Shallow Lakes In A Changing World

This volume comprises the proceedings of the 5th International Symposium on Shallow Lakes, held at Dalfsen, The Netherlands, in June 2005. The theme of the symposium was Shallow Lakes in a Changing World, and it dealt with water-quality issues, such as changes in lake limnology, especially those driven by eutrophication and pollution, increased nutrient loading and productivity, perennial blooms of cyanobacteria and loss of biodiversity.

Ecology of Shallow Lakes brings together current understanding of the mechanisms that drive the diametrically opposite states of water clarity, shown by the cover paintings, found in many shallow lakes and ponds. It gives an outline of the knowledge gained from field observations, experimental work, and restoration studies, linked by a solid theoretical framework. The book focuses on shallow lakes, but the lucid treatment of plankton dynamics, resuspension, light climate and the role of vegetation is relevant to a much wider range of aquatic systems. The models that are used remain simple and most analyses are graphical rather than algebraic. The text will therefore appeal to students, scientists and policy makers in the field of ecology, fisheries, pollution studies and water management, and also to theoreticans who will benefit from the many real-world examples of topics such as predation and competition theory, bifurcation analysis and catastrophe theory. Perhaps most importantly, the book is a remarkable example of how large field experiments and simple models can catalyze our insight into complex ecosystems. Marten Scheffer wrote this book while at the Institute of Inland Water Management and Waste Treatment, RIZA, Lelystad, The Netherlands. He is currently at the Department of Water Quality Management and Aquatic Ecology of the Wageningen Agricultural University. Reviews `Much rarer are textbooks that so succinctly sum up the state-of-the-art knowledge about a subject that they become instant `bibles'. This book is one of these. It is probably one of the best biological textbooks I have read. Scheffer masterfully pulls all this information together under one cover and presents a coherent account, which will serve as a benchmark for the subject. The reader will not gain any great insight into the breeding biology of pike from this book, nor learn much about dragonflies or newts. They will, however, come to understand the essential nature of shallow lakes or, as the author puts it, `how shallow lakes work'. Overall, this book will be of great interest to practical and theoretical ecologists, students and managers in all fields of biology. All freshwater ecologists should certainly read it.' Simon Harrison in Journal of Ecology, 86 `The book by Scheffer can be seen as a milestone in the recognition of shallow lakes as a research topic in its own right. Scheffer uses three approaches concurrently to unravel the functioning of shallow lakes: 1) statistical analysis of large datasets from a variety of lakes; 2) simple abstract models made up of a few non-linear ordinary differential equations, which he calls `mini-models'; and 3) logical reasoning based on a mixture of results from fieldwork, experiments and models. What is new is that Scheffer links mathematics very nicely with what one feels is a correct description of the functioning of a shallow lake. Employing logical reasoning, Scheffer combines all these sources of knowledge into a general, coherent picture of the functioning of a shallow lake.' Wolf Mooij in Aquatic Ecology, 32

This book focuses on a selection of articles presented during the 6th International Shallow Lakes Congress, held in Punta del Este, Uruguay, in November 2008. Both the congress and the articles included in this volume raise a number of key issues. The expansion of research on shallow lakes around the world poses questions on the general validity of the theoretical framework developed in cool and cold temperate shallow lakes. In particular, comparisons along latitudinal gradients in Europe and America have shown that the functioning of lakes differs with the predominant climate and with their sensitivity to water level changes. This may have profound practical consequences for lake management and rehabilitation strategies. The results of controlled experiments and space-for-time (including latitudinal gradient) studies suggest that eutrophication symptoms likely become worse with an increase in mean temperature caused by climate warming. Consequently, the vulnerability of these ecosystems to external impacts such as changes in water level, arrival or introduction of exotic species, increase in nutrient loading and agrochemicals, will likely increase. It thus seems clear that nutrient inputs should be lowered to a much greater extent than previously thought in order to keep lakes’ diversity and conservation value, as well as to increase the chances of maintaining the still pristine lakes in a clear-water, high-biodiversity state.

Describing the natural state of eight important lakes in Asia and the human impact on these lake ecosystems, this book offers a valuable reference guide. Over the past several decades the Aral Sea, Dead Sea, Lake Balkhash and other major lakes in Asia have undergone significant changes with regard to their size, water level, chemical composition, and flora and fauna. Most of these changes resulted from the loss of water from tributaries (now used for irrigation farming) or increasing consumption in local industries and households. However, significant human impacts may have begun as early as 2000 years ago. In addition to the three lakes mentioned above, Lake Sevan (Armenia), the Caspian Sea (Azerbaijan, Iran, Kazakhstan, Russia, Turkmenistan), Lake Issyk-Kul (Kyrgyzstan), and Lake Lop Nur (China) are discussed as the most prominent examples of changing lake ecosystems. In contrast, an example of an almost pristine lake ecosystem is included with the report on Lake Uvs Nuur (Mongolia). For each lake, the book summarizes its origin and early geological history, and reconstructs its natural state and variability on the basis of proxy records from drilled or exposed lake sediments that have accumulated since the last ice age. The frequently observed reductions in lake level and size during most recent decades led often to significant environmental impacts in the respective lake catchments including vegetation deterioration, soil erosion and badland formation, soil salinization or the formation of sinkholes.

In the late 1970s. the adverse effects of man-made eutrophication became manifest in many countries. which explains. perhaps. why there was such a broad interest when the former Resources and Environment Area of the International Institute for Applied Systems Analysis (IIASA) organized a workshop on the subject. There was such an enthusiasm among the partici pants that two further workshops were quickly organized. one on deep and the other on shallow lake eutrophication problems. The organization of these meetings was extremely stimulating. and the round table discussions among scientists from both West and East remain thought provoking for those who took part. The general feeling emerged that the complexity and multifaceted nature of the problem, even though perhaps not fully recognized at that time. clearly demanded a systems analysis approach. No wonder. then. that the request made by the Hungarian Member Organization of nASA to adopt Lake Balaton as a "real life laboratory" for an nASA case study fell on fertile ground. the more so since it appeared that shallow lake eutrophication had received less attention and was less well understood than that of deep lakes. And so the nASA Lake Balaton Case Study began. with the appointment of Gerrit van Straten as the first leader of the project.

"The United Nations World Water Development Report", published every three years, is a comprehensive review providing an authoritative picture of the state of the world's freshwater resources. It offers best practices as well as in-depth theoretical analyses to help stimulate ideas and actions for better stewardship in the water sector. It is the only report of its kind, resulting from the collaboration and contributions of the 26 UN agencies, commissions, program, funds, secretariats and conventions that have a significant role in addressing global water concerns.

The declining trends of wildlife habitats and species populations are obvious consequences of the socio-economic, political, ecological, and technological changes occurring globally. Along with human population growth, there is a growing wave of wildlife diseases, invasive alien species, human-wildlife conflicts, climate change, poaching, infrastructure development, and economic options that are ecologically damaging. These changes have implications on the management of wildlife resources. Managing Wildlife in a Changing World draws experiences from different parts of the world on status, challenges, and efforts of reversing the current negative trends on wildlife habitats and species in the face of these changes. This book is useful for academicians, researchers, policy makers, conservation practitioners, students, and other interested readers.