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For several years there has been a growing interest in understanding the dynamics of parasites in ecosystems, as well as the diversity of ways in which they influence ecosystem functioning through their effects on host populations and communities. 'Parasitism and Ecosystems' summarises current knowledge

"Cover " -- "Half Title " -- "Title Page " -- "Copyright Page " -- "The Editors" -- "Contributors" -- "Preface" -- "Table of Contents " -- "PART ONE: IMPACT OF MULTIPLE STRESSES ON ECOSYSTEMS" -- "Chapter 1: Evaluation and Impact of Multiple-Stressors on Ecosystems: Three Classic Case Histories" -- "Chapter 2: Extrapolation and Scaling in Ecotoxicology" -- "Chapter 3: A Framework for Evaluating Organism Responses to Multiple Stressors: Mechanisms of Effect and Importance of Modifying Ecological Factors" -- "Chapter 4: Forest Ecosystems and Air Pollution: The Importance of Multiple Stress Interactions on a Regional and Global Scale" -- "Chapter 5: Multiple Environmental Stresses on the Fragile Lake Tahoe Ecosystem" -- "PART TWO: ESTABLISHING THE HEALTH OF ECOSYSTEMS" -- "Chapter 6: Ecosystem Health: Some Perspectives" -- "Chapter 7: Physiology and Ecological Health" -- "Chapter 8: Biomarkers: Are There Linkages to Ecological Effects?" -- "Chapter 9: Establishing the Health of Ecosystems" -- "Chapter 10: Establishing the Health of Ecosystems: The Role of Risk Assessment" -- "Chapter 11: Stressors in the Marine Environment" -- "Chapter 12: An Attempt to Explain Ecological Health with a Metaphor" -- "Chapter 13: Future Directions for Ecotoxicological Methods" -- "PART THREE: FUTURE METHODS IN ECOTOXICOLOGY" -- "Chapter 14: Development and Application of Immunoassays for Biological and Environmental Monitoring" -- "Chapter 15: Using Surface Probe Localized 31P NMR Spectroscopy to Understand Sublethal Environmental Actions

During February 2000, the Churchill Northern Studies Centre hosted the Fourth Circumpolar Ecosystems Conference and Workshop. ., the objective of the Circumpolar Ecosystems meeting was to bring together Northerners and scientists to exchange information and discuss relevant options for sharing indigenous knowledge and scientific research. This has been done in the traditional winter environment that dominates northern processes and lifestyles. A number of themes were developed at the meeting. One theme was adaptation to the changing climate. Although in general the ongoing warming has brought a decline in the period of annual snow and ice cover, the timing of seasons has become unpredictable. Changes in large-scale atmospheric circulation have been associated with a greater input of contaminants from southern latitudes, which is a major cause of concern. Another theme was that the approach to the coastal marine environments must be consolidated. For example, aspects of the Hudson Bay ecosystem involve the jurisdictions of three provinces and one territory, as well as aboriginal, federal, and international jurisdictions. It was suggested that a cooperative framework is needed in approaching systems like that of Hudson Bay. The final theme was that we need strong north-south communication and the establishment of a comprehensive northern ecological monitoring and assessment network in support of the issues relating to the other themes. The discussions relating specifically to Hudson Bay have been published by the Churchill Northern Studies Centre (2000) as a report entitled "Addressing Climate Change in Hudson Bay: An Integrated Approach." .

There is a general lack of understanding of the role of lipids in aquatic ecosystems. The fundamental purpose of this book is to synthesize the divergent literature on aquatic lipids into a coordinated, digestible form. A large part of the book addresses lipid composition and production in freshwater organisms, with chapters on phytoplankton, zooplankton and benthic invertebrates. A common theme throughout the book is the function of lipids in aquatic food webs, with a chapter devoted exclusively to lipids as indicators of health in fish populations. A complementary chapter highlights the role of lipids and essential fatty acids in mariculture. Methodologies to determine the lipid content of aquatic samples and suggestions as to the utility of fatty acids as trophic markers are provided. There is a chapter on the role of lipids in the bioaccumulation and bioconcentration of toxicants and another on the relationships between lipids and surface films and foams. The final chapter highlights the similarities and differences between lipids of marine and freshwater origin. Students and researchers in ecology, phycology, aquatic toxicology, physiological ecology and limnology will find this an invaluable guide and reference