'A lake is the landscape's most beautiful and expressive feature. It is earth's eye; looking into which the beholder measures the depth of his own nature. The fluviatile trees next the shore are the slender eyelashes which fringe it, and the wooded hills and cliffs around are its overhanging brows.' 'A field of water betrays the spirit that is in the air. It is continually receiving new life and motion from above.' 'Nothing so fair, so pure, and at the same time so large, as a lake, perchance, lies on the surface ofthe earth. Sky water. It needs no fence. Nations come and go without defiling it. It is a mirror which no stone can crack, whose quicksilver will never wear off, whose gilding Nature continually repairs; no storms, no dust, can dim its surface ever fresh; - a mirror in which all impurity presented to its sinks, swept and dusted by the sun's hazy brush, - this the light dust-cloth, - which retains no breath that is breathed on it, but sends its own to float as clouds high above its surface, and be reflected in its bosom still.' (Henry David Thoreau: 'Walden; or Life in the Woods'. Fourth printing, April 1953, Ri!lehart & Company, New York).

Cell signalling lies at the heart of many biological processes and currently is the focus of intense research interest. In multicellular organisms, it is central to how different types of cell communicate with each other and how they detect and respond to extracellular signals. Intercellular communication is vital to single-celled organisms as well, allowing them to respond to environmental cues and signals.

To date, much of the understanding of signalling mechanisms has come from research on specific cell types (eg mouse lymphocyte and cardiomyocyte) or on organisms in which communication systems such as nervous and endocrine systems are well established. This volume therefore aims to 'fill the gap' by concentrating on 'simple organisms' where the elements of those signalling systems first evolved. Many of the groups covered contain important pathogens or parasites, and the potential for manipulating signalling pathways for therapeutic intervention will be highlighted.

Concentrations of dissolved organic matter (DOM) in lakes are often an order of magnitude greater than concentrations of particulate organic matter; nevertheless, the biogeochemical analysis of DOM is described in only a few textbooks on limnology (most thoroughly by Wetzel). The orgins of dissolved organic substances are largely photosynthetic; DOM is either autochthonously synthesized by littoral and pelagic flora through secretions and autolysis of cellular contents, or allochthonously generated in terrestrial systems of the drainage basin, composing largely of humic substances refractory to rapid microbial degradation. The role of DOM in lacustrine ecosystems, as energy source and system regulator, however, is still poorly known. The aim of this book is: (1) to present state-of-the-art reviews of the role of dissolved autochthonous and allochthonous organic matter in pelagial and littoral zones; and (2) to focus attention on poorly understood but critical topics and hence to provide direction for future research activity.

The Netherlands, like the other industrialized countries in the northern hemisphere, is faced with increas ing environmental pro blems. Being a country rich in water - at least in terms of surface area - and low-lying, problems related to water are as old as the nation itself. The problems in regard to water quality are becoming more acute and complicated due to the progressive rise in air and ground pollution. Glaring examples are the acid rains and contamination of ground-water resources by toxic, and often illegal, waste dumps. Being a delta country, the Netherlands is also very vulnerable to pollution from the*water sources outside the country's national boundaries, i.e. the rivers Rhine, Meuse and ScheIdt. Not only the national but also the international authorities are active in developing measures to both prevent and combat water pollution, and to restore as far as possible the natural balance or a 'reasonable' water quality. The pollution abatement programmes are based on ecological theories; accepting waterbodies as aquatic ecosystems, the authorities concerned try to influence and lead the progresses in the systems to reach or maintain the desired ecosystem structure. Suter II (1981) mentioned a number of reasons why the attempts to use ecosystem theories to assess the impacts on the environment have been disappointing to date. It is clear that one of the reasons for the failure is lack of proper knowledge.

