Search results for: the-impact-of-species-changes-in-african-lakes

The Impact of Species Changes in African Lakes

Author : P. Hart
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The African lakes are an extremely important ecosystem and the subject of much study relating to species introductions and loss of biodiversity. This book provides a thorough review of the whole subject and will be of great interest to fish biologists, fisheries workers, ecologists, environmental scientists and conservationists.

Limnology Climatology and Paleoclimatology of the East African Lakes

Author : A.Ivan Johnson
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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.

Africa s Lakes

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Prepared as part of UNEP's contribution to the 11th World Lakes Conference (held in Nairobi, Kenya in November 2005), this publication examines the environmental changes taking place to Africa's lakes by analysing ground photographs, current and historical satellite images and scientific evidence. Changes highlighted include the rapid shrinking of Lake Songor in Ghana, partly as a result of intensive salt production, and the extraordinary changes in the Zambezi river system as a result of the building of the Cabora Basa dam site. Other impacts, some natural and some human-made and which can only be truly appreciated from space, include the extensive deforestation around Lake Nakuru in Kenya, and the falling water levels of Lake Victoria which is now about a metre lower than it was in the early 1990s. The analysis recognises the importance of Africa's lakes as a source of livelihoods for many local communities, their contribution to the socio-economic development of the continent and the need for the sustainable management of these resources in order to help overcome poverty and meet internationally agreed development goals by 2015.

CIFA Technical Paper

Author : Food and Agriculture Organization of the United Nations. Committee for Inland Fisheries of Africa
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Handbook of Fish Biology and Fisheries

Author : Paul J. B. Hart
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Recent decades have witnessed strong declines in fish stocks around the globe, amid growing concerns about the impact of fisheries on marine and freshwater biodiversity. Fisheries biologists and managers are therefore increasingly asking about aspects of ecology, behaviour, evolution and biodiversity that were traditionally studied by people working in very separate fields. This has highlighted the need to work more closely together, in order to help ensure future success both in management and conservation. The Handbook of Fish Biology and Fisheries has been written by an international team of scientists and practitioners, to provide an overview of the biology of freshwater and marine fish species together with the science that supports fisheries management and conservation. This volume, subtitled Fisheries, focuses on a wide range of topics, including the history of fisheries science, methods of capture, marketing, economics, major models used in stock assessments and forecasting, ecosystem impacts, marine protected areas and conservation. It builds on material in Volume 1, Fish Biology, which ranges from phylogenetics and biogeography to physiology, recruitment, life histories, genetics, foraging, reproductive behaviour and community ecology. Together, these books present the state of the art in our understanding of fish biology and fisheries and will serve as valuable references for undergraduates and graduates looking for a comprehensive source on a wide variety of topics in fisheries science. They will also be useful to researchers who need up-to-date reviews of topics that impinge on their fields, and decision makers who need to appreciate the scientific background for management and conservation of aquatic ecosystems. To order volume II, go to the box in the top right hand corner. Alternatively to order volume I, go to: http://www.blackwellpublishing.com/book.asp?ref=0632054123 or to order the 2 volume set, go to: http://www.blackwellpublishing.com/book.asp?ref=0632064838. Provides a unique overview of the study of fish biology and ecology, and the assessment and management of fish populations and ecosystems. The first volume concentrates on aspects of fish biology and ecology, both at the individual and population levels, whilst the second volume addresses the assessment and management of fish populations and ecosystems. Written by an international team of expert scientists and practitioners. An invaluable reference tool for both students, researchers and practitioners working in the fields of fish biology and fisheries.

The Nile Waters

Author : Joseph Awange
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This book is useful to those in water resources management and policy formulations, hydrologists, environmentalists, engineers and researchers. Exploiting advanced statistical techniques and the latest state-of-the-art multi-mission satellites, surface models and reanalysis products, this book provides the first comprehensive weighing of the changes in the Nile River Basin’s (NRB: ~ 3,400,000 km2 ) stored waters' compartments, surface, soil moisture and groundwater, and their association to climate variability/change and anthropogenic impacts on the one hand. On the other hand, it argues on the need for equitable use of the NRB’s waters by all 11 countries within its basin, and doing away with obsolete Nile treaties that were signed by Britain, Egypt and Sudan, which prohibit the use of the Nile by 8 upstream countries. With Ethiopia’s construction of Africa’s largest dam (GERD; Grand Ethiopian Renaissance Dam) along the Blue Nile, which is expected to take several years to fill, the Nile is back on the news. Combined with Uganda’s Nalubaale, Kiira and Bujagali dams on the White Nile, these human-induced impacts (i.e., damming), coupled with those of climate variability/change, are expected to exacerbate tension with the low stream countries (Egypt and Sudan) fearing the cut in theNile’s total volume. Furthermore, the Nile river, arguably the world’s longest river (6800 km), impacts on the livelihood of over 300 million people of 11 countries within its basin. This population is expected to double in the next twenty-five years, thereby putting extreme pressure on its water resources. An in-depth analysis of changes in the Nile’s stored waters, therefore, is essential to inform its management and sustainable equitable use. Owing to its sheer size, however, obtaining in-situ data from “boots on the ground” is practically impossible, paving way to the space-based weighing of the Nile River Basin using a suite of high spatio-temporal remotely sensed and reanalysis products, as well as those of hydrological models. “Arguably, the Nile River is the most unique river in the world. It spans extremes of rainfall from being measured by meters to being measured by centimeters, from the humid tropics to the driest of deserts. Yet, thirsty people live throughout this basin and therefore the demands on its water resources are uneven. Knowing the water amounts throughout the entire Nile Basin is a critical step for governments and international treaties to avoid the “Tragedy of the Commons”. Africa can embrace this future through the leadership of Prof. Awange and others like him who have devoted their careers to Africa’s waters” —Doug Alsdorf, Ph.D., Professor of Geophysics at the Ohio State University (USA).

