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  • 1
    Electronic Resource
    Electronic Resource
    High-performance epitaxial Na0.5K0.5NbO3 thin films by magnetron sputtering (2002)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 81 (2002), S. 337-339 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Epitaxial Na0.5K0.5NbO3 (NKN) thin films have been grown on LaAlO3 substrates by rf magnetron sputtering of a stoichiometric, high-density, ceramic target. X-ray diffraction analysis showed c-axis oriented cube-on-cube growth. Micrometer size interdigital capacitor (IDC) structures were defined on the surface of the NKN film using photolithography. The electrical characterization at 1 MHz showed dissipation factor tan δ of 0.010, tunability 16.5% at 200 kV/cm and dielectric permittivity cursive-epsilonr=470. The frequency dispersion of cursive-epsilonr between 1 kHz and 1 MHz was 8.5% and the IDCs showed very good insulating properties with leakage current density on the order of 30 nA/cm2 at 400 kV/cm. The polarization loop exhibits weak ferroelectric hysteresis with maximum polarization 23.5 μC/cm2 at 600 kV/cm. These results are promising for tunable microwave devices based on rf sputtered NKN thin films. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1492854
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    Paper (German National Licenses)
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  • 2
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    Marine benthic ecological functioning over decreasing taxonomic richness (2015)
    Elsevier
    In:  Journal of Sea Research, 98 . pp. 49-56.
    Details
    Publication Date: 2015-06-09
    Description: Highlights: • Reduced taxon-richness (96%, 151–6 taxa) leads to overall reduction in function. • Functional richness remained high (66% of tot.) even at the lowest taxon richness. • Analysis of changes in trait categories showed the importance of multifunctionality. • Number of taxa per trait category gives complementary information to the FD index. • Rare species did not express unique traits. Alterations to ecosystem function due to reductions in species richness are predicted to increase as humans continue to affect the marine environment, especially in coastal areas, which serve as the interface between land and sea. The potential functional consequences due to reductions in species diversity have attracted considerable attention recently but little is known about the consequence of such loss in natural communities. We examined how the potential for function is affected by natural reductions in taxon richness using empirical (non-simulated) coastal marine benthic macrofaunal data from the Skagerrak-Baltic Sea region (N. Europe), where taxon richness decreases 25-fold, from 151 to 6 taxa. To estimate functional changes we defined multiple traits (10 traits and 51 categories) on which trait category richness, Functional diversity (FD) and number of taxa per trait category were calculated. Our results show that decrease in taxon richness leads to an overall reduction in function but functional richness remains comparatively high even at the lowest level of taxon richness. Although the taxonomic reduction was sharp, up to 96% of total taxon richness, we identified both potential thresholds in functioning and subtler changes where function was maintained along the gradient. The functional changes were not only caused by reductions in taxa per trait category, some categories were maintained or even increased. Primarily, the reduction in species richness altered trait categories related to feeding, living and movement and thus potentially could have an effect on various ecosystem processes. This highlights the importance of recognising ecosystem multifunctionality, especially at low taxonomic richness. We also found that in this system rare species (singletons) do not stand for the functional complexities and changes. Our findings were consistent with theoretical and experimental predictions and suggest that a large proportion of the information about alterations of function is found in measures such as functional diversity and number of taxa per trait category.
    Type: Article , PeerReviewed
    Format: text
    DOI: 10.1016/j.seares.2014.04.010
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    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 3
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    Marine benthic ecological functioning over decreasing taxonomic richness (2015)
    Elsevier
    In:  Journal of Sea Research, 98 . pp. 49-56.
    Details
    Publication Date: 2016-02-25
    Description: Highlights: • Reduced taxon-richness (96%, 151–6 taxa) leads to overall reduction in function. • Functional richness remained high (66% of tot.) even at the lowest taxon richness. • Analysis of changes in trait categories showed the importance of multifunctionality. • Number of taxa per trait category gives complementary information to the FD index. • Rare species did not express unique traits. Abstract: Alterations to ecosystem function due to reductions in species richness are predicted to increase as humans continue to affect the marine environment, especially in coastal areas, which serve as the interface between land and sea. The potential functional consequences due to reductions in species diversity have attracted considerable attention recently but little is known about the consequence of such loss in natural communities. We examined how the potential for function is affected by natural reductions in taxon richness using empirical (non-simulated) coastal marine benthic macrofaunal data from the Skagerrak-Baltic Sea region (N. Europe), where taxon richness decreases 25-fold, from 151 to 6 taxa. To estimate functional changes we defined multiple traits (10 traits and 51 categories) on which trait category richness, functional diversity (FD) and number of taxa per trait category were calculated. Our results show that decrease in taxon richness leads to an overall reduction in function but functional richness remains comparatively high even at the lowest level of taxon richness. Although the taxonomic reduction was sharp, up to 96% of total taxon richness, we identified both potential thresholds in functioning and subtler changes where function was maintained along the gradient. The functional changes were not only caused by reductions in taxa per trait category, some categories were maintained or even increased. Primarily, the reduction in species richness altered trait categories related to feeding, living and movement and thus potentially could have an effect on various ecosystem processes. This highlights the importance of recognising ecosystem multifunctionality, especially at low taxonomic richness. We also found that in this system rare species (singletons) did not stand for the functional complexities and changes. Our findings were consistent with theoretical and experimental predictions and suggest that a large proportion of the information about alterations of function is found in measures such as functional diversity and number of taxa per trait category.
