms acting on that scale.

scholarly journals Comparative reproductive biology of deep-sea ophiuroids inhabiting polymetallic-nodule fields in the Clarion-Clipperton Fracture Zone

2021 ◽  
Author(s):  
Sven R Laming ◽  
Magdalini Christodoulou ◽  
Pedro Martinez Arbizu ◽  
Ana Hilário
Keyword(s):  
Reproductive Biology ◽  
Fracture Zone ◽  
Deep Sea ◽  
Sex Ratios ◽  
Reproductive Mode ◽  
Environmental Drivers ◽  
Polymetallic Nodule ◽  
Clipperton Fracture Zone ◽  
Domains Of Life ◽  
Clarion Clipperton Fracture Zone

AbstractDeep-sea mining in the Pacific Clarion-Clipperton Fracture Zone (CCZ), a low-energy sedimentary habitat with polymetallic nodules, is expected to have considerable and long-lasting environmental impact. The CCZ hosts extraordinarily high species diversity in nearly all domains of Life present. Data on species biology and ecology remain scarce, however. The current study describes the reproductive biology of Ophiosphalma glabrum (Lütken & Mortensen, 1899) (Ophiosphalmidae) and Ophiacantha cosmica (Lyman, 1878) (Ophiacanthidae), two ophiuroids frequently found in the CCZ. Specimens collected in Spring 2015 and 2019 in four contract areas (BGR, IOM, GSR, Ifremer) and one Area of Particular Interest (APEI 3) were examined morphologically and histologically. Size-class frequencies (disc diameter and oocytes feret diameters), sex ratios, gametogenic status, putative reproductive mode and a simple proxy for fecundity are presented. Habitat use differs in each. While O. glabrum is epibenthic, occurring as single individuals, O. cosmica often form size-stratified groups living on stalked sponges, suggesting gregarious settlement or retention of offspring (though no brooding individuals were found). Further molecular analyses are needed to establish whether O. cosmica groups are familial. In O. glabrum, for which sample sizes were larger, sex ratios approximated a 1:1 ratio with no size-structuring. In both species, individuals were at various stages of gametogenic maturity but no ripe females were identified. Based on this, O. glabrum is most probably gonochoric. Reproductive mode remains inconclusive for O. cosmica. Both species are presumptively lecithotrophic, with vitellogenic-oocyte feret diameters exceeding 250 µm. Oocyte feret diameters at times exceeded 400 µm in O. glabrum, indicating substantial yolk reserves. Estimates of instantaneous fecundity (vitellogenic specimens of O. glabrum only) were confounded by interindividual variability in gonad characteristics. The well-furnished lecithotrophic larvae of O. glabrum would be capable of dispersing even under food-impoverished conditions. The current study examines ophiuroid reproductive biology over multiple localities in the CCZ concurrently for the first time, at sites characterised by differing productivity regimes. The reproductive biology of each species is thus discussed with reference to past evolutionary (habitat stability), contemporary (food supply) and future environmental drivers (potential impacts of deep-sea mining).

scholarly journals Arctic benthic diversity research with PANABIO: scale, sharing, and modelling

2018 ◽  
Author(s):  
Dieter Piepenburg ◽  
Jan Holstein ◽  
Paul Kloss ◽  
Thomas Brey ◽  
Casper Kraan
Keyword(s):  
Sea Ice ◽  
Benthic Communities ◽  
Public Information ◽  
Environmental Drivers ◽  
Ecosystem Functions ◽  
Marine Biota ◽  
Distribution Models ◽  
Ice Dynamics ◽  
Environmental Forcing ◽  
Sea Ice Dynamics

Arctic marine biota areaffected profoundly and at large scales by accelerating environmental change, such as ocean warming and sea-ice decline. Moreover, increasing human activities add further cumulative pressures. Substantial shifts in ecosystem functions and services,including biodiversity, are expected. Tounderstand, predict, and mitigate the profound ecologicalconsequences of such shifts, it is critical to identify and analyzetherelationships between environmental drivers and ecosystem functionsata range of scales (local, regional, and pan-Arctic). We address this challenge by means of apan-Arctic knowledge system on benthicbiota(PANABIO). Underpinned by international efforts to combine data and expertise, PANABIO integrates quality-controlled and geo-referenceddata on benthiccommunities in a public information system. The system allows for (a) providingecological baseline-data to gauge ecosystem changes, (b) analysingcoupling mechanisms between environmental drivers and ecosystemfunctions/services on regional and pan-Arctic scales, (c) developing futureecosystem scenarios in response to external forcing, and (d) creating onlinestakeholder-orientedvisualization and analysis tools. The talk will demonstrate the huge up-scaling of benthic data with PANABIO, our achievements to support data-sharing, as well as first results of community-level distribution models to discern benthic communities in relation to multiple-factor environmental forcing, including sea-ice dynamics.

scholarly journals Benthic communities in the deep Mediterranean Sea: exploring microbial and meiofaunal patterns in slope and basin ecosystems

