16 results on '"Schumacher, Mia"'
Search Results
2. Sonar meets AI: Revolutionäre Ansätze in der Geisternetzearbeit
- Author
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Dederer, Gabriele, Lee, Mareen, Röhling, Anne, Stolte, Andrea, Werner, Stefanie, Schumacher, Mia, Fenn, Crayton, Howe, Christian, Frank, Wolfgang, Viehberg, Finn, Lamp, Jochen, Gondlach, Kai, editor, Brinkmann, Birgit, editor, Brinkmann, Mark, editor, and Plath, Julia, editor
- Published
- 2024
- Full Text
- View/download PDF
3. Variation between plant species in pollen digestion rates in the green lacewing Chrysoperla carnea
- Author
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González, Ezequiel, primary, Bianchi, Felix J. J. A., additional, Wizorek, Sarah, additional, Schumacher, Mia, additional, and Entling, Martin H., additional
- Published
- 2022
- Full Text
- View/download PDF
4. The Atlantic Ocean landscape: A basin-wide cluster analysis of the Atlantic near seafloor environment
- Author
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Schumacher, Mia, primary, Huvenne, Veerle A. I., additional, Devey, Colin W., additional, Arbizu, Pedro Martínez, additional, Biastoch, Arne, additional, and Meinecke, Stefan, additional
- Published
- 2022
- Full Text
- View/download PDF
5. Habitat variability and faunal zonation at the Ægir Ridge, a canyon-like structure in the deep Norwegian Sea
- Author
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Brix, Saskia, primary, Kaiser, Stefanie, additional, Lörz, Anne-Nina, additional, Le Saout, Morgane, additional, Schumacher, Mia, additional, Bonk, Frederic, additional, Egilsdottir, Hronn, additional, Olafsdottir, Steinunn Hilma, additional, Tandberg, Anne Helene S., additional, Taylor, James, additional, Tewes, Simon, additional, Xavier, Joana R., additional, and Linse, Katrin, additional
- Published
- 2022
- Full Text
- View/download PDF
6. Habitat variability and faunal zonation at the Ægir Ridge, a canyon-like structure in the deep Norwegian Sea
- Author
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Brix, Saskia, Kaiser, Stefanie, Lörz, Anne-Nina, Le Saout, Morgane, Schumacher, Mia, Bonk, Frederic, Egilsdottír, Hrönn, Ólafsdóttir, Steinunn Hilma, Tandberg, Anne Helene S., Taylor, James, Tewes, Simon, Xavier, Joana R., Linse, Katrin, Brix, Saskia, Kaiser, Stefanie, Lörz, Anne-Nina, Le Saout, Morgane, Schumacher, Mia, Bonk, Frederic, Egilsdottír, Hrönn, Ólafsdóttir, Steinunn Hilma, Tandberg, Anne Helene S., Taylor, James, Tewes, Simon, Xavier, Joana R., and Linse, Katrin
- Abstract
The Ægir Ridge System (ARS) is an ancient extinct spreading axis in the Nordic seas extending from the upper slope east of Iceland (∼550 m depth), as part of its Exclusive Economic Zone (EEZ), to a depth of ∼3,800 m in the Norwegian basin. Geomorphologically a rift valley, the ARS has a canyon-like structure that may promote increased diversity and faunal density. The main objective of this study was to characterize benthic habitats and related macro- and megabenthic communities along the ARS, and the influence of water mass variables and depth on them. During the IceAGE3 expedition (Icelandic marine Animals: Genetics and Ecology) on RV Sonne in June 2020, benthic communities of the ARS were surveyed by means of a remotely-operated vehicle (ROV) and epibenthic sledge (EBS). For this purpose, two working areas were selected, including abyssal stations in the northeast and bathyal stations in the southwest of the ARS. Video and still images of the seabed were usedtoqualitatively describebenthic habitats based on the presence of habitat-forming taxa and the physical environment. Patterns of diversity and community composition of the soft-sediment macrofauna, retrieved from the EBS, were analyzed in a semiquantitative manner. These biological data were complemented by producing high-resolution bathymetric maps using the vessel’s multi-beam echosounder system. As suspected, we were able to identify differences in species composition and number of macro- and megafaunal communities associated with a depth gradient. A biological canyon effect became evident in dense aggregates of megafaunal filter feeders and elevated macrofaunal densities. Analysis of videos and still images from the ROV transects also led to the discovery of a number ofVulnerable Marine Ecosystems (VMEs) dominated by sponges and soft corals characteristic of the Arctic region. Directions for future research encompass a more detailed, quantitative study of the megafauna and more coherent sampling over the
- Published
- 2022
7. The Atlantic Ocean landscape: A basin-wide cluster analysis of the Atlantic near seafloor environment
