IOW Logo
Banner

Current Projects

  • (For Details click here!)
    Methane is a known greenhouse gas that severely enhances climate change on earth, yet not all methane sources into atmosphere have been identified. A process that might be of importance is the production of methane by microorganisms within the anoxic guts of certain zooplankton species and their fecal pellets. This production takes place in the upper oxygenated water column and thus could have a direct impact on the methane flux between ocean and atmosphere. We hypothesize that highly productive regions like marginal seas, which have never been studied in detail in this context before, are areas of enhanced zooplankton-mediated methane production, which most probably causes the subthermocline methane anomaly that have been sporadically identified in the oxygenated water column of the Baltic Sea. In the ZooM project, we will combine methane chemistry, microbiology, and zooplanktology in a multidisciplinary approach to investigate zooplankton-associated methanogenesis in detail using the Baltic Sea as a model system. We plan to investigate the following key questions: (1) Is the subthermocline methane anomaly a widespread phenomenon in the Baltic Sea, which shows a temporal and spatial variability? (2) Does zooplankton-associated methane production have the potential to support the methane anomaly in the shallow water and how are copepod species and environmental factors like food composition influencing methane production? (3) Which microbes are involved in zooplankton-associated methane production and can we detect differences in methanogenic assemblages and their activities between copepod guts and their fecal pellets?
  • (For Details click here!)
    The process of microbial methane oxidation in the water column is only insufficiently investigated. Water column studies in the vicinity of gas bubble releasing seep sites show, that the majority of dissolved methane is immediately oxidized by microbes after its injection into the water body, and that only a small fraction of methane is reaching the surface water and the atmosphere. In this project, our multidisciplinary approach is investigating the link between sedimentary and pelagic methanotrophy at gas bubble releasing seep sites (study area: Coal Oil Point, Santa Barbara Basin, California). We hypothesize that at these sites methane oxidizing microbes are transport by gas bubbles from the sediment into the water column. In detail we use gas chemistry and molecular biology to (1) identify the zone of methane oxidation and the organisms responsible for the turnover of methane in the sediment, (2) prove the process of methane oxidation within the surrounding water column, and (3) verify the transport of sedimentary methane oxidizing microbes by gas bubbles through the collection of gas bubbles in different water depths.
  • The service of sediments in German coastal seas – evaluating the function of marine benthic systems in the context of human use – Service functions of the Baltic Sea- (SECOS): WP 2.4 "Gas exchange at the sediment water interface"
    (For Details click here!)
    Coastal and marginal seas operate as natural reaction sites for the processing and accumulation of land-derived discharges, e.g. nutrients, toxic substances, biotic/abiotic material. The main locations of accumulation as well as chemical/biological modification are almost the sediments. Surprisingly, their key position in the complex land-sea interaction is insufficiently studied and assessed so far. Within the framework of the BMBF-project SECOS („The service of sediments in German coastal seas“), the distribution and quantitative relevance of sedimentary services will be mapped and modelled in the range of the German Baltic Sea waters. Existing management tools for marine coastal systems will be improved, including human impacts and projections of future scenarios. This will be realised by the functional assessment of those sedimentary areas that are most relevant contributors to desired feedbacks to the environment and society. Thus, a first approach of a monetary “ecosystem service” assessment will be generated and all results will be presented in summarised habitat maps. Within the work package 2.4 “Gas exchange at the sediment- water interface”, fluxes of the greenhouse gases CH4, N2O and CO2 will be determined for key sediment types. This aims for a mechanistic understanding of the loss of CH4 and N2O from sediments as a first step towards implementation in the model framework. Therefore, modern analytic methods will be applied such as gas chromatography and mass spectrometry. The sampling will be performed at 20-30 m water depths with a benthic chamber lander system. A first ship cruise with “RV Alkor” is planned for March 2014.
  • (Für Details bitte hier klicken)

    “Ocean acidification” due to increasing atmospheric CO2 levels has become an important issue in chemical and biological oceanography. This refers in particular to the Baltic Sea which in most regions is characterized by a low buffer capacity. Thus the need for precise, accurate, and traceable pH measurements on a uniform and internationally accepted scale has gained importance during the last decades. Additionally, investigation and determination of the entire marine CO2 system are useful tools to study biogeochemical processes in the Baltic Sea. However, using pH for the calculations of the CO2 system requires a high accuracy and must refer to the “total” scale which is the basis for the currently best available dissociation constants. In the Baltic pH-monitoring was carried out during recent decades. Attempts were undertaken to detect trends in pH. But the results were ambiguous and revealed severe inconsistencies. To meet the demands for both effective monitoring and biogeochemical research, we propose to develop and to construct a flow-through pH measurement device suitable for continuous measurements on platforms such as VOS lines as well as for the measurement of discrete samples. The determination of the pH will be based on spectrophotometry using m-cresol purple as indicator dye. The method has been successfully applied to ocean waters. However, additional investigations are required to adapt spectrophotometric pH measurements to the specific hydrochemical characteristics of the Baltic Sea. The outcome of the project will be the development of a prototype system for accurate pH-measurements, investigations of chemical parameters and their theoretical and mathematical description and additionally the further hard- and software development. The project has a duration of 3 years (4/2014 - 3/2017), a budget of 415.000 €, and is funded by the EU and the national research councols of Germany, Poland, and Sweden. The project is coordinated by Prof Dr. Gregor Rehder (IOW). PINBAL is funded by the Bonus programme through the European Community's Seventh Framework Programme (FP/2007-2013) under implementation agreement n R&I/I3/2012/BONUS made with BONUS, the joint Baltic Sea research and development programme.