    Type: Article , PeerReviewed
    Format: text
    DOI: 10.1016/j.seares.2014.04.010
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    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 4
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    A generic framework to assess the representation and protection of benthic ecosystems in European marine protected areas (2020)
    In:  EPIC3Aquatic Conservation: Marine and Freshwater Ecosystems, 30(7), pp. 1253-1275, ISSN: 1052-7613
    Details
    Publication Date: 2020-07-15
    Description: There is concern across the International Council for the Exploration of the Sea (ICES) region that a consideration of vulnerable components and the wider support mechanisms underpinning benthic marine ecosystems may be lacking from the process of marine protected area (MPA) designation, management and monitoring. In this study, MPAs across six European ecoregions were assessed from a benthic ecology perspective. The study included 102 MPAs, designated by 10 countries, and focused on three aspects regarding the role of the benthos in: (i) the designation of MPAs; (ii) the management measures used in MPAs; and (iii) the monitoring and assessment of MPAs. Qualitative entries to a questionnaire based on an existing framework (EU project ‘Monitoring Evaluation of Spatially Managed Areas’, (MESMA) were collected by 19 benthic experts of the ICES Benthic Ecology Working Group. A pedigree matrix was used to apply a numerical scale (score) to these entries. The results showed clear differences in scores between ecoregions and between criteria. The designation‐phase criteria generally achieved higher scores than the implementation‐phase criteria. Poor designation‐phase scores were generally reiterated in the implementation‐phase scores, such as scores for assessment and monitoring. Over 70% of the MPA case studies were found to consider the benthos to some extent during selection and designation; however, this was not followed up with appropriate management measures and good practice during the implementation phase. Poor spatial and temporal coverage of monitoring and ineffective indicators is unlikely to pick up changes caused by management measures in the MPA. There is concern that without adequate monitoring and adaptive management frameworks, the MPAs will be compromised. Also, there could be an increased likelihood that, with regard to the benthos, they will fail to meet their conservation objectives. This assessment was successful in highlighting issues related to the representation and protection of the benthos in MPAs and where changes need to be made, such as expanding the characterization and monitoring of benthic species or habitats of interest. These issues could be attributable to an ongoing process and/or an indication that some MPAs only have ‘paper protection’.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
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  • 5
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    A General-Purpose Biotic Index to Measure Changes in Benthic Habitat Quality across Several Pressure Gradients (2021)
    In:  EPIC3Journal of Marine Science and Engineering, 9, pp. 654
    Details
    Publication Date: 2021-07-01
    Description: Realistic assessments of the ecological status of benthic habitats, as requested by European directives such as the Water Framework Directive and the European Marine Strategy Framework Directive, require biotic indices capable of detecting anthropogenic impact without having preliminary knowledge of the occurring pressures. In this context, a new general-purpose biotic index (GPBI) based on the deviation of benthic macrofauna community composition and structure from a valid reference (i.e., good ecological status) is proposed. GPBI is based on the assumption that as a site becomes impacted by a pressure, the most sensitive species are the first to disappear, and that stronger impacts lead to more important losses. Thus, it explicitly uses the within-species loss of individuals in the tested station in comparison to one or several reference stations as the basis of ecological status assessment. In this study, GPBI is successfully used in four case studies considering the impact of diversified pressures on benthic fauna: (1) maerl extraction in the northern Bay of Biscay, (2–3) dredging and trawling in the North Sea, and (4) hypoxic events at the seafloor in the Gullmarfjord. Our results show that GPBI was able to efficiently detect the impact of the different physical disturbances as well as that of hypoxia and that it performs better than commonly used pressure-specific indices (M-AMBI and TDI). Signal detection theory was used to propose a sound good/moderate ecological quality status boundary, and recommendations for future monitoring are also provided based on the reported performance of GPBI.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
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  • 6
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    Working Group on Fisheries Benthic Impact and Trade-Offs (WGFBIT; outputs from 2021 meeting). (2022)
    International Council for the Exploration of the Sea | Copenhagen, Denmark
    Details
    Publication Date: 2022-03-10