- Author
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Schumacher, Mia, Huvenne, Veerle A. I., Devey, Colin W., Arbizu, Pedro M., Biastoch, Arne, Meinecke, Stefan, Schumacher, Mia, Huvenne, Veerle A. I., Devey, Colin W., Arbizu, Pedro M., Biastoch, Arne, and Meinecke, Stefan
- Abstract
Landscape maps based on multivariate cluster analyses provide an objective and comprehensive view on the (marine) environment. They can hence support decision making regarding sustainable ocean resource handling and protection schemes. Across a large number of scales, input parameters and classification methods, numerous studies categorize the ocean into seascapes, hydro-morphological provinces or clusters. Many of them are regional, however, while only a few are on a basin scale. This study presents an automated cluster analysis of the entire Atlantic seafloor environment, based on eight global datasets and their derivatives: Bathymetry, slope, terrain ruggedness index, topographic position index, sediment thickness, POC flux, salinity, dissolved oxygen, temperature, current velocity, and phytoplankton abundance in surface waters along with seasonal variabilities. As a result, we obtained nine seabed areas (SBAs) that portray the Atlantic seafloor. Some SBAs have a clear geological and geomorphological nature, while others are defined by a mixture of terrain and water body characteristics. The majority of the SBAs, especially those covering the deep ocean areas, are coherent and show little seasonal and hydrographic variation, whereas other, nearshore SBAs, are smaller sized and dominated by high seasonal changes. To demonstrate the potential use of the marine landscape map for marine spatial planning purposes, we mapped out local SBA diversity using the patch richness index developed in landscape ecology. It identifies areas of high landscape diversity, and is a practical way of defining potential areas of interest, e.g. for designation as protected areas, or for further research. Clustering probabilities are highest (100%) in the center of SBA patches and decrease towards the edges (< 98%). On the SBA point cloud which was reduced for probabilities <98%, we ran a diversity analysis to identify and highlight regions that have a high number of different SBAs per ar
- Published
- 2022
- Full Text
- View/download PDF
8. Variation between plant species in pollen digestion rates in the green lacewing Chrysoperla carnea
- Author
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González, Ezequiel, Bianchi, Felix J.J.A., Wizorek, Sarah, Schumacher, Mia, Entling, Martin H., González, Ezequiel, Bianchi, Felix J.J.A., Wizorek, Sarah, Schumacher, Mia, and Entling, Martin H.
- Abstract
Pollen are an important food source for numerous insects and may be used as natural markers in ecological studies. However, to make inferences about the movement rates of insects based on their gut contents, information on pollen digestion rates is needed. Here, we assessed how the consumption and digestion rates of pollen ingested by Chrysoperla carnea Stephens (Neuroptera: Chrysopidae) adults are influenced by plant species, temperature, and sex. We offered pollen of two insect-pollinated plants – Acer pseudoplatanus L. (Sapindaceae) and Helianthus annuus L. (Asteraceae) – and two wind-pollinated plants – Fraxinus excelsior L. (Oleaceae) and Quercus rubra L. (Fagaceae) – differing in size and protein content, to adult lacewings at two temperatures, 20 and 25 °C. After feeding, lacewings were allowed to digest pollen for up to 14 days, sampled at 10 time intervals. At each of these intervals, lacewings were frozen and the internal pollen were obtained through acetolysis and quantified under a light microscope. The number of pollen grains decreased exponentially over time and declined faster for Acer than for the other three plant species. The half-life and the time at which 95% of the pollen grains were digested were lower for Acer than for the other plant species. Lacewings consumed more pollen grains from Acer and Quercus than from Fraxinus and Helianthus. Male lacewings consumed 30% fewer pollen grains than females, but without differences in their digestion rates. Our results show that lacewings consumed higher amounts of high-protein pollen (Acer and Quercus) and that digestion rates differed among plant species, which could be linked to their structural characteristics. The variable digestion rates of pollen grains may influence the study of lacewing diet composition. Studies that make inferences about the pollen diet or movement ecology of lacewings by analysing their gut contents should account for species-specific pollen digestion rates.
