Download or read book Modelling the Growth of Northern Cod written by Zakiyah Mohammed and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We develop a body size growth model of Northern cod (Gadus morhua) in Northwest Atlantic Fisheries Organization (NAFO) Divisions 2J3KL during 2009-2013. We use individual length-at-age data from the bottom trawl survey in these divisions during 2009-2013. We use the Von Bertalanffy (VonB) model extended to account for between-individual variations in growth, and variations that may be caused by the methods which fish are caught and sampled for length and age measurements. We assume between-individual variation in growth appears because individuals grow at a different rate (k), and they achieve different maximum sizes (l∞). We also included measurement error in length and age in our model since ignoring these errors can lead to biased estimates of the growth parameters. We use the structural errors-invariables (SEV) approach to estimate individual variation in growth, ageing error variation, and the true age distribution of the fish. Our results shows the existence of individual variation in growth and ME in age. According to the negative log likelihood ratio (NLLR) test, the best model indicated: 1) different growth patterns across divisions and years. 2) Between individual variation in growth is the same for the same division across years. 3) The ME in age and true age distribution are different for each year and division.
Download or read book A Cohort Time series Von Bertalanffy Growth Model for Northern Cod Gadus Morhua and Estimation of the Age of Tagged Cod written by N. Cadigan and published by . This book was released on 2016 with total page 81 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atlantic Cod written by George A. Rose and published by John Wiley & Sons. This book was released on 2019-02-26 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive handbook, covering all aspects of the Atlantic cod including the biology, ecology, life histories, behaviour, commercial exploitation and conservation Not only is Atlantic cod one of the most valuable food fish in the world’s oceans, it is an important component of North Atlantic ecosystems and has been subject to much research into its biology, ecology and exploitation. After hundreds of years of exploitation, overfishing in the last half of the 20th Century caused many stocks to collapse, most famously the Northern cod stock off Newfoundland and Labrador, Canada. Since then, most cod stocks have been better researched and managed, but remain in a variety of states, from fully recovered to continued decline. This book, written by world experts, describes that research and management, and the importance of cod and its fisheries on North Atlantic cultures and economies, with impacts well beyond the range of the species. Atlantic Cod: Bio-Ecology of the Fish offers insightful chapter coverage of cod nomenclature, taxonomy, phylogeny and morphology; physiology and ecophysiology; reproduction and spawning behavior; early life history and pre-recruitment processes; migrations, movements and stock identity; feeding, growth and energetics; the place of cod in the ecosystem; the exploitation of cod through history and present day commercial fisheries and precautionary management for sustainable fisheries; impacts of climate change on cod biology and ecology; and the future of the species and its fisheries. Discusses the major commercial importance of Atlantic cod through history Provides a comprehensive treatment of the bio-ecology of the most researched and highly exploited fully marine species Examines how the decline (and recovery) of cod stocks is of great political and scientific interest An essential purchase for marine fisheries scientists Atlantic Cod: Bio-Ecology of the Fish is a vital book for all fisheries scientists, managers and fish biologists.
Download or read book A Cohort Time series Von Bertalanffy Growth Model for Northern Cod Gadus Morhua and Estimation of the Age of Tagged Cod written by and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Age cannot be determined at the time of tagging and it is usually not possible to determine the age at capture because fishermen only report the capture and they usually do not return the fish for age determination. [...] We estimate this model from survey growth data and use the model to estimate length at age (L@A) and to estimate the age of a tagged fish given the year and season (i.e. [...] In addition, the size of a cod in the spring may be considerably less than in the fall, especially for younger cod. [...] In this paper we develop a time-series VonB growth model to estimate the L@A of Northern cod from the various sizes that have been tagged and at the various times of the year and locations that tagging has occurred. [...] The model is designed to account for the features we identified in the exploratory data analyses above.
Download or read book Modelling Temperature Effects on Population specific Growth Patterns of Atlantic Cod Gadus Morhua written by Nadezhda Sokolova and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Human-induced climate change has been affecting oceans' temperatures for several decades (IPCC, 2014). Temperature is one of the most important environmental factors influencing metabolic rates and therefore development, growth and reproduction of terrestrial and marine organisms (Clarke, 2017). Growth rates of ectotherms (e.g. fish species) are expected to be altered by climate-induced temporal and spatial changes in ocean temperatures (Pörtner, 2010; Pörtner et al., 2014). Studies suggest that warming will have differential effects on fish body size with the major trend of reduction in mean species size across latitudes (Forster et al., 2012; Cheung et al., 2013; Audzijonyte et al., 2020). The thesis aims to bridge advanced knowledge and methodology of various kinds of research, such as climate physics and climate modelling, theoretical, experimental and observational biology, and biophysical modelling in order to investigate temperature effects on fish growth from both historical and future climate perspectives. In particular, the study is dedicated to the main subject - the role of different thermal environments in shaping the growth patterns of Atlantic cod (Gadus morhua) with the focus on the Northeast Atlantic populations. Additionally, the author addresses methodological aspects, advantages and limitations of a modelling study in a context of eco-physiological research and introduces an open source modelling tool that can help link findings from experimental (physiology) and observational (ecology) studies.
