Most aquatic ecosystems have variable water levels. These water-level fluctuations (WLF) have multiple effects on the organisms above and below the waterline. Natural WLF patterns in lakes guarantee both productivity and biodiversity, while untimely floods and droughts may have negative effects. Human impacts on WLF have led to a stabilization of the water levels of many lakes by hydraulic regulation, untimely drawdown due to water use, or floods due to water release from hydropower plants in the catchments. This book provides a first review in this field. It presents selected papers on the ecological effects of WLF in lakes, resulting from a workshop at the University of Konstanz in winter 2005. Issues addressed here include the extent of WLF, and analyses of their effects on different groups of biota from microorganisms to vertebrates. Applied issues include recommendations for the hydrological management of regulated lakes to reduce negative impacts, and a conceptual framework is delivered by an extension of the floodpulse concept for lakes. Current impacts on water use, including increasing demands on drinking and irrigation water, hydropower etc., and climate change effects on WLF make this book an essential resource for aquatic ecologists, engineers, and decision-makers dealing with the management of lake ecosystems and their catchments.

Perturbations linked to the direct and indirect impacts of human activities during the Anthropocene affect the structure and functioning of aquatic ecosystems to varying degrees. Some perturbations involve stress to aquatic life, including soil and water acidification, soil erosion, loss of base cations, release of trace metals/organic compounds, and application of essential nutrients capable of stimulating primary productivity. Superimposed onto these changes, climate warming impacts aquatic environments via altering species’ metabolic processes and by modifying food web interactions. The interaction stressors is difficult to predict because of the differential response of species and taxonomic groups, interacting additively, synergistically, or antagonistically. Whenever different trophic levels respond differently to climate warming, food webs are restructured; yet, the consequences of warming-induced changes for the food web structure and long-term population dynamics of different trophic levels remain poorly understood. Such changes are crucial in lakes, where food web production is mainly due to ectotherms, which are highly sensitive to changes in their surrounding environment. Due to its remarkable physical inertia, including thermal stability, global warming also has a profound effect on groundwater ecosystems. Combining contemporary and palaeo data is essential to understand the degree to which mechanisms of stressors impact on lake biological communities and lake ecosystem functioning. The degree to which alterations can affect aquatic ecosystem structure and functioning also requires functional diversity to be addressed at the molecular level, to reconstruct the role different species play in the transfer of material and energy through the food web. In this issue, we present examples of the impact of different stressors and their interaction on aquatic ecosystems, providing long-term, metabolic, molecular, and paleolimnological analyses.

Currently, anthropogenic activities have caused unprecedented destruction of the environment at alarming rates, leading to undesirable alterations in air, land, and water. The process of environment degradation has been accelerated by industrial processes, which result in waste as well as over-consumption of natural resources. The ecological balance has been disturbed, and resources have shrunk. All this has resulted in climate change, which has emerged as a major concern in the 21st century. Changes in the environment are driven by demand for energy, water, and food to raise the standard of living. These are also responsible for climate change, with contributions from deforestation and CO2 emissions from fossil fuels such as coal and petroleum. The present volume discusses some of the main issues regarding environmental degradation and the causes as well as the impact of climate change, which is impacting the ecosystem. The effects of various pollutants, causes of climate change with case studies on geochemistry and glaciers, etc., and measures to reduce the impact on biodiversity, health, etc. are discussed in detail in its chapters. In a nutshell, this volume discusses in detail the following issues: • Anthropogenic and natural factors in environmental degradation • Climate change history, causes, and threats to abiotic and biotic systems • Case studies on the impact of climate change and living systems • Mitigation and preparedness for the future

This condensed volume summarizes updated knowledge on the warm-monomictic subtropical Lake Kinneret, including its geophysical setting, the dynamics of physical, chemical and biological processes and the major natural and anthropogenic factors that affect this unique aquatic ecosystem. This work expands on a previous monograph on Lake Kinneret published in 1978 and capitalizes on the outcome of more than 40 years of research and monitoring activities. These were intensively integrated with lake management aimed at sustainable use for supply of drinking water, tourism, recreation and fishery. The book chapters are aimed at the limnological community, aquatic ecologists, managers of aquatic ecosystems and other professionals. It presents the geographic and geological setting, the meteorology and hydrology of the region, continues with various aspects of the pelagic and the littoral systems. Finally, the last section of the book addresses lake management, demonstrating how the accumulated knowledge was applied in order to manage this important source of freshwater. The section on the pelagic system comprises the heart of the book, addressing the major physical processes, external and internal loading, the pelagic communities (from bacteria to fish), physiological processes and the major biogeochemical cycles in the lake.

This book provides a comprehensive and systematic analysis of the morphodynamic process of the Changjiang River from upstream to estuary in the Anthropocene. As the longest river in China, the Changjiang River has nurtured Chinese civilization with ample natural resources for thousands of years. Evidence highlights that the Changjiang River has experienced intensive human interference and indicated dramatic changes in the Anthropocene, including “no flood in flood season, no dry in dry season” in discharge; “less flood in flood season, more dry in dry season” in sediment; riverbed shifts from accretion to erosion; lakes in the middle-lower reach turn from sediment sink to source; estuarine tidal flat exhibits self-organization characteristics and maintains the current accretion state; estuarine branches that connect to the sea show district morphodynamic patterns; and depocenters of the submerged delta indicate periodic shifts. The book stresses that dam construction upstream, practically the Three Gorges Dam, the world’s largest hydraulic engineering project, has significant influences on the hydrology and geomorphology of the middle-lower reach but has a slight effect on estuarine delta development. The geomorphological structure of the estuarine channel is dominated by local land reclamation, navigation, and dredging. This book clarifies the river-estuary morphodynamics of the Changjiang River and indicates the general features of global mega rivers under human interference as well as their own response mechanisms. This book also exhibits the potential risk of river-estuary deltas in the future, as both material and dynamics are experiencing acceleration adjustment.

The growing impacts of economic activities and climate change on the conditions of rivers throughout the world, require a new, integrated approach towards river basin management, an approach that can also cope with an uncertain future. In this volume, leading European scientists and representatives of major stakeholder groups present risk-informed management as this new approach, as developed in the European Commission-funded project RISKBASE. It aims to improve the ecological quality of river basins and thus to sustain the goods and services they provide for the benefit of society. Risk-informed management involves the integrated application of three key-principles: · Being well informed · Managing adaptively · Pursuing a participatory approach The authors explain and underpin these principles in detail, offer inspiring examples from practice and connect them to the implementation of the European Water Framework Directive (WFD). This book is intended for scientists, consultants and practitioners concerned about river basins, world-wide, as well as the drafters and implementers of the WFD River Basin Management Plans.