- Published
- 2022
9. The Atlantic Seascape: A Basin-wide Multivariate Cluster Analysis of Atlantic Seabed Areas
- Author
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Schumacher, Mia
- Abstract
Classifications of the marine environment give a comprehensive and easy overview into ocean regimes with similar characteristics and are therefore a helpful tool for sustainable ocean management and conservation. There have been many efforts to define seascapes and habitats by classifications using different approaches applied at a wide range of scales. However, most of the Atlantic-wide classifications available are based on hierarchical schemes with often arbitrary thresholds. This study presents a basin-wide landscape classification of the Atlantic sea floor environment based on global datasets of 9 input variables: bathymetry, slope, terrain ruggedness index, topographic position index, sediment thickness, salinity, dissolved oxygen, temperature and current velocity. To reduce subjectivity within the analysis, we used unsupervised classification techniques on the normalised variables: a K-Means clustering algorithm was run on a random data subset as a first step to identify the cluster centres which were then taken as input for a random forest prediction of the remaining data set. The optimum number of classes was determined based on the Caliński-Harabasz criterion. The result is a map of the Atlantic realm subdivided into 8 seascape domains. Some are clearly defined by geological/geomorphological properties, while others are dominated by hydrographic properties, or by a mixture of both sea floor terrain and water column characteristics. The largest class is the abyssal plain with very deep water and extremely low hydrographic and seasonal change – in contrast to the smallest class which incorporates coastal and river outflow regions that are subject to high seasonal variations and cover a broad range of temperature, oxygen and salinity values. All domains were further compared to a similar existing classification by Harris and Whiteway (2009) and datasets (e.g. seamount locations) to assess to what extent the objectively identified landscape classes are represented in previous classification schemes.
- Published
- 2021
10. Inter-Comparison of the Spatial Distribution of Methane in the Water Column From Seafloor Emissions at Two Sites in the Western Black Sea Using a Multi-Technique Approach
- Author
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Grilli, Roberto, primary, Birot, Dominique, additional, Schumacher, Mia, additional, Paris, Jean-Daniel, additional, Blouzon, Camille, additional, Donval, Jean Pierre, additional, Guyader, Vivien, additional, Leau, Helene, additional, Giunta, Thomas, additional, Delmotte, Marc, additional, Radulescu, Vlad, additional, Balan, Sorin, additional, Greinert, Jens, additional, and Ruffine, Livio, additional
- Published
- 2021
- Full Text
- View/download PDF
11. Inter-Comparison of the Spatial Distribution of Methane in the Water Column From Seafloor Emissions at Two Sites in the Western Black Sea Using a Multi-Technique Approach
- Author
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Grilli, Roberto, Birot, Dominique, Schumacher, Mia, Paris, Jean-daniel, Blouzon, Camille, Donval, Jean-pierre, Guyader, Vivien, Leau, Helene, Giunta, Thomas, Delmotte, Marc, Radulescu, Vlad, Balan, Sorin, Greinert, Jens, Ruffine, Livio, Grilli, Roberto, Birot, Dominique, Schumacher, Mia, Paris, Jean-daniel, Blouzon, Camille, Donval, Jean-pierre, Guyader, Vivien, Leau, Helene, Giunta, Thomas, Delmotte, Marc, Radulescu, Vlad, Balan, Sorin, Greinert, Jens, and Ruffine, Livio
- Abstract
Understanding the dynamics and fate of methane (CH4) release from oceanic seepages on margins and shelves into the water column, and quantifying the budget of its total discharge at different spatial and temporal scales, currently represents a major scientific undertaking. Previous works on the fate of methane escaping from the seafloor underlined the challenge in both, estimating its concentration distribution and identifying gradients. In April 2019, the Envri Methane Cruise has been conducted onboard the R/V Mare Nigrum in the Western Black Sea to investigate two shallow methane seep sites at ∼120 m and ∼55 m water depth. Dissolved CH4 measurements were conducted with two continuous in-situ sensors: a membrane inlet laser spectrometer (MILS) and a commercial methane sensor (METS) from Franatech GmbH. Additionally, discrete water samples were collected from CTD-Rosette