Symposium on Resource Use and Conservation of the African Great Lakes Bujumbura 1989

Author : Ro McConnell
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The Nile

Author : Henri J. Dumont
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What have we learnt about the Nile since the mid-1970s, the moment when Julian Rzóska decided that the time had come to publish a comprehensive volume about the biology, and the geological and cultural history of that great river? And what changes have meanwhile occurred in the basin? The human popu- tion has more than doubled, especially in Egypt, but also in East Africa. Locally, industrial development has taken place, and the Aswan High Dam was clearly not the last major infrastructure work that was carried out. More dams have been built, and some water diversions, like the Toshka lakes, have created new expanses of water in the middle of the Sahara desert. What are the effects of all this on the ec- ogy and economy of the Basin? That is what the present book sets out to explore, 33 years after the publi- tion of “The Nile: Biology of an Ancient River”. Thirty-seven authors have taken up the challenge, and have written the “new” book. They come from 13 different countries, and 15 among them represent the largest Nilotic states (Egypt, Sudan, Ethiopia, Uganda, and Kenya). Julian Rzóska died in 1984, and most of the - authors of his book have now either disappeared or retired from research. Only Jack Talling and Samir Ghabbour were still available to participate again.

Freshwater Fisheries Ecology

Author : John F. Craig
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Inland fisheries are vital for the livelihoods and food resources of humans worldwide but their importance is underestimated, probably because large numbers of small, local operators are involved. Freshwater Fisheries Ecology defines what we have globally, what we are going to lose and mitigate for, and what, given the right tools, we can save. To estimate potential production, the dynamics of freshwater ecosystems (rivers, lakes and estuaries) need to be understood. These dynamics are diverse, as are the earths freshwater fisheries resources (from boreal to tropical regions), and these influence how fisheries are both utilized and abused. Three main types of fisheries are illustrated within the book: artisanal, commercial and recreational, and the tools which have evolved for fisheries governance and management, including assessment methods, are described. The book also covers in detail fisheries development, providing information on improving fisheries through environmental and habitat evaluation, enhancement and rehabilitation, aquaculture, genetically modified fishes and sustainability. The book thoroughly reviews the negative impacts on fisheries including excessive harvesting, climate change, toxicology, impoundments, barriers and abstractions, non-native species and eutrophication. Finally, key areas of future research are outlined. Freshwater Fisheries Ecology is truly a landmark publication, containing contributions from over 100 leading experts and supported by the Fisheries Society of the British Isles. The global approach makes this book essential reading for fish biologists, fisheries scientists and ecologists and upper level students in these disciplines. Libraries in all universities and research establishments where biological and fisheries sciences are studied and taught should have multiple copies of this hugely valuable resource. About the Editor John Craig is Editor-in-Chief of the Journal of Fish Biology and has an enormous range of expertise and a wealth of knowledge of freshwater fishes and their ecology, having studied them around the globe, including in Asia, North America, Africa, the Middle East and Europe. His particular interests have been in population dynamics and life history strategies. He is a Fellow of the Linnean Society of London and the Royal Society of Biology.

Ecological Dynamics of Tropical Inland Waters

Author : Jack F. Talling
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A synthesis of tropical freshwater systems which illustrates the basic theory of freshwater biology.

