PhD-Topics 3rd cohort

Call for 13 PhD-candidates 2022 - 2024

Application

You can apply for up to 3 topics. Please prioritise in your application!

Candidates are asked to send their applications in English language including: one page letter of motivation, CV and copies of relevant certificates (including minimum Master Certificate, Master Transcript, Bachelor Certificate and Bachelor Transcript) in one single pdf-file via e-mail to baltic.transcoast(at)uni-rostock.de  until 12 September 2021. Please use the subject "Jobposting P 156/2021" for your E-Mail. Applications arrving later or in other formats cannot be accepted.

The official job offer can be found here (German) and here (English).

 

Topics

  • Biology

B1-3 Salinity acclimation in brackish wetland systems

Coastal peatlands are facing irregular salinity changes by both, flooding as well as spray. Many of the typical peatland plants are salinity-sensitive, resulting in some peculiarities of taxonomic composition as well as productivity of peatland associations. The principal objective of the PhD project B1 is to identify acclimation kinetics and salinity limits of coastal peatland plants with a focus on sexual reproduction, including resting stages.

In detail, characterisation of salinity-dependent acclimation of photosynthesis as well as determination of salinity limits for all stages of sexual reproduction shall be conducted by a combination of field measurements, mesocosm experiments and lab incubations in order to gather a sound knowledge basis for estimating the effects of, e.g. coastal retreat measures and sea-level rise scenarios.

We are looking for a PhD candidate with a deep interest in Plant Autecology and an according education (e.g. MSc. Plant biology, Plant Physiology etc.; familiar with the common techniques of photosynthesis response assessments, especially pulse-based chlorophyll fluorometry). The candidate should be able to perform fieldwork in difficult terrain and possess a valid driving licence.

Candidates will graduate in Biology at the Faculty of Mathematics and Natural Sciences of the University of Rostock. This PhD-project is part of the interdisciplinary DFG Research Training Group Baltic TRANSCOAST (www.baltic-transcoast.de) and a high motivation for interdisciplinary training and work is expected.

Further questions can be directed to Prof. Hendrik Schubert: hendrik.schubert(at)uni-rostock.de

 

B2-3 Mikrophytobenthic structure and function along terrestrial-marine gradients

Microphytobenthic communities exert ecologically important functions on top of sediments in shallow coastal zones, which are poorly understood along terrestrial-marine gradients. During photosynthesis they excrete organic compounds (DOC) to stabilize sediment surfaces and to feed heterotrophic microorganisms in the microbial loop. The main goal of the PhD project B2 is to quantify I.) primary production, II.) DOC release/mineralization and III.) its consequences for the carbon and other biogeochemical cycles along defined terrestrial-marine gradients. The successful candidate shall experimentally work with benthic diatoms and analyse carbon fixation and DOC exudation as function of photosynthesis and various physico-chemical parameters. Mesocosm experiments will be planned and conducted in an inter-disciplinary manner with other PhD-projects from the Baltic TRANSCOAST consortium.

We are looking for a PhD applicant with a deep interest in microphytobenthic function and an according education (MSc. or Diploma in biology, marine biology, microbiology, biogeochemistry, environmental sciences etc.). This PhD-project is part of the interdisciplinary DFG Research Training Group Baltic TRANSCOAST (www.baltic-transcoast.de) and a high motivation for interdisciplinary training and work is expected. Candidates will graduate in Ecology or Marine Biology at the Faculty of Mathematics and Natural Sciences of the University of Rostock.

Further questions can be directed to Prof. Ulf Karsten: ulf.karsten(at)uni-rostock.de

 

B3-3 Influence of polyphosphate accumulating organisms on the phosphorus dynamics in shallow coastal waters

With rising sea water levels coastal areas will be increasingly flooded and may therefore contribute significantly to the nutrient fluxes from land to sea. Especially the input of phosphate to the Baltic Sea is a crucial parameter determining the eutrophication state of this vulnerable environment. In this context, polyphosphate is an important and largely understudied component of aquatic phosphorus cycling. In principal, all living organisms contain polyphosphate but only under certain circumstances some microorganisms accumulate very large amounts of phosphate in the form of polyphosphate. This energy rich compound may than be degrade again if the environmental conditions change, resulting in a pulse of phosphate from the sediments. During our earlier studies we could show that in frequently flooded coastal areas bacterial mats may retain phosphorus with a surprisingly high efficiency. We also enriched successfully two model organisms of this process in cultures (Beggiatoa sp. and Lyngbya sp.). For the third phase of the project we are aiming to study the gene expression of enriched model organisms under conditions of polyphosphate accumulation and break down and compare the patterns of gene expression to in situ gene expressions at our field sites. With this approach we are aiming to identify key genes and key organisms and trying to untangle the seasonal dynamics of this process.