Estuaries exist along the edge of the oceans and seas, and are char acterized by the dilution of sea water by inflowing fresher waters. The motion and interaction of these two types of water (fresh and salt water) determine the salinity distribution within the estuary and that, in turn, affects the organisms residing there. The purpose of this vol ume is to review the status of our understanding of estuarine circu lation and how the circulation patterns affect living and nonliving resources in estuaries. For many years, the primary paradigm for estuarine circulation was the two-layered net or nontidal gravitational circulation pattern first proposed by Dr. Donald Pritchard in his studies of the James River estuary. During the last decade or so, research has focused on the many variations about this theme and the factors that control the transport processes. Many of these aspects are covered in the initial papers in this volume. Water movement, of course, is of interest be cause it transports marine organisms, sediments, and pollutants. Es tuarine circulation has a significant effect on estuarine food chains, and on the distribution and abundance of organisms, such as the American oyster, that are freely transported by the currents during larval stages. The intent is to bring together many of these topics in a single volume. This volume is dedicated to Dr. Donald W."

Based on research in Bolinao, this book assesses the importance of small-scale disturbance by burrowing shrimps. It covers the distribution of burrowing shrimp disturbance, the behavior of the snapping shrimp Alpheus macellarius in situ and as observed from tank experiments, and the effects of short-term burial and leaf clipping on the growth patterns of the dominant seagrass Thalassia hemprichii. The book examines the role of bioturbation by burrowing shrimps in seagrass meadows, foraging strategies of A. macellarius and its mutualistic symbiosis with Cryptocentrus spp., shrimp disturbance and T. hemprichii, and small-scale disturbance and large-scale dynamics.

This volume contains the Proceedings of the Third International Conference on Copepoda, held at the British Museum (Natural History) in London during August 1987. The central theme of the conference was the biology of marine planktonic copepods, although the scientific programme was extremely varied reflecting the wide range of life styles adopted by copepods. The three invited symposia held during the conference focussed attention on particular topical areas of research within the field of marine plankton, and also provided reviews of chosen aspects of copepod biology. These symposia were highly successful. The papers they contained were both informative and stimulating and they bring to this volume a lasting significance. Each symposium was organised by its chairman; Bruce Frost (University of Washington) decided on the balance of topics, selected the speakers and introduced the session on 'The biology and taxonomy of Calanus', Roger Harris (Marine Biological Association) performed the same vital role for 'Experimental studies: rate processes in field populations of planktonic copepods', and Howard Roe (Institute of Oceanographic Sciences) for 'Oceanic and deep-sea copepods'. The impact of these papers will be much enhanced by the large number of high quality contributed and poster papers on marine plankton and by the invited review of 'Copepod luminescence' by Peter Herring (Institute of Oceano graphic Sciences). The fascinating review of 'Copepod eyes' by Mike Land FRS (University of Sussex) is not published here."

P. G. Sly Canada Centre Inland Waters, P.O. Box 5050, Burlington, Ontario L7R 4A6, Canada Keywords: symposium, sediments, freshwater Following the highly successful First Symposium work of the symposium: on Research into the Interactions between Sedi- I. Summary of sediment dynamics and distribu- ments and Freshwater held in Amsterdam, in 1976, tion in fluvial and lacustrine environments. it was decided that a second symposium in this 2. Land use effects on sediment yields,and quality. series should be held to continue the discussions on 3. Sediments in mass balance models, including progress in this rapidly expanding field of aquatic total loadings. science. The Second Symposium was held at 4. Sediments as concentrating mechanisms of nat- Queen's University, Kingston, Ontario, between 15 ural and anthropogenic, organic and inorganic and 18 June 1981. It was originally intended to hold materials. the meeting in Toronto a year earlier, but because 5. Release mechanisms, and transfer to biosystem, of difficulties in planning and the high cost of ac- from bed and suspended solids. commodation it was necessary to revise the original 6. Short- and long-term dating methods, spatial program and schedule. and temporai consistency, bioturbation and dif- The symposium received generous support from fusion.

