Das Projekt "Traeger von Vital- und Schadstoffen in den Umweltabteilungen: Bitte um Finanzierung der Koordinierung und Systemanalyse (Art, Verhalten und Rolle)" wird vom Umweltbundesamt gefördert und von Universite de Geneve, Institut F.-A. Forel durchgeführt. Man-made pollution of the environment is mainly due to inputs of pollutants and their transport in the geosphere, to storage and transformation by biological and chemical processes. The evaluation, prevention and clean up of pollution needs a thorough understanding of the concerned natural processes. The study of biogeochemical cycles in the environment is therefore one of the main topics of natural sciences in environmental research. The Swiss National Foundation for Scientific research started at the beginning of 1994 a new coordinated research program on biogeochemical cycles. The main goal of this Module 2 of the Priority Program Environment is the creation of a Swiss multidisciplinary network in the field of biogeochemical cycles, allowing as many research groups as possible to participate. The purpose of this common program is to investigate qualitatively and quantitatively the role of carriers on the fluxes of vital and detrimental compounds inside compartments and at the compartment boundaries: air, soil, sediments, surface water, subsurface and ground water. During 1994-1995, research will be focused in particular on sub micron colloids which are very little known. Leading Questions: What are the macroscopic processes of contaminant transport in complex natural environments (system analysis)? Occurence and properties of colloidal carriers in the air, the soil and the water? Mobility of colloidal carriers of contaminants? Implications for the contaminant transport (sorption, desorption, transformation)? Methods of sampling, preparation, analysis?
Das Projekt "European Project on Ocean Acidification (EPOCA)" wird vom Umweltbundesamt gefördert und von Centre National de la Recherche Scientifique durchgeführt. Objective: The overall goal of the European Project on Ocean Acidification (EPOCA) is to fill the numerous gaps in our understanding of the effects and implications of ocean acidification. EPOCA aims to document the changes in ocean chemistry and biogeography across space and time. Paleo-reconstruction methods will be used on several archives, including foraminifera and deep-sea corals, to determine past variability in ocean chemistry and to tie these to present-day chemical and biological observations. EPOCA will determine the sensitivity of marine organisms, communities and ecosystems to ocean acidification. Molecular to biochemical, physiological and ecological approaches will be combined with laboratory and field-based perturbation experiments to quantify biological responses to ocean acidification, assess the potential for adaptation, and determine the consequences for biogeochemical cycling. Laboratory experiments will focus on key organisms selected on the basis of their ecological, biogeochemical or socio-economic importance. Field studies will be carried out in systems deemed most sensitive to ocean acidification. Results on the chemical, biological and biogeochemical impacts of ocean acidification will be integrated in biogeochemical, sediment and coupled ocean-climate models to better understand and predict the responses of the Earth system to ocean acidification. Special attention will be paid to the potential feedbacks of the physiological changes in the carbon, nitrogen, sulfur and iron cycles. EPOCA will assess uncertainties, risks and thresholds ('tipping points') related to ocean acidification at scales ranging from sub-cellular, to ecosystem and from local to global. It will also assess pathways of CO2 emissions required to avoid these thresholds and describe the state change and the subsequent risk to the marine environment and Earth system should these emissions be exceeded.
Das Projekt "Novel technologies to reveal the impacts of nutrient limitation in aquatic systems: from biodiversity to biogeochemical cycles" wird vom Umweltbundesamt gefördert und von Universite de Geneve, Institut F.-A. Forel durchgeführt. Both lakes and oceans are important for the global carbon cycle and thus the regulation of climate processes. Due to climate change and human activities, aquatic systems are subject to increasing pressure with changes already observed at multiple levels affecting their functioning. It is therefore urgent to understand the dynamic of aquatic systems, if one wants to predict their response to changing conditions. Phytoplankton, act as engineers, initiating the incorporation of terrestrial and atmospheric compounds into the food chain and driving their biogeochemical cycling. They not only respond rapidly to their environment, they also profoundly alter aquatic chemistry, affecting the reactivity, recycling, remineralisation and therefore fate of many elements. As such, phytoplankton affect the dynamics of aquatic systems with effects at both local and global scales. Phytoplankton can thus be used as sentinel to assess the dynamics and changes in aquatic systems. One of the most prominent reported controls of phytoplankton biomass, biodiversity and productivity is nutrient limitation, reported in most of the ocean and numerous lakes. Iron (Fe), nitrogen (N) and phosphorous (P) are the main limiting nutrients in aquatic systems. Nutrient limitation affects the functioning of aquatic systems and their contribution to the global carbon cycle. Despite numerous studies, the parameters controlling nutrient limitation and their accessibility to phytoplankton (viz. bioavailability) remain largely unknown. The aim of this project is to identify nutrient (Fe, N, P) limitation in different aquatic systems, and to improve our understanding of aquatic biogeochemistry - from gene expression, chemistry and bioavailability through to the impact on biodiversity under current and future conditions. The study regions include the largest lake in Western Europe, Lake Geneva; the Southern Ocean, a pivotal region for the global carbon cycle; and the Tasman Sea, one of the most sensitive regions to predicted climate change. All these regions are associated with significant socio-economical value. Here, a rigorous multi-disciplinary laboratory and field approach will be used to provide complementary data sets to shed light on how nutrients affect the biodiversity, the biogeochemical cycles of key elements and the functioning of natural systems. The laboratory approach (1) explore the mechanisms controlling nutrient biological accessibility using relevant axenic phytoplankton cultures and (2) allows the calibration and validation of biological and chemical sensors to rapidly monitor nutrient limitation in aquatic systems. In addition, field work will (1) explore the link and the seasonality between important physical, biological and chemical parameters and (2) use perturbation experiments to investigate the complexity of the link between nutrients and natural planktonic assemblages. (...)