    Description: The Working Group on Fisheries Benthic Impact and Trade-offs (WGFBIT) develops methods and performs assessments to evaluate benthic impact from fisheries at regional scale, while con-sidering fisheries and seabed impact trade-offs. In this report, new fishery benthic impact assessments are carried out for several sub-regions in the Mediterranean (Greek waters, South Adriatic Sea, Sicily waters). For other regions, updates of the whole assessment or specific steps only were presented. A standard advice sheet for the regional benthic assessments, intended as input to the next generation of the ICES Ecosystem and Fisheries Overviews, was finalised and compiled for some regions as example (Greek wa-ters, Baltic Sea). A validation of the longevity relationships using new data was executed for the Kattegat area and the Southern North Sea. In relation to the methodology, some recommenda-tions were formulated concerning the update on depletion rates, the use of epifauna- or infauna-based data, guidance on which set of epibenthic species to include and the time scale for setting the average swept-area-ratio (SAR) used in model fitting and assessment. A benchmarking pro-cess comparing available benthic impact assessment approaches for MSFD descriptor 6 “Seafloor integrity” is needed, as the WGFBIT approach (relative benthic state) is not the only way to assess benthic impacts from physical disturbances. A start was made to explore how to incorporate more explicitly ecosystem functioning in to the WGFBIT seafloor assessment methodology. An improved understanding of the relationships between total community biomass and ecosystem functioning may assist in setting acceptable thresholds for ecosystem impacts from trawling. Furthermore, an improved understanding of the link between species functional effect traits and proxies and processes for specific ecosystem functions could help increase our ability to predict the impact of fishing disturbance on benthic ecosystem functioning more accurately. The ecosys-tem function we focus on is the biogeochemical cycling of organic matter. Two approaches were discussed (i) Biological traits approach focusing on the linkage between biological traits and eco-system functions and (ii) biogeochemical modelling approach using the established the OMEXDIA model.
    Description: FBIT
    Description: Published
    Description: Non Refereed
    Keywords: Fishery ; Fishing pressure ; Fisheries Benthic Impact ; Trade-offs ; AIS data ; VMS data ; Longevity ; Fishing gear technology ; Spatial modelling
    Repository Name: AquaDocs
    Type: Report
    Format: 133pp.
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  • 7
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    ICES (2023): Working Group on Fisheries Benthic Impact and Trade-offs (WGFBIT). (2023)
    International Council for the Exploration of the Sea (ICES) | Copenhagen, Denmark
    Details
    Publication Date: 2023-02-28
    Description: The Working Group on Fisheries Benthic Impact and Trade-offs (WGFBIT) develops methods and performs assessments to evaluate benthic impact from fisheries at regional scale, while con- sidering fisheries and seabed impact trade-offs. In this report, new fishery benthic impact assessments (ToR A) are shown out for several sub- regions in (French Mediterranean, Celtic Seas). For other regions, updates of the whole assess- ment or specific steps only were presented. To further standardise the different components of the WGFBIT approach across all (sub-)re- gional assessments, a more detail overview of those components was compiled. These compo- nents were slightly different among those regions, related to variation in data availability, envi- ronmental characteristics and implementation possibilities among the (sub-)regions. In WGFBIT, assessments are sometimes based on trawl or grab data, which are sampling differ- ent components of the seafloor ecosystem and can have consequences on the created sensitivity layer. Therefore, there is looked in more detail how the sensitivity outcome (and layers) can dif- fer due to the use of benthic data gathered with different gears (grab/core, trawl or video). The preliminary comparability analyses are performed on different levels: (1) based on co-located sampling; (2) comparing sensitivity maps of the (sub-) area, based on different gears. There were differences observed in longevity distribution at locations sampled with different gears and dif- ferences in data and models lead also to differences in the sensitivity layers. The WGFBIT seafloor assessment framework is not the only way to assess benthic impacts from physical disturbance. A discussion session was held on how the future workflow on advice that ICES WGFBIT assessment contribute to, will be organized. Marine sediments harbour significant levels of biodiversity that play a key role in ecosystem functions and services such as biogeochemical cycling, carbon storage and the regulation of cli- mate. Through the removal of fauna, changes in physico-chemical nature and resuspension of sediment, bottom trawling may result in significant changes in the ecosystem functioning of shelf seas. An assumption of the current PD model is that high community biomass implies higher ecosystem functioning. However, total community biomass does not necessarily reflect changes in species and functional trait composition which play a key role in regulating ecosystem func- tions. ToR D is working on an improved understanding of the link between species functional effect traits and proxies and processes for specific ecosystem functions to improve our ability to predict the impact of fishing disturbance on benthic ecosystem functioning more accurately. Links between species traits and biogeochemical parameters and the impact of trawling on these links are being explored using multivariate ordination analyses using different fauna and bioge- ochemical datasets collected in the North Sea, Celtic Sea, Kattegat, Baltic Sea and the eastern Mediterranean. Changes due to trawling in the trajectories of species densities over time and the concurrent changes in the bioturbation and bioirrigation potential of communities are being modelled using a combination of data-driven mechanistic model and a biogeochemical model. We report on the different data analysis methods that ToR D members have developed over the last year.
