Dieser Datensatz enthält die Schiedsamtsbezirke in der Stadt Osnabrück. Das Stadtgebiet ist in 4 Bezirke aufgeteilt, in denen jeweils eine Schiedsperson zuständig ist.
In coastal and marginal seas with stable stratification and reduced water exchange, hypoxic deep-water conditions are a frequently observed phenomenon. The so-called redoxcline, developing under such conditions at the top of the anoxic layer, is characterized by strong biogeochemical gradients, which are the location of some important microbially mediated element transformations. Here, our project hypothesis is that the rapid and intermittent modification of the local biogeochemical and microbiological conditions associated with lateral intrusions, in particular due to turbulent mixing between intrusions and ambient waters, constitutes an essential component of the redoxcline system. We plan to study this link between hydrography, turbulent mixing, biogeochemical processes, and microbial activities, taking the central Baltic Sea with its well-defined redoxcline as an example. A recently established autonomous profiling system in the Central Baltic Sea will provide high-resolution data, allowing us to determine the long-term variability of hydrographic, biogeochemical, and mixing parameters associated with the intrusions. The impact of mixing for the microbial activities and communities will be investigated during ship cruises, combining observations of mixing parameters, and representative biogeochemical and microbial transformation processes.
Tropical Atlantic climate recently experienced shifts of great socio-economic importance. The oceanic changes were largest in the eastern boundary upwelling systems, globally important regions for marine productivity and climate. African countries bordering the Atlantic depend upon their ocean-societal development, fisheries, and tourism. They were strongly affected by these changes and will face important adaptation challenges associated with global warming. Paradoxically, the Tropical Atlantic is a region of key uncertainty in the earth-climate system: state-of-the-art climate models exhibit large systematic error, climate change projections are highly uncertain, and it is largely unknown how climate change will impact marine ecosystems. PREFACE takes on the challenge to redress this situation through the first comprehensive assessment of the Tropical Atlantic. Together European and African expertise will combine regional and global scale modelling capabilities, field experiments and observation systems to achieve this. PREFACE Objectives -To reduce uncertainties in our knowledge of the functioning of Tropical Atlantic climate, particularly of climate-related ocean processes (including stratification) and dynamics, coupled ocean, atmosphere, and land interactions; and internal and externally forced climate variability. -To better understand the impact of model systematic error and its reduction on seasonal-to-decadal climate predictions and on climate change projections. To improve the simulation and prediction of Tropical Atlantic climate on seasonal, and longer time scales, and contribute to better quantification of climate change impacts in the region. -To improve understanding of the cumulative effects of the multiple stressors of climate variability, greenhouse induced climate change (including warming and deoxygenation), and fisheries on marine ecosystems, functional diversity, and ecosystem services (e.g., Fisheries) in the Tropical Atlantic. -To assess the socio-economic vulnerabilities and evaluate the resilience of the welfare of West African fishing communities to climate-driven ecosystem shifts and global markets.
Hybrids of the water flea Daphnia occur in many lakes. However, little is known about the factors that cause the success of Daphnia hybrids. In a joint project of two laboratories we study the possible role of biotic interactions in the maintenance of a Daphnia hybrid complex. Daphnia hyalina, D. galeata and their hybrids occur in Bodensee and in Greifensee. The parent species are more abundant in Lake Constance, while hybrids dominate in Greifensee. Both lakes differ in important aspects (morphometry, trophic state), which is reflected by different biotic influences con Daphnia. Compared to Lake Constance, Daphnia in Greifensee are more often exposed to low quality food (toxic blue-greens) and have less of a refuge from fish predation (due the anoxic hypolimnion). Differences between both lakes in the invertebrate predation regime and in the parasite load of Daphnia are very probable. Besides field sampling programmes, we want to establish a collection of about 50 Daphnia clones from both lakes (parent species and hybrids, recent clones and old clones hatched from sediment cores). These clones will be used for life history experiments in the laboratory to test the influences of low quality food, of fish kairomones, of invertebrate predator kairomones and of a protozoan parasite. Food quality and invertebrate predator experiments will be done in Konstanz; parasite and fish experiments will be done in Dübendorf.
Anhand der Auswertung von Langzeitdaten deutscher TS unterschiedlicher geografischer Regionen sollen die direkten und indirekten Folgen der Klimaerwärmung unter Betrachtung der jeweiligen Bewirtschaftungsmaßnahmen analysiert werden. Zusätzlich werden mit Freilandprobenahmen an drei sächsischen Talsperren Veränderungen im Metalimnion, welches in besonderer Weise von den Folgen des Klimawandels und veränderter TS-Bewirtschaftung beeinflusst ist, untersucht.
Dieses Teilprojekt wird den Zusammenhang zwischen schnell ablaufenden Änderungen in der oberflächennahen Zirkulation bzw. Warmwasser-Deckschicht und Schwankungen in den Sauerstoffminimumzonen (SMZ) im tropischen Ozean für die letzten 20.000 Jahre untersuchen. Dabei sollen Sedimentkerne zur Erstellung von Zeitserien für die ozeanische Klimavariabilität auf Zeitskalen von Jahrhunderten bis Jahrtausenden dienen, die möglicherweise Schwankungen in der Intensität von SMZ gesteuert haben. Der Vergleich solcher natürlichen hydrographischen und biogeochemischen Schwankungen mit den heute ablaufenden Änderungen in den tropischen SMZ soll dann Hinweise geben, ob in jüngsten Aufzeichnungen möglicherweise anthropogene Klimaeffekte erkennbar sind.
