The Experts below are selected from a list of 8400 Experts worldwide ranked by ideXlab platform
Steven E Campana - One of the best experts on this subject based on the ideXlab platform.
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a validated description of age and growth of western atlantic bluefin tuna Thunnus thynnus
Canadian Journal of Fisheries and Aquatic Sciences, 2008Co-Authors: John D Neilson, Steven E CampanaAbstract:Current stock assessments of western Atlantic bluefin tuna (Thunnus thynnus) use age-structured population analyses, but the age assignment in the population model is made using an age–length relat...
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a validated description of age and growth of western atlantic bluefin tuna Thunnus thynnus
Canadian Journal of Fisheries and Aquatic Sciences, 2008Co-Authors: John D Neilson, Steven E CampanaAbstract:Current stock assessments of western Atlantic bluefin tuna (Thunnus thynnus) use age-structured population analyses, but the age assignment in the population model is made using an age–length relationship derived from mark and recapture studies largely completed during the 1970s. In our study, the deposition of bomb radiocarbon was used as a dated mark to validate age inferences of bluefin tuna and to compare the validated ages with those predicted from the age–length relationship. The results support the view that the age–length relationship currently in use for the assessment overestimates growth rate and the ultimate size of the fish. These findings have implications for the estimation of stock productivity and may negatively impact the rebuilding schedules established by fisheries managers.
John Neilsonj Neilson - One of the best experts on this subject based on the ideXlab platform.
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complex migration routes of atlantic bluefin tuna Thunnus thynnus question current population structure paradigm
Canadian Journal of Fisheries and Aquatic Sciences, 2010Co-Authors: Benjamin Galuardi, Francois Royer, Walt Goletw Golet, John Loganj Logan, John Neilsonj NeilsonAbstract:Movements of Atlantic bluefin tuna (Thunnus thynnus, ABFT) from specific western Atlantic forage grounds are not well described, and the extent of their spawning areas is mainly surmised. In 2005 a...
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complex migration routes of atlantic bluefin tuna Thunnus thynnus question current population structure paradigm
Canadian Journal of Fisheries and Aquatic Sciences, 2010Co-Authors: Benjamin Galuardi, Francois Royer, Walt Goletw Golet, John Loganj Logan, John Neilsonj NeilsonAbstract:Movements of Atlantic bluefin tuna (Thunnus thynnus, ABFT) from specific western Atlantic forage grounds are not well described, and the extent of their spawning areas is mainly surmised. In 2005 and 2006, we deployed 41 pop-up satellite archival tags (PSATs) on adult Atlantic bluefin tuna off the coast of Nova Scotia, Canada, and on Georges Bank. During the assumed spawning period, 56% of the tagged ABFT occupied a known spawning area, while 44% were located in distant oceanic regions. Assuming obligate annual spawning, these results are inconsistent with the notion of spawning site fidelity to the Gulf of Mexico. The ocean-wide migrations of adult ABFT tagged on a common forage ground suggest evidence of a metapopulation requiring more spatially explicit management than the current simple two-stock structure.
John D Neilson - One of the best experts on this subject based on the ideXlab platform.
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a validated description of age and growth of western atlantic bluefin tuna Thunnus thynnus
Canadian Journal of Fisheries and Aquatic Sciences, 2008Co-Authors: John D Neilson, Steven E CampanaAbstract:Current stock assessments of western Atlantic bluefin tuna (Thunnus thynnus) use age-structured population analyses, but the age assignment in the population model is made using an age–length relat...
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a validated description of age and growth of western atlantic bluefin tuna Thunnus thynnus
Canadian Journal of Fisheries and Aquatic Sciences, 2008Co-Authors: John D Neilson, Steven E CampanaAbstract:Current stock assessments of western Atlantic bluefin tuna (Thunnus thynnus) use age-structured population analyses, but the age assignment in the population model is made using an age–length relationship derived from mark and recapture studies largely completed during the 1970s. In our study, the deposition of bomb radiocarbon was used as a dated mark to validate age inferences of bluefin tuna and to compare the validated ages with those predicted from the age–length relationship. The results support the view that the age–length relationship currently in use for the assessment overestimates growth rate and the ultimate size of the fish. These findings have implications for the estimation of stock productivity and may negatively impact the rebuilding schedules established by fisheries managers.