The mangrove, seagrass and coral reef ecosystems are of paramount ecological importance but have already undergone great degradation, which is advancing at an alarming rate. If present trends continue, the natural resource basis of the economy and ecology of tropical coastal regions will soon be ruined. This was the unanimous conclusion of the 110 scientists from 23 countries who gathered in Mombasa, Kenya, for a Symposium on the ecology of these ecosystems. Mangrove forest systems yield large amounts of fish, crabs, prawns and oysters. They are also valuable sources of fuelwood, timber, tannin and other natural products. Their non-marketable value is of equal importance: stabilization of the coastline, an indispensable nursery ground for numerous marine species with commercial value, a natural filter maintaining the clarity of nearshore water, a home for resident and migratory birds and other wildlife. Many of the true mangrove flora and fauna are now endangered by the clearing of the mangroves. It has been shown that in many countries between 25 and 100% of the mangrove forest has been destroyed alraedy in the last twenty years. The international scientific assembly concluded that much can be done to stop the degradation of these damaged ecosystems and to rehabilitate them. But new techniques must be found to use them on a sustainable basis for long-term economic return and for the well-being of coastal human settlements and a healthy environment.

The global scale of alien species invasions is becoming more and more evident in the beginning ofthe new millennium. Though the problem ofbiological invasions became a rapidly growing research area, there are large gaps still, both geographically and the matically, to be filled in the near future. This book is the first attempt to provide an overall picture of aquatic species invasions in Europe. Its geographical scope stretches from Irish waters in the west to Volga River and the Caspian Sea in the east, and from Mediterranean in the south up to the Arctic coast of Europe. Not all parts of the continent could be equally covered, as in some countries species invasions are not studied yet. The book tends to represent the array of all major European aquatic systems on the broadest geographical and ecological scope possible from fully saline seas, semi-enclosed brackish water bodies and coastallagoons to freshwater lakes, major river systems and waterways. The key objectives include the present status and impacts caused by non-native aquatic species in European waters. Please note that lengthy species lists submitted for publication and additional informa tion were put on the Internet, as the electronical version of these tables benefits from computer assisted search for data (http: //www. ku. lt/nemo/EuroAquaInvaders. htm). Altogether more than 100 scientists from 24 countries have joined to synthesize the available information on bioinvasions. However, the book does not claim to be fully comprehensive."

The Baltic Sea and its coastal zones have been intensively utilised for centuries. Settlements, industry, fisheries and trade are still concentrated in the coastal zones. Concurrently, the coast is a web of sensitive and highly valuable ecosystems which suffer from ongoing degradation. Increasing demands and pressures on coastal ecosystems require integrated coastal zone management. This book reflects the current state and problems of coastal ecosystems in the entire Baltic region, highlighting obstacles and future solutions for integrated management.

This is the first comprehensive study of an east African lake for thirty years. It represents the culmination of research expeditions which stretch back twenty years and is thus able to pick up long term changes which the individual research activities do not reveal. Lake Naivasha is a tropical lake whose natural fluctuations are now dwarfed by human impacts. Papers show how the irrigation for horticulture and power cooling has reduced the lake depth significantly; exotic arrivals have altered the plant community beyond recognition and its commercial value as a fishery and a tourist feature are reduced by over use. Despite this, the lake has considerable conservation value at present. It provides a different case study in the ever-growing library of the effects of human follies. Lake Naivasha has achieved global importance in the past ten years because its waters are used to sustain the largest horticultural industry in Africa. The book highlights its fragility under such pressure and points out the way towards sustainable use of the water and the ecosystem.

Increasing interest in marine biology and its relevance to environmental issues creates a demand for authoritative reviews of recent research. Oceanography and Marine Biology has addressed this demand for nearly 40 years. This annual review considers basics of marine research, special topics, and emerging new areas. Regarding the marine sciences as a unified field, the text features contributors who are actively engaged in biological, chemical, geological, and physical aspects of marine science. This edition includes a full color insert and covers such topics as the ecological status of the Great Barrier Reef, the effects of coral bleaching on fisheries, and the biology of octopus larvae.