Download or read book Biology and Ecology of Atlantic Cod written by Nataliia Kulatska and published by CRC Press. This book was released on 2024-10-31 with total page 301 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atlantic cod is an important fish species in human history and continues to be a major influence on North Atlantic fisheries management, as stock collapses and recoveries impact coastal communities and shelf sea food webs. This book provides an overview of Atlantic cod biology and ecology, focussing on regional differences in life-history and stock dynamics that affect productivity and the challenges faced by management. By comparing the success of management approaches and the local influence of changing climate and food webs, the book highlights the different pressures facing stocks and identifies knowledge gaps across the species’ range.
Download or read book Estimation of Cod Gadus Morhua Growth in NAFO Subdiv 3Ps and Divs 3KL in 1997 99 from Tagging Experiments written by and published by . This book was released on 2000 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes & presents results from a model used for estimating growth of Atlantic cod in NAFO Subdivision 3Ps and Divisions 3KL during 1997-99. Information from tag returns from the commercial, sentinel, & food fisheries in these regions during 1997-99 is used to estimate growth based on known lengths-at-release & times-at-liberty. The model incorporates the Von Bertalanffy growth model, modified to accommodate seasonal variations in growth, as well as a measurement bias component. The basic approach has been studied fairly extensively in the fisheries literature, and the paper presents a review of this literature. Important biases in estimating growth from tagging data are identified, and the magnitude of the bias in the analysis is estimated using a simple simulation. The estimated model is used to predict cod growth for times-at-liberty ranging from 0 to 3 years, and for fish lengths ranging between 40 & 90 centimetres.
Download or read book Modeling Uncertainty in Fish Population Dynamics written by Yan Jiao and published by . This book was released on 2004 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Resiliency of Gadid Stocks to Fishing and Climate Change written by Gordon H. Kruse and published by University of Alaska Press. This book was released on 2008 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comparative Developmental Physiology written by Stephen J. Warburton and published by Oxford University Press. This book was released on 2006 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presenting assessments of work in the field of developmental physiology - from experimental, theoretical, and molecular perspectives - this text examines the future directions this key area will take.
Download or read book General Technical Report RM written by and published by . This book was released on 1982 with total page 772 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modelling and Quantitative Methods in Fisheries written by Malcolm Haddon and published by CRC Press. This book was released on 2011-03-11 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: With numerous real-world examples, Modelling and Quantitative Methods in Fisheries, Second Edition provides an introduction to the analytical methods used by fisheries' scientists and ecologists. By following the examples using Excel, readers see the nuts and bolts of how the methods work and better understand the underlying principles. Excel workb
Download or read book Neural Computing and Applications to Marine Data Analytics written by Jun Li and published by Frontiers Media SA. This book was released on 2022-03-30 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modelling and Quantitative Methods in Fisheries Second Edition written by Malcolm Haddon and published by CRC Press. This book was released on 2001-05-31 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: With numerous real-world examples, Modelling and Quantitative Methods in Fisheries, Second Edition provides an introduction to the analytical methods used by fisheries’ scientists and ecologists. By following the examples using Excel, readers see the nuts and bolts of how the methods work and better understand the underlying principles. Excel workbooks are available for download from CRC Press website. In this second edition, the author has revised all chapters and improved a number of the examples. This edition also includes two entirely new chapters: Characterization of Uncertainty covers asymptotic errors and likelihood profiles and develops a generalized Gibbs sampler to run a Markov chain Monte Carlo analysis that can be used to generate Bayesian posteriors Sized-Based Models implements a fully functional size-based stock assessment model using abalone as an example This book continues to cover a broad range of topics related to quantitative methods and modelling. It offers a solid foundation in the skills required for the quantitative study of marine populations. Explaining important and relatively complex ideas and methods in a clear manner, the author presents full, step-by-step derivations of equations as much as possible to enable a thorough understanding of the models and methods.
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.
Download or read book Improving Fish Stock Assessments written by National Research Council and published by National Academies Press. This book was released on 1998-02-27 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ocean harvests have plateaued worldwide and many important commercial stocks have been depleted. This has caused great concern among scientists, fishery managers, the fishing community, and the public. This book evaluates the major models used for estimating the size and structure of marine fish populations (stock assessments) and changes in populations over time. It demonstrates how problems that may occur in fisheries dataâ€"for example underreporting or changes in the likelihood that fish can be caught with a given type of gearâ€"can seriously degrade the quality of stock assessments. The volume makes recommendations for means to improve stock assessments and their use in fishery management.
