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Globally, freshwater ecosystems are considered to be under severe threat from human pressure and climate change (Vörösmarty et al., 2010). Malmqvist and Rundle (2002) suggest that running water is the most impacted upon ecosystem on Earth due to being surrounded by dense human settlements and exploited for domestic and industrial water supply, irrigation, electricity generation and waste disposal. For example, the progressive over-exploitation of surface water resources for irrigation and urban uses in the Colorado River Basin has resulted most years in no runoff reaching the river's delta (Gleick, 2003) […]. Hereafter, natural and anthropogenic driving forces will be referred to as global and regional driving forces, respectively. The future effects of these forces up to the 2050s will be assessed in quantitative scenarios implemented in a hydrological model. It is believed that using this nomenclature (i.e. global and regional instead of natural and anthropogenic) better reflects considered environmental stressors, since global-scale driving forces will include not only climatic change but also changes in CO2, atmospheric carbon dioxide and plant physiological parameters, whereas regional-scale driving forces will include changes in land use, agriculture development and agricultural water management. Hence, the difference is that the first group of driving forces acts globally and independently on the study area, whereas the second group includes factors that are specific to the study area. Furthermore, in order to expand on the title of this thesis, impacts in the present study will be assessed not only on the flow regime as such, but also on ist ecological functions, i.e. on the environmental flow regime. This is motivated mainly by the semi-natural character of the study area, that is unique in Poland and in Europe, but it also underlines the novelty of this thesis, as going beyond the pure impacts on the flow regime in a scenario-modelling framework is rare in hydrological science, if achieved at all.

Our understanding of the ecology of running waters has come a long way during the past few years. From being a largely descriptive subject, with a few under­ tones concerned with such things as fisheries, pollution or control of blackflies, it has evolved into a discipline with hypotheses, such as the River Continuum Concept (Vannote et a/. 1980), and even a book suggesting that it offers opportunity for the testing of ecological theory (Barnes & Minshall 1983). However, perusal of the literature reveals that, although some of the very early studies were concerned with large rivers (references in Hynes 1970), the great mass of the work that has been done on running water has been on streams and small rivers, and information on larger rivers is either on such limited topics as fisheries or plankton, scattered among the journals, or not available to the general limnologist. The only exceptions are a few books in this series of publications, such as those on the Nile (Rz6ska 1976), the Volga (Morduckai­ Boltovskoi 1979) and the Amazon {Sioli 1984), and the recent compendium by Whitton (1984) on European rivers, among which there are a few that rate as large.

This book contains 26 contributions dealing with the biology of aquatic oligochaetes and covers a wide range of topics including taxonomy, morphology, ultrastructure, embryology, reproduction, feeding biology, ecotoxicity, community studies, and species distribution. Descriptions of new taxa in tropical areas, including Amazonian forest soils, as well as overviews on the biodiversity of aquatic oligochaetes in Australia and European groundwaters, are presented. New morphological characteristics in both marine and freshwater species are described and interpreted. Laboratory studies contribute to the knowledge of oligochaete feeding biology and reproduction. The use of aquatic oligochaetes in ecological risk assessment is analysed in detail, and standardised experimental designs for studies on bioaccumulation and pollutant transfer by food are included. Finally, a number of papers present the effects of oliogochaetes on the performance of an activated sludge plant, and multivariate approaches to the spatial and/or temporal distribution and composition of oligochaete communities in many different areas of the world, from the scale of a river to the scale of the microhabitat. The broad scope of this volume is a reflection of recent rends, not only in oligochaete research, but also in general applied biological studies.

Coastal populations of shellfish have been exploited by humans for millennia as an easily accessible source of fresh protein. Unfortunately, because the intertidal zone and the shallow coastal margins are so intertwined with man's activities, these shellfish stocks are now severely threatened around the world. Issues such as anthropogenic pollution, harmful algal blooms, overfishing, loss of habitat, and local stakeholder conflicts are all contributing to an alarming decline in the natural productivity of these regions. There have now been five International Conferences on Shellfish Restoration (ICSR) since 1996, which have focused the attention on transferring scientific knowledge into practical remedial and restorative actions for shellfish populations. This volume represents a selection of contributions from the third meeting in Cork, Ireland, 1999. It includes papers on lobsters, sea urchins, whelks, clams, mussels, and scallops, with a thematic emphasis on ranching, disease, environmental interactions, fisheries management, aquaculture, restoration, toxic algal blooms, and toxicity testing.