2026-09-20T17:07:09Z https://www.fdr.uni-hamburg.de/oai2d

oai:fdr.uni-hamburg.de:16146 2024-10-30T08:27:40Z user-rtg2530 user-uhh

Martens, Nele Biederbick, Johanna Schaum, C.-Elisa 2024-10-27 Picophytoplankton are important primary producers, but not always adequately recognized, e.g. due to methodological limitations. In this study, we combined flow cytometry and metabarcoding to investigate seasonal and spatial patterns of picophytoplankton abundance and community composition in the Elbe estuary. Due to the mixing of freshwater and seawater and the tidal currents this ecosystem is characterized by typical estuarine features such as salinity gradients and high turbidity. Picophytoplankton (mostly picoeukaryotes such as Mychonastes and Minidiscus) contributed on average 70 % (SD = 14 %) to the total phytoplankton counts. In summer picocyanobacteria (e.g. Synechococcus) played a more significant role. The contributions of picophytoplankton to the total phytoplankton were particularly high from summer to winter as well as in the mid estuary. However, at salinities of around 10 PSU in the mixing area of freshwater and seawater the proportion of picophytoplankton was comparably low (average 49 %, SD = 13 %). Our results indicate that picophytoplankton prevail in the Elbe estuary year-round with respect to cell counts. Picophytoplankton could occupy important niche positions to maintain primary production under extreme conditions where larger phytoplankton might struggle (e.g. at high or low temperature, high turbidity and in areas with high grazing pressure), and also benefit from high nutrient availability here. However, we did not find evidence that they played a particularly significant role at the salinity interface. Our study highlights the importance of including picophytoplankton when assessing estuarine phytoplankton as has been suggested for other ecosystems such as oceans. https://www.fdr.uni-hamburg.de/record/16146 10.1002/pei3.70014 oai:fdr.uni-hamburg.de:16146 eng info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode picocyanobacteria, picoeukaryotes, salinity, temperature, turbidity Picophytoplankton prevail year-round in the Elbe estuary info:eu-repo/semantics/article publication-article

oai:fdr.uni-hamburg.de:17912 2025-09-01T19:43:10Z user-uhh user-rtg2530

Saadaoui Youssef Porada Philipp Beer Christian 2024-06-10 This repository contains two essential scripts used in the "Quantifying aggregation bias in marsh carbon flux estimates caused by rhizosphere oxygen heterogeneity" paper 1. Data processing script (process_ICBM.m): This script processes data from the simulation of the ICBM, focusing on the heterotrophic respiration of incubated soil samples. 2. Simulation script (DAMM_ready_final_publish.m): This script calibrates the DAMM respiration model to incubation medians, builds gas- and aqueous-phase oxygen proxies, and quantifies aggregation bias from oxygen heterogeneity. Runs end-to-end and exports all the figures in (PDF/PNG). https://www.fdr.uni-hamburg.de/record/17912 10.25592/uhhfdm.17912 oai:fdr.uni-hamburg.de:17912 eng doi:10.25592/uhhfdm.14376 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode Scripts for modeling and simulating soil heterotrophic respiration info:eu-repo/semantics/other other

oai:fdr.uni-hamburg.de:14334 2025-09-14T18:11:56Z user-uhh user-rtg2530

Panunporn Tutiyasarn Peter Mueller Gibran Romero-Mujalli Bryce Van Dam Jens Hartmann Philipp Porada 2025-04-15 Data set for the publication titled "Soil carbon dioxide levels control salt marsh alkalinity generation" Journal Title: Limnology and Oceanography Print ISSN: 0024-3590 Online ISSN: 1939-5590 Article ID: LNO70062 For the calculation please refer to the equations in the publication. This project was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) as part of the project 'Biota-mediated effects on carbon cycling in estuaries' (grant no. 407270017/RTG2530). https://www.fdr.uni-hamburg.de/record/14334 10.25592/uhhfdm.14334 oai:fdr.uni-hamburg.de:14334 eng doi:10.25592/uhhfdm.14333 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode Soil carbon dioxide levels control salt marsh alkalinity generation info:eu-repo/semantics/other dataset

oai:fdr.uni-hamburg.de:14151 2024-10-30T07:26:05Z user-uhh user-rtg2530

Martens, Nele Schaum, C.-Elisa 2023-05-17 Poster of preliminary study results as presented at the ASLO conference 2023. Please find publication of final results elsewhere (https://doi.org/10.1098/rspb.2023.2713). https://www.fdr.uni-hamburg.de/record/14151 10.25592/uhhfdm.14151 oai:fdr.uni-hamburg.de:14151 eng doi:10.1098/rspb.2023.2713 doi:10.25592/uhhfdm.14150 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode Picophytoplankton Mixotrophy Green algae Organic Carbon Acquisition of Estuarine Phytoplankton info:eu-repo/semantics/conferencePoster poster

