Download or read book Age Structured Analysis of Pacific Herring from Norton Sound Alaska written by Erik H. Williams and published by . This book was released on 1996 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Age-structured assessment models are used for many exploitable herring stocks in Alaska in order to forecast the abundance of returning herring. The purpose of this study is to determine if an age-structured assessment model could be developed for Norton Sound herring. Commercial catch and sampling data for Norton Sound herring were obtained from the Alaska Department of Fish and Game. Natural mortality estimates were obtained from analysis of life history parameters. Initial starting values for the age-structured model weere obtained from cohort analysis. Two types of models, with and without a pooled age group, were fit to the data. A parametric bootstrap analysis utilizing a beta distribution fit to observed age compositions was performed in order to obtain standart deviations of the estimates. Model fits indicated that inclusion of a pooled age group (10+) worked best. The fit of this model to the data is comparable to previous age-structured assessments of Alaska herring stocks." -- from the Abstract.
Download or read book Interrelationships of Pacific Herring Clupea Pallasi Populations and Their Relation to Large scale Environmental and Oceanographic Variables written by Erik Hamilton Williams and published by . This book was released on 1999 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recruitment estimates for Pacific herring, Clupea pallasi, populations in the Bering Sea and Northeast Pacific Ocean are highly variable, difficult to forecast, and crucial for determining optimum harvest levels. Age-structured population models for annual stock assessments of the sac-roe fisheries rely on fishery and survey age composition data tuned to an auxiliary survey of total biomass. In Chapter 1, the first age-structured model for Norton Sound herring was developed similarly to existing models. Estimates of variability from age-structured stock assessment models for Pacific herring are often not calculated. In Chapter 2, a parametric bootstrap procedure using a fit of the Dirichlet distribution to observed age composition data was developed as a quick and easy method for computing error estimates of model estimates. This bootstrap technique was able to capture variability beyond that of the multinomial distribution. This technique can provide estimates of variability for existing population models with age composition data requiring little change to the original model structure. Recruitment time series from Pacific herring stock assessment models for 14 populations in the Bering Sea and Northeast Pacific Ocean were analyzed for links to the environment. For some populations, recruitment series were extended backward in time using cohort analysis. In chapter 3, correlation and multivariate cluster analyses were applied to determine herring population associations. There appear to be four major herring groups: Bering Sea, outer Gulf of Alaska, coastal Southeast Alaska, and British Columbia. These associations were combined with an exploratory correlation analysis of environmental data in chapter 4. Appropriate time periods for environmental variables were determined for use in Ricker type environmentally dependent spawner-recruit forecasting models. Global and local scale environmental variables were examined in forecasting models, resulting in improvements in recruitment forecasts compared to models without environmental data. The exploratory correlation analysis and best fit models, determined by jacknife error prediction, indicated temperature data corresponding to the year of spawning resulted in the best forecasting models. The Norton Sound age-structured model, parametric bootstrap procedure, and recruitment forecasting models serve as enhancements to the decision process of managing Pacific herring fisheries.
Download or read book Analysis and Comparison of Age structured Assessment Models for Two Pacific Herring Populations written by Peter-John F. Hulson and published by . This book was released on 2007 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Substantial research has been devoted to identify causes for decline the of Prince William Sound (PWS) Pacific herring in the early 1990's because of the proximity to the 1989 Exxon Valdez oil spill (EVOS). A potential source for decline has been identified with the isolation of disease in the PWS population. There have been limited investigations of PWS Pacific herring population dynamics related to other stocks in the Gulf of Alaska. The objective of this thesis was to compare observations and age-structured assessment (ASA) model results between PWS and Sitka Sound Pacific herring. Data conflicts were evaluated in the PWS ASA model and indicate that hypotheses about natural mortality in the four years subsequent to EVOS depend on the type and weighting of population indices. In Sitka, the ASA model was used to show that time-dependent natural mortality can be estimated. Comparison between PWS and Sitka indicated that age structure and recruitment have been comparable, but abundance indices and weight-at-age data have not been similar after 1993. The differences identified in this thesis between PWS and Sitka imply uniqueness in natural mortality and condition within each Pacific herring population"--Leaf iii.
