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.

The Great Lakes are the largest collection of fresh surface water on earth, and more than 40 million Americans and Canadians live in their basin. Will we divert water from the Great Lakes, causing them to end up like Central Asia's Aral Sea, which has lost 90 percent of its surface area and 75 percent of its volume since 1960? Or will we come to see that unregulated water withdrawals are ultimately catastrophic? Peter Annin writes a fast-paced account of the people and stories behind these upcoming battles. Destined to be the definitive story for the general public as well as policymakers, The Great Lakes Water Wars is a balanced, comprehensive look behind the scenes at the conflicts and compromises that are the past-and future-of this unique resource.