Author: John R. Hunter
Publisher: Food & Agriculture Org.
ISBN: 9789251024713
Category : Nature
Languages : en
Pages : 88
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Book Description
Weaknesses in understanding of tuna distributions and movements have constrained the development of rational management policies. Uncertainties exist in: the selection of management plans and catch and effort data that are representative of a stock; quantification of exchange of adults among management jurisdictions and fishing gears; and identification of the relationships between the environment and tuna movements. This report summarizes a series of discussions between a panel and groups of experts on how to increase understanding of these and other tuna problems. We discuss the uncertainties in current management policy caused by lack of understanding of tuna movement dynamics. We describe and evaluate the research approaches presently used to describe the movements of tunas--mark and recapture and acoustic tracking-- and those which might be used or are just being applied, including new tagging systems, measurement of physiological state and microconstituents of mineralized tissue. Actions needed to improve the knowledge of tuna movements are: 1) establish international arrangements to share tuna movement data, to analyse movements on an oceanwide and worldwide basis and to link international oceanographic programs; 2) increase number and kinds of observations of movements of tuna in the vertical plane; 3) develop and use technology for tracing the actual paths followed by tunas over extended periods and for measuring movements independent of the fishery; and 4) conduct intensive studies on tuna movement dynamics which combine old with the new technologies discussed in the report.
Author: Brittany Syra Graham
Publisher:
ISBN:
Category : Yellowfin tuna
Languages : en
Pages : 476
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Book Description
Delta15N and delta13C values of animals can be used as natural tags to trace their movements through ecosystems. This method to studying animal movements requires isotopic variation at the base of the food web. Baseline delta15N values show strong geographical patterns in the eqPac. If tuna migrated extensively within these isotope gradients, little isotopic variation would be observed in tuna because baseline delta15N values would be integrated. Delta15N values of yellowfin, bigeye, and skipjack tuna showed ca. 12 0/00 variation, but spatially coherent structure in the eqPac. CSIA results revealed that this delta15N variation relates more to tuna movements than differences in their TL. Thus, the high isotopic variation observed in tuna reflects their restricted movements in the EqPac and differences between the species indicate different movement rates. In summary, this study established that isotope values of tunas are indicators of their foraging behavior, habitat utilization, and movements.
Author: Brian Fry
Publisher: Springer Science & Business Media
ISBN: 0387337458
Category : Science
Languages : en
Pages : 318
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Book Description
A solid introduction to stable isotopes that can also be used as an instructive review for more experienced researchers and professionals. The book approaches the use of isotopes from the perspective of ecological and biological research, but its concepts can be applied within other disciplines. A novel, step-by-step spreadsheet modeling approach is also presented for circulating tracers in any ecological system, including any favorite system an ecologist might dream up while sitting at a computer. The author’s humorous and lighthearted style painlessly imparts the principles of isotope ecology. The online material contains color illustrations, spreadsheet models, technical appendices, and problems and answers.
Author: Robert Colgate Francis
Publisher:
ISBN:
Category : Tuna fisheries
Languages : en
Pages : 55
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Book Description
Author: Barbara Ann Block
Publisher: Gulf Professional Publishing
ISBN: 9780123504432
Category : Nature
Languages : en
Pages : 490
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Book Description
Annotation Tuna are biologically fascinating, with many specializations such as endothermy (warm-bloodedness), aerobic capacity, and migratory abilities. The primary focus of this book is the physiology of tuna with respect to biomechanics, thermoregulation, and morphology. An evolutionary and phylogenetic backdrop illustrates the importance of comparative perspectives. Because of the economic importance of tuna, a secondary focus of the book is tuna aquaculture and conservation.
Author: National Research Council
Publisher: National Academies Press
ISBN: 0309051819
Category : Technology & Engineering
Languages : en
Pages : 167
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Book Description
This book reviews and evaluates the scientific basis of U.S. management of fisheries for Atlantic bluefin tuna. In particular, it focuses on the issues of stock structure and stock assessments used by the National Oceanic and Atmospheric Administration's National Marine Fisheries Service for management under the International Convention for the conservation of Atlantic Tunas.
Author: Shomura, Richard S.
Publisher:
ISBN: 9789251034545
Category : Fisheries
Languages : en
Pages : 456
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Book Description
Author: Barbara A. Block
Publisher: JHU Press
ISBN: 1421429640
Category : Science
Languages : en
Pages : 361
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Book Description
The most thorough and current account of scientific research on bluefin tunas—the largest, most sought-after tunas in the world Bluefin tunas are dominant keystone predators known for their impressive size, strength, endurance, and speed. Electronic tags have revealed that they can dive to great depths (over 6000 feet) and migrate vast distances—from frigid subpolar seas to warm tropical waters—for spawning. Prized for their rich taste and unique texture, bluefin tunas are also a worldwide commodity of great value. However, over the past few decades, overfishing throughout their range has led to significant population reductions. In The Future of Bluefin Tunas, Barbara A. Block brings together renowned bluefin experts from 15 different countries to share the latest information on the science, fisheries policy, and management decisions related to each of the three species within the Thunnus group—Atlantic, Pacific, and Southern. Synthesizing basic and applied research, the book delves into every aspect of these majestic fish, from their life history and genetic makeup to their ecology and migrations. Ichthyologists and marine scientists dedicated to the study of these fishes report on the latest stock assessments, explore the results of advances such as biologging and DNA sampling, and assess the potential of bluefin tuna aquaculture. The Future of Bluefin Tunas provides critical research findings to inform decisions that will impact tunas and the ocean ecosystems they affect. Scientists, fisheries managers, policymakers, and marine conservationists will take away key data from this timely volume to help them ensure these remarkable fish continue in perpetuity.
Author: José Luis Cort
Publisher: Springer
ISBN: 3030115453
Category : Science
Languages : en
Pages : 123
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Book Description
This open access book is an original contribution to the knowledge on fishing and research associated with one of the most enigmatic fish of our seas: bluefin tuna, Thunnus thynnus (L.). Based on available evidence, it reconstructs the possible methods used to catch large spawners in the Strait of Gibraltar thousands of years ago and describes the much more recent overfishing that led to a great reduction in the catches of the trap fishery on the area and the disappearance of the northern European fisheries. It is the first book to relate the overfishing of juvenile fishes in certain areas to the decline of large spawners in other very distant areas, revealing one of the main underlying causes of this decline, which has remained a mystery to the fishing sector and scientists alike for over 50 years. This finding should serve to prevent similar cases from arising in the future.
Author:
Publisher:
ISBN:
Category : Fisheries
Languages : en
Pages : 28
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Book Description
