Lipids in Aquatic Ecosystems provides a comprehensive summary of the most recent literature on the role of lipids in aquatic systems from many world experts. Essential fatty acids (EFAs), or omega-3 and omega-6 fatty acids as they are known in the popular press, have garnered considerable attention in the technical and popular literature during the last decade. Lipids are important energy storage molecules in most organisms. However, equally or even more important, specific lipids (e.g. EFAs) play critical roles in a wide range of physiological processes such as regulating the structural properties of cell membranes and serving as precursors to eicosanoid signaling molecules (i.e. prostaglandins, prostacyclins, the thromboxanes and the leukotrienes). It is well established the EFAs have important impacts on human health, and it is widely agreed that the classic "Western diet" is particularly imbalanced vis-à-vis foods containing omega-3 versus omega-6 fatty acids. But beyond the specialist literature, it is not widely known that the most physiologically important long chain, polyunsaturated omega-3 fatty acids, i.e. eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are produced de novo principally by aquatic algae. Furthermore, within aquatic ecosystems these molecules may be synthesized from precursor fatty acid molecules and/or concentrated as they are conveyed to animals consumed by humans. For example, in salmonid fish DHA and EPA constitute ~40% of total fatty acids, whereas in typical marine and freshwater phytoplankton EPA and DHA account for between 2% and 20% of total fatty acids. In humans, EPA and DHA play key roles in heart health, immune and inflammatory responses, visual acuity as well being major components of neurological tissues such as the brain and spinal cord. This realization has prompted great concern in the fisheries management community that the world's natural supply of EPA and DHA is being overexploited. There is also concern that global climate change and/or eutrophication processes may be modifying the production and availability of these molecules in aquatic ecosystems.

"Evidence now suggests that the roles of essential fatty acids as growth promoters and as indices of health and nutrition are fundamentally similar in freshwater and marine ecosystems. Lipids in Aquatic Ecosystems integrates this divergent literature into a coordinated, digestible form.Chapters are organized so as to discuss and synthesize the flow of lipids from lower to higher trophic levels, up to and including humans. Linkages between the production, distribution and pathways of these essential compounds within the various levels of the aquatic food webs, and their ultimate uptake by humans and other terrestrial organisms, are highlighted throughout the book. This book will be of interest to researchers and resource managers working with aquatic ecosystems."

Algal lipids and effect of the environment on their biochemistry.- Formation and Transfer of Fatty Acids in Aquatic Microbial Food Webs: Role of Heterotrophic Protists.- Ecological significance of sterols in aquatic food webs.- Fatty acids and oxylipins as semiochemicals.- Integrating lipids and contaminants in aquatic ecology and ecotoxicology.- Crustacean zooplankton fatty acid composition.- Fatty Acid Ratios in Freshwater Fish, Zooplankton and Zoobenthos - Are There Specific Optima?.- Preliminary estimates of the export of omega-3 highly unsaturated fatty acids (EPA+DHA) from aquatic to terrestrial ecosystems.- Biosynthesis of polyunsaturated fatty acids in aquatic ecosystems: general pathways and new directions.- Health and condition in fish: the influence of lipids on membrane competency and immune response.- Lipids in marine copepods: latitudinal characteristics and perspective to global warming.- Tracing aquatic food webs using fatty acids: from qualitative indicators to quantitative determination.- Essential fatty acids in aquatic food webs.- Human life: caught in the food web.