We are seeking a candidate with a robust background and vivid interest in aquatic microbiology, microbial ecology, geomicrobiology or a related field. The candidate should present an above average MSc degree in microbiology, marine biology, biogeochemistry or environmental sciences. Prior experiences in cultivation of microorganisms, field studies, laboratory incubations or analysis of gene expression patterns are desirable but not necessarily required. The candidate should be dedicated to and enthusiastic about collaborative work with other PhDs, as well as an interest in broad ecological training, which takes place in the DFG Research Training Group Baltic TRANSCOAST.     

Further questions can be directed to Prof. Heide Schulz-Vogt: heide.schulz-vogt(at)io-warnemuende.de

 

B4-3 Dynamics and consequences of benthic oxygen production and consumption in shallow coastal sediments

Solute and oxygen exchange across the sediment-water interface, particularly in shallow waters environments, are affected by primary production, benthic fauna, bioturbation, concentration gradients, sediment characteristics and hydrographic conditions to name a few. While different sets of conditions act in open coastal sediments, sheltered bays or flooded coastlands, the change of fluxes may be very dynamic. Data on the dynamics and variability of fluxes including their control are rare. The planned investigations aim at documenting continuous day and night cycles of oxygen and nutrient fluxes, particularly of nitrogen, via benthic chambers in the field. Concomitant determinations of the fauna and factors involved, as well as laboratory experiments using microelectrode and planar optode technology are planned. This and previous investigations within the DFG Research Training Group Baltic Transcoast should allow for an evaluation of the role of primary production in the oxygen budget and general diagenesis of the particular sediment. The candidate will closely collaborate with working groups B2 (microphytobenthos), B5 (stressors for bioturbating organisms), G5 (N-diagenesis) and H4 (hydrography).

We are looking for a dedicated PhD candidate with strong interest in microbial processes in shallow water environments and interest in experimental field work. The candidate should present an above average MSc degree in marine biology, biogeochemistry or environmental science. Scientific diving ability is not mandatory, but helpful. The successful candidate should be dedicated to and enthusiastic about collaborative work with other PhDs, as well as an interest in broad ecological training, which takes place in the DFG Research Training Group Baltic TRANSCOAST.

Further questions can be directed to Dr. Stefan Forster: stefan.forster(at)uni-rostock.de

 

B5-3 Impacts of eutrophication-related stressors on physiological and ecological performance of keystone species of macrozoobenthos in shallow coastal zones

Coastal habitats play a key role in ecosystem processes at the sea-land interface of the Baltic Sea. Due to their shallow depth and proximity to the land, these habitats experience high levels of abiotic stress due to salinity fluctuations, pollution and hypoxia driven by the land-derived freshwater and nutrient inputs intensified by climate change and sea level rise. These stressors can strongly affect sediment-dwelling marine organisms that serve as ecosystem engineers in these habitats, yet the physiological mechanisms and potential ecological consequences of these effects are not well understood. This Ph.D. project will focus on the effects of multiple stressors due to coastal eutrophication on energy metabolism, physiological stress and ecological performance of common Baltic Sea bioturbators. Bioturbators (such as Mya arenaria or Hediste diversicolor) will be exposed in the lab to multiple stressors (pH and oxygen fluctuations, and elevated ammonium levels) mimicking different scenarios of coastal eutrophication, and their physiological and ecological performance (whole-organism metabolism, feeding, bioirrigation and bioturbation) will be assessed.  Physiological and molecular mechanisms underlying stress-induced shifts in performance will be determined by investigating the multiple stressor effects on mitochondrial functions, enzymatic activities, metabolite profiles and cellular energy status of the organisms. This study will allow determining the role of metabolic disturbances due to multiple stressors on physiological performance of marine bioturbators and assess implications for ecological functions of these important ecosystem engineers. The candidate will closely collaborate with working groups B4 (nutrient and oxygen fluxes in the sediment) and G5 (N-diagenesis).

A successful candidate for this position is expected to have a strong background in animal physiology or biochemistry and/or marine ecology at M.Sc. level (with above average grade), willingness to learn diverse laboratory and field methods in ecology, physiology, and molecular biology, strong time management and communication skills, and an ability to work independently and in a team. A prior experience working with marine invertebrates would be an asset. The successful candidate should be dedicated to and enthusiastic about collaborative work with other PhDs, as well as an interest in broad ecological training, which takes place in the DFG Research Training Group Baltic TRANSCOAST.       

