TY  - JOUR
A1  - Pieck, Angelika
A1  - Herlemann, Daniel P. P.
A1  - Juergens, Klaus
A1  - Grossart, Hans-Peter
T1  - Particle-Associated Differ from Free-Living Bacteria in Surface Waters of the Baltic Sea
JF  - Frontiers in microbiology
N2  - Many studies on bacterial community composition (BCC) do not distinguish between particle associated (PA) and free-living (FL) bacteria or neglect the PA fraction by pre-filtration removing most particles. Although temporal and spatial gradients in environmental variables are known to shape BCC, it remains unclear how and to what extent PA and FL bacterial diversity responds to such environmental changes. To elucidate the BCC of both bacterial fractions related to different environmental settings, we studied surface samples of three Baltic Sea stations (marine, mesohaline, and oligohaline) in two different seasons (summer and fall/winter). Amplicon sequencing of the 16S rRNA gene revealed significant differences in BCC of both bacterial fractions among stations and seasons, with a particularly high number of PA operational taxonomic units (OTUs at genus-level) at the marine station in both seasons. "Shannon and Simpson indices" showed a higher diversity of PA than FL bacteria at the marine station in both seasons and at the oligohaline station in fall/winter. In general, a high fraction of bacterial OTUs was found exclusively in the PA fraction (52% of total OTUs). These findings indicate that PA bacteria significantly contribute to overall bacterial richness and that they differ from FL bacteria. Therefore, to gain a deeper understanding on diversity and dynamics of aquatic bacteria, PA and FL bacteria should be generally studied independently.
KW  - microbial communities
KW  - microbial diversity
KW  - particle-associated and free-living bacteria
KW  - Baltic Sea
KW  - salinity gradient
KW  - seasons
KW  - 454-pyrosequencing
Y1  - 2015
U6  - https://doi.org/10.3389/fmicb.2015.01297
SN  - 1664-302X
VL  - 6
PB  - Frontiers Research Foundation
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Schibalski, Anett
A1  - Körner, Katrin
A1  - Maier, Martin
A1  - Jeltsch, Florian
A1  - Schröder, Boris
T1  - Novel model coupling approach for resilience analysis of coastal plant communities
JF  - Ecological applications : a publication of the Ecological Society of America
N2  - Resilience is a major research focus covering a wide range of topics from biodiversity conservation to ecosystem (service) management. Model simulations can assess the resilience of, for example, plant species, measured as the return time to conditions prior to a disturbance. This requires process-based models (PBM) that implement relevant processes such as regeneration and reproduction and thus successfully reproduce transient dynamics after disturbances. Such models are often complex and thus limited to either short-term or small-scale applications, whereas many research questions require species predictions across larger spatial and temporal scales. We suggest a framework to couple a PBM and a statistical species distribution model (SDM), which transfers the results of a resilience analysis by the PBM to SDM predictions. The resulting hybrid model combines the advantages of both approaches: the convenient applicability of SDMs and the relevant process detail of PBMs in abrupt environmental change situations. First, we simulate dynamic responses of species communities to a disturbance event with a PBM. We aggregate the response behavior in two resilience metrics: return time and amplitude of the response peak. These metrics are then used to complement long-term SDM projections with dynamic short-term responses to disturbance. To illustrate our framework, we investigate the effect of abrupt short-term groundwater level and salinity changes on coastal vegetation at the German Baltic Sea. We found two example species to be largely resilient, and, consequently, modifications of SDM predictions consisted mostly of smoothing out peaks in the occurrence probability that were not confirmed by the PBM. Discrepancies between SDM- and PBM-predicted species responses were caused by community dynamics simulated in the PBM and absent from the SDM. Although demonstrated with boosted regression trees (SDM) and an existing individual-based model, IBC-grass (PBM), our flexible framework can easily be applied to other PBM and SDM types, as well as other definitions of short-term disturbances or long-term trends of environmental change. Thus, our framework allows accounting for biological feedbacks in the response to short- and long-term environmental changes as a major advancement in predictive vegetation modeling.
KW  - Baltic Sea
KW  - hybrid model
KW  - Lolium perenne
KW  - model coupling
KW  - Scirpus maritimus
KW  - transient dynamics
Y1  - 2018
U6  - https://doi.org/10.1002/eap.1758
SN  - 1051-0761
SN  - 1939-5582
VL  - 28
IS  - 6
SP  - 1640
EP  - 1654
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Haberland, Christian
A1  - Hampe, Oliver
A1  - Autenrieth, Marijke
A1  - Voss, Manja
T1  - Balaenoptera borealis Lesson, 1828
BT  - rediscovery of a holotype
JF  - Mammalia
N2  - The whereabouts of the Balaenoptera borealis holotype, the skeleton of a 1819 stranded specimen, have been unknown since the World War II (WWII). Due to nomenclatural confusion, deficient documentation, and finally WWII bombing, which destroyed predominantly cetacean material in the Museum fib Naturkunde Berlin (MfN), the type skeleton of the sei whale sank into oblivion. Construction activities enabled a recent search and study on the remaining whale material. Here, we provide evidence that the type specimen was not destroyed. On the basis of species-wide and individual characters of the type material such as the shape of cranial elements and the pattern of the maxillary foramina, we show that the skull and mandibles, the vertebral column (except the atlas), and the ribs of the holotype remain intact. Further evidence that these skeletal remains belong to the previously missing holotype is provided by the characteristics of the spine. In addition, we analyzed ancient DNA from bone samples and confirm they are B. borealis, and the occurrence of same mitochondrial haplotypes indicate that the bones belong to the same individual. Additionally, a blue inscription was discovered at the caudal epiphysis of a thoracic vertebra; historical research matched this inscription with the material belonging to the former Anatomical-Zootomical Museum, from which the holotype was once bought.
