Download or read book Stock Assessment for Fishery Management written by Daniel D. Hoggarth and published by Food & Agriculture Org.. This book was released on 2006 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication contains guidelines for fish stock assessment and fishery management using the software tools and other outputs developed by the UK Department for International Development's Fisheries Management Science Programme (FMSP) from 1992 to 2004. It includes a CD-ROM with the installation files for each of the four FMSP software tools: LFDA (Length Frequency Data Analysis), CEDA (Catch Effort Data Analysis), YIELD and ParFish (Participatory Fisheries Stock Assessment).
Download or read book Development of Spatial Operating Models to Test Survey Design and Calibrate a New Survey Index for Northwest Atlantic Fisheries Organization Subarea 0 1 offshore Greenland Halibut Reinhardtius Hippoglossoides written by Quang C. Huynh and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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.
Download or read book FAO ICLARM stock assessment tools written by F. C. Gayanilo and published by Food & Agriculture Org.. This book was released on 1997 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fish Stock Assessment Manual written by Emygdio L. Cadima and published by Food & Agriculture Org.. This book was released on 2003 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: This manual examines mathematical models applied in fish stock assessment, including models and variation rates; cohort models and analyses; stock fishing patterns, components, stock-recruitment relations, short- and long-term stock projections; fisheries resources management with regards to biological reference points and regulation measures; production models; estimation of parameters; and exercises.
Download or read book Review of Northeast Fishery Stock Assessments written by National Research Council and published by National Academies Press. This book was released on 1998-04-17 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: The collapse of cod, flounder, and haddock fish stocks in the Northeast United States has caused widespread concern among managers and fishers in the United States and Canada. The diminishing stocks have forced managers to take strict regulatory measures. Numerous questions have been raised about the adequacy of stock assessment science used to evaluate the status of these stocks and the appropriateness of the management measures taken. Based on these concerns, Congress mandated that a scientific review of the methodology and data used to evaluate these stocks be conducted. In this volume, the committee concludes that although there are improvements to be made in data collection, modeling uncertainty, and communicating between fishers, managers, and scientists, the scientific methods used in the Northeast stock assessments are sound. Recommendations are made on how the stock assessment process can be improved.
Download or read book Evaluating the Performance and Applicability of State space Stock Assessment Models written by Emily Morgan Liljestrand and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fisheries stock assessment models are used to estimate population demographics and dynamics such as abundance, biomass, and fishing mortality from input fishery data including total catch, composition of catch, and fishing effort. A goal of stock assessment is to accurately quantify population and fishery dynamics so stocks can be managed to achieve fishery objectives and long-term sustainability. Accurate and precise model estimates can be attained by using models and techniques that account for ecological complexity like variability in quantities across ages, years, or regions without overparameterization. The state-space framework is one such statistical technique that may allow for incorporating more stochasticity such that the model can better reflect reality. The state-space modeling framework assumes that unobserved "states" develop over time due to process error modeled as a random effect and that observed data have expected values based on these states but differ from expectations due to observation error.State-space stock assessment models (SSSAM) have experienced an outpouring of research and application in the past decade as computation processing power and novel software has facilitated the approximation of the high-level integrals necessary for SSSAM. SSSAM allows for several time-varying processes in recruitment, numbers at age, mortality, selectivity, and catchability, and has become an essential part of the contemporary fisheries modeling toolbox. With their swift advancement, it is important to understand best practices of applying state-space stock assessment models, and how data availability, the variability of process or observation error, and model structure may influence model results and accuracy.In Chapter 1 I built an age-based state-space stock assessment model that used fisheries dependent data, rather than fisheries independent surveys, as an index of abundance and was applied to Lake Michigan lake whitefish (Coregonus clupeaformis). The model predicted greater℗ abundance and lower mortality compared to the non-state-space model and domed rather than asymptotic selectivity. The state-space model also had reduced retrospective patterns in recruitment. Chapters 2 and 3 each used a simulation-estimation framework to generate catch and index data using a state-space stock assessment that assumed process variability in recruitment, expected survival (abundance), and selectivity. Simulations were based on a Gulf of Maine haddock (Melanogrammus aeglefinus) model and assumed different degrees of process and observation variance (Chapter 2) or assumed observation error likelihood distributions for the proportions at age (Chapter 3) to generate data. Simulated data were input into several estimation models with alternative assumptions about contributing sources of process variability and/or observation error distributions. The results show that state-space models which assume several sources of process variability can produce unbiased estimates even when processes are constant over time. The state-space models were able to estimate process variance in several stochastic processes under a broad range of true values. However, assuming variability in expected survival when it is deterministic can lead to the model not converging. Unbiased results are achieved when the observation likelihood is structured to account for inter-age correlation and overdispersion though such a framework may have difficulty allocating variance between process and observation sub-models.The concluding chapter places this work in the context of other age-based stock assessment models and argues for the inclusion of state-space in the modeling toolbox, as they can account for multiple time-varying processes and be used in a broad range of data contexts. This work provides a blueprint for where and how SSSAM may be best utilized in the future, particularly with data limited or data poor stocks and in cases where the process variance is unknown and should be estimated within the model.