Further questions can be directed to Prof. Inna Sokolova: inna.sokolova(at)uni-rostock.de

 

  • (Bio-)Geoechmistry

G1-3 Biogeochemistry - hydrology coupling and element cycling at the land-sea interface of the southern Baltic Sea

At the land-sea interface, the transfer of solutions and transformation of substances is of particular relevance, e.g., for eutrophication, ocean and soil acidification, development of coastal hypoxia, and the coastal water cycle. Anthropogenic activity like rewetting may change the biogeochemical processes in changing the amount and composition of electron acceptors and the transport of dissolved substances at the sediment/soil-water interface. Sulfur cycling associated with the mineralization of organic matter and the formation of authigenic minerals may be enhanced, phosphorous may be mobilized and dissolved organic matter released. The processes in near-coastal wetlands may be impacted furthermore by the import and export of water and substances.

 The successful candidate will investigate water transfer and organic matter cycling and associated processes like authigenic mineral formation in the sulfur-nutrient-metal cycles in the field, a mesocosm, and the laboratory, e.g., by the use of isotope partitioning and core incubations. Benthic biogeochemical processes in wetlands and coastal areas under impact of submarine groundwater discharge and flooding by seawater are in the focus of the study. The investigations will contribute to a budget for processes and inventories and the understanding the role of coastal areas in times of climate change.

We are looking for a PhD candidate enthusiastic about biogeochemical and/or hydrological processes in wetlands and coastal areas with a strong background in biogeochemistry and/or hydrology and ideally field experience (e.g., MSc. in geochemistry, chemistry, soil science, environmental sciences etc.). Candidates will work at the Leibniz Institute for Baltic Sea Research and graduate at the University of Rostock. The successful candidate should be dedicated to collaborative work with other PhDs, as well as an interest in broad biogeochemical training, which takes place in the interdisciplinary DFG Research Training Group Baltic TRANSCOAST and the working environment.          

Further questions can be directed to Prof. Michael Böttcher: michael.boettcher(at)io-warnemuende.de

 

G2-3 Time scales of trace gas dynamics and underlying processes in peat lands overlain by brackish waters

The rewetting of formerly drained coastal peatlands is currently discussed as a potential measure to reduce carbon dioxide emissions and thus to mitigate global warming. However, it has been also shown that short-term emission of methane can partly counteract these efforts. Newly rewetted peatlands thus offer a unique opportunity to study the temporal development of greenhouse gas (GHG) fluxes and the underlying controlling processes.

During the 2nd cohort of Baltic TRANSCOAST, we established the infrastructure and technology for sensor-based high resolution monitoring of GHG as well as several other parameters in the working area Drammendorf, which was rewetted by brackish water in winter 2019/2020. Building on this work, this PhD thesis will emphasize on the different time-scales and governing mechanisms of GHG fluxes and relate these to hydrodynamical, biogeochemical and potentially also microbiological controls. To reach these goals, strong interaction with various of the other subprojects within Baltic TRANSCOAST is foreseen. Lab- and field experimental work may be additionally incorporated into the work program.

We are looking for a PhD applicant with a deep interest in biogeochemical processes and climate-related research, and with a strong affinity to the use of advanced technology for field observations. The applicant should hold a M.Sc. in chemistry, biogeochemistry, hydrology or a related field of environmental natural sciences. A background in engineering sciences might also be considered. Experience in the handling of large data streams using  appropriate statistical software or programs (R, MatLab, Python) would be desirable, but is not required. Candidates will work at the Leibniz Institute for Baltic Sea Research and graduate at the University of Rostock. The successful candidate should be dedicated to collaborative and interdisciplinary work with other PhDs, as well as have a genuine interest in broad biogeochemical training, which takes place in the DFG Research Training Group Baltic TRANSCOAST. 

Further questions can be directed to Prof. Gregor Rehder: gregor.rehder(at)io-warnemuende.de     

 

G3-3 Drivers of methane production and emission in coastal peatlands

Greenhouse gas (GHG) exchange in coastal peatlands shows considerable variation in space and time that we don’t understand in detail yet. It is well known, that water level and water chemistry exert a strong control on GHG exchange in peatlands. Coastal peatlands, however, may be subject to strong water level dynamics sometimes also associated with strong variations in salinity making predictions about GHG emissions under future conditions even more challenging. Whereas the physical and chemical environment in the rhizosphere is mainly controlling CH4 production either directly or through the impact on the microbiological community, the morphology and physiology of the emergent macrophytes mainly controls the CH4 emission patterns. Both properties eventually determine the CH4 exchange rates of the ecosystem. Driven by changes to the hydrological regime (see H1), the vegetation patterns as well as the microbial communities and the biogeochemical cycling (see all topics G) in coastal peatlands may change considerably. Thus, changes in water table, sulfate concentrations, and other water properties may shift the dominant anaerobic decomposition paths, for instance from methanogenesis to sulfate reduction.

