Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Investigations Of Disease Factors Affecting Declines Of Pacific Herring Populations In Prince William Sound
Download Investigations Of Disease Factors Affecting Declines Of Pacific Herring Populations In Prince William Sound full books in PDF, epub, and Kindle. Read online Investigations Of Disease Factors Affecting Declines Of Pacific Herring Populations In Prince William Sound ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Investigations of Disease Factors Affecting Declines of Pacific Herring Populations in Prince William Sound by : Gary D. Marty
Download or read book Investigations of Disease Factors Affecting Declines of Pacific Herring Populations in Prince William Sound written by Gary D. Marty and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Investigations of Disease Factors Affecting Declines of Pacific Herring Populations in Prince William Sound by : Richard M. Kocan
Download or read book Investigations of Disease Factors Affecting Declines of Pacific Herring Populations in Prince William Sound written by Richard M. Kocan and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Invitation to Submit Restoration Proposals for Federal Fiscal Year 1999 by :
Download or read book Invitation to Submit Restoration Proposals for Federal Fiscal Year 1999 written by and published by . This book was released on 1998 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Long-term Ecological Change in the Northern Gulf of Alaska by : R.B. Spies
Download or read book Long-term Ecological Change in the Northern Gulf of Alaska written by R.B. Spies and published by Elsevier. This book was released on 2006-12-12 with total page 609 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive text is a major synthesis on ecological change in the Gulf of Alaska. It encompasses the structural and annual changes, forces of change, long-ecological changes in the atmosphere and ocean, plankton, fish, birds and mammals, and the effects of the 1989 Exxon Valdez Oil Spill. With 5 major sections, Long-term Ecological Change in the Northern Gulf of Alaska first describes the physical features, the atmosphere and physical oceanography, the annual production cycle, the forage base for higher animals and trophic transfer, and the adaptations for survival in this changing environment for 9 portal species. Then, the major forces of change are introduced: climate, geophysics, fisheries and harvesting, species interactions, disease and contaminants. Next, the long-term records of change in physical factors and biological populations are presented, as well as the potential reasons for the biological changes. Following is the history of the Exxon Valdez oil spill and its long-term effects. And, finally, the emergent properties of the ecosystem are discussed and an attempt is made to weigh the importance of the major forcing factors in terms of their temporal and spatial scales of influence. * Examines important data on long-term change in the ecosystem and the forcing factors that are responsible for it * Provides an account of the 1989 Exxon Valdez oil spill with emphasis on the long-term effects * Describes the effects of climate change, geophysical change, species interactions, harvesting, disease, the 1989 oil spill, and marine contaminants on key populations of marine organisms
Book Synopsis Prince William Sound Herring by : Stanley Donald Rice
Download or read book Prince William Sound Herring written by Stanley Donald Rice and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Fiscal Year 1999 Draft Work Plan by :
Download or read book Fiscal Year 1999 Draft Work Plan written by and published by . This book was released on 1998 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Analysis and Comparison of Age-structured Assessment Models for Two Pacific Herring Populations by : Peter-John F. Hulson
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.
Book Synopsis Modeling and Stock Assessment of Prince William Sound Pacific Herring by : Trevor A. Branch
Download or read book Modeling and Stock Assessment of Prince William Sound Pacific Herring written by Trevor A. Branch and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Report on the ongoing monitoring of the Pacific herring population in the Prince William Sound in the aftermath of the Exxon Valdez Oil Spill. The report outlines ongoing projects including annual stock assessments using a Bayesian model, an assessment of disease data, analysis of factors affecting natural mortality and recruitment, a study on changes in spawning patterns, and testing of hypotheses for changes in spawning timing.
