The large lakes of the East African Rift Valley are among the oldest on Earth, and are vital resources for the people of their basins. They are unique among the large lakes of the world in terms of their sensitivity to climatic change, rich and diverse populations of endemic species, circulation dynamics and water-column chemistry, and long, continuous records of past climatic change. A comprehensive study of the large African lakes is long overdue. The scientific justification for such an effort is noted in the previous paragraph and is illustrated in great detail in this volume. Societal need for the sustainable utilization of these lakes offers an even more compelling reason for examination of biological food webs, water quality, and past climate variability in East Africa. The lakes provide the most important source of protein for the people of the African Rift Valley, and fish populations are shifting dramatically in response to fishing pressure, introduction of exotic species, land use impact on water quality, and perhaps climatic change. Current estimates of primary productivity, the underpinning of the food resource, are extremely crude and based on only a few spot measurements.

The large lakes of the East African Rift Valley are among the oldest on Earth, and are vital resources for the people of their basins. They are unique among the large lakes of the world in terms of their sensitivity to climatic change, rich and diverse populations of endemic species, circulation dynamics and water-column chemistry, and long, continuous records of past climatic change. A comprehensive study of the large African lakes is long overdue. The scientific justification for such an effort is noted in the previous paragraph and is illustrated in great detail in this volume. Societal need for the sustainable utilization of these lakes offers an even more compelling reason for examination of biological food webs, water quality, and past climate variability in East Africa. The lakes provide the most important source of protein for the people of the African Rift Valley, and fish populations are shifting dramatically in response to fishing pressure, introduction of exotic species, land use impact on water quality, and perhaps climatic change. Current estimates of primary productivity, the underpinning of the food resource, are extremely crude and based on only a few spot measurements.

The idea for this book was born at the June 1996 meeting of the IDEAL Steering Committee in Milwaukee, Wisconsin. We had just completed a successful and stimulating special symposium during the annual meeting of the American Society for Limnology and Oceanography, and enthusiasm was running high for the production of a volume that could assemble in one place the scientific findings that were starting to emerge from East Africa. IDEAL, an International Decade for the East African Lakes, had ended one round of field investigations, many of which had been centered on Lake Victoria. As the climatologists, geologists, paleolimnologists, and biologists displayed their results and debated interpretations, it appeared that some paradigms were shifting, and that new explanations of climate history and modem processes were taking shape. The Steering Committee endorsed the production of a volume that would draw together the different research results that were emerging and which would be representative of the scope of science issues that exist within IDEAL. This book follows in the spirit of The Limnology, Climatology, and Paleoclimatology of the East African Lakes, published in 1996, but has a somewhat different purpose. The previous publication also included original science results, but it was conceived to review the state of knowledge, identify critical problems, and point to new paths of inquiry. It accompanied the development of our first Science and Implementation Plan for the East African Lakes.

The Second International Symposium on the East African Lakes was held from 10-15 January 2000 at Club Makokola on the southern shore of Lake Malawi. The symposium was organized by the International Decade for the East African Lakes (IDEAL), a research consortium of African, European and North American scientists interested in promoting the investigations of African Great Lakes as archives of environmental and climatic dynamics. Over one hundred African, European and North American scientists with special expertise in the tropical lakes participated in the symposium which featured compelling presentations on the limnology, climatology, palaeoclimatology and biodiversity of the East African Lakes. It is their papers that comprise this book. The large lakes of East Africa are important natural resources that are heavily utilized by their bordering countries for transportation, water supply, fisheries, waste disposal, recreation and tourism. The lakes are unique in many ways: they are sensitive to climatic change and their circulation dynamics, water-column chemistry and biological complexity differ significantly from large lakes at higher latitudes; they have long, continuous, high resolution records of past climatic change; and they have rich and diverse populations of endemic organisms. These unique properties and the significance of the palaeolimnological records demand and attract research interest from around the world.

