Talk:The backbarrier tidal flats in the southern North Sea - A multidisciplinary approach to reveal the main driving forces shaping the system

Job Dronkers July 2023: I have removed the following two sections of this article as they are no longer relevant.

The Research Group on BioGeoChemistry of Tidal Flats

Extensive ecosystem research projects were carried out in the German Wadden Sea funded by the Federal Ministry of Science and Technology and the states of Schleswig-Holstein and Lower Saxony in the mid to late 1990s (Dittmann 1999; Umweltbundesamt 2004). Despite the substantial efforts to understand the system as a whole, the participants in these studies retrospectively came to the conclusion that too little attention had been paid to two fundamental aspects, i.e. the tidal circulation system as the main morphological driving force and the microbial world at the base of the food web as the most important player maintaining the delicate balance of primary production and biomass recycling.

As a consequence, a few years later – profiting also from scientific and technical developments in physical sensor technology, analytical chemistry of trace components, molecular biological methods, and mathematical modelling – a new interdisciplinary research project was designed that aimed at closing the gap of knowledge on the overall functioning of the physical, chemical and biological processes in tidal flats. Thanks to generous funding by the Deutsche Forschungsgemeinschaft (DFG, Bonn) and the State of Lower Saxony, the DFG Research Group on BioGeoChemistry of Tidal Flats commenced its work in spring of 2001 and – with two extensions after thorough reviewing by external experts – continued for eight years into 2009. This special issue of Ocean Dynamics forms an essential part of the final report of the project covering most of the important aspects of the overall work and its results, although a large number of manuscripts, many of them referred to in the articles of this special issue, have already been published earlier in a variety of international scientific journals. Indeed, data processing and evaluation will still carry on for years to come. Many of the final data sets have already been forwarded to the PANGAEA open access information system (http://www.pangaea.de), and many more will follow.

The project was co-ordinated by the Institute of Chemistry and Biology of the Marine Environment (ICBM) at the Carl von Ossietzky University of Oldenburg (Germany), cooperation partners in northwest region of Germany including the Max Planck Institute for Marine Microbiology (Bremen), the Senckenberg Institute (Wilhelmshaven), the Terramare Research Centre (Wilhelmshaven; merged with ICBM in 2008), and the Institute of Physics of the University of Oldenburg. Some of the scientists involved continued their cooperation with contributions to the research group even after they adopted leading positions at other institutions, e.g., at the Institute of Baltic Sea Research Warnemünde (IOW), the GKSS Research Centre (Geesthacht), and the University of Cardiff (UK). Important milestones of the interdisciplinary effort were several coordinated field campaigns involving several boats and ships, and even an airplane. In this way, both experimental and analytical research groups were brought together in the Wadden Sea at the same time, for several days or longer, to collect data under the same environmental conditions. As these data sets were particularly valuable for validation purposes in ecosystem modelling, it was the Mathematical Modelling Group of ICBM who organised and coordinated the field campaigns.
The research objectives in the initial grant proposal were phrased as follows: "The investigations of the Research Group aim at a fundamental understanding of important processes in a tidal flat system. For this purpose, biogeochemical transformations on water-column-suspended particles, at the sediment-water interface and in the sediments will be studied. Considering the hydrodynamic conditions, the influence of the different processes on the material budgets will be determined. A mathematical ecosystem model will be developed for the biogeochemical processes in the tidal flat sediments and at the sediment-water interface. On a higher level, a material budget will be established for a selected tidal flat area on the East Frisian North Sea coast (backbarrier tidal flat of Spiekeroog island). The results of the experimental study of sediment transport will be described mathematically with a hydrodynamical model. In addition, a tight coupling of methods for analyzing nonlinear dynamic systems with ecological problems will be used to reveal how spatial, temporal and/or spatio-temporal structures are formed due to nonlinear interaction of reaction, diffusion and advection and if exceeding a critical threshold leads to the spontaneous formation of new structures or dynamics. With this fundamental methodological contribution to the field of integrative modelling, the Research Group would like to take a significant step forward to the development of a comprehensive mathematical model of tidal flat systems which beyond the initially selected study area should be applicable also to other tidal flat areas and similarly complex systems. The work of the Research Group is based on the results of past ecosystem research projects in the same coastal area, but in the analysis of the material budget and particularly in the integrative modelling it will break new scientific ground due to the innovative methodological concepts applied."

Acknowledgements

Fig. 10. Members of the DFG review group experience the typical working conditions in November 2006 when pore water sampling took place in heavy wind, rain and hail and at temperatures just above freezing.

As the coordinator of the Research Group on BioGeoChemistry of Tidal Flats and its elected speaker for eight years, I am very grateful to my 70 or so research colleagues who over the entire running time of the project cooperated so well and made my job so easy. I would also like to address my gratitude to the many technicians, workshop personnel, student helpers, and to Ursel Gerken as the main administrative staff member, all of whom contributed an immense share to the project. The project could not have been successful without the supportive efforts of captains and crew members of several research vessels and the drivers of smaller boats. We highly appreciate the support of the Wadden Sea National Park Administration who granted permission to work within the limits of the National Park with its different protected zones, as well as fruitful cooperation with the local fishermen and their representatives. The support by many more individuals and authorities has been or will be acknowledged in the many publications that have come out of this project. The Deutsche Forschungsgemeinschaft (DFG, Bonn, grant no. FOR 432) carried the main burden of the financial load that was required to run this project. This is highly appreciated, but we are also grateful to the Ministry of Science and Culture of the State of Lower Saxony and the University of Oldenburg, as well as the other partner organizations for additional financial support. Finally, we are grateful to the board of reviewers that evaluated the proposals and voted positively for the project to be funded – especially those who visited the Janssand study site in November 2006 in harsh weather conditions of storm, rain, hail and near-freezing temperatures (Fig. 10). Last but not least, we are indebted to the many referees of our publications including those for this special issue of Ocean Dynamics.