2013 ◽  
Vol 10 (7) ◽  
pp. 4861-4878 ◽  
Author(s):  
K. Sevastou ◽  
N. Lampadariou ◽  
P. N. Polymenakou ◽  
A. Tselepides
Keyword(s):  
Deep Sea ◽  
Eastern Mediterranean ◽  
Benthic Communities ◽  
Significant Proportion ◽  
Aegean Sea ◽  
Organic Content ◽  
Environmental Drivers ◽  
Central Mediterranean ◽  
Data Set ◽  
Habitat Variability

Abstract. The long-held perception of the deep sea consisting of monotonous slopes and uniform oceanic basins has over the decades given way to the idea of a complex system with wide habitat heterogeneity. Under the prism of a highly diverse environment, a large dataset was used to describe and compare spatial patterns of the dominant small-size components of deep-sea benthos, metazoan meiofauna and microbes, from Mediterranean basins and slopes. A grid of 73 stations sampled at five geographical areas along the central-eastern Mediterranean Basin (central Mediterranean, northern Aegean Sea, Cretan Sea, Libyan Sea, eastern Levantine) spanning over 4 km in depth revealed a high diversity, irrespective of the benthic group or level of taxonomic analysis. A common decreasing bathymetric trend was detected for meiobenthic abundance, major taxa diversity and nematode genera richness, but no differences were found between the two habitats (basin vs slope). In contrast, microbial richness is significantly higher at the basin ecosystem and tends to increase with depth. Multivariate analyses (β- and δ-diversity and ordination analysis) complemented these results and underlined the high within-habitat variability of benthic communities. Meiofaunal communities in particular were found to change gradually and vary more towards the abyss. On the other hand, microbial communities were highly variable, even among samples of the same area, habitat and bathymetry. A significant proportion of the variation of benthic communities and their descriptors was explained by depth and proxies of food availability (sedimentary pigments and organic content), but the combination of predictor variables and the strength of the relationship varied depending on the data set used (based on type of habitat, benthic component, taxonomic level). This, along with the observed high within-habitat variability suggests that other factors, which tend to vary at local scale (hydrodynamics, substrate structure, geochemistry, food quality, etc.), may also relate to the observed benthic patterns. Overall, the results presented here suggest that differences in small-size benthos between the basin and slope habitats are neither strong nor consistent; it appears that within-habitat variability is high, differences among depth ranges are important and further investigation of possible environmental drivers of benthic patterns is needed.

scholarly journals Comparative Reproductive Biology of Deep-Sea Ophiuroids Inhabiting Polymetallic-Nodule Fields in the Clarion-Clipperton Fracture Zone

2021 ◽  
Vol 8 ◽  
Author(s):  
Sven R. Laming ◽  
Magdalini Christodoulou ◽  
Pedro Martinez Arbizu ◽  
Ana Hilário
Keyword(s):  
Reproductive Biology ◽  
Fracture Zone ◽  
Deep Sea ◽  
Sex Ratios ◽  
Reproductive Mode ◽  
Environmental Drivers ◽  
Polymetallic Nodule ◽  
Clipperton Fracture Zone ◽  
Domains Of Life ◽  
Clarion Clipperton Fracture Zone

Deep-sea mining in the Pacific Clarion-Clipperton Fracture Zone (CCZ), a low-energy sedimentary habitat with polymetallic nodules, is expected to have considerable and long-lasting environmental impact. The CCZ hosts extraordinarily high species diversity across representatives from all Domains of Life. Data on species biology and ecology remain scarce, however. The current study describes the reproductive biology of Ophiosphalma glabrum (Ophiosphalmidae) and Ophiacantha cosmica (Ophiacanthidae), two ophiuroids frequently found in the CCZ. Specimens collected in Spring 2015 and 2019 in four contract areas were examined morphologically and histologically. Size-class frequencies (disc diameter and oocytes feret diameters), sex ratios, gametogenic status, putative reproductive mode, and a simple proxy for fecundity are presented. Habitat use differs in each. While O. glabrum is epibenthic, occurring as single individuals, O. cosmica often forms size-stratified groups living on stalked sponges, suggesting gregarious settlement or retention of offspring (though no brooding individuals were found). Further molecular analyses are needed to establish whether O. cosmica groups are familial. In O. glabrum, for which sample sizes were larger, sex ratios approximated a 1:1 ratio with no size-structuring. In both species, individuals were at various stages of gametogenic maturity, but no ripe females were identified. Based on this, O. glabrum is most probably gonochoric. Reproductive mode remains inconclusive for O. cosmica. Both species are presumptively lecithotrophic, with vitellogenic-oocyte feret diameters exceeding 250 μm. Oocyte feret diameters at times exceeded 400 μm in O. glabrum, indicating substantial yolk reserves. Estimates of instantaneous fecundity (vitellogenic specimens of O. glabrum only) were confounded by interindividual variability in gonad characteristics. The well-furnished lecithotrophic larvae of O. glabrum would be capable of dispersing even under food-impoverished conditions. The current study examines ophiuroid reproductive biology over multiple localities in the CCZ concurrently for the first time, at sites characterised by differing productivity regimes. The reproductive biology of each species is thus discussed with reference to past evolutionary (habitat stability), contemporary (food supply), and future environmental drivers (potential impacts of deep-sea mining).

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