In the thermocline of lakes and oceans high-frequency internal waves are considered to be the major source of turbulent kinetic energy and a key process driving vertical mixing. In Lake Constance the most energetic high-frequency waves are typically solitary waves generated at the steepened front of the basin scale internal Kelvin wave. The main questions addressed in this project are how stratification, the characteristics of the internal front and lake-morphometry affect the occurrence and properties of solitary wave trains at the internal front in Lake Constance, how much energy is lost from these solitary waves and the wave front to turbulence in the open water and how the properties of solitary wave trains change along their path of propagation. The study will combine the analysis of existing data on high-frequency temperature time series from several years with a new field experiment. The empirical investigations will be complemented by numerical modeling solving the Korteweg-de Vries / Korteweg-de Vries-Burgers equation with spatially varying coefficients to simulate solitary wave trains at the internal front. The spatial differences in solitary wave amplitude, the frequency of the occurrence of solitary waves provided by the statistical analysis and the empirical estimates of energy dissipation during the passage of solitary waves will provide a basis to assess the role of solitary waves for the energy flux from basin scale motion to turbulence and for mixing in the open water.
Das Schwarze Meer ist das weltweit größte anoxische Becken, dessen einmalige Verhältnisse die Untersuchung wichtiger biologischer und biogeochemischer Prozesse an pelagischen Redoxklinen möglich macht. Durch die Bestimmung dieser mikrobiologischen/biogeochemischen Prozesse und deren Umsatzraten in den gekoppelten Stickstoff-, Phosphor-, Schwefel-, Mangan- und Eisenkreisläufen an der Redoxkline, werden Änderungen in der Funktionsweise dieses speziellen Systems als Reaktion auf externe Umweltfaktoren sichtbar. Ein Ziel ist die Erfassung und Erklärung der pelagischen Grundbedingungen in der Deckschicht des Schwarzen Meeres, die für den vertikalen Partikelfluss und die Dynamik der Redoxkline relevant sind. Es wird die Dynamik gelöster Stoffe und der Partikel in ihrer Abhängigkeit von dem externen natürlichen und anthropogen erzeugten Partikelfluss sowie ihrer internen Dynamik untersucht. Wir nehmen an, dass authigene mineralische Mn-Fe-P Phasen signifikant zu dem Phosphatkreislauf, der Primärproduktion, und schließlich auch zum Spurenmetallinventar anoxischer Sedimente und Becken beiträgt. Ein weiterer wichtiger Aspekt ist der Eintrag anthropogener organischer Schadstoffe und Radiotracer in die gesamte Wassersäule und in das Sediment. Das Sediment schließlich wird als wertvolles Archiv die jüngere Vergangenheit des Schwarzen Meeres, die langzeitige Dynamik der pelagischen Redoxkline und, über den Flusseintrag, die regionalen Klimasignale der großen nördlichen Einzugsgebieten dokumentieren. Darüber hinaus werden die geochemischen Eigenschaften der Sedimente aus dem oxischen, suboxischen und anoxischen Milieu verglichen. Das mit vier Schwerpunkten versehene, im Bereich der Meeresforschung angesiedelte, deutsch-ukrainische Projekt wird durch gemeinsame Expeditionen mit der ukrainischen 'Prof. Vodyanitsky' und der deutschen 'Meteor' flankiert und durch die gegenseitige Vorstellung von Techniken und der gemeinsamen Entwicklung von Untersuchungskonzepten gestärkt.
Objective: Hypoxic (low oxygen) conditions in aquatic ecosystems increase in number, duration and extent due to global warming and eutrophication. Global warming will lead to degassing of oxygen, increased stratification, reduced deep-water circulation and changes in wind patterns affecting transport and mixing. Projected increases in hypoxia (e.g. doubling of dead zones) are accompanied by enhanced emission of greenhouse gases, losses in biodiversity, ecosystem functions and services such as fisheries, aquaculture and tourism. A better understanding of global changes in oxygen depletion requires a global observation system continuously monitoring oxygen at high resolution, including assessment of the role of the seafloor in controlling the sensitivity of aquatic systems to and recovery from hypoxia. Here we propose to monitor oxygen depletion and associated processes in aquatic systems that differ in oxygen status or sensitivity towards change: open ocean, oxic with high sensitivity to global warming (Arctic), semi-enclosed with permanent anoxia (Black Sea, Baltic Sea) and seasonally or locally anoxic land-locked systems (fjords, lagoons, lakes) subject to eutrophication. We will improve the capacity to monitor oxygen depletion globally, by implementing reliable long-term sensors to different platforms for in situ monitoring; and locally by training and implementing competence around the Black Sea. Our work will contribute to GEOSS tasks in the water, climate, ecosystem and biodiversity work plans, and comply to GEOSS standards by sharing of observations and products with common standards and adaptation to user needs using a state of the art world data centre. We will connect this project to the GOOS Regional Alliances and the SCOR working group and disseminate our knowledge to local, regional and global organisations concerned with water and ecosystem health and management.
It shall be investigated, how the spring succession of phyto- and zooplankton will change in response to the predicted climate change, in particular to winter warming. Plankton from the Kiel Bight, Baltic Sea, will serve as a model system for moderately deep water bodies, where the phytopankton spring bloom can start before the onset of thermal stratification. While the start of the phytoplankton spring bloom is predicted to be independent of temperature, growth processes of heterotrophs obviously are. This should lead to changed synchronies in the growth and activity patterns of the different components of the plankton community and to a potential mismatch in the demand- supply relationship between consumers and their food organisms. With the help of indoor mesocosm experiments (8 units) and a simultaneous field monitoring program (started already in 2002) the response of phytoplankton and zooplankton growth and activity patterns, shifts in species composition, patterns of resource limitation, matter and energy transfer between trophic levels, and zooplankton fecundity shall be studied.