'The criterion of true beauty', wrote Fulke Greville, 1st Baron of Burke, 'is that it increases on examination; if false, that it lessens. There is therefore something in true beauty that corresponds with right reason, and it is not the mere creation of fantasy.' The authors of this compact volume have increased the beauty of an area that is commonly and rightly ac knowledged to be one of the loveliest parts of the Great Lakes. They have done this by integrating the historical, industrial, and cultural influences on 'Lake Manitoulin' in sixteen manuscripts. It is enigmatic that Lake Huron, the second of the Great Lakes to be discovered by European explorers, has been the last to be adequately described Iimnologicaliy. As recently as 1966, for example, Alfred M. Beeton wrote in Limnology in North America: ' ... even a list of the more common species comprising the plankton of Lake Huron could be an original contribution to scientific literature.' Comparable statements could have been made for sediments, benthos, and water chemistry. This volume reflects a change of course and Georgian Bay and the North Channel of Lake Huron are now on the scientific map. Science is 'right reason'. Its application to Georgian Bay and the North Channel is a welcome and timely addition for the renewal of public, political, and scientific interest in the conservation of the Great Lakes."

This book addresses the needs of professional and amateur taxonomists on the subject of ascidians in Asia. This is the first book of its kind and features color illustrations done by the authors in Asia. This book provides a brief overview of ascidians in addition to both the taxonomy and distribution of ascidians along India's southern coast. It also opens a new arena for marine researchers in the field of ascidians in Asia. This book is the outcome of the authors' 15 years of research experience in the field of ascidians, making it very helpful for researchers, coastal planners, port authorities and the proper management of coastal thermal plants and atomic power plants.

The southwestern Amazon basin, centering on the Territory of Rondoenia and the State of Acre, is symbolically if not exactly geographically, the Wild Wild West of Brazil's northern rainforest fron tier. In Brazil the name Rondoenia evokes exaggerated images of lawlessness, land feuding, and indigent peasants in search of a homestead. Despite the problems and the perception, the region has pushed ahead, in the view of the govern ment, with large-scale deforestation and the establishment of cattle ranches and agricultural farms raising manioc, rice, bananas, and other cash crops. The mining industry has been launched with the exploitation oftin stone, and the recent gold rush has attracted thousands of miners that are sifting alluvial deposits along the rivers for the precious ore. In an energy-short world, the region boasts of its large hydroelectric potential waiting development in the rivers falling off the Brazilian Shield and draining into the Rio Madeira. Planners are optimistic that Rondoenia's resources, once developed, will more than justify, at least in this corner of the rainforest frontier, the Economic Conquest ofthe Amazon. Sandwiched between the economic take-off and the dream, however, are the biological resources - the plants and animals - that must serve as sources of energy and food until human dominated ecosystems replace naturaiones. These resources are, ofnecessity, being heavily attacked to support the shaky economy of the region, but they are very poorly understood in terms of potential productivity and proper management.

With increasing interest in the field and its relevance in global environmental issues, Oceanography and Marine Biology: An Annual Review provides authoritative reviews that summarize results of recent research in basic areas of marine research, exploring topics of special and topical importance while adding to new areas as they arise. This volume, part of a series that regards the all marine sciences as a complete unit, features contributions from experts involved in biological, chemical, geological, and physical aspects of marine science. Including a full color insert and an extensive reference list, the text is an essential reference for researchers and students in all fields of marine science.

This Workshop was organized to assess the status of knowledge on the behaviour of phosphorus in sediments and to define gaps and reassess research strategies, particularly with respect to prevalent methodology and future approach; and to define gaps and reassess research strategies for water management measures in aquatic ecosystems, especially in relation to the release of phosphorus from the sediments and its impact on the functioning of the whole system.