oai:fdr.uni-hamburg.de:13893 2024-03-19T10:25:29Z user-uhh user-rtg2530

Grüterich, Luise Woodhouse, Jason Nicholas Mueller, Peter Tiemann, Amos Ruscheweyh, Hans-Joachim Sunagawa, Shinichi Grossart, Hans-Peter Streit, Wolfgang R. 2023-06-07 This dataset supports the paper: "Environmental controls of dark CO2 fixation in wetland microbiota". It contains genecluster abundances, annotations, taxonomy and membership for the metagenomic and metatranscriptomic analyses aswell as ASV tables for the 16S rRNA gene analyses. https://www.fdr.uni-hamburg.de/record/13893 10.25592/uhhfdm.13893 oai:fdr.uni-hamburg.de:13893 eng doi:10.25592/uhhfdm.12482 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode Wood-Ljungdahl pathway, reverse TCA cycle, metagenomics, metatranscriptomics Dataset to: Environmental controls of dark CO2 fixation in wetland microbiota info:eu-repo/semantics/other dataset

oai:fdr.uni-hamburg.de:14377 2025-09-01T19:43:10Z user-rtg2530 user-uhh

Saadaoui Youssef Porada Philipp Beer Christian 2024-06-10 This repository contains two essential scripts used in the "Ideas and perspectives: Exploring effects of variation in plant root traits on carbon emissions from estuarine marshes" paper 1. Data processing script (process_ICBM.m): This script processes data from the simulation of the ICBM, focusing on the heterotrophic respiration of incubated soil samples. 2. Simulation script (perspective_script.m): this script was used to perform the simulation of soil respiration in the study. it compares different model configurations, with and without explicit representation of plant trait variation. https://www.fdr.uni-hamburg.de/record/14377 10.25592/uhhfdm.14377 oai:fdr.uni-hamburg.de:14377 eng doi:10.25592/uhhfdm.14376 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode Scripts for modeling and simulating soil heterotrophic respiration info:eu-repo/semantics/other other

oai:fdr.uni-hamburg.de:18341 2026-02-27T13:50:48Z user-uhh user-rtg2530

Menzel, Andrea-Carolin Ostertag, Eva Müller, Peter Nolte, Stefanie Rich, Roy Jensen, Kai 2025-05-05 Salt marshes provide vital ecosystem services, including coastal protection and carbon sequestration. Roots play a key role in delivering these ecosystem services, as they stabilize soils and contribute to organic carbon accumulation. This study examines the impact of an experimental 3C temperature increase in a temperate salt marsh on belowground biomass dynamics across three elevation zones (pioneer zone, low marsh, and high marsh) and two temperature treatments (ambient, + 3°C) over a period of 3 yr (2019–2021). The elevation zones reflect different hydrological conditions. We found minimal effects of warming on belowground biomass, except in the high marsh during 2019, where drought and warming caused a shift to deeper rooting depths (- 53 +/- 19% in the upper soil depth, + 272 +/- 129% in the lower soil depth). Overall, root biomass was lowest in the high marsh (72.0 +/- 94.5 g m2) and highest in the low marsh (360.2 +/- 174.7 g m2), followed by the pioneer zone (218.7 +/- 233.8 g m2). In all years, root biomass peaked in summer (248.5 +/- 235.5 g m2) after rising from spring (181.4 +/- 183.4 g m2) and declining in autumn (216.5 +/- 209.4 g m2). Our findings suggest that a temperature increase of + 3°C above ambient temperatures has a marginal impact on root biomass dynamics, indicating that soil-stabilizing functions and belowground contributions to carbon sequestration may remain intact under global warming. Moreover, interactions between tidal regime and interannual precipitation patterns seem to play a more important role for root biomass variations. https://www.fdr.uni-hamburg.de/record/18341 10.25592/uhhfdm.18341 oai:fdr.uni-hamburg.de:18341 doi:10.25592/uhhfdm.18340 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode belowground biomass root dynamics experimental warming salt marshes marsh zones seasonal changes Hydrology mediates salt marsh belowground biomass response to warming info:eu-repo/semantics/article publication-article

