Variability And Asynchrony In Salmon Returns

Download Variability And Asynchrony In Salmon Returns full books in PDF, epub, and Kindle. Read online Variability And Asynchrony In Salmon Returns ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!

Variability and Asynchrony in Salmon Returns

Author : Brooke M. Davis
Publisher :
ISBN 13 :
Total Pages : 74 pages
Book Rating : 4.:/5 (936 download)

DOWNLOAD NOW!

Book Synopsis Variability and Asynchrony in Salmon Returns by : Brooke M. Davis

Download or read book Variability and Asynchrony in Salmon Returns written by Brooke M. Davis and published by . This book was released on 2015 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pacific salmon are well-known for their unique life-history characteristics, complex population structures, and the wide range of ecosystem services they provide. Variability in life-history characteristics across and within species, along with their tendency to return to their natal sites, leads to phenotypically distinct populations that create portfolios of populations within watersheds. Pacific salmon are important for supporting valuable fisheries and for supporting key ecosystem processes in the marine and freshwater environment. Alaskan sockeye salmon populations display overall population stability despite large commercial harvests, a characteristic that has been attributed to their intact population complexity. Those fish that are not captured by the commercial fishery support key ecosystem processes in freshwater environments. This yearly, pulsed, resource subsidy provides a reliable source of food and nutrients to the watersheds where sockeye salmon spawn and die. These complex populations may pose challenges for management due to difficulties separating the contributions of individual populations or habitats to the overall population complex (or portfolio). In Chapter 1 we used abundance data for sockeye salmon (Oncorhynchus nerka) spawning in a set of eight streams in the Wood River watershed, southwest Alaska, to demonstrate how natural patterns of variability affect the ability of fixed assessment windows to characterize the contribution of an individual spawning population to the entire portfolio. Additionally, simulated data are used to explore how different levels of synchrony and autocorrelation affect the ability of monitoring schemes to estimate the contributions of individual populations to a portfolio. We find that the ability of fixed assessment windows to characterize a population's contribution to a portfolio is distinctly limited; asynchronous or independent dynamics among populations in a portfolio, and the presence of autocorrelation that creates slow changes in productivity, weaken the ability to characterize a stream's potential contribution to a portfolio. These results suggest that the structure of complex portfolios, and the presence of directional changes in productivity within individual populations, need to be taken into account when carrying out environmental risk assessments that aim to measure the contribution of an individual population or piece of habitat to dynamics observed at broader spatial and temporal scales. The reliable yearly pulse of marine-derived nutrients, in the form of spawning salmon, provides inland freshwater habitats with food and nutrients in the form of live fish, their gametes, and their carcasses. The highest quality food is provided by live fish and their eggs, which are important food sources for resident fish, bears, and birds, are only available for a short period. While the effects of this specific resource pulse are widely appreciated, little attention has been paid to the role that timing plays in conferring benefits to consumers, and previous research has mainly focused on biomass as the main control on the magnitude of effects. In Chapter 2 we used multiple in-stream counts of adult sockeye salmon abundance within the spawning season, and tagging data to estimate in-stream life span, to estimate how the amount of time that consumers have access to live salmon as a food resource is related to the adult spawner density in an individual stream. Our results demonstrate that duration of salmon availability as a food source is non-linearly related to escapement; across 3 orders of magnitude of spawner abundance, salmon were available to predators from about 2 weeks to about 5 weeks. This saturating relationship indicates that higher escapement values may not translate to proportionally higher benefits for consumers when these benefits are available during a fleeting window of opportunity. This result demonstrates that ecosystem based fisheries management (EBFM) of anadromous salmon should assume that benefits inferred to consumers are inherently time-mediated, and the numerical benefits of increased salmon density will not be straight-forward to estimate. Conservation strategies to maintain a range of spawn timing across watersheds may be the most successful for maintaining the importance of salmon subsidies in watersheds.