Benjamin Galuardi - One of the best experts on this subject based on the ideXlab platform.
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complex migration routes of atlantic bluefin tuna Thunnus thynnus question current population structure paradigm
Canadian Journal of Fisheries and Aquatic Sciences, 2010Co-Authors: Benjamin Galuardi, Francois Royer, Walt Goletw Golet, John Loganj Logan, John Neilsonj NeilsonAbstract:Movements of Atlantic bluefin tuna (Thunnus thynnus, ABFT) from specific western Atlantic forage grounds are not well described, and the extent of their spawning areas is mainly surmised. In 2005 a...
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complex migration routes of atlantic bluefin tuna Thunnus thynnus question current population structure paradigm
Canadian Journal of Fisheries and Aquatic Sciences, 2010Co-Authors: Benjamin Galuardi, Francois Royer, Walt Goletw Golet, John Loganj Logan, John Neilsonj NeilsonAbstract:Movements of Atlantic bluefin tuna (Thunnus thynnus, ABFT) from specific western Atlantic forage grounds are not well described, and the extent of their spawning areas is mainly surmised. In 2005 and 2006, we deployed 41 pop-up satellite archival tags (PSATs) on adult Atlantic bluefin tuna off the coast of Nova Scotia, Canada, and on Georges Bank. During the assumed spawning period, 56% of the tagged ABFT occupied a known spawning area, while 44% were located in distant oceanic regions. Assuming obligate annual spawning, these results are inconsistent with the notion of spawning site fidelity to the Gulf of Mexico. The ocean-wide migrations of adult ABFT tagged on a common forage ground suggest evidence of a metapopulation requiring more spatially explicit management than the current simple two-stock structure.
Barbara A Block - One of the best experts on this subject based on the ideXlab platform.
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stock of origin catch estimation of atlantic bluefin tuna Thunnus thynnus based on observed spatial distributions
Canadian Journal of Fisheries and Aquatic Sciences, 2021Co-Authors: Emilius A Aalto, Francesco Ferretti, Matthew V Lauretta, John F Walter, Michael J W Stokesbury, Robert J Schallert, Barbara A BlockAbstract:Atlantic bluefin tuna (Thunnus thynnus) are a large, highly migratory fish distributed throughout the North Atlantic Ocean and adjacent seas currently managed as two discrete stocks: western and ea...
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habitat and behaviour of yellowfin tuna Thunnus albacares in the gulf of mexico determined using pop up satellite archival tags
Journal of Fish Biology, 2009Co-Authors: Kevin C Weng, Michael J W Stokesbury, Andre Boustany, Andrew C Seitz, S K Miller, Barbara A BlockAbstract:This study presents the first data on movement, habitat use and behaviour for yellowfin tuna Thunnus albacares in the Atlantic Basin. Six individuals were tracked in the Gulf of Mexico using pop-up satellite archival tags. Records up to 80 days in length were obtained, providing information on depth and temperature preferences as well as horizontal movements. Thunnus albacares in the Gulf of Mexico showed a strong preference for the mixed layer and thermocline, consistent with findings for this species in other ocean basins. Fish showed a diel pattern in depth distribution, remaining in surface and mixed layer waters at night and diving to deeper waters during the day. The vertical extent of T. albacares habitat appeared to be temperature limited, with fish generally avoiding waters that were >6° C cooler than surface waters. The vertical and thermal habitat usage of T. albacares differs from that of bigeye Thunnus obesus and bluefin Thunnus thynnus, Thunnus orientalis and Thunnus maccoyii tunas. These results are consistent with the results of earlier studies conducted on T. albacares in other oceans. # 2009 The Authors Journal compilation # 2009 The Fisheries Society of the British Isles
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life history and stock structure of atlantic bluefin tuna Thunnus thynnus