Download or read book Stock Assessment written by Vincent F. Gallucci and published by CRC Press. This book was released on 2023-05-31 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stock Assessment: Quantitative Methods and Applications for Small Scale Fisheries is a book about stock assessment as it is practiced. It focuses on applications for small scale or artisanal fisheries in developing countries, however it is not limited in applicability to tropical waters and should also be considered a resource for students of temperate fishery management problems. It incorporates a careful sample design, various mathematical models as a basis for predicting consequences for stock exploitation, and discusses the impact of exploitation on non-targeted species. This was a unique concept involving a collaborative effort between U.S. and host country scientists to address issues of regional and global concern through innovative research. Unlike other books on stock assessment that show mathematical models, this is the only book of its kind that discusses how an assessment is carried out. It looks at the field as a whole and includes sampling, age determination and acoustics. The book represents the culmination of a nine-year program financed by the United States Agency for International Development to provide new or improved methods of stock assessment for artisanal fisheries.
Download or read book Risk Evaluation and Biological Reference Points for Fisheries Management written by National Research Council Canada and published by NRC Research Press. This book was released on 1993 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Papers presented: 1) Reference points for fisheries management: the western Canadian experience; 2) Reference points for fisheries management: the eastern Canadian experience; 3) Reference points for fisheries management: the ICES experience; 4) Spawning stock biomass per recruit in fisheries management: foundation and current use; 5) The development of a management procedure for the South African anchovy resource; 6) How much spawning per recruit is enough?; 7) The behaviour of Flow, Fmed and Fhigh in response to variation in parameters used for their estimation; 8) The Barents Sea capelin stock collapse: a lesson to learn; 9) Variance estimates for fisheries assessment: their importance and how best to evaluate them; 10) Evaluating the accuracy of projected catch estimates from sequential population analysis and trawl survey abundance estimates; 11) Bootstrap estimates of ADAPT parameters, their projection in risk analysis and their retrospective patterns; 12) Analytical estimates of reliability for the projected yield from commercial fisheries; 13) Risk evaluation of the 10% harvest rate procedure for capelin in NAFO Division 3L; 14) Using jackknife and Monte Carlo simulation techniques to evaluate forecast models for Atlantic salmon; 15) Monte Carlo evaluation of risks for biological reference points used in New Zealand fishery assessments; 16) A comparison of event free risk analysis to Ricker spawner-recruit simulation: an example with Atlantic menhaden; 17) Choosing a management strategy for stock rebuilding when control is uncertain; 18) Risks and uncertainties in the management of a single-cohort squid fishery: the Falkland Islands Illex fishery as an example; 19) Risks of over- and under-fishing new resources; 20) Estimation of density-dependent natural mortality in British Columbia herring stocks through SSPA and its impact on sustainable harvesting strategies; 21) The comparative performance of production-model and ad hoc tuned VPA based feedback-control management procedures for the stock of Cape hake off the west coast of Africa; 22) A proposal for a threshold stock size and maximum fishing mortality rate; 23) Biological reference points for Canadian Atlantic gadoid stocks; 24) Stochastic locally-optimal harvesting; 25) ITQ based fisheries management; 26) Bioeconomic methods for determining TACs; 27) Management strategies: fixed or variable catch quotas; 28) Bioeconomic impacts of TAC adjustment strategies: a model applied to northern cod; 29) Experimental management programs for two rockfish stocks off British Columbia; 30)A brief overview of the experimental approach to reducing uncertainty in fisheries management; 31) Fisheries management organizations: a study of uncertainty.