Populations in Varying Environments

Author : Lauren Ann Yamane
Publisher :
ISBN 13 : 9781369201086
Total Pages : pages
Book Rating : 4.2/5 (1 download)

DOWNLOAD NOW!

Book Synopsis Populations in Varying Environments by : Lauren Ann Yamane

Download or read book Populations in Varying Environments written by Lauren Ann Yamane and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This research aimed to understand the mechanisms underlying variability in population abundances over time. Many studies have suggested that age-structured demographic rates and interactions together with density-dependent regulation are important in determining how populations fluctuate in response to changes in the environment. More recent research has determined that through a phenomenon called cohort resonance, the combination of age-structure, density-dependence, and environmental stochasticity can result in population sizes fluctuating over two characteristic time scales. These time scales include short time scales equal to the mean population spawning age (i.e., generational frequencies), and also long time scales. These specific time scales of variability (the population's sensitivities to changing environmental conditions) have been found in empirical time series of cod and tuna abundances. Salmon populations also have demographic characteristics that make them particularly susceptible to cohort resonance. However, the potential importance of cohort resonance for salmon populations rests on whether supplementation with hatchery fish reduces the strength of the cohort resonance effect, and to what extent it might dampen the increase in variability associated with increased harvest rates (Chapter 1). Of additional importance in evaluating the potential for cohort resonance to drive salmon population variability is how life history characteristics might strengthen or diminish the effect. I examined how the central spawning age of the population and the fraction of spawners at that central age affect the sensitivity of populations to both low frequencies (environmental variability over long time scales) and generational frequencies (Chapter 2). Finally, I analyzed how temporal variability in the time series of subpopulations (specifically asynchrony) within a broader aggregate stock can lead to statistical dampening of variability at the stock level through the portfolio effect (Chapter 3). I developed a new metric, which quantifies the variability reduction possible with increased diversity among subpopulation dynamics (the Diversity Deficit; DD). I provide an example of applying this metric to retrospectively identify gains and losses in statistical independence for the Sacramento River Fall-run Chinook (SRFC) salmon stock. I found that compared to increased fishing levels, hatchery fish had a relatively small effect on the overall population variability (Chapter 1). However, the addition of hatchery fish to a population could alter the time scales of variability in salmon population time series, specifically magnifying fluctuations at intermediate to longer time scales. Such periods of population variability are normally reduced with higher levels of fishing. In addition, supplementation can be expected to have less of an effect on reversing the increased variability in abundances occurring over generational time scales. However, it is important to note that these effects occurred when populations were supplemented for extremely long periods of time. Analyses of the effects of the spawning age distribution revealed that higher central spawning ages increased population sensitivity to low frequencies, but had little impact on the generational frequencies (Chapter 2). The opposite was true for the fraction of central age spawners. Increasing the fraction of central age spawners did little to excite low frequency variability, but it greatly increased the population's propensity to exhibit sensitivity to generational frequencies. Analyses for the SRFC stock revealed that there has been an increase in the DD over time (Chapter 3). Thus, stock variability could have been reduced to a greater extent if independence among subpopulation dynamics had been restored. However, the mechanism of lost independence among subpopulation abundances is largely attributed to a rise in correlations with a single subpopulation, early in the time series.

Return to the River

Author : Richard N. Williams
Publisher : Elsevier
ISBN 13 : 0080454305
Total Pages : 720 pages
Book Rating : 4.0/5 (84 download)

DOWNLOAD NOW!

