Destruction of habitat is the major cause for loss of biodiversity including variation in life history and habitat ecology. Each species and population adapts to its environment, adaptations visible in morphology, ecology, behaviour, physiology and genetics. Here, the authors present the population ecology of Atlantic salmon and brown trout and how it is influenced by the environment in terms of growth, migration, spawning and recruitment. Salmonids appeared as freshwater fish some 50 million years ago. Atlantic salmon and brown trout evolved in the Atlantic basin, Atlantic salmon in North America and Europe, brown trout in Europe, Northern Africa and Western Asia. The species live in small streams as well as large rivers, lakes, estuaries, coastal seas and oceans, with brown trout better adapted to small streams and less well adapted to feeding in the ocean than Atlantic salmon. Smolt and adult sizes and longevity are constrained by habitat conditions of populations spawning in small streams. Feeding, wintering and spawning opportunities influence migratory versus resident lifestyles, while the growth rate influences egg size and number, age at maturity, reproductive success and longevity. Further, early experiences influence later performance. For instance, juvenile behaviour influences adult homing, competition for spawning habitat, partner finding and predator avoidance. The abundance of wild Atlantic salmon populations has declined in recent years; climate change and escaped farmed salmon are major threats. The climate influences through changes in temperature and flow, while escaped farmed salmon do so through ecological competition, interbreeding and the spreading of contagious diseases. The authors pinpoint essential problems and offer suggestions as to how they can be reduced. In this context, population enhancement, habitat restoration and management are also discussed. The text closes with a presentation of what the authors view as major scientific challenges in ecological research on these species.

Pacific salmon are an important biological and economic resource of countries of the North Pacific rim. They are also a unique group of fish possessing unusually complex life histories. There are seven species of Pacific salmon, five occurring on both the North American and Asian continents (sockeye, pink, chum, chinook, and coho) and two (masu and amago) only in Asia. The life cycle of the Pacific salmon begins in the autumn when the adult female deposits eggs that are fertilized in gravel beds in rivers or lakes. The young emerge from the gravel the following spring and will either migrate immediately to salt water or spend one or more years in a river or lake before migrating. Migrations in the ocean are extensive during the feeding and growing phase, covering thousands of kilometres. After one or more years the maturing adults find their way back to their home river, returning to their ancestral breeding grounds to spawn. They die after spawning and the eggs in the gravel signify a new cycle. Upon this theme Pacific salmon have developed many variations, both between as well as within species. Pacific Salmon Life Histories provides detailed descriptions of the different life phases through which each of the seven species passes. Each chapter is written by a scientist who has spent years studying and observing a particular species of salmon. Some of the topics covered are geographic distribution, transplants, freshwater life, ocean life, development, growth, feeding, diet, migration, and spawning behaviour. The text is richly supplemented by numerous maps, illustrations, colour plates, and tables and there is a detailed general index, as well as a useful geographical index.

From guppies to Galapagos finches and from adaptive landscapes to haldanes, this compilation of contributed works provides reviews, perspectives, theoretical models, statistical developments, and empirical demonstrations exploring the tempo and mode of microevolution on contemporary to geological time scales. New developments, and reviews, of classic and novel empirical systems demonstrate the strength and diversity of evolutionary processes producing biodiversity within species. Perspectives and theoretical insights expand these empirical observations to explore patterns and mechanisms of microevolution, methods for its quantification, and implications for the evolution of biodiversity on other scales. This diverse assemblage of manuscripts is aimed at professionals, graduate students, and advanced undergraduates who desire a timely synthesis of current knowledge, an illustration of exciting new directions, and a springboard for future investigations in the study of microevolution in the wild.

As salmonids have been reared for more than a century in many countries, one might expect that principles are well established and provide a solid foundation for salmonid aquaculture. Indeed, some of the methods used today in salmonid rearing are nearly identical to those employed one hundred years ago. Areas of salmonid research today include nutrition, smolt and stress physiology, genetics and biotechnology.The purpose of this book is to provide a useful synthesis of the biology and culture of salmonid fishes. The important practices in salmonid culture as well as the theory behind them is described. This volume will be of interest to students, researchers, fisheries biologists and managers as well as practising aquaculturists.

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.