deployment and standard laboratory methane analysis was performed by gas chromatography coupled with either purge-and-trap or headspace techniques. The resulting vertical profiles (from both in situ and discrete water sample measurements) of dissolved methane concentration follow an expected exponential dissolution function at both sites. At the deeper site, high dissolved methane concentrations are detected up to ∼45 m from the seabed, while at the sea surface dissolved methane was in equilibrium with the atmospheric concentration. At the shallower site, sea surface CH4 concentrations were four times higher than the expected equilibrium value. Our results seem to support that methane may be transferred from the sea to the atmosphere, depending on local water depths. In accordance with previous studies, the shallower the water, the more likely is a sea-to-atmosphere transport of methane. High spatial resolution surface data also support this hypothesis. Well localized methane enriched waters were found near the surface at both sites, but their locations appear to be decoupled with the ones of the se
- Published
- 2021
- Full Text
- View/download PDF
12. Depth transects and connectivity along gradients in the North Atlantic and Nordic Seas in the frame of the IceAGE project (Icelandic marine Animals: Genetics and Ecology), Cruise No. SO276 (MerMet17-06), 22.06.2020 - 26.07.2020, Emden (Germany) - Emden (Germany)
- Author
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Brix, Saskia, Taylor, James, Le Saout, Morgane, Mercado-Salas, Nancy, Kaiser, Stefanie, Lörz, Anne-Nina, Gatzemeier, Nicole, Jeskulke, Karen, Kürzel, Karlotta, Neuhaus, Jenny, Paulus, Eva, Uhlir, Carolin, Korfhage, Severin, Bruhn, Marco, Stein, Tina, Wilsenack, Maik, Siegler, Viola, Schumacher, Mia, Lux, Thorsten, Gärtner, Lisa, Abegg, Friedrich, Pieper, Martin, Bodendorfer, Matthias, Cuno, Patrick, Huusmann, Hannes, Matthiessen, Torge, Bischof, Florian, and Suck, Inken
- Published
- 2020
13. Measuring methane from the seafloor to the atmosphere: an integrated experiment in the Black Sea
- Author
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Paris, Jean-Daniel, primary, Ruffine, Livio, additional, Leau, Hélène, additional, Giunta, Thomas, additional, Donval, Jean-Pierre, additional, Guyader, Vivien, additional, Birot, Dominique, additional, Schumacher, Mia, additional, Greinert, Jens, additional, Grilli, Roberto, additional, Blouzon, Camille, additional, Delmotte, Marc, additional, Longo, Manfredi, additional, Scire, Sergio, additional, Italiano, Francesco, additional, Lazzaro, Gianluca, additional, Balan, Sorin, additional, Scalabrin, Carla, additional, and Douillard, Thibault, additional
- Published
- 2020
- Full Text
- View/download PDF
14. Reference document for methane harmonized monitoring
- Author
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Paris, Jean-Daniel, Leau, H��l��ne, Ruffine, Livio, Giunta, Thomas, Donval, Jean-Pierre, Guyader, Viven, Birot, Dominique, Scalabrin, Carla, Brandilly, Christophe, Douillard, Thibault, Schumacher, Mia, Longo, Manfredi, Scire, Sergio, Italiano, Francesco, Lazzaro, Gianluca, Grilli, Roberto, and Blouzon, Camille
- Subjects
13. Climate action ,Methane, marine, ENVRI, research infrastructures - Abstract
ENVRIplus (Theme 1 'Technical innovation') developed a joint pilot experiment to measure methane transfer from the seafloor to the atmosphere, in a pilot study involving RIs ICOS, Eurofleets, EMSO and ACTRIS. The pilot experiment developed joint monitoring strategy for methane detection at various levels starting from the seafloor and moving across the water column, the water/air interface and the atmosphere. The Romanian sector of the Black Sea is the selected location. This area hosts a large number of emission sites of methane-rich gases, from the continental shelf to the deepest part of the basin. It is consequently a good candidate for investigating the fate of marine methane, from the sedimentary column to the atmosphere by combining the expertise and technologies of six EU teams. The methodology applied integrates (1) sampling from the three spheres (lithosphere, hydrosphere and atmosphere) for laboratory measurements of methane concentration by well-proven standard methods together with ��13C-CH4 analysis, (2) in situ measurements of methane concentration and ��13C- CH4 into the water column and the atmosphere, and (3) the deployment of a seafloor observatory for a short monitoring period (4-5 days) to evaluate the temporal variability of gas fluxes.