    Description: ICES
    Description: Published
    Description: Refereed
    Keywords: WGFBIT ; Fishery Benthic Impact ; Benthic Impact ; Human impact ; Fishery management ; Benthos ; Seabed ecoystem
    Repository Name: AquaDocs
    Type: Report
    Format: 112pp.
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  • 8
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    Workshop to Scope Assessment Methods to Set Thresholds (WKBENTH2) (2022)
    International Council for the Exploration of the Sea | Copenhagen, Denmark
    Details
    Publication Date: 2022-12-11
    Description: The Marine Strategy Framework Directive (MSFD) requires Member States to achieve good environmental status (GES) across their marine waters. The EU have requested ICES to advise on methods for assessing adverse effects on seabed habitats, through selection of relevant indicators for the assessment of benthic habitats and seafloor integrity and associated threshold values for GES in relation to Descriptor 6 – Seabed integrity under the MFSD. Two sets of criteria were developed to evaluate indicators and thresholds respectively for evaluation of suitability for assessing GES. 16 indicator and 12 threshold criteria were compiled and weighted by importance. The criteria were designed for evaluation at a subregional or regional level. The scoring for these criteria is meant as a guidance when choosing indicators and thresholds, so failure to meet one criterion will not necessarily prevent the use of the indicator or thresh-old in an assessment. The framework was evaluated for 6 indicators and for 11 methods for setting thresholds. The criteria were found to be useful for evaluation both indicators and thresholds. The process works most consistently when there are experts in the group on both the criteria themselves and on the indicators and thresholds. The MFSD Descriptor 6 determination of GES needs both a quality threshold (when are seabed habitats in a good state in a specific location) and an extent threshold (proportion of the assessment area that needs to have seabed habitats in good state). Eleven different methods for setting thresholds were identified, of which more are suitable for setting quality than for extent thresholds. Preferred methods identified an ecologically-motivated difference between a good and de-graded state, rather than another transition. Quality thresholds based on the lower boundary of the range of natural variation were considered most promising. This approach can be used for most, but not all, indicators. The WK collated a standardized dataset to test the specificity, sensitivity and/or responsiveness of sampling-based benthic indicators to pressure gradients for evaluation by WKBENTH3. Risk-based methods will be evaluated as maps and by scored sensitivity and impact score per MSFD habitat type and subdivision. Participants provided input into the selection of indicators for the compilation of indicators. A template was developed for documenting the characteristics of each indicator to facilitate the evaluation of the indicators.
    Description: ICES
    Description: Published
    Description: Non Refereed
    Keywords: Marine Strategy Framework Directive ; MSFD ; ICES ; Seabed integrity
    Repository Name: AquaDocs
    Type: Report
    Format: 98pp.
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  • 9
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    ICES (2018) Interim Report of the Benthos Ecology Working Group (BEWG) (2018)
    ICES CM 2018/EPDSG:03
    In:  EPIC3ICES CM 2018/EPDSG:03, 29 p.
    Details
    Publication Date: 2024-05-23
    Repository Name: EPIC Alfred Wegener Institut
    Type: Other , notRev
    Format: application/pdf
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  • 10
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    ICES (2017) Report of the Benthos Ecology Working Group (BEWG) (2017)
    ICES CM 2017/SSGEPD:03
    In:  EPIC3ICES CM 2017/SSGEPD:03, 37 p.
    Details
    Publication Date: 2024-05-23
    Repository Name: EPIC Alfred Wegener Institut
    Type: Other , notRev
    Format: application/pdf
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