oai:fdr.uni-hamburg.de:18666 2026-05-04T07:03:26Z user-rtg2530 user-uhh

Martens, Nele Schaum, C.-Elisa 2026-05-03 The present dataset contains the raw data underlying the publication "Organic compounds drive growth in phytoplankton taxa from different functional groups" (https://doi.org/10.1098/rspb.2023.2713). The data collection was carried out as part of the DFG-funded project “Biota-mediated effects on carbon cycling in estuaries” within the RTG2530 (grant number 407270017). We provide a data sheet each with the processed data and metadata, as well as the raw data as .fcs files (flow cytometric data) which can be read with the provided R script. Information about the strains has been previously published (http://doi.org/10.25592/uhhfdm.18668). https://www.fdr.uni-hamburg.de/record/18666 10.25592/uhhfdm.18666 oai:fdr.uni-hamburg.de:18666 eng doi:10.1098/rspb.2023.2713 doi:10.25592/uhhfdm.18668 doi:10.25592/uhhfdm.18665 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode mixotrophy, estuary, green algae Use of organic compounds by phytoplankton from the Elbe estuary (ecoplate data) info:eu-repo/semantics/other dataset

oai:fdr.uni-hamburg.de:15940 2026-07-10T14:48:10Z user-uhh user-rtg2530

Biederbick, Johanna Möllmann, Christian Russnak, Vanessa Koppelmann, Rolf 2026-07-02 This repository contains abiotic data and abundance/biomass data on zooplankton collected in the Elbe estuary. Title: Salinity, turbidity and chlorophyll drive zooplankton succession in a temperate estuary under anthropogenic pressure Estuarine zooplankton are vital primary consumers and essential for estuarine ecosystem functioning and productivity, but they face strong physico-biochemical gradients and often anthropogenically altered habitats that impact their succession. Detailed zooplankton community studies are scarce and outdated for the turbid and dredged Elbe estuary in northern Germany. We provide a comprehensive overview of micro-, meso- and macrozooplankton dynamics in the tidal Elbe River by examining their spatio-temporal succession relative to environmental factors. Using redundancy analyses, we analyzed zooplankton assemblages and abiotic conditions at six stations along a salinity gradient during seasonal sampling in 2021 and 2022. Salinity and chlorophyll a emerged as key factors structuring community patterns, with turbidity further affecting the spatial distribution. An autotrophic zone with high chlorophyll a levels and low turbidity was confined to a shallow freshwater zone upstream of the dredged Hamburg Harbor region, supporting a community dominated by freshwater micro- and mesozooplankton, such as rotifers and cladocerans, peaking in spring and summer. Eurytemora affinis was the most abundant copepod year-round throughout the estuary, exhibiting a marked tolerance to high turbidity. Coastal meso- and macrozooplankton taxa such as Acartia spp., Paracalanus parvus, and Mesopodopsis slabberi colonized only the lower estuarine zone due to their affinity for high salinities. Compared to earlier studies, overall zooplankton abundance has declined, potentially in response to climatic changes and environmental alterations from recent hydrological interventions. This study enhances our understanding of the environmental drivers shaping estuarine zooplankton dynamics, which is essential for their conservation in the face of global change. https://www.fdr.uni-hamburg.de/record/15940 10.25592/uhhfdm.15940 oai:fdr.uni-hamburg.de:15940 eng doi:10.25592/uhhfdm.15939 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode Limnology and Oceanography Elbe estuary Zooplankton community Rotifers Copepods Mysids Spatio-temporal variability Anthropogenic impacts Meta data: Salinity, turbidity and chlorophyll drive zooplankton succession in a temperate estuary under anthropogenic pressure info:eu-repo/semantics/other dataset

oai:fdr.uni-hamburg.de:16150 2024-10-30T08:27:36Z user-rtg2530 user-uhh

Martens, Nele 2024-06-11 Poster shown in the context of evaluating the RTG2530 progress by the DFG. https://www.fdr.uni-hamburg.de/record/16150 10.25592/uhhfdm.16150 oai:fdr.uni-hamburg.de:16150 eng doi:10.1098/rspb.2023.2713 doi:10.1016/j.envres.2024.119126 doi:10.25592/uhhfdm.16149 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode Phytoplankton in the Elbe estuary info:eu-repo/semantics/conferencePoster poster

oai:fdr.uni-hamburg.de:13235 2025-09-18T06:01:08Z user-rtg2530 user-uhh

Laurin Steidle 2023-09-08 This repository contains the model configuration and output for the publication: Phytoplankton Retention Mechanisms in Estuaries: A Case Study of the Elbe Estuary. Due to their role as primary producers, phytoplankton is essential for the proliferation of estuarine ecosystems. However, as small drifting organisms, phytoplankton cannot resist currents. Estuaries not only represent challenging habitats due to a strong salinity gradient, but also have net transport into oceans. So far, little is known about how phytoplankton retain themselves in estuaries. We present a new individual-based Lagrangian model of the Elbe estuary examining possible retention mechanisms of phytoplankton. In more detail, we investigated how reproduction, sinking and rising, as well as diel vertical migration might allow for population survival. We find that rising favors the retention success, fast sinking cause the opposite. We further provide first estimates on outwashing losses. Our simulations illustrate that shallow stretches of water along the river banks are essential for the long-term survival of phytoplankton populations. These results give important indications for ecosystem-based management of estuaries. https://www.fdr.uni-hamburg.de/record/13235 10.25592/uhhfdm.13235 oai:fdr.uni-hamburg.de:13235 eng doi:10.25592/uhhfdm.13234 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode Phytoplankton, Elbe, Estuary, Particle Tracking, Oceantracker Phytoplankton Retention Mechanisms in Estuaries: A Case Study of the Elbe Estuary info:eu-repo/semantics/other dataset