Book Synopsis Return to the River by : Richard N. Williams

Download or read book Return to the River written by Richard N. Williams and published by Elsevier. This book was released on 2005-11-21 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt: Return to the River will describe a new ecosystem-based approach to the restoration of salmon and steelhead populations in the Columbia River, once one of the most productive river basins for anadromous salmonids on the west coast of North America. The approach of this work has broad applicability to all recovery efforts throughout the northern hemisphere and general applicability to fisheries and aquatic restoration efforts throughout the world. The Pacific Northwest is now embroiled in a major public policy debate over the management and restoration of Pacific salmon. The outcome of the debate has the potential to affect major segments of the region's economy - river transportation, hydroelectric production, irrigated agriculture, urban growth, commercial and sport fisheries, etc. This debate, centered as it is on the salmon in all the rivers, has created a huge demand for information. The book will be a powerful addition to that debate. A 15 year collaboration by a diverse group of scientists working on the management and recovery of salmon, steelhead trout, and wildlife populations in the Pacific Northwest Includes over 200 figures, with four-color throughout the book Discusses complex issues such as habitat degradation, juvenile survival through the hydrosystem, the role of artificial production, and harvest reform

Influence of Environmental Variability on Chinook Salmon and Coho Salmon Population Dynamics

Author : David Patrick Kilduff
Publisher :
ISBN 13 : 9781303792144
Total Pages : pages
Book Rating : 4.7/5 (921 download)

DOWNLOAD NOW!

Book Synopsis Influence of Environmental Variability on Chinook Salmon and Coho Salmon Population Dynamics by : David Patrick Kilduff

Download or read book Influence of Environmental Variability on Chinook Salmon and Coho Salmon Population Dynamics written by David Patrick Kilduff and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding how different populations respond to a variable environment is necessary to anticipate and evaluate population persistence as environmental conditions change, possibly through climate change. To understand specifically how atmospheric and oceanographic processes translate to fluctuations in age-structured populations requires knowledge of temporal and spatial variability patterns in both the population and environmental signals, and a mechanistic understanding of how that variability acts in age-structured populations. Recruitment and abundance in many Pacific salmon populations covary with indices of ocean productivity; however, exactly how environmental forcing interacts with population dynamic mechanisms to produce fluctuations remains unclear, which impedes effective management and conservation. This dissertation examines how patterns of ocean survival in Chinook salmon (Oncorhynchus tshawytscha) have changed in recent decades (Chapter 1), identifies a new link between changes observed in low-frequency Pacific oceanographic and climatic conditions that affects both coho salmon (O. kisutch) and Chinook salmon (Chapter 2), and describes how the power spectrum of environmental variability in survival rates influences population persistence in an age-structured population model using spring-run Chinook salmon from Butte Creek, California as an example (Chapter 3). In Chapter 1, I show that the spatial and temporal covariability in Chinook salmon ocean survival rates has increased along the west coast of North America from 1980 to 2006. In Chapter 2, I show that the dominant mode of variability in ocean survival of both Chinook and coho salmon covaries with the North Pacific Gyre Oscillation, an important index of ecosystem productivity in the northeast Pacific Ocean that is linked to changing climatic forcing in the tropical Pacific Ocean. In Chapter 3, I show that the spectrum of environmental variability matters in understanding population variability and extinction risk of age-structured populations in terms of cohort resonance.

Ecology

Author : Michael Begon
Publisher : John Wiley & Sons
ISBN 13 : 1119279372
Total Pages : 864 pages
Book Rating : 4.1/5 (192 download)

DOWNLOAD NOW!