The successful candidate will investigate these matters based on field monitoring of GHG exchange and the characterisation of the microbiological communities in different coastal peatlands at the German Baltic Sea coast. Water and peat physical and chemical conditions as well as data on vegetation composition and biomass growth may be included based on collaborations within Baltic TRANSCOAST. In addition, the candidate may design and perform lab experiments (incubations/mesocosms).

We are looking for a PhD candidate deeply interested in GHG exchange and the processes of methanogenesis and related biogeochemical pathways in peatlands and an according education (e.g. MSc. in geosciences, environmental engineering, agriculture etc.). Candidates will graduate in Landscape Ecology at the Faculty of Agricultural and Environmental Sciences of the University of Rostock, which offers doctorate degrees in Environmental Engineering (Dr. Ing) and Agricultural Sciences (Dr. agr).

Further questions can be directed to Dr. Gerald Jurasinski: gerald.jurasinski(at)uni-rostock.de

 

G5-3 Impact of land-derived substance on coastal nitrogen cycling and nitrogen fixation

The exchange of substances across terrestrial-marine or sediment-water interfaces is poorly understood but an important driver of biological processes such as primary production, nitrogen fixation, or nitrification in the shallow Baltic Sea and adjacent flooded coastal marshes. Since nitrogen inputs on land and in the Baltic Sea are strongly human-driven, the consequences of these inputs should be understood in order to mitigate the effects. Previous projects within Baltic TRANSCOAST have investigated processes such as the role of ammonium release by seawater intrusion and its effects on nitrification rates in flooded coastal peatlands. A generally valid pattern of how the microbial processes are controlled is only beginning to emerge. This project will therefore study microbial processes in coastal waters and adjacent flooded areas and how currents, sediment resuspension, bioirrigation and other bio-physico-chemical processes impact the rates. The work will be done both experimentally and in the field. Particularly close collaboration is planned with B2 (microphytobenthos), B5 (stressors for bioturbating organisms), H4 (hydrography) and B4 (oxygen dynamic).

We are looking for a dedicated PhD candidate with strong interest in microbial processes in shallow water and flooded land environments. An above average Master's degree in marine biology, biogeochemistry or environmental science should be available. Enthusiasm for working closely with other PhDs and conducting collaborative experiments and fieldwork should be present, as well as an interest in broad ecological training, since the PhD takes place within the DFG Research Training Group Baltic TRANSCOAST (www.baltic-transcoast.de) at the Leibniz Institute of Baltic Sea Research and the University of Rostock.

Further questions can be directed to Prof. Maren Voss: maren.voss(at)io-warnemuende.de

 

  • Hydro(geo)logy/Oceanography

H1-3 Modelling solute transport in coastal peatlands

Water and solutes are exchanged between low lying coastal peatlands and the Baltic Sea by flooding events and submarine discharge of fresh groundwater. These interactions are governed by hydraulic gradients and geological settings, and they influence the biogeochemical cycling and greenhouse gas production both on land and at sea. Rewetting of peatlands fundamentally alters water and solute fluxes. H1 aims at assessing the influence of changing climatic and hydrologic boundary conditions on nutrient fluxes in coastal peatlands. The successful candidate shall quantify the export of substances from a formerly drained, rewetted peatland via the ditch system and submarine groundwater discharge both experimentally and – as the focus – by numerical groundwater modelling. Furthermore, the propagation of seawater into the soil after sporadic or regular flooding of coastal peatlands shall be investigated to better understand the distribution of solutes and their temporal dynamics within the soil profile.

We are looking for a PhD candidate with a deep interest in groundwater, biogeochemical processes and numerical modelling and an according education (e.g. MSc. in geosciences, environmental engineering, etc.). This PhD-project is part of the interdisciplinary DFG Research Training Group Baltic TRANSCOAST (www.baltic-transcoast.de) and a high motivation for interdisciplinary training and work is expected. A driver's licence is required. The candidate will graduate in Soil Physics at the Agricultural and Environmental Sciences Faculty of the University of Rostock. The Agricultural and Environmental Sciences Faculty offers degrees in Environmental Engineering and Agricultural Sciences.