oai:fdr.uni-hamburg.de:16111 2025-09-14T18:11:48Z user-uhh user-rtg2530

Laurin Steidle 2024-10-17 This repository contains the model i.e. simulation output, the oceantracker model itself, and the script to produce the plots used in the publication ``` Title: Effects of coagulation processes on phytoplankton mortality in the Elbe estuary from a Lagrangian perspective Authors: Laurin Steidle, Johannes Pein, Adrian Burd, Ross Vennell Url: https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2025.1624762/abstract DOI: 10.3389/fmars.2025.1624762 ``` The repository was created by Laurin Steidle (laurin.steidle@uni-hamburg.de). Feel free to reach out. 1. If you would like to reproduce the plots you will need to download the "model_output_archive.tar.xy.part*", unpack it, and run the the "collapse_paper_plot.ipynb". To unpack the model output data (from a unix based machine) ``` # join the parts together cat model_output_archive.tar.xy.part* > model_output_archive.tar.xz # and unpack them tar -xJf model_output_archive.tar.xz ``` 2. If you would like to reproduce the output you will need to download "oceantracker.tar.xy". To install it take a look at the documentation (https://oceantracker.github.io/oceantracker/_build/html/index.html) The short version of it is: ``` mamba create --name oceantracker mamba activate oceantracker cd oceantracker pip install -e . ``` The model configuration used to produce the paper output is ```22_07_29_depth_losses_v57.py```. (You can also find it in oceantracker/experiments/collapse/) Sadly, I am not allowed to share the simulation input i.e. the hydrodynamics publicly. You can reach out to Johannes Pein (johannes.pein@hhereonereon.de) or me directly to me to get the hydrodynamics. https://www.fdr.uni-hamburg.de/record/16111 10.25592/uhhfdm.16111 oai:fdr.uni-hamburg.de:16111 eng doi:10.25592/uhhfdm.16110 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode Frontiers in Marine Science Volume 12 - 202 Phytoplankton Estuary Lagrangian Particle-tracking modeling Aggregation Mortality Elbe Effects of coagulation processes on phytoplankton mortality in the Elbe estuary from a Lagrangian perspective info:eu-repo/semantics/other software

oai:fdr.uni-hamburg.de:16618 2025-09-14T18:12:04Z user-uhh user-rtg2530

Biederbick, Johanna Renz, Jasmin Russnak, Vanessa Möllmann, Christian Koppelmann, Rolf 2025-01-04 Meta data for the thesis chapter "Population dynamics and production of Eurytemora affinis in the Elbe estuary". https://www.fdr.uni-hamburg.de/record/16618 10.25592/uhhfdm.16618 oai:fdr.uni-hamburg.de:16618 eng doi:10.25592/uhhfdm.16617 info:eu-repo/semantics/restrictedAccess METADATA: Population dynamics and production of Eurytemora affinis in the Elbe estuary info:eu-repo/semantics/other dataset

oai:fdr.uni-hamburg.de:18705 2026-07-28T09:09:08Z user-uhh user-rtg2530

Martens, Nele Schaum, C.-Elisa 2026-05-22 The present dataset contains 16S and 18S sequencing data (metabarcoding) from the Elbe estuary. The data collection was carried out as part of the DFG-funded project “Biota-mediated effects on carbon cycling in estuaries” within the RTG2530 (grant number 407270017). The aim was to analyze phytoplankton composition. Bulk water samples were taken at six different stations along the estuary in different seasons in 2021 and 2022. We provide the raw data as .fastq files, as well as metadata, processed data and a README file. The README file contains important information about methodological constraints. The 18S data, and part of the 16S data (picocyanobacteria) have been previously published (https://doi.org/10.1016/j.envres.2024.119126; https://doi.org/10.1002/pei3.70014). https://www.fdr.uni-hamburg.de/record/18705 10.25592/uhhfdm.18705 oai:fdr.uni-hamburg.de:18705 eng doi:10.1016/j.envres.2024.119126 doi:10.1002/pei3.70014 doi:10.25592/uhhfdm.18704 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode phytoplankton diatoms picophytoplankton DNA cyanobacteria Phytoplankton metabarcoding data from the Elbe estuary (16S and 18S sequencing) info:eu-repo/semantics/other dataset

