There is a difficult polarity between reality and ecologically desirable goals of stream ecosystem management in Switzerland. Most streams are exposed to a variety of impacts. Due to a high intensity of anthropogenic activity there is a high pressure on land and water use. Essential water uses have to be guaranteed. On the other hand there is also a strong need to preserve or restore (bring back ecological integrity) or rehabilitate streams (bring back 'relative ecological integrity'). Stream assessment should, therefore, produce sound data suitable for characterizing the ecological condition of streams and for supporting their sustainable management. The methods should include a system approach as the basic unit and sound scientific principles of ecological integrity emphasizing habitat connectivities. The methods should allow: • the condition of streams to be rationally described and judged, • identification of different kind of impacts on a stream, • verification of the effects of water protection measures, • identification of suitable future actions in the context of a whole stream system. In order to cover the various requirements a modular concept for stream system-oriented analysis was developed. Altogether nine modules are elaborated. Each module deals with specific stream features (two hydrodynamic and ecomorphological modules, five biological modules, two chemical and ecotoxicological modules). Single modules, several modules, or all of them may be applied, depending on the purpose of the analysis. For each module a cost-effective survey procedure (rapid method) and a progressively more rigorous method providing more detailed information is suggested. Based on the result of the analysis, stream rehabilitation concepts can then be elaborated in cooperation with managers, river engineers and biologists.

Using the regional scale, nutrient-flow simulation model MODIFFUS, an estimate of phosphorus (P) and nitrogen (N) inputs from diffuse sources into surface waters over the Swiss part of the Rhine watershed downstream of large lakes was performed for the years 1985, 1996 and 2001. The data are required for purposes of national monitoring and for reporting to international panels such as the International Commission for the Protection of the Rhine (ICPR) and the Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR). Total diffuse P and N losses, including natural background losses, decreased from 547 tons (t) P and 19 219 t N in 1985, to 423 t P and 17 902 t N in 1996, and 393 t P and 16 610 t N in 2001. Total reductions between 1985 and 2001 of 154 t P and 2 609 t N correAquatic Sciences sponded to 28 % and 14 % of the total diffuse, and 38 % and 18 % of the anthropogenic diffuse losses, respectively. These reductions are mainly attributable due to a decrease in agricultural land and partly to measures in agricultural practice. However, discharges from point sources (wastewater treatment plants and stormwater overflows) also have fallen substantially over the period. Over the Swiss part of the Rhine watershed, the international target of 50 % reduction in the total inputs into surface waters of P and N was achieved for P (reduction of 51%), but not for N (reduction of 23%). Comparison of the calculated losses of P and N from all sources with the loads measured in the Rhine near Basel shows the calculations to be realistic.

An estimate of diffuse sources of heavy metals (Hg, Cd, Cu, Zn, Pb, Cr, Ni) in the Rhine catchment stressed the urban storm water discharges in the German part and drainage flow in the Dutch part as the most important pathways. Additional sources are erosion and, to a far lesser extent, atmospheric deposition on open water areas. All other pathways were of minor importance. Meanwhile, after reduction of the point sources by between 72-95%, the diffuse sources dominate the total emissions. For several metals the anthropogenic diffuse sources amounted to 40-80%, the point sources to 15-40% and the geogeneous sources to 5-40%. The estimated inputs sufficiently agreed with the loads of the river Rhine. For the estimation, mean values were used for the water masses and the substance concentrations of the different hydrological pathways. It is recommended to undertake further studies on diffuse sources of heavy metals in urban areas and on the possibilities to improve urban storm water management. The calculation methods and the recommendations of the International Commission for the Protection of the Rhine (ICPR) are explained in detail.

The internet has become a major place of business for criminals. Due to the properties of cyberspace, crime committed on or by means of the internet is typically transnational in nature. This poses a significant obstacle for law enforcement authorities. As a rule, transnational exercise of enforcement jurisdiction traditionally constitutes a violation of another State’s territorial sovereignty. But do the same rules apply in the ‘global cyberspace?’ This article examines the applicability of the principle of territorial sovereignty in cyberspace. It rejects solutions that treat cyberspace as a common good and argues that transborder online criminal investigations infringe the territorial sovereignty of the State where the accessed data are located. Consequently, the analysis assesses justifications for such infringements on the basis of international treaty law, customary international law, and circumstances precluding wrongfulness. For the most intricate cases of loss of location, the analysis develops a carefully delimited, new solution based on the principle of necessity. The article also sheds light on future perspectives and advocates for a ‘cooperative cyberspace’ of investigators to counterbalance the unfettered global cyberspace of perpetrators.