Concluded Projects

  • (For details please klick here)
    In the year 2006, ICOS was recognized as an important research infrastructure by the Council of the European Union Research Ministers and it was added to the priority list (“roadmap”) of the European Strategy Forum on Research Infrastructures (ESFRI). ICOS aims to create an atmosphere, land and ocean monitoring network, able to reliably quantify sinks and sources of greenhouse gases and its catchment areas throughout Europe, and thus to identify and to document changes in the carbon cycle, for at least 20 years. ICOS allows to monitor and to assess the impact of human activities on the climate as well as the success and efficiency of avoidance and abatement strategies. The german component of ICOS (ICOS-D) is in its pilot phase since 2012. The entire installation of the monitoring network should be completed by 2016. In the framework of ICOS-D, the IOW further expands the required instrumentation installed on a ferry, operating on a regular and direct link between Travemünde and Helsinki (the FINNMAID, owned and operated by the shipping company Finnlines). Currently, hydrographical and biological basic parameters are being collected by the Finnish side (Project ALGALINE) whereas measurements of pCO2, pCH4 and oxygen content in the surface water are being conducted by the IOW. Being the only observation line established in a marginal sea, the „BALTIC-VOS“ line plays an important in connecting land and sea based observations in ICOS-D (VOS = voluntary observing ships). Due to anthropogenic impacts (eutrophication, warming), the already over decades documented changes in the Baltic Sea ecosystem are particularly strong and make this observation line especially suited to examine effects of a change in use or adopted environmental strategies on trace gas fluxes. Furthermore, it plays a key role in the development of a seagoing data acquisition system for the “Big Three” of trace gases relevant for the climate: CO2, CH4, N2O. Involved persons (IOW): Gregor Rehder (PI), Wanda Gülzow (project-funded scientist), Michael Glockzin (project-funded engineer).
  • (For details please klick here)
    ...under construction...
  • (For details please klick here)
    Methane is an important atmospheric trace gas with a relevant impact on earth’s climate. Although aquatic systems represent the most significant source of atmospheric methane, the importance of the marine system seems to be marginal. One effective mechanism that is limiting the flux of methane from the sedimentary reservoir into the atmosphere is the microbial oxidation of methane in the sediment. Compared to the number of studies on the microbial processes of methane oxidation in sediments, water column studies are scarce. Long-time stagnation periods within the deep basins of the central Baltic Sea (Gotland- and Landsort-Deep) have caused anoxic conditions in the deep water with strongly elevated methane concentrations. The transition zone between the oxic and anoxic water bodies (redoxcline) allows a systematic sampling of the water depth that is relevant for the turnover of methane. Thus, the detailed study of the microbial methane oxidation in the Gotland- and Landsort-Deep enables us to get new insights into the cycle of methane in the Baltic Sea that may can be used for a better understanding of the methane turnover in other anoxic/oxic basins in the world. In our multidisciplinary approach we (1) quantify the processes of the turnover of methane in the water column of the Gotland- and Landsort-Deep, (2) identify the organisms which are relevant for the turnover of methane in the water column and study their footprint in the sedimentary geological record, (3) integrate our results into hydrodynamic-biochemical numerical model.
  • (For details please klick here)
    Our objective in the third phase of the SPP is to determine the transport of methane, hydrogen and3-helium in the plumes originating from the Logatchev vent field on the Mid-Atlantic Ridge. We(IFM-GEOMAR and IOW) intend to conduct tow-yo CTD surveys of these dissolved gases within adistance of a few kilometers from these vents. We will combine this information with long-term currentmonitoring measurements that will be carried out by Fischer and Visbek (IFM-GEOMAR). The tow-yo surveys will be conducted at the beginning and at the end of the moored profiler/current metermonitoring, on F/S MERIAN cruises 06/2 and 10/3, in order to provide cross-sectional snap shots of the gas distributions in conjunction with these time-series records. Additional vertical CTD-rosette sampling stations will be placed along the 100 km length of the rift valley axis that starts from the 15°20’N Fracture Zone in order to obtain an estimate of the inventories of these gases in this segment. Methane and hydrogen will be measured on board these expeditions; helium isotope measurements will be conducted at the University of Bremen subsequently. We will also measure dissolved methane and hydrogen concentrations in the vent fluids collected during these expeditions, and we shall measure the methane 13C/12C ratio in all gas samples collected on these expeditions. We will be working with M. Perner on kinetic incubation experiments for the purpose of measuring hydrogen consumption rates due to the activity of bacteria found in the vent fluids.
  • (For details please klick here)
    BALTIC GAS aims to understand how climate change and long-term eutrophication affect the accumulation of shallow gas and the emission of methane and hydrogen sulfide from the seabed to the water column and atmosphere. The outcome of the project will be a new understanding and quantitative synthesis of the dynamics and budget of methane in the seabed, an important but poorly understood component of the Baltic ecosystem response to natural and human- induced impacts. The project aims to develop a predictive model of gas accumulation and emission under realistic scenarios of climate change and eutrophication, which will improve the knowledge base for necessary future policy actions. The multidisciplinary project will involve 12 partner institutions from 5 nations and will apply modern advanced technology and novel combinations of approaches.
  • (For details please klick here)
    Under construction...
  • (For details please klick here)
    The Gotland Deep Environmental Sampling Station (GODESS) is a profiling mooring, meaning that a profiling body with the payload (the instruments making measurements) is ascending and descending through the water column at predefined times or intervals. During a deployment of the mooring (typically between 3 and 6 months) repeated profiles of the measured parameters are registered so that we gain an insight of the changes and dynamics during this deployment period. A special interest for this station is the redoxcline in the Gotland Basin between the oxygenated surface layers and the anoxic deep layer.