oai:fdr.uni-hamburg.de:19092 2026-08-09T09:08:54Z user-rtg2530 user-uhh

Martens, Nele Schaum, C.-Elisa 2026-07-28 The present dataset contains flow cytometric data from the Elbe estuary. The data collection was carried out as part of the DFG-funded project “Biota-mediated effects on carbon cycling in estuaries” within the RTG2530 (grant number 407270017). The aim was to analyze phytoplankton abundance and composition (in terms of e.g. size classes, eukaryotes/ prokaryotes). Water samples from 8 different stations along the estuary were collected from 2021 – 2022. We provide the raw data as .fcs files, an R script to read the files, as well as metadata and processed data. Part of this data has been included in a previous publication, which focused on picophytoplankton (https://doi.org/10.1002/pei3.70014). https://www.fdr.uni-hamburg.de/record/19092 10.25592/uhhfdm.19092 oai:fdr.uni-hamburg.de:19092 eng doi:10.1002/pei3.70014 doi:10.25592/uhhfdm.19091 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode picophytoplankton cyanobacteria eukaryotes particles Flow cytometric data from the Elbe estuary (Phytoplankton) info:eu-repo/semantics/other dataset

oai:fdr.uni-hamburg.de:14143 2024-02-28T15:11:54Z user-uhh user-rtg2530

Martens, Nele Ehlert, Emilia Putri, Widhi Sibbertsen, Martje Schaum, C.-Elisa 2024-02-07 Phytoplankton are usually considered autotrophs, but an increasing number of studies show that many taxa are able also to use organic carbon. Acquiring nutrients and energy from different sources might enable an efficient uptake of required substances and provide a strategy to deal with varying resource availability, especially in highly dynamic ecosystems such as estuaries. In our study, we investigated the effects of 31 organic carbon sources on the growth (proxied by differences in cell counts after 24 h exposure) of 17 phytoplankton strains from the Elbe estuary spanning four functional groups. All of our strains were able to make use of at least 1 and up to 26 organic compounds for growth. Pico-sized green algae such as Mychonastes, as well as the nano-sized green alga Monoraphidium in particular were positively affected by a high variety of substances. Reduced light availability, typically appearing in turbid estuaries and similar habitats, resulted in an overall poorer ability to use organic substances for growth, indicating that organic carbon acquisition was not primarily a strategy to deal with darkness. Our results give further evidence for mixotrophy being a ubiquitous ability of phytoplankton and highlight the importance to consider this trophic strategy in research. https://www.fdr.uni-hamburg.de/record/14143 10.1098/rspb.2023.2713 oai:fdr.uni-hamburg.de:14143 eng doi:10.6084/m9.figshare.c.7055608.v1 doi:10.5061/dryad.zkh1893g8 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode picophytoplankton mixotrophy estuary green algae Organic compounds drive growth in phytoplankton taxa from different functional groups info:eu-repo/semantics/article publication-article

oai:fdr.uni-hamburg.de:14308 2024-05-20T10:35:39Z user-rtg2530 user-uhh

Martens, Nele Russnak, Vanessa Woodhouse, Jason Grossart, Hans-Peter Schaum, C.-Elisa 2024-07-01 In estuaries, phytoplankton are faced with strong environmental forcing (e.g. high turbidity, salinity gradients). Taxa that appear under such conditions may play a critical role in maintaining food webs and biological carbon pumping, but knowledge about estuarine biota remains limited. This is also the case in the Elbe estuary where the lower 70 km of the water body are largely unexplored. In the present study, we investigated the phytoplankton composition in the Elbe estuary via metabarcoding. Our aim was to identify key taxa in the unmonitored reaches of this ecosystem and compare our results from the monitored area with available microscopy data. Phytoplankton communities followed distinct seasonal and spatial patterns. Community composition was similar across methods. Contributions of key classes and genera were correlated to each other (p < 0.05) when obtained from reads and biovolume (R2 = 0.59 and 0.33, respectively). Centric diatoms (e.g. Stephanodiscus) were the dominant group - comprising on average 55 % of the reads and 66 - 69 % of the biovolume. However, results from metabarcoding imply that microscopy underestimates the prevalence of picophytoplankton and flagellates with a potential for mixotrophy (e.g. cryptophytes). This might be due to their small size and sensitivity to fixation agents. We argue that mixotrophic flagellates are ecologically relevant in the mid to lower estuary, where, e.g., high turbidity render living conditions rather unfavorable, and skills such as phagotrophy provide fundamental advantages. Nevertheless, further findings - e.g. important taxa missing from the metabarcoding dataset - emphasize potential limitations of this method and quantitative biases can result from varying numbers of gene copies in different taxa. Further research should address these methodological issues but also shed light on the causal relationship of taxa with the environmental conditions, also with respect to active mixotrophic behavior. https://www.fdr.uni-hamburg.de/record/14308 10.1016/j.envres.2024.119126 oai:fdr.uni-hamburg.de:14308 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode Environmental Research 252 Microscopy, Mediophyceae, Picophytoplankton, 18S, Cryptophyceae Metabarcoding reveals potentially mixotrophic flagellates and picophytoplankton as key groups of phytoplankton in the Elbe estuary info:eu-repo/semantics/article publication-article