Download or read book Stock Assessment written by Vincent F. Gallucci and published by CRC Press. This book was released on 1995-10-25 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stock Assessment: Quantitative Methods and Applications for Small Scale Fisheries is a book about stock assessment as it is practiced. It focuses on applications for small scale or artisanal fisheries in developing countries, however it is not limited in applicability to tropical waters and should also be considered a resource for students of temperate fishery management problems. It incorporates a careful sample design, various mathematical models as a basis for predicting consequences for stock exploitation, and discusses the impact of exploitation on non-targeted species. This was a unique concept involving a collaborative effort between U.S. and host country scientists to address issues of regional and global concern through innovative research. Unlike other books on stock assessment that show mathematical models, this is the only book of its kind that discusses how an assessment is carried out. It looks at the field as a whole and includes sampling, age determination and acoustics. The book represents the culmination of a nine-year program financed by the United States Agency for International Development to provide new or improved methods of stock assessment for artisanal fisheries.
Download or read book Quantitative Fisheries Stock Assessment written by R. Hilborn and published by Springer Science & Business Media. This book was released on 1992 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book really began in 1980 with our first microcomputer, an Apple II +. The great value of the Apple II + was that we could take the computer programs we had been building on mainframe and mini-computers, and make them available to the many fisheries biologists who also had Apple II + 's. About 6 months after we got our first Apple, John Glaister came through Vancouver and saw what we were doing and realized that his agency (New South Wales State Fisheries) had the same equipment and could run the same programs. John organized a training course in Australia where we showed about 25 Australian fisheries biologists how to use microcomputers to do many standard fisheries analyses. In the process of organizing this and sub sequent courses we developed a series of lecture notes. Over the last 10 years these notes have evolved into the chapters of this book.
Download or read book Fish Stock Assessment Manual written by Emygdio L Cadima and published by Daya Books. This book was released on 2007 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: This manual starts with an introduction to the mathematical models applied in fish stock assessment. The basic assumptions about a model and the concepts of variation rates of a characteristic in relation to time are presented. The concept of cohort and models for the individual growth of the cohort are developed. In the chapter concerning the study of the stock, the fishing pattern and its components are defined, the most used models for the stock-recruitment relation are presented, as well as the short- and long-term projections of a stock. With regard to fisheries resources management, the discussion is focused on the biological reference points. Finally, the general methods of estimating parameters with special relevance to the cohort analysis by age and length are described. The exercises from the last course held in the Instituto de Investigacao das Pescas e do Mar, Portugal are presented by the author and the scientist Manuela Azevedo. Contents Chapter 1: Introduction; The importance of fisheries, Fisheries resources management; Fisheries resources research, Fish stock assessment; Chapter 2: Models and Rates; Models, Rates, Simple linear model, Exponential model; Chapter 3: Cohort; Cohort-Introduction, Evolution of the number of a cohort, in an interval of time, Catch, in number, over an interval T1, Cohort during the exploitable life, Simplification of beverton and holt; Chapter 4: Stock; Stock over a one year period, Fishing pattern over a one year period, Short-term projections of the stock, Stock-recruitment (S-R) relation, Relation between R and B (R-S relation); Chapter 5: Biological Reference Points and Regulation Measures; Biological reference points for the management and conservation of fisheries resources, Biological target reference points (Fmax, F0.1, Fmed and FMSY), Biological limit reference points (Bloss, MBAL, Fcrash and Floss), Precautionary reference points-Fpa, Bpa, Fisheries regulation measures; Chapter 6: Production Models; Basic assumption about the evolution of the biomass of a non exploited stock, Exploited stock, Variation of the biomass in the interval Ti, Long term projections (LT) (Equilibrium conditions), Biomass and fishing level indices, Biological target reference points (TRP), Types of production models, Short term projections; Chapter 7: Estimation of Parameters; Simple linear regression-least squares method, Multiple linear regression-least squares method, Non-linear model-method of gauss-newton-least squares method, Estimation of growth parameters, Estimation of M-Natural mortality coefficient, Estimation of Z-total mortality coefficient, Estimation of the parameters of the stock-recruitment (S-R) relation, Estimation of the matrix [F] and of the matrix [N]-cohort analyses-AC and LCA; Chapter 8: Exercises; Mathematical revision, Rates, Simple linear model, Exponential model, Cohort-evolution in number, Cohort-catch in number, Individual growth in length and weight, Cohort during all life-biomass and catch in weight, Cohort during its life-simplification of beverton and holt model, Stock-short term projection, Stock-long term projection, Stock-recruitment relation, Fmax, F0.1, Fmed and FMSY, MBAL and Bloss, Floss and Fcrash, Production models (equilibrium)-schaefer, Production models (equilibrium)-abundance and fishing level indices, Production models-short term projection, Simple linear regression-estimation of the parameters of the W-L relation and growth parameters (ford-walford, gulland and holt and stamatopoulos and caddy), Multiple linear model-revision of matrices-estimation of the parameters of fox integrated model (IFOX), Non linear regression-estimation of the growth parameters and of the S-R relation (gauss-newton method), Estimation of M, Estimation of Z, Age cohort analysis (LCA), Examination-written test (lisbon, dec 1977).