Further questions can be directed to Dr. Manon Janssen: manon.janssen(at)uni-rostock.de

 

H2-3 The geochemical footprint of flux and solute transport anomalies in coastal peatlands

The physical and hydraulic properties of peat soils are unique in comparison to mineral substrates. The principal objective of the PhD project H2 is to define the role of peat layers in coastal systems with respect to water and compound exchange processes between land and sea. The successful candidate shall experimentally analyse hydraulic and solute transport properties of various peat substrates. The PhD project investigates the quality of pore water and tests the hypothesis that different pore size classes have an individual geochemical footprint. The experimental investigations include on-site infiltration tests with saline and fresh water. Existing modelling approaches based on physical laws shall be employed to analyse experimental data. All experiments will be planned and conducted in an inter-disciplinary manner with hydro-physical and geochemical working groups from the Baltic TRANSCOAST consortium (see for instance G1, G3, G5, H1, H3) 

We are looking for a PhD candidate with a deep interest in soil hydraulic processes and an according education (e.g. MSc. in geosciences, environmental engineering, agriculture etc.). This PhD-project is part of the interdisciplinary DFG Research Training Group Baltic TRANSCOAST (www.baltic-transcoast.de) and a high motivation for interdisciplinary training and work is expected. Candidates will graduate in Soil Physics at the Agricultural and Environmental Sciences Faculty of the University of Rostock. The Agricultural and Environmental Sciences Faculty offers degrees in Environmental Engineering and Agricultural Sciences.

Further questions can be directed to Prof. Bernd Lennartz: bernd.lennartz(at)uni-rostock.de

 

H3-3 Hydrodynamic processes in coastal waters and their interaction with terrestrial hydrology

Surface and groundwater discharges from land are transported into the coastal ocean by complex interconnected patterns of currents and turbulent mixing. On the other hand, the coastal ocean waters may intrude into the terrestrial hydrology by means of flooding shallow coastal regions or reversed groundwater flow in sub-terranean estuaries. The coastal zone under investigation is located at the essentially non-tidal Baltic Sea coast which is characterised by highly episodic sea level fluctuations. The principal objective of the PhD project H3 is to quantify these interactions statistically and to gain a theoretical understanding of the underlying processes. The successful candidate shall numerically simulate, validate and analyse these relations by means of a high-resolution coastal ocean model existing and further developed at IOW. The PhD candidate will closely collaborate with the other hydrodynamic working groups from the Baltic TRANSCOAST consortium (H1, H2 and H4), but within this truly interdisciplinary project will also help understanding transport and transformation processes of biogeochemical and biological compounds. 

We are looking for a PhD candidate with a deep interest in Physical Oceanography and experience with coastal ocean modelling. The successful candidate should have an MSc. degree in one of the MINT disciplines with basic knowledge in Physical Oceanography. This PhD-project is part of the interdisciplinary DFG Research Training Group Baltic TRANSCOAST (www.baltic-transcoast.de) and a high motivation for interdisciplinary training and work is expected. Candidates will graduate in Physical Oceanography at the Physics Institute within the Mathematical & Natural Sciences Faculty of the University of Rostock.

Further questions can be directed to Prof. Hans Burchard: hans.burchard(at)io-warnemuende.de

 

H4-3 Turbulent transport and mixing of discharged ground water on structured surfaces at the coastal benthic seafloor

The project focuses on the investigation of the discharge of ground water through a structured, permeable seabed. In the benthic boundary layer, the turbulent flow and mixing under simulated marine conditions will be quantified to evaluate the influence of various boundary conditions.  In the current period of research, the influence of the seafloor topography, particularly the surface structuring, on the transport of the discharged ground water will be the primary focus. The results will allow adjusting the governing equations for transport and mixing processes in the boundary layer with respect to the surface conditions. This will allow validating and refining the closure models of the numerical simulation procedures of our partner projects.

The student will continue a laboratory experiment representing the flow conditions in the Baltic Sea near the coastline. We will perform design and construction work on the experimental setup. Laser-optical methods (PIV, LIF) will be employed to obtain fields of concentration and velocity. A prior education in experimental fluid mechanics (M.Sc. level) is required, the knowledge of laser-optical methods is beneficial. This PhD-project is part of the interdisciplinary DFG Research Training Group Baltic TRANSCOAST (www.baltic-transcoast.de)  and a high motivation for interdisciplinary training and work is expected. Candidates will graduate in Fluid Mechanics (Dr.-Ing.)  at the Faculty of Mechanical Engineering and Marine Technology at the University of Rostock.

Further questions can be directed to Dr. Martin Brede: martin.brede(at)uni-rostock.de