15. Reference document for methane harmonized monitoring
- Author
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Paris, Jean-Daniel, Leau, Hélène, Ruffine, Livio, Giunta, Thomas, Donval, Jean-Pierre, Guyader, Viven, Birot, Dominique, Scalabrin, Carla, Brandilly, Christophe, Douillard, Thibault, Schumacher, Mia, Longo, Manfredi, Scire, Sergio, Italiano, Francesco, Lazzaro, Gianluca, Grilli, Roberto, and Blouzon, Camille
- Subjects
13. Climate action ,Methane, marine, ENVRI, research infrastructures - Abstract
ENVRIplus (Theme 1 'Technical innovation') developed a joint pilot experiment to measure methane transfer from the seafloor to the atmosphere, in a pilot study involving RIs ICOS, Eurofleets, EMSO and ACTRIS. The pilot experiment developed joint monitoring strategy for methane detection at various levels starting from the seafloor and moving across the water column, the water/air interface and the atmosphere. The Romanian sector of the Black Sea is the selected location. This area hosts a large number of emission sites of methane-rich gases, from the continental shelf to the deepest part of the basin. It is consequently a good candidate for investigating the fate of marine methane, from the sedimentary column to the atmosphere by combining the expertise and technologies of six EU teams. The methodology applied integrates (1) sampling from the three spheres (lithosphere, hydrosphere and atmosphere) for laboratory measurements of methane concentration by well-proven standard methods together withδ13C-CH4analysis, (2)in situmeasurements of methane concentration andδ13C- CH4into the water column and the atmosphere, and (3) the deployment of a seafloor observatory for a short monitoring period (4-5 days) to evaluate the temporal variability of gas fluxes.
16. The Atlantic Seascape: A Basin-wide Multivariate Cluster Analysis of Atlantic Seabed Areas
- Author
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Schumacher, Mia
- Subjects
13. Climate action ,14. Life underwater ,15. Life on land - Abstract
Classifications of the marine environment give a comprehensive and easy overview into ocean regimes with similar characteristics and are therefore a helpful tool for sustainable ocean management and conservation. There have been many efforts to define seascapes and habitats by classifications using different approaches applied at a wide range of scales. However, most of the Atlantic-wide classifications available are based on hierarchical schemes with often arbitrary thresholds. This study presents a basin-wide landscape classification of the Atlantic sea floor environment based on global datasets of 9 input variables: bathymetry, slope, terrain ruggedness index, topographic position index, sediment thickness, salinity, dissolved oxygen, temperature and current velocity. To reduce subjectivity within the analysis, we used unsupervised classification techniques on the normalised variables: a K-Means clustering algorithm was run on a random data subset as a first step to identify the cluster centres which were then taken as input for a random forest prediction of the remaining data set. The optimum number of classes was determined based on the Caliński-Harabasz criterion. The result is a map of the Atlantic realm subdivided into 8 seascape domains. Some are clearly defined by geological/geomorphological properties, while others are dominated by hydrographic properties, or by a mixture of both sea floor terrain and water column characteristics. The largest class is the abyssal plain with very deep water and extremely low hydrographic and seasonal change – in contrast to the smallest class which incorporates coastal and river outflow regions that are subject to high seasonal variations and cover a broad range of temperature, oxygen and salinity values. All domains were further compared to a similar existing classification by Harris and Whiteway (2009) and datasets (e.g. seamount locations) to assess to what extent the objectively identified landscape classes are represented in previous classification schemes.
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