Download or read book Fishery Stock Assessment Models written by Fritz Funk and published by Alaska Sea Grant College Program. This book was released on 1998 with total page 1060 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume bring fisheries modelers up to date on stock assessment modeling as a research tool. It has 55 peer-reviewed papers from all parts of the world, presented at the 1997 symposium Fishery Stock Assessment Models for the 21st Century, in Anchorage, Alaska.
Download or read book A Review of Length based Approaches to Assessing Fish Stocks written by J. A. Gulland and published by Food & Agriculture Org.. This book was released on 1992 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: This document reviews the several fish stock assessment methods based on length-frequency analysis. Emphasis is placed on sampling and collection of length-frequency data, to the estimation of population parameters such as growth, mortality and recruitment and the estimation of catch selectivity. Attention is given to the conversion of length to age using age-length keys, slicing length-frequency composition, and using modes. It reviews long-and short-term effects of changes in selection and fishing mortality, and discusses methods for long-term assessments and for short-term projections. The manual gives several examples of the most common methods used and stresses the advantages of using personal computers and the most recent software for data processing and analysis.
Download or read book Introduction to Tropical Fish Stock Assessment Exercises written by Per Sparre and published by . This book was released on 1998 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: In Part 1, Manual, a selection of methods on fish stock assessment is described in detail, with examples of calculations. Special emphasis is placed on methods based on the analysis of length-frequencies. After a short introduction to statistics, it covers the estimation of growth parameters and mortality rates, virtual population methods, including age-based and length-based cohort analysis, gear selectivity, sampling, prediction models, including Beverton and Holt's yield per recruit model and Thompson and Bell's model, surplus production models, multispecies and multifleet problems, the assessment of migratory stocks, a discussion on stock/recruitment relationships and demersal trawl surveys, including the swept-area method. The manual is completed with a review of stock assessment, where an indication is given of methods to be applied at different levels of availability of input data, a review of relevant computer programs produced by or in cooperation with FAO, and a list of references, including material for further reading. In Part 2, Exercises, a number of exercises is given with solutions. The exercises are directly related to the various chapters and sections of the manual.
Download or read book FAO ICLARM Stock Assessment Tools II written by F. C. Gayanilo and published by Food & Agriculture Org.. This book was released on 2005 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: The revised version of FiSAT (FiSAT II) is a program package consisting of methodologies for use with computers, enabling users to formulate some management options for fisheries, especially in data-sparse, tropical contexts. FiSAT II was developed mainly for the analysis of length-frequency data, but also enables related analyses, of size-at-age, catch-at-age, selection and other data typically collected for tropical fish stock assessment. This volume is complemented by "FiSAT - FAO-ICLARM stock assessment tools. Vol. 2: Reference manual" ISBN 92-5-104047-8.
Download or read book Stock Assessment written by Vincent F. Gallucci and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stock Assessment: Quantitative Methods and Applications for Small Scale Fisheries is a book about stock assessment as it is practiced. It focuses on applications for small scale or artisanal fisheries in developing countries, however it is not limited in applicability to tropical waters and should also be considered a resource for students of temperate fishery management problems. It incorporates a careful sample design, various mathematical models as a basis for predicting consequences for stock exploitation, and discusses the impact of exploitation on non-targeted species. This was a unique concept involving a collaborative effort between U.S. and host country scientists to address issues of regional and global concern through innovative research.Unlike other books on stock assessment that show mathematical models, this is the only book of its kind that discusses how an assessment is carried out. It looks at the field as a whole and includes sampling, age determination and acoustics.The book represents the culmination of a nine-year program financed by the United States Agency for International Development to provide new or improved methods of stock assessment for artisanal fisheries.