Book Synopsis Ecology by : Michael Begon

Download or read book Ecology written by Michael Begon and published by John Wiley & Sons. This book was released on 2020-11-11 with total page 864 pages. Available in PDF, EPUB and Kindle. Book excerpt: A definitive guide to the depth and breadth of the ecological sciences, revised and updated The revised and updated fifth edition of Ecology: From Individuals to Ecosystems – now in full colour – offers students and practitioners a review of the ecological sciences. The previous editions of this book earned the authors the prestigious ‘Exceptional Life-time Achievement Award’ of the British Ecological Society – the aim for the fifth edition is not only to maintain standards but indeed to enhance its coverage of Ecology. In the first edition, 34 years ago, it seemed acceptable for ecologists to hold a comfortable, objective, not to say aloof position, from which the ecological communities around us were simply material for which we sought a scientific understanding. Now, we must accept the immediacy of the many environmental problems that threaten us and the responsibility of ecologists to play their full part in addressing these problems. This fifth edition addresses this challenge, with several chapters devoted entirely to applied topics, and examples of how ecological principles have been applied to problems facing us highlighted throughout the remaining nineteen chapters. Nonetheless, the authors remain wedded to the belief that environmental action can only ever be as sound as the ecological principles on which it is based. Hence, while trying harder than ever to help improve preparedness for addressing the environmental problems of the years ahead, the book remains, in its essence, an exposition of the science of ecology. This new edition incorporates the results from more than a thousand recent studies into a fully up-to-date text. Written for students of ecology, researchers and practitioners, the fifth edition of Ecology: From Individuals to Ecosystems is anessential reference to all aspects of ecology and addresses environmental problems of the future.

Ecology, Genetics and Evolution of Metapopulations

Author : Ilkka A. Hanski
Publisher : Academic Press
ISBN 13 : 0080530699
Total Pages : 717 pages
Book Rating : 4.0/5 (85 download)

DOWNLOAD NOW!

Book Synopsis Ecology, Genetics and Evolution of Metapopulations by : Ilkka A. Hanski

Download or read book Ecology, Genetics and Evolution of Metapopulations written by Ilkka A. Hanski and published by Academic Press. This book was released on 2004-05-17 with total page 717 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ecology, Genetics and Evolution of Metapopulations is acollection of specially commissioned articles that looks at fragmented habitats, bringing together recent theoretical advances and empirical studies applying the metapopulation approach. Several chapters closely integrate ecology with genetics and evolutionary biology, and others illustrate how metapopulation concepts and models can be applied to answer questions about conservation, epidemiology, and speciation. The extensive coverage of theory from highly regarded scientists and the many substantive applications in this one-of-a-kind work make it invaluable to graduate students and researchers in a wide range of disciplines. Provides a comprehensive and authoritative account of all aspects of metapopulation biology, integrating ecology, genetics, and evolution Developed by recognized experts, including Hanski who won the Balzan Prize for Ecological Sciences Covers novel applications of the metapopulation approach to conservation

Estuarine variability

Author : Douglas A. Wolfe
Publisher : Elsevier
ISBN 13 : 1483289389
Total Pages : 524 pages
Book Rating : 4.4/5 (832 download)

DOWNLOAD NOW!

Book Synopsis Estuarine variability by : Douglas A. Wolfe

Download or read book Estuarine variability written by Douglas A. Wolfe and published by Elsevier. This book was released on 2013-10-22 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt: Approx.509 pages

Principles of Salmonid Culture

Author : W. Pennell
Publisher : Elsevier
ISBN 13 : 0080539661
Total Pages : 1071 pages
Book Rating : 4.0/5 (85 download)

DOWNLOAD NOW!

Book Synopsis Principles of Salmonid Culture by : W. Pennell

Download or read book Principles of Salmonid Culture written by W. Pennell and published by Elsevier. This book was released on 1996-10-11 with total page 1071 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

The Atlantic Salmon

Author : Eric Verspoor
Publisher : John Wiley & Sons
ISBN 13 : 0470995831
Total Pages : 520 pages
Book Rating : 4.4/5 (79 download)

DOWNLOAD NOW!

Book Synopsis The Atlantic Salmon by : Eric Verspoor

Download or read book The Atlantic Salmon written by Eric Verspoor and published by John Wiley & Sons. This book was released on 2008-04-15 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atlantic Salmon is a cultural icon throughout its North Atlantic range; it is the focus of probably the World’s highest profile recreational fishery and is the basis for one of the World’s largest aquaculture industries. Despite this, many wild stocks of salmon are in decline and underpinning this is a dearth of information on the nature and extent of population structuring and adaptive population differentiation, and its implications for species conservation. This important new book will go a long way to rectify this situation by providing a thorough review of the genetics of Atlantic salmon. Sponsored by the European Union and the Atlantic Salmon Trust, this book comprises the work of an international team of scientists, carefully integrated and edited to provide a landmark book of vital interest to all those working with Atlantic salmon.

