Das Projekt "key coastal processes in the mesotrophic Skagerrak and the oligotrophic northern Aegean : a comparative study" wird vom Umweltbundesamt gefördert und von ISW Wassermesstechnik Dr. Hartmut Prandke durchgeführt. General Information: This project focuses on investigation and modelling of key processes that affect flow and cycling of carbon and nutrients. In particular, we aim to study how processes change over scales from microns to tens of metres, and to compare processes under two contrasting situations, stratified and mixed water masses. By comparing the Skagerrak with the NE Aegean, we will be able to study differences in functioning between a mesotrophic and an oligotrophic system. There are important differences in sedimentological and geochemistry setting such as higher content of calcareous material in the N. Aegean which are expected to lead to different rates and processes of nutrient recycling, and erosion, transport, deposition, and accumulation of particulate matter. Nutrient regimes are very different and the Skagerrak is relatively turbid with high light attenuation whereas the N. Aegean has clearer water with extremely low attenuation. It is thus likely that not only will primary production processes be different but behavioural differences in zooplankton e.g. predator avoidance, vertical migration, grazing etc. Biological coagulation (packaging) processes are likely to be very different between the two areas and this is expected to have a major influence on flux rates. The benthic systems differ in that biomass and abundances are higher in the Skagerrak but species diversity is higher in the N. Aegean. Thus the processes and rates of mineralisation and material burial will vary. The project is formed around a set of hypotheses defined for each of the key processes identified. The work will be aimed not at establishing mass balances by direct measurement, but will instead focus on the characterisation and modelling of the key processes occurring. Novel aspects include use of high frequency samplers to make in situ measurements of the microstructure, which can considerably improve our understanding of the vertical turbulent transport and of the velocity fluctuations across frontal areas to gain better insight into local biological and physical processes. A state of the art benthic lander will be used to measure respiration and recycling rates of carbon and nutrient elements in sediments in-situ. Large temporal and spatial variability in the near-surface turbulence is expected, which will be investigated on the basis of measurements and l-D modelling. Processes in the organic part of the benthic nitrogen cycle are of major interest as these processes, their regulation and quantitative importance, to a large degree determines the nitrogen sources that eventually will escape to the overlying water. Thus, knowledge on factors regulating processes of organic nitrogen turnover is necessary in the understanding of mechanisms regulating the internal loading. Further, this knowledge is indispensable in the construction of predictive models. ... Prime Contractor: University of Oslo, Department of Biology, Division of Zoology; Oslo; Norway.
Das Projekt "Modular instrument package and its application in mediterranean hydrothermalresearch" wird vom Umweltbundesamt gefördert und von Universität Kiel, GEOMAR Forschungszentrum für marine Geowissenschaften durchgeführt. General Information/Project description: This project is a multi-disciplinary project (science and engineering technology) which contributes to better understanding of the marine hydrothermal system at volcanic arc zones of the European marginal seas. Investigations are based on 1) the knowledge we have obtained in the last years about hydrothermal systems; 2) the deep-towed instrument OFOS (ocean floor observation system), 3) sensor packages which were partly developed for down hole chemical measurements. Investigations are concentrated on hydrothermal plumes as indicators for hydrothermal mineral forming processes in relation to the tectonic setting of the Aegean arc and other potential sites in the Mediterranean Sea. Promising areas will be identified from seismicity, seafloor topography and magnetic anomaly surveys. This will be followed by the search for a hydrothermal plume produced by an active vent field. The significant chemical signal of the plume will be identified by on-line in-situ measurement of temperature, particle density, H2S, Mn, Fe, Zn, Pb. Output from the sensors will be linked to navigational information to produce a map of the plume. These measurements will be done under video observation as the whole system will be linked to the OFOS.