Book Synopsis Fiscal Year 1999 Draft Work Plan by : Exxon Valdez Oil Spill Trustee Council
Download or read book Fiscal Year 1999 Draft Work Plan written by Exxon Valdez Oil Spill Trustee Council and published by . This book was released on 1998 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Pacific Herring Juvenile Winter Survival and Recruitment in Prince William Sound by : Fletcher Sewall
Download or read book Pacific Herring Juvenile Winter Survival and Recruitment in Prince William Sound written by Fletcher Sewall and published by . This book was released on 2020 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: Small pelagic fish abundances can vary widely over space and time making them difficult to forecast, partially due to large changes in the number of individuals that annually recruit to the spawning population. Recruitment fluctuations are largely driven by variable early life stage survival, particularly through the first winter for cold temperate fishes. Winter survival may be influenced by juvenile fish size, energy stores, and other factors that are often poorly documented, which may hamper understanding recruitment processes for economically and ecologically important marine species. The goal of this research was to improve understanding of recruitment of Pacific herring (Clupea pallasii) within Prince William Sound (PWS) through recruitment modeling and by identifying factors influencing winter survival of young-of-the-year (YOY) herring. Towards this end, my dissertation addresses three specific objectives: 1) incorporate oceanographic and biological variables into a herring recruitment model, 2) describe patterns in growth and condition of PWS YOY herring and their relationship to winter mortality risks, and 3) compare the growth, condition, swimming performance, and mortality of YOY herring that experience different winter feeding levels. In the recruitment modeling study, annual mean numbers of PWS herring recruits-per-spawner were positively correlated with YOY walleye pollock (Gadus chalcogrammus) abundance in the Gulf of Alaska, hence including a YOY pollock index within a standard Ricker model improved herring recruitment estimates. Synchrony of juvenile herring and pollock survival persisted through the three-decade study period, including the herring stock collapse in the early 1990s. While the specific mechanism determining survival is speculative, size-based tradeoffs in growth and energy storage in PWS YOY herring indicated herring must reach a critical size before winter, presumably to reduce size-dependent predation. Large herring switched from growth to storing energy, and ate more high-quality euphausiid prey, which would delay the depletion of lipid stores that compelled lean herring to forage. Lipid stores were highest in the coldest year of the seven-year field study, rather than the year with the best diets. With diets controlled in a laboratory setting, spring re-feeding following restricted winter diets promoted maintenance of size and swimming ability, but had little effect on mortality rates compared to fish continued on restricted rations. Declines in gut mass, even among fully fed herring, and low growth potential suggest limited benefits to winter feeding. Mortalities due to food restriction compounded by disease were highest among herring that fasted through winter months, and among small herring regardless of feeding level. Taken together, these findings illustrate the importance of achieving a critical size and high lipid stores in the critical period before winter to promote YOY herring winter survival and ultimately recruitment.
Book Synopsis Effect of Disease on Recovery of Pacific Herring in Prince William Sound, Alaska by : Gary D. Marty
Download or read book Effect of Disease on Recovery of Pacific Herring in Prince William Sound, Alaska written by Gary D. Marty and published by . This book was released on 2000 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Effect of Disease on Recovery of Pacific Herring in Prince William Sound, Alaska by : Gary D. Marty
Download or read book Effect of Disease on Recovery of Pacific Herring in Prince William Sound, Alaska written by Gary D. Marty and published by . This book was released on 2001 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Physical and Biological Factors Affecting Pacific Herring Egg Loss in Prince William Sound, Alaska by : Christopher N. Rooper
Download or read book Physical and Biological Factors Affecting Pacific Herring Egg Loss in Prince William Sound, Alaska written by Christopher N. Rooper and published by . This book was released on 1996 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: The biomass of Prince William Sound herring (Clupea pallasi) is estimated from egg deposition surveys. Because surveys occur after spawning, a correction for egg loss is required. I constructed ANOVA models based on environmental factors to estimate the egg loss correction in 1990-1991 and 1994-1995. The models explained 52% to 85% of the data variation. Depth of spawn was the primary factor determining egg loss, and air exposure could be substituted for depth. The correction factor was estimated at 33%. The total loss of eggs from spawning to hatching ranged from 67.40% to 100% averaging 76.06%, Two processes affecting egg loss, wave action and fish predation, were also examined. Typical wave energies were not found to contribute significantly to egg loss, but a threshold wave energy may exist beyond which egg loss is high. Consumption of eggs by greenling (Hexagrammidae) was estimated at 2.2% to 8.5% of the total spawn.