KW  - Baltic Sea
KW  - holotype
KW  - museum collection
KW  - sei whale
KW  - skeleton
Y1  - 2019
U6  - https://doi.org/10.1515/mammalia-2017-0149
SN  - 0025-1461
SN  - 1864-1547
VL  - 83
IS  - 4
SP  - 343
EP  - 351
PB  - De Gruyter
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Kettner, Marie Therese
A1  - Oberbeckmann, Sonja
A1  - Labrenz, Matthias
A1  - Grossart, Hans-Peter
T1  - The Eukaryotic Life on Microplastics in Brackish Ecosystems
JF  - Frontiers in Microbiology
N2  - Microplastics (MP) constitute a widespread contaminant all over the globe. Rivers and wastewater treatment plants (WWTP) transport annually several million tons of MP into freshwaters, estuaries and oceans, where they provide increasing artificial surfaces for microbial colonization. As knowledge on MP-attached communities is insufficient for brackish ecosystems, we conducted exposure experiments in the coastal Baltic Sea, an in-flowing river and a WWTP within the drainage basin. While reporting on prokaryotic and fungal communities from the same set-up previously, we focus here on the entire eukaryotic communities. Using high-throughput 18S rRNA gene sequencing, we analyzed the eukaryotes colonizing on two types of MP, polyethylene and polystyrene, and compared them to the ones in the surrounding water and on a natural surface (wood). More than 500 different taxa across almost all kingdoms of the eukaryotic tree of life were identified on MP, dominated by Alveolata, Metazoa, and Chloroplastida. The eukaryotic community composition on MP was significantly distinct from wood and the surrounding water, with overall lower diversity and the potentially harmful dinoflagellate Pfiesteria being enriched on MP. Co-occurrence networks, which include prokaryotic and eukaryotic taxa, hint at possibilities for dynamic microbial interactions on MP. This first report on total eukaryotic communities on MP in brackish environments highlights the complexity of MP-associated biofilms, potentially leading to altered microbial activities and hence changes in ecosystem functions.
KW  - microeukaryotes
KW  - plastic-associated biofilms
KW  - Baltic Sea
KW  - polyethylene
KW  - polystyrene
KW  - diversity profiles
KW  - network analysis
KW  - next-generation sequencing
Y1  - 2019
U6  - https://doi.org/10.3389/fmicb.2019.00538
SN  - 1664-302X
VL  - 10
PB  - Frontiers Media
CY  - Lausanne
ER  - 
TY  - GEN
A1  - Kettner, Marie Therese
A1  - Oberbeckmann, Sonja
A1  - Labrenz, Matthias
A1  - Grossart, Hans-Peter
T1  - The Eukaryotic Life on Microplastics in Brackish Ecosystems
T2  - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2  - Microplastics (MP) constitute a widespread contaminant all over the globe. Rivers and wastewater treatment plants (WWTP) transport annually several million tons of MP into freshwaters, estuaries and oceans, where they provide increasing artificial surfaces for microbial colonization. As knowledge on MP-attached communities is insufficient for brackish ecosystems, we conducted exposure experiments in the coastal Baltic Sea, an in-flowing river and a WWTP within the drainage basin. While reporting on prokaryotic and fungal communities from the same set-up previously, we focus here on the entire eukaryotic communities. Using high-throughput 18S rRNA gene sequencing, we analyzed the eukaryotes colonizing on two types of MP, polyethylene and polystyrene, and compared them to the ones in the surrounding water and on a natural surface (wood). More than 500 different taxa across almost all kingdoms of the eukaryotic tree of life were identified on MP, dominated by Alveolata, Metazoa, and Chloroplastida. The eukaryotic community composition on MP was significantly distinct from wood and the surrounding water, with overall lower diversity and the potentially harmful dinoflagellate Pfiesteria being enriched on MP. Co-occurrence networks, which include prokaryotic and eukaryotic taxa, hint at possibilities for dynamic microbial interactions on MP. This first report on total eukaryotic communities on MP in brackish environments highlights the complexity of MP-associated biofilms, potentially leading to altered microbial activities and hence changes in ecosystem functions.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 741 
KW  - microeukaryotes
KW  - plastic-associated biofilms
KW  - Baltic Sea
KW  - polyethylene
KW  - polystyrene
KW  - diversity profiles
KW  - network analysis
KW  - next-generation sequencing
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-434996
SN  - 1866-8372
IS  - 741
ER  -