oai:fdr.uni-hamburg.de:16148 2024-10-30T08:27:38Z user-rtg2530 user-uhh

Martens, Nele Ehlert, Emilia Putri, Widhi Sibbertsen, Martje Schaum, C.-Elisa 2024-09-17 Poster shown at the ICYMARE 2024 in Bremen. https://www.fdr.uni-hamburg.de/record/16148 10.25592/uhhfdm.16148 oai:fdr.uni-hamburg.de:16148 eng doi:10.1098/rspb.2023.2713 doi:10.25592/uhhfdm.16147 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode Organic compounds drive growth in phytoplankton taxa from different functional groups info:eu-repo/semantics/conferencePoster poster

oai:fdr.uni-hamburg.de:18072 2026-03-27T17:53:20Z user-uhh user-rtg2530

Remmers, Sina 2025-10-30 This dataset is the base of the project, that investigates the biodiversity, community composition, and functional roles of carabid beetles across salinity gradients in the terrestrial marshlands of the Elbe Estuary. The overarching goal is to understand how carabid beetle assemblages contribute to ecosystem connectivity, functioning, and carbon cycling within these ecotonal systems. This research is part of the graduate school program “Biota-Mediated Effects on Carbon Cycling in Estuaries”. https://www.fdr.uni-hamburg.de/record/18072 10.25592/uhhfdm.18072 oai:fdr.uni-hamburg.de:18072 doi:10.25592/uhhfdm.18071 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode Diversity and Functional Roles of Carabid Beetles across Salinity Gradients in Marshlands info:eu-repo/semantics/other dataset

oai:fdr.uni-hamburg.de:18568 2026-04-21T18:13:44Z user-uhh user-rtg2530

Jesse Theilen Victoria Sarrazin Elena Hauten Raphael Koll Christian Moellmann Andrej Fabrizius Ralf Thiel 2025-05-01 Anthropogenic perturbations paired with increasing climatic changes, affect the biota composition and ecosystem services provided by highly productive estuarine transitional ecosystems worldwide. To determine driving forces affecting fish stocks in an estuarine habitat, we created a periodic time series over the last four decades (1984–2022) combining fish species compositions and densities with environmental conditions along the course of the temperate mesotidal Elbe estuary. We detected major changes in the species composition alongside with changes in life cycle guilds composition. With a relative increase of marine-estuarine opportunists and reduction of diadromous species, the fish fauna of the Elbe estuary has become more similar in guild structure compared to macro tidal estuaries in Europe. Improvements in water quality in the 1990s were accompanied by increased fish densities, specially smelt (Osmerus eperlanus), until 2010. Anthropogenic hydromorphological interventions, however, could have led to an increase in suspended particular matter until 2022, which combined with reduced river runoff and poor oxygen concentrations in summer months acted as poor environmental conditions for fishes in the estuary. Mean fish densities dropped by over 91 % compared to 2010 to an all-time low in the data. This reduction was primarily a result of a decline of the key species smelt in the system along with declines of twaite shad (Alosa fallax), flounder (Platichthys flesus), ruffe (Gymnocephalus cernua), common bream (Abramis brama) and other species. On the contrary, marine species herring (Clupea harengus) and whiting (Merlangius merlangus) densities increased. Overall, the time-series provides insight into the strong impact of human intervention that are however expected to lead to further stressors. https://www.fdr.uni-hamburg.de/record/18568 10.1016/j.ecss.2025.109208 oai:fdr.uni-hamburg.de:18568 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode Environmental factors shaping fish fauna structure in a temperate mesotidal estuary: Periodic insights from the Elbe estuary across four decades info:eu-repo/semantics/article publication-article

oai:fdr.uni-hamburg.de:18668 2026-05-04T07:03:26Z user-rtg2530 user-uhh

Martens, Nele Schaum, C.-Elisa 2026-05-03 17 phytoplankton strains were isolated from the Elbe estuary as part of the DFG-funded project “Biota-mediated effects on carbon cycling in estuaries” within the RTG2530 (grant number 407270017). Strains are used for experimental work (see e.g. https://doi.org/10.1098/rspb.2023.2713). Here we provide a list of strains with metadata and further sequencing material. Strains are hosted at the IMF (Institute of Marine Ecosystem and Fishery Science) by the working group 'Plankton Ecology and Evolution'. https://www.fdr.uni-hamburg.de/record/18668 10.25592/uhhfdm.18668 oai:fdr.uni-hamburg.de:18668 eng doi:10.1098/rspb.2023.2713 doi:10.25592/uhhfdm.18667 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode phytoplankton, picophytoplankton Phytoplankton strains isolated from the Elbe estuary info:eu-repo/semantics/other other