Book Synopsis Population Structure of Pacific Herring in Prince William Sound by : Anthony John Gharrett
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:
Book Synopsis Fiscal Year 1997 [i.e. 1998] Draft Work Plan by : Exxon Valdez Oil Spill Trustee Council
Download or read book Fiscal Year 1997 [i.e. 1998] Draft Work Plan written by Exxon Valdez Oil Spill Trustee Council and published by . This book was released on 1997 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Draft, Exxon Valdez Oil Spill Restoration Plan by : Exxon Valdez Oil Spill Trustee Council
Download or read book Draft, Exxon Valdez Oil Spill Restoration Plan written by Exxon Valdez Oil Spill Trustee Council and published by . This book was released on 1993 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Modeling Population Collapse and Recovery in Herring by : John T. Trochta
Download or read book Modeling Population Collapse and Recovery in Herring written by John T. Trochta and published by . This book was released on 2021 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: Population collapse in forage fish occurs both naturally and due to overfishing, and is a challenge to sustainable fisheries management. Sustained low abundance can result in prolonged fishery closures and impact the abundance of other species via predation or competition. The time taken to recover from collapse is determined by uncertain factors that control population dynamics and can widely vary between populations. Herring (Clupea spp.) are a major group of forage fishes with numerous populations throughout the Northern Hemisphere, that have sustained commercial fisheries for centuries and indigenous fishers for far longer, and support ecologically and economically valuable species including various pinnipeds, whales, seabirds, and predatory fishes. Herring populations across the world have shown varying durations of population collapse since the start of industrial fishing while hypotheses of the underlying factors have been underdetermined across and within individual populations. The Pacific herring (Clupea pallasii) population in Prince William Sound, Alaska is a modern enduring example of prolonged population collapse whose population dynamics remain largely uncertain and unpredictable despite intensive monitoring and modeling. In this dissertation, I explore and evaluate factors that potentially influence population collapse and recovery within herring. My overarching goal is to better inform the population dynamics of herring and more specifically improve the Bayesian stock assessment model of Prince William Sound herring. In Chapter 1, I conducted a meta-analysis on time series collected for 64 populations worldwide to statistically characterize population collapse and recovery in herring and model predictors of recovery times in adult biomass and recruitment. After collapse, herring populations recovered in 11 years on average, with a few populations remaining collapsed for multiple decades. Amongst populations, recovery time duration did not coincide with fishery closures, which occurred at low abundance in most Pacific herring populations but no Atlantic herring populations. Faster recovery in biomass was best associated with higher average recruitment and higher oceanographic variability in both sea surface height anomalies and sea surface temperatures. In Chapter 2, I modeled ecological factors impacting natural mortality and recruitment in Prince William Sound herring using a custom-built Bayesian age-structured stock assessment model. Support for individual factors was evaluated using multiple Bayesian model selection criteria and alternative modeling assumptions about the ecological data representing these factors. There was strongest evidence for effects on herring natural mortality from pink salmon abundance in Prince William Sound had the most broad and consistent support. Statistical support differed by the type of selection criteria, model assumptions regarding covariates, and time period modeled, resulting in generally weak evidence for most individual effects and the suggestion that results are sensitive to model flexibility. In Chapter 3, I developed a novel modeling framework and conducted a simulation study to test the usefulness of age-specific antibody, or seroprevalence, data in assessing the impact of disease-associated mortality on herring, for use in stock assessment models. Viral hemorrhagic septicemia virus (VHSV) in Prince William Sound herring is used as a case study due to its association with fish kills and well-established ecological principles for its epizootiology from extensive monitoring of VHSV in herring populations. I found that incorporating seroprevalence data within stock assessment can accurately inform infection history and disease mortality and improve population estimates. The first real application of age-specific VHSV seroprevalence is demonstrated with the Prince William Sound herring stock assessment. While motivated from VHSV in herring, these models can be easily adapted to different host populations and pathogens and I present advice for future applications of disease data within stock assessment.
![Download Fiscal Year 1997 [i.e. 1998] Draft Work Plan PDF Online Free](https://books.google.com/books/content/images/frontcover/C1YRAAAAYAAJ?fife=w200-h370)
