The SPHERE aims to study sulphur (S) and carbon (C) dynamics between different environmental compartments (atmosphere, water, sediment, biota) of the sea- and fresh-water environment including distribution between organic, inorganic, dissolved, colloidal and nanoparticulate fractions. S and C cycles in the aqueous environment are recognized as important factors for regulating global climate. Nowadays, human activities have vastly affected the S and C cycles. The aquatic ecosystem responses to likely changes in physical, chemical and socio-economic forcing induced by global climate changes, including warming, acidification, biodiversity modifications as well changes in frequency of extreme events (flooding, dust input, hypoxia-anoxia appearance) and by growing anthropogenic pressures will be considered under SPHERE. Effects of the main natural and anthropogenic forcing (extreme events, eutrophication, global changes) related with S and C dynamics will be studied. The SPHERE objectives are: 1) testing and improving existing methods and development of new methods essential for S and organic matter (OM) characterization in water and atmospheric environment; 2) to estimate exchanges and interactions of S and C with other natural and potentially toxic trace elements within and between the major environmental compartments; 3) to monitor and couple S and C dynamics under extreme events (stratification-destratification, hypoxia-anoxia, extreme atmospheric inputs); 4) to synthesize all obtained data for assessment of ecosystem vulnerability and ecological status, in line with water framework directive and national strategy. The SPHERE will be implemented in the period of 4 years through 5 workpackages: 1) OM properties and dynamics; 2) S speciation and dynamic; 3) S, C interaction with trace metals and importance of chalcogenide nanoparticles; 4) thermodynamic predictions for S and C distribution and dynamics; 5) project management.