oai:fdr.uni-hamburg.de:14367 2024-06-16T10:36:34Z user-uhh user-rtg2530

Neiske Friederike Becker N Joscha Eschenbach Annette Beer Christian 2024-06-10 The dataset consists of results from a series of ICBM model runs based on incubation experiments conducted on soil samples from the Elbe marshes near Hamburg, Northern Germany. These samples were incubated under aerobic conditions for periods ranging from 316 to 465 days. The primary objective was to study carbon cycling and estimate respiration rates across a range of soil organic carbon contents. https://www.fdr.uni-hamburg.de/record/14367 10.25592/uhhfdm.14367 oai:fdr.uni-hamburg.de:14367 eng doi:10.25592/uhhfdm.14366 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode Simulation of heterotrophic respiration of incubated soil samples based on the Introductory Carbon Balance Model (ICBM). info:eu-repo/semantics/other dataset

oai:fdr.uni-hamburg.de:15932 2024-10-30T08:25:18Z user-uhh user-rtg2530

Ostertag Menzel 2024-09-24 Raw data of minirhizotron root study https://www.fdr.uni-hamburg.de/record/15932 10.25592/uhhfdm.15932 oai:fdr.uni-hamburg.de:15932 doi:10.25592/uhhfdm.15931 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode Root dynamics in salt marshes info:eu-repo/semantics/other dataset

oai:fdr.uni-hamburg.de:14727 2024-12-12T10:17:02Z user-uhh user-rtg2530

Biederbick, Johanna Möllmann, Christian Hauten, Elena Russnak, Vanessa Lahajnar, Niko Hansen, Thomas Dierking, Jan Koppelmann, Rolf 2024-07-17 Zooplankton in estuaries encounter complex physical and biogeochemical processes that affect the quantity, quality and origin of their food sources. The knowledge about how zooplankton deal with highly variable organic matter sources is sparse. Here, we investigated the spatial and temporal patterns of zooplankton trophic dynamics and carbon sources in the intensively dredged, eutrophic Elbe estuary. For this purpose, we applied elemental and stable isotope analysis (δ13C and δ15N) on particulate organic matter (POM) and dominant meso- and macrozooplankton species including ichthyoplankton from five stations along the entire salinity gradient of the estuary in 2022. The δ13C values of POM (-29.2 to -23.0 ‰) indicated a mixture of riverine, terrestrial and coastal carbon sources used by most taxa for their diet. Eurytemora affinis (-34.0 to -23.3 ‰) and Mesopodopsis slabberi (-22.2 to -20.0 ‰) exhibited a broader range in δ13C than POM, suggesting selective feeding on single POM components depending on the season. In winter and autumn, under high suspended matter loads and limited availability of high-quality autochthonous phytoplankton, zooplankton showed increased tendency for carnivory (higher δ15N values). Our study revealed a high trophic plasticity of estuarine Elbe zooplankton to buffer hydrological related alterations in their food source by dietary niche partitioning and a flexible switch in their feeding behaviour. https://www.fdr.uni-hamburg.de/record/14727 10.25592/uhhfdm.14727 oai:fdr.uni-hamburg.de:14727 eng doi:10.25592/uhhfdm.14726 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode ICES Journal of Marine Science Elbe estuary Estuarine zooplankton Trophodynamics Stable isotopes Allochthonous and autochthonous carbon sources Selective feeding Spatial and Temporal Patterns of Zooplankton Trophic Interactions and Carbon Sources in the Eutrophic Elbe Estuary (Germany) info:eu-repo/semantics/other dataset