Sustainable Fish Production in Lake Nasser

Author : John F. Craig
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Fish and Fisheries of Lakes and Reservoirs in Southeast Asia and Africa

Author : ASEAN-EEC Aquaculture Development and Coordination Programme
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Ecology of Fresh Waters

Author : Brian Moss
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This new edition of an established textbook provides a comprehensive and stimulating introduction to rivers, lakes and wetlands, and was written as the basis for a complete course on freshwater ecology. Designed for undergraduate and early postgraduate students who wish to gain an overall view of this vast subject area, this accessible guide to freshwater ecosystems and man's activities will also be invaluable to anyone interested in the integrated management of freshwaters. The author maintains the tradition of clarity and conciseness set by previous editions, and the text is extensively illustrated with photographs and diagrams. Examples are drawn from the author's experience in many parts of the world, and the author continues to stress the human influence. The scientific content of the text has been fully revised and updated, making use of the wealth of data available since publication of the last edition. Professor Brian Moss is a lecturer in Applied Ecology at the University of Liverpool, and has written three previous editions of this well-established textbook.

Africa Environment Outlook

Author : Naciones Unidas. Programa para el desarrollo
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This publication is a complementary document to the Africa Environment Outlook report (ISBN 9280721011) and focuses on the interaction between the local environment and human livelihoods. The publication is divided into two sections: case studies explaining how various types of environmental change impact on people making them vulnerable to poverty, food security and diseases; and examples of interventions carried out to reduce environmental degradation and human vulnerability, providing lessons and recommendations for future actions.

Ancient Lakes Biodiversity Ecology and Evolution

Author : Andrew Rossiter
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Ancient lakes are currently a topic of great international interest. They are renowned as hotspots of biodiversity, their habitats being unparalleled 'natural laboratories' in which to study the mechanisms of evolution and speciation in situ This volume provides a taxonomically and geographically diverse overview of the latest research on the biodiversity, ecology and evolution of organisms in ancient lakes. In over thirty chapters written by an international group of expertise with hands-on expertise of their topics, it places emphasis on the unique biological importance of these biotas, with their high species diversity and endemism. Copyright © Libri GmbH. All rights reserved.

Environmental Impacts of Cage Aquaculture in the Southeast Arm of Lake Malawi

Author : Mangaliso John Gibson Symon Gondwe
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Lake Malawi is a great lake not only because of its size (30,800 km2) but also because of its unique fish diversity. The lake contains the highest number of freshwater fish species in the world. The fish species are hypothesized to have radiated within the lake, which is 1-2 million years old. The collapse of the capture fishery in Lake Malawi between the 1970s and 1990s led to the launch of cage culture of indigenous fish species in 2004 in the south east arm of the lake. While cage culture has been practiced for many years in temperate lakes and seas, the fish farm in Lake Malawi is the first in the African Great Lakes and, therefore, not much information currently exists that is relevant to the impact of cage culture on such a large, species-rich tropical lake. Consequently, a study was done between January and December, 2007, at the fish farm in Lake Malawi to determine potential impacts of cage wastes on the environment. The study found that, just like in temperate systems where 70-87% of C, N and P added through feed get dispersed into the environment, discharges from fish cages in Lake Malawi were between 71-88% of the nutrients added through feed. The discharges were proportional to the amount of feed added so that as production and feed supply increase over time, more cage wastes would be generated and released into the environment. The discharges were exacerbated by poor stocking and feeding regimes. Production periods were longer (mean of 376"42 days) than if recommended stocking and feeding rates were followed. Feed quality may also have affected production performance and waste generation in the cages, but was not studied. The cage wastes were incorporated into the food web and support the wild fishes in the vicinity of the fish farm. Impacts of the cage wastes on the water column and sediments in the vicinity of the cages were minimal during the study period, probably because of rapid and efficient dispersion of the wastes by strong water currents, that averaged 9.3 cm s-1, through the cages and high consumption of the cage wastes by large numbers of wild fishes which aggregated around the cages. The wild fishes also helped to disperse the cage wastes over a larger area through consumption, translocation and defecation. However, as production increases, the amount of cage wastes generated may overwhelm mitigation by dispersion by water currents and consumption by wild fishes, particularly if many cages are deployed close together and interfere with current flows. Based on my observations, a fish farm that produces 15,000 tonnes fish/yr in Lake Malawi would generate 1249, 113 and 21 megamoles/yr of C, N and P, respectively, that are comparable or higher than DOC, TDN and TDP loadings observed in the most disturbed large river systems draining into Lake Malawi. The impacts of these river systems in Lake Malawi have been well documented, particularly around river mouths and in the more densely populated and shallower southern portion of the lake, where algal communities and their sedimentation rates have begun to change. Cage culture discharges may accelerate these changes.

The Cichlid Fishes of the Great Lakes of Africa Their Biology and Evolution

Author : Geoffrey Fryer
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Biodiversity of the Zambezi Basin Wetlands Main report

Author : Jonathan Timberlake
File Size : 46.20 MB
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Proceedings of the International Conference on African Fish and Fisheries

Author :
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Freshwater Forum

Author :
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