Sea Turtles: Field Research and Conservation is a comprehensive reference of experiences with sea turtle species from global experts. This book looks at the human side of protecting and studying these unique animals around the world, as well as the challenges involved, such as cultural differences and conducting research in remote locations. Led by a renowned expert in sea turtle conservation, this book addresses the largest issue facing sea turtle species currently; nearly all species of sea turtles are endangered due to poaching, fishing snares, climate change, and more. Chapters in this book range from the use of cutting-edge technology to learn more about this elusive reptile, to working with communities with long histories of sea turtle trade and consumption. It provides readers with firsthand accounts of sea turtle conservation efforts from conservationists based around the world and offers important suggestions and solutions for ensuring the future of these sea turtle species. Sea Turtles: Field Research and Conservation is the ideal resource for field biologist and marine conservationists, specifically those working in marine herpetology and with sea turtle species. Policymakers concerned with marine conservation, wildlife protection, and sustainable development, will also find this a useful reference for efforts and directions to enact change and save sea turtles from extinction.

The nemerteans are a fascinating, common and often locally abundant group of invertebrates, yet for long have attracted the attention of only a handful of scientists. In recent years, however, increasing numbers of people have developed diverse research interests in the group with the result that our knowledge of these worms has rapidly advanced. Clearly there is a need for a regular series of international meetings where individuals working on these animals can meet to exchange ideas, review developments concerning nemertean biology and freely discuss future proposals. The first such meeting was held in Philadelphia during December 1983. Twenty-seven scientists from eight countries participated in the Second International Meeting on Nemertean Biology, held at the Tjarno Marine Biological Laboratory, Sweden, 11-15 August 1986. The meeting was divid ed into five sessions: two dealt with ecological studies, two with nemertean taxonomy, and the final session covered aspects of general biology. A total of 26 papers was presented; four, by N. Anadem, G. Berg, 1. Bierne, and 1.M. TurbeviIIe, were for different reasons not submitted for inclusion in this volume. Three additional presentations were made on behalf of B. Kulikova, E. N. WiIImer, and Z. Yin, all of whom were unable to participate in the meeting.

This volume contains papers presented either in oral or poster form at the international symposium Limnology of Mountain Lakes', held at Stara Lesna (Slovakia) between 1 and 7 July 1991. Several papers covered contributions from the fields of physical and chemical limnology, palaeolimnology, zooplankton, phytoplankton and phytobenthos, and bacteria. Acidification, a process affecting water chemistry and biota of many mountain lakes in Europe was dealt with also. A series of papers on the lakes in Sumava has highlighted different aspects of these lakes, which are in the last stage of acidification. Other geographical areas covered extensively were the Tatras and the Alps. "

This series is dedicated to serving the growing community of scholars and practitioners concerned with the principles and applications of environ mental management. Each volume is a thorough treatment of a specific topic of importance for proper management practices. A fundamental objective of these books is to help the reader discern and implement man's stewardship of our environment and the world's renewable re sources. For we must strive to understand the relationship between man and nature, act to bring harmony to it, and nurture an environment that is both stable and productive. These objectives have often eluded us because the pursuit of other individual and societal goals has diverted us from a course of living in balance with the environment. At times, therefore, the environmental manager may have to exert restrictive control, which is usually best applied to man, not nature. Attempts to alter or harness nature have often failed or backfired, as exemplified by the results of imprudent use of herbicides, fertilizers, water, and other agents. Each book in this series will shed light on the fundamental and applied aspects of environmental management. It is hoped that each will help solve a practical and serious environmental problem."

The recent progress achieved in aquatic genomics research has important implications in science and aquaculture. Researchers' success in genome sequencing of the fugu has provided a foundation not only for comparative fish genomics but also for genetic studies of other vertebrates. This volume, with contributions by leading scientists from around the world, provides the latest information on genomic studies of a variety of aquatic organisms including fish, crustaceans, and shellfish, with descriptions of such methodologies as genome analysis, gene mapping, DNA markers, and EST analysis. Other topics include regulation of gene expression, stress and immune responses, sex differentiation, hormonal control, and transgenic fish. This book is a valuable resource for all scientists whose work involves aquatic organisms, especially for those in the fields of aquatic genomics, fish immunology, and aquatic biotechnology.