Download or read book Alaska Fishery Research Bulletin written by and published by . This book was released on 1997 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Age Composition Weight Length and Sex of Herring Clupea Pallasii Used for Reduction in Alaska 1929 66 written by Gerald M. Reid and published by . This book was released on 1971 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Preliminary Forecasts of Catch and Stock Abundance for Alaska Herring Fisheries written by and published by . This book was released on 1993 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Alaska Herring History written by James Mackovjak and published by University of Alaska Press. This book was released on 2022-07-18 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: Part I: Herring: The Fish and Its Utilization, 1878-1966 -- Alaska Herring: The Basics -- Early Development of Alaska's Herring Industry -- Salted Herring: The Early Years -- Early Alaska Herring Fishery Regulation and Research -- Alaska's Herring Industry Expands: 1924-1931 -- A Chronicle of Alaska's Herring Industry: 1932-1948 -- A Chronicle of Alaska's Herring Industry: 1949-1966 -- Bait Herring -- Part II: Roe Herring -- Alaska's Roe-Herring Fishery, Its Genesis and Management -- Sitka Sound Roe-Herring Fishery -- Resurrection Bay and Prince William Sound Roe-Herring Fisheries -- Lower Cook Inlet and Kodiak Area Roe-Herring Fisheries -- Togiak Roe-Herring Fishery -- Norton Sound Herring Fisheries -- Food Herring in the Modern Era -- Part III: Herring Spawn on Kelp -- Genesis of Alaska's Herring Spawn-on-Kelp Fishery -- Prince William Sound Herring Spawn-on-Kelp Fisheries, 1981-1993 -- Alaska Herring Spawn-on-Kelp Pound Fisheries -- Togiak and Norton Sound Herring Spawn-on-Kelp Fisheries.
Download or read book Stock Assessment and Management of Pacific Herring in Prince William Sound Alaska 1990 written by Timothy T. Baker and published by . This book was released on 1991 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Population Structure of Pacific Herring in Prince William Sound written by Anthony John Gharrett and published by . This book was released on 1986* with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pacific Herring Clupea Harengus Pallasii Age and Growth Analysis in Southeastern Alaska for the Years 1977 1978 1979 and 1980 written by Dennis Blankenbeckler and published by . This book was released on 1982 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Catch age Analysis of Prince William Sound Alaska Herring 1973 1988 written by Fritz Funk and published by . This book was released on 1990 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Report of a modified form of catch-age analysis with use of observation of absolute abundance as auxiliary information, applied to herring (Clupa harengus pallasi) of Prince William Sound (southcentral Alaska), 1973-1988.
Download or read book Population Structure of Pacific Herring Clupea Harengus Pallasi in Eastern Prince William Sound Alaska written by Charles Burkey and published by . This book was released on 1986 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Current References in Fish Research written by and published by . This book was released on 1998 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Preliminary Forecasts of Catch and Stock Abundance for 1993 Alaska Herring Fisheries written by Fritz Funk and published by . This book was released on 1993 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cohort Analysis of Pacific Herring in the Togiak District Alaska 1980 90 written by Timothy T. Baker and published by . This book was released on 1991 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: A cohort analysis model that incorporated catch, natural mortality, availability (recruitment) and growth parameters was developed and applied to estimate spawning population biomass of Pacific herring (Clupea harengus pallasi) in Togiak District, Alaska.
Download or read book Improving Fish Stock Assessments written by Committee on Fish Stock Assessment Methods and published by National Academies Press. This book was released on 1998-03-13 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 data--for example underreporting or changes in the likelihood that fish can be caught with a given type of gear--can seriously degrade the quality of stock assessments. The volume makes recommendations for means to improve stock assessments and their use in fishery management.