Routledge Handbook of Ecosystem Services

Author : Marion Potschin
Publisher : Routledge
ISBN 13 : 1317687035
Total Pages : 929 pages
Book Rating : 4.3/5 (176 download)

DOWNLOAD NOW!

Book Synopsis Routledge Handbook of Ecosystem Services by : Marion Potschin

Download or read book Routledge Handbook of Ecosystem Services written by Marion Potschin and published by Routledge. This book was released on 2016-01-22 with total page 929 pages. Available in PDF, EPUB and Kindle. Book excerpt: The idea that nature provides services to people is one of the most powerful concepts to have emerged over the last two decades. It is shaping our understanding of the role that biodiverse ecosystems play in the environment and their benefits for humankind. As a result, there is a growing interest in operational and methodological issues surrounding ecosystem services amongst environmental managers, and many institutions are now developing teaching programmes to equip the next generation with the skills needed to apply the concepts more effectively. This handbook provides a comprehensive reference text on ecosystem services, integrating natural and social science (including economics). Collectively the chapters, written by the world's leading authorities, demonstrate the importance of biodiversity for people, policy and practice. They also show how the value of ecosystems to society can be expressed in monetary and non-monetary terms, so that the environment can be better taken into account in decision making. The significance of the ecosystem service paradigm is that it helps us redefine and better communicate the relationships between people and nature. It is shown how these are essential to resolving challenges such as sustainable development and poverty reduction, and the creation of a green economy in developing and developed world contexts.

Population Dynamics for Conservation

Author : Louis W. Botsford
Publisher : Oxford University Press
ISBN 13 : 0191075914
Total Pages : 352 pages
Book Rating : 4.1/5 (91 download)

DOWNLOAD NOW!

Book Synopsis Population Dynamics for Conservation by : Louis W. Botsford

Download or read book Population Dynamics for Conservation written by Louis W. Botsford and published by Oxford University Press. This book was released on 2019-09-26 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: The management and conservation of natural populations relies heavily on concepts and results generated from models of population dynamics. Yet this is the first book to present a unified and coherent explanation of the underlying theory. This novel text begins with a consideration of what makes a good state variable, progressing from the simplest models (those with a single variable such as abundance or biomass) to more complex models with other key variables of population structure (including age, size, life history stage, and space). Throughout the book, attention is paid to concepts such as population variability, population stability, population viability/persistence, and harvest yield. Later chapters address specific applications to conservation such as recovery planning for species at risk, fishery management, and the spatial management of marine resources. Population Dynamics for Conservation is suitable for graduate-level students. It will also be valuable to academic and applied researchers in population biology. This overview of population dynamic theory can serve to further their population research, as well as to improve their understanding of population management.

Evolution Illuminated

Author : Andrew P. Hendry
Publisher : Oxford University Press, USA
ISBN 13 : 019514385X
Total Pages : 521 pages
Book Rating : 4.1/5 (951 download)

DOWNLOAD NOW!

Book Synopsis Evolution Illuminated by : Andrew P. Hendry

Download or read book Evolution Illuminated written by Andrew P. Hendry and published by Oxford University Press, USA. This book was released on 2004 with total page 521 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work gives a critical overview on the evolution and population biology of salmon and their relatives. It should appeal to investigators in each of the scientific disciplines it integrates - evolutionary biology, ecology, salmonid biology, management and conservation. Variation in salmonids can be used to illustrate virtually all evolution.