oai:fdr.uni-hamburg.de:18339 2026-02-23T16:18:05Z user-rtg2530 user-uhh

Tobias-Hünefeldt, Sven P. von Beusekom; Justus E.E. Russnak, Vanessa Dähnke, Kirstin Streit, Wolfgang R. Grossart, Hans-Peter 2024-03-26 Estuaries are important components of the global carbon cycle; exchanging carbon between aquatic, atmospheric, and terrestrial environments, representing important loci for blue carbon storage and greenhouse gas emissions. However, how estuarine gradients affect sinking/suspended particles, and dissolved organic matter dynamic interactions remains unexplored. We fractionated suspended/sinking particles to assess and characterise carbon fate differences. We investigated bacterial colonisation (SYBR Green I) and exopolymer concentrations (TEP/CSP) with microscopy staining techniques. C/H/N and dry weight analysis identified particle composition differences. Meanwhile, nutrient and carbon analysis, and excitation and emission matrix evaluations with a subsequent parallel factor (PARAFAC) analysis characterised dissolved organic matter. The lack of clear salinity driven patterns in our study are presumably due to strong mixing forces and high particle heterogeneity along the estuary, with only density differences between suspended and sinking particles. Elbe estuary particles' organic portion is made up of marine-like (sinking) and terrestrial-like (suspended) signatures. Salinity did not have a significant role in microbial degradation and carbon composition, although brackish estuary portions were more biologically active. Indicative of increased degradation rates, leading to decreased greenhouse gas emissions, which are especially relevant for estuaries, with their disproportionate greenhouse gas emissions. Bacterial colonisation decreased seawards, indicative of decreased degradation, and shifts in microbial community composition and functions. Our findings span diverse strands of research, concerning steady carbon contributions from both marine and terrestrial sources, carbon aromaticity, humification index, and bioavailability. Their integration highlights the importance of the Elbe estuary as a model system, providing robust information for future policy decisions affecting dissolved and particulate matter dynamics within the Elbe Estuary. https://www.fdr.uni-hamburg.de/record/18339 10.1016/j.scitotenv.2024.171962 oai:fdr.uni-hamburg.de:18339 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode Science of the Total Environment 926 171962 Seasonality, rather than estuarine gradient or particle suspension/sinking dynamics, determines estuarine carbon distributions info:eu-repo/semantics/article publication-article

oai:fdr.uni-hamburg.de:18383 2026-03-27T17:53:14Z user-uhh user-rtg2530

Remmers, Sina Remmers, Sina 2026-02-24 This dataset includes stable isotope (δ¹³C and δ¹⁵N) measurements of four ground-dwelling carabid beetle species, along with baseline samples from plants, soil and invertebrate bycatch collected in freshwater and saltwater marshes along the Elbe estuary in northern Germany. The data support analyses of resource integration and transfer within estuarine ecotones on biogeochemical processes and consumer-mediated carbon fluxes. The overarching goal is to understand how carabid beetle assemblages contribute to ecosystem connectivity, functioning, and carbon cycling within these ecotonal systems. This research is part of the graduate school program “Biota-Mediated Effects on Carbon Cycling in Estuaries”. https://www.fdr.uni-hamburg.de/record/18383 10.25592/uhhfdm.18383 oai:fdr.uni-hamburg.de:18383 doi:10.25592/uhhfdm.18382 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode stable isotopes, marsh ecosystems, carabid beetles, estuary, carbon flux Carabid Beetles as Local Carbon Mediators in Estuarine Ecosystems-Stable Isoptope Analysis info:eu-repo/semantics/other dataset

oai:fdr.uni-hamburg.de:14172 2026-03-27T17:53:10Z user-uhh user-rtg2530

Laurin Steidle Ross Vennell Malcolm Smeaton Romain Chaput Ben Knight 2026-03-20 # Dataset for Publication: "OceanTracker 0.5: Fast Adaptable Lagrangian Particle Tracking in Structured and Unstructured Grids" https://www.fdr.uni-hamburg.de/record/14172 10.25592/uhhfdm.14172 oai:fdr.uni-hamburg.de:14172 eng doi:10.31223/X5WM6Z doi:10.25592/uhhfdm.14171 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode oceantracker opendrift parcels lagrangian computational speed OceanTracker 0.5: Fast Adaptable Lagrangian Particle Tracking in Structured and Unstructured Grids info:eu-repo/semantics/other dataset

oai:fdr.uni-hamburg.de:18779 2026-06-22T09:52:00Z user-rtg2530 user-uhh

Remmers, Sina Dausmann, Kathrin 2026-06-17 This dataset includes data from an experimental study on thermal physiology in four carabid beetle species from a freshwater tidal marsh in the Elbe estuary. Individuals of Carabus auratus, C. granulatus, C. nemoralis and Limodromus assimilis were exposed to a series of temperature treatments. Oxygen consumption was measured via optical respirometry (FireSting) to calculate metabolic rate and body-mass loss was measured as proxy for water loss. The dataset contains the processed values used for statistical analysis with associated specimen and experimental metadata. https://www.fdr.uni-hamburg.de/record/18779 10.25592/uhhfdm.18779 oai:fdr.uni-hamburg.de:18779 doi:10.25592/uhhfdm.18778 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode thermal physiology, water loss, energy expenditure, desiccation resistance, carabid beetles, tidal marsh Thermal responses of metabolic rate and water loss in carabids info:eu-repo/semantics/other dataset