Reviews in Fisheries Science, 2007Co-Authors: Jaime Alvarado R Bremer, Gregorio De Metrio, Aldo Corriero, Eric D Prince, Heidi Dewar, Richard T Kraus, Barbara A Block, David H. Secord.h. SecorAbstract:Our understanding of the biology of Atlantic bluefin tuna (Thunnus thynnus) has increased profoundly in the last decade, and the progress is attributed to the development and application of a variety of novel tools. Here we provide a comprehensive examination of available data on the life history and stock structure of T. thynnus by re-examining current databases and literature and highlighting findings from recent studies using approaches such as archival tags and natural markers (e.g., genetics, otolith chemistry). The present review provides a detailed synthesis on the reproductive biology, feeding ecology, growth, mortality, migration, and stock structure of T. thynnus. In addition to characterizing key life history attributes and discussing stock-specific (east versus west) differences, the implication of trans-Atlantic movement and mixing are addressed. We also identify significant data needs that still exist and must be addressed to promote effective management and rapid recovery of T. thynnus popu...
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a new satellite technology for tracking the movements of atlantic bluefin tuna
Proceedings of the National Academy of Sciences of the United States of America, 1998Co-Authors: Barbara A Block, Charles J. Farwell, Heidi Dewar, Eric D PrinceAbstract:The movements of Atlantic bluefin tuna (Thunnus thynnus thynnus) have captured the interest of scientists and fishers since the time of Aristotle. This tuna is unique among bony fish for maintaining elevated body temperatures (21°C above ambient) and attaining large size (up to 750 kg). We describe here the use of a pop-off satellite tag, for investigating the Atlantic-wide movements and potential stock overlap of western and eastern Atlantic bluefin tuna. The tag also archives data on water temperatures. The objectives of this study were to evaluate the effectiveness of the technology, study the movements of Atlantic bluefin tuna, examine their thermal niche, and assess survivorship of tagged fish. The pop-off satellite technology provides data independent of commercial fisheries that, when deployed in sufficient quantity, should permit a critical test of the stock structure hypotheses for Atlantic bluefin tuna.
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archival tagging of atlantic bluefin tuna Thunnus thynnus thynnus
Marine Technology Society Journal, 1998Co-Authors: Barbara A Block, Charles J. Farwell, Eric D Prince, Heidi Dewar, Thomas D Williams, Douglas S FudgeAbstract:The size, power, and speed of tunas and other pelagic fishes (e.g. swordfish, marlins, sailfish) have made it a challenge to study their biology. These species are most often composed of large populations with broad geographic ranges and individuals are capable of traversing ocean basins in weeks or months. Data on dispersal patterns are hard to obtain because of the limited resolution of analytical tools available for studying pelagic fish. What is currently needed are technologies that can augment conventional tagging data sets to better define the geographic ranges and potential overlap of stocks. Archival, satellite and molecular technologies offer the fisheries research community the new techniques required to resolve the movement patterns and stock structure of highly migratory species. We describe in this paper our use of archival tags on Atlantic bluefin tuna (Thunnus thynnus thynnus). Archival tags provide a record of thynnus ambient and internal body temperature, pressure, and light. From light intensity, augmented with data on sea surface temperature, it is possible to estimate latitude and longitude. In recent years, archival tags have dramatically increased the understanding of the biology of several species of fish. Use of the tags has the potential to address major questions concerning stock structure hypotheses of Atlantic bluefin tunas. We have developed the handling and surgical procedures necessary for internal placement of archival tags in medium and giant bluefin up to 234 kg. Additional studies to examine the survivorship and healing rate of archival tagged fish are being conducted using captive tuna populations in Monterey, California and acoustic and satellite technologies on wild fish.