The Behavior and Ecology of Pacific Salmon and Trout

Author : Thomas P. Quinn
Publisher : UBC Press
ISBN 13 : 0774842431
Total Pages : 392 pages
Book Rating : 4.7/5 (748 download)

DOWNLOAD NOW!

Book Synopsis The Behavior and Ecology of Pacific Salmon and Trout by : Thomas P. Quinn

Download or read book The Behavior and Ecology of Pacific Salmon and Trout written by Thomas P. Quinn and published by UBC Press. This book was released on 2011-11-01 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Behavior and Ecology of Pacific Salmon and Trout explains the patterns of mate choice, the competition for nest sites, and the fate of the salmon after their death. It describes the lives of offspring during the months they spend incubating in gravel, growing in fresh water, and migrating out to sea to mature. This thorough, up-to-date survey should be on the shelf of everyone with a professional or personal interest in Pacific salmon and trout. Written in a technically accurate but engaging style, it will appeal to a wide range of readers, including students, anglers, biologists, conservationists, legislators, and armchair naturalists.

Atlantic Salmon Ecology

Author : Øystein Aas
Publisher : John Wiley & Sons
ISBN 13 : 1444348191
Total Pages : 492 pages
Book Rating : 4.4/5 (443 download)

DOWNLOAD NOW!

Book Synopsis Atlantic Salmon Ecology by : Øystein Aas

Download or read book Atlantic Salmon Ecology written by Øystein Aas and published by John Wiley & Sons. This book was released on 2011-07-05 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Atlantic salmon is one of the most prized and exploited species worldwide, being at the centre of a massive sports fishing industry and increasingly as the major farmed species in many countries worldwide. Atlantic Salmon Ecology is a landmark publication, both scientifically important and visually attractive. Comprehensively covering all major aspects of the relationship of the Atlantic salmon with its environment, chapters include details of migration and dispersal, reproduction, habitat requirements, feeding, growth rates, competition, predation, parasitsm, population dynamics, effects of landscape use, hydro power development, climate change, and exploitation. The book closes with a summary and look at possible future research directions. Backed by the Norwegian Research Council and with editors and contributors widely known and respected, Atlantic Salmon Ecology is an essential purchase for all those working with this species, including fisheries scientists and managers, fish biologists, ecologists, physiologists, environmental biologists and aquatic scientists, fish and wildlife department personnel and regulatory bodies. Libraries in all universities and research establishments where these subjects are studied and taught should have copies of this important publication. Comprehensive and up-to-date coverage of Atlantic Salmon Atlantic Salmon is one of the world's most commercially important species Backed by the Norwegian Research Council Experienced editor and internationally respected contributors

Michigan Discussions in Anthropology

Author :
Publisher :
ISBN 13 :
Total Pages : 168 pages
Book Rating : 4.3/5 (91 download)

DOWNLOAD NOW!

Book Synopsis Michigan Discussions in Anthropology by :

Download or read book Michigan Discussions in Anthropology written by and published by . This book was released on 1991 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Pacific Salmon Life Histories

Author : Cornelis Groot
Publisher : UBC Press
ISBN 13 : 9780774803595
Total Pages : 602 pages
Book Rating : 4.8/5 (35 download)

DOWNLOAD NOW!

Book Synopsis Pacific Salmon Life Histories by : Cornelis Groot

Download or read book Pacific Salmon Life Histories written by Cornelis Groot and published by UBC Press. This book was released on 1991 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Ecology of Atlantic Salmon and Brown Trout

Author : Bror Jonsson
Publisher : Springer Science & Business Media
ISBN 13 : 9400711891
Total Pages : 720 pages
Book Rating : 4.4/5 (7 download)

DOWNLOAD NOW!

Book Synopsis Ecology of Atlantic Salmon and Brown Trout by : Bror Jonsson

Download or read book Ecology of Atlantic Salmon and Brown Trout written by Bror Jonsson and published by Springer Science & Business Media. This book was released on 2011-05-03 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.