Theory Instrumentation NIR analysis of sediment samples Uses of NIRS in palaeolimnology Future perspectives Summary References Fly-ash particles. Neil Rose 319 12. Introduction A brief history Methods of extraction and enumeration Temporal distribution Spatial distribution Source apportionment The future Summary Acknowledgements References Part III: Stable Isotope Techniques 13. Application of stable isotope techniques to inorganic and biogenic carbonates. Emi Ito 351 Introduction Nomenclature and systematics of lake-water Mg/Ca and Sr/Ca ratios of lake-water of dissolved inorganic carbon (DIC) Carbonates in lake-sediments Mollusks Ostracodes Charaphytes Isotope analysis Preparation of carbonate samples for isotope analysis Conclusions Summary Acknowledgments References 14. Carbon and oxygen isotope analysis of lake sediment cellulose: methods and applications. Brent B. Wolfe, Thomas W. D. Edwards, Richard J. Elgood & Kristina R. M. Beuning 373 xi Introduction Stable isotope tracers in lake Historical development Methods Key criteria for paleohydrologic reconstruction Applications Future research directions Summary Acknowledgements References Nitrogen isotopes in palaeolimnology. Michael R. Talbot 15. 401 Introduction Nitrogen in lakes: forms and distribution Nitrogen isotopes Nitrogen isotope studies in palaeolimnology: sampling and measurement Some examples Closing remarks Summary Acknowledgments References Glossary, acronyms and abbreviations 441 Index 493 xiii PREFACE The explosive growth of paleolimnology over the past two decades has provided impetus for the publication of this series of monographs detailing the numerous advances and new techniques being applied to the interpretation of lake histories. This is the second volume in the series and deals mainly with physical and geochemical analytical techniques.

Freshwater Biodiversity is a much underestimated component of global biodiversity, both in its diversity and in its potential to act as models for fundamental research in evolutionary biology and ecosystem studies. Freshwater organisms also reflect quality of water bodies and can thus be used to monitor changes in ecosystem health. The present book comprises a unique collection of primary research papers spanning a wide range of topics in aquatic biodiversity studies, and including a first global assessment of specific diversity of freshwater animals. The book also presents a section on the interaction between scientists and science policy managers. A target opinion paper lists priorities in aquatic biodiversity research for the next decade and several reactions from distinguished scientists discuss the relevance of these items from different points of view: fundamental ecology, taxonomy and systematics, needs of developing countries, present-day biodiversity policy at European and at global scales. It is believed that such a platform for the interaction between science and science policy is an absolute necessity for the efficient use of research budgets in the future.

The Antarctic fish fauna has evolved over a long period of geographic and climatic isolation. In the course of this evolution, Antarctic fish have developed specialized adaptations, some of which characterize these organisms as unique. In strong contrast to the continental shelf faunas elsewhere, the Antarctic shelf ichthyofauna is dominated by a single highly endemic group, the Notothenioidei. This group of perciform fish probably first appeared and diversified in the early Tertiary. The development of the Polar Front (referred to as the Antarctic Convergence in the older literature) resulted in a natural oceanographic barrier to migration in either direction, and thus became a key factor in the evolution of Antarctic fish. The dominance of the Antarctic continental shelf fauna by a single taxonomic group of fish provides a simplified natural laboratory for exploring the wealth of physiological, biochemical and ecological adaptations that characterize the fauna. Understanding of the patterns of adaptation in this highly specialized group of fish can tell us much about of evolution.

This book is an essential knowledge base for both ecological restoration and management. Although tropical lakes are not identical, and therefore require individually developed and restoration and management practices; there are general principles in both restoration and management that can be derived from the case histories in this book and the limnological literature in general.

A synthesis of tropical freshwater systems which illustrates the basic theory of freshwater biology.

The focus of this book is on the key water-related vulnerabilities to climate change in Africa, particularly in its most vulnerable areas, exploring potential management responses to such vulnerabilities. The African countries are particularly exposed and vulnerable to the negative impacts of climate change, with important impacts on water resources and hydrological systems, water availability, water resource management and sea level variations. Already, under various anthropogenic pressures, the status of water resources in Africa has been changing over the past decades, with decreasing water quality, falling groundwater levels, and variability in rainfall, both in terms of timing and intensity. Climate change will further accelerate the rate of change, affecting the ability of people and societies to respond in a timely manner. It is clear that there is no quick fix to the pressures imposed on water resources by climate change. Increasing the resilience of ecosystems and communities to extreme events such as flooding and drought, and integrating climate change risks and opportunities into development decision-making is indeed a key challenge, as much a technical climate-change one, as a political and developmental challenge. The book, in this regard, intends to contribute to the debate around climate change in relation to water resources management in Africa, and in particular inform policy decisions and actions that will improve governments’ and communities’ ability to manage the challenges of climate change and variability in relation to the aquatic ecosystems that they depend on. The knowledge collected in this book will benefit policy makers, researchers, as well as other stakeholders.