Download or read book Stock Structure and Seasonal Migration Patterns of Atlantic Cod Gadus Morhua Based on Inshore Tagging Experiments in Divs 3KL During 1995 97 written by John Brattey and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stock Structure and Seasonal Movements of Atlantic Cod Gadus Morhua in NAFO Divs 3KL Inferred from Recent Tagging Experiments written by John Brattey and published by . This book was released on 2000 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seasonal Migration Patterns of Atlantic Cod Gadus Morhua in NAFO Subdivision 3Ps Based on Tagging Experiments During 1997 98 written by John Brattey and published by . This book was released on 1999 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seasonal Migration Patterns of Atlantic Cod Gadus Morhua in NAFO Subdivision 3Ps Based on Tagging Experiments During 1997 98 written by John Brattey and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Estimation of Exploitation and Migration Rates of Atlantic Cod Gadus Morhua in NAFO Subdiv 3Psc and Divs 3KL During 1997 and 1998 Based on Tagging Experiments written by Noel G. Cadigan and published by . This book was released on 1999 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Exploitation Rates and Movements of Atlantic Cod Gadus Morhua in NAFO Divs 3KL Based on Tagging Experiments Conducted During 1997 2002 written by and published by . This book was released on 2003 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes & presents results of a mark-recapture study of Atlantic cod in Divisions 3KL (east coast Newfoundland) initiated in 1997 & continued in 2002. The purpose of the study was to provide information on movement patterns & stock structure of inshore cod as well as to obtain estimates of exploitation rates on cod tagged in different inshore regions. The method for estimating exploitation, similar to that described in Brattey et al. (2001, 2002), incorporates a new method of accounting for tag loss (Cadigan & Brattey, 2003). The report gives annual estimates of exploitation for each tagging experiment conducted over the period. It also summarizes the spatial & temporal distribution of recaptures of tagged cod released in various regions of 3KL and reported as recaptured up to the end of December 2002.
Download or read book Stock Structure Movements and Exploitation of Atlantic Cod Gadus Morhua in NAFO Divs 2J 3KL Based on Tagging Experiments Conducted During 1999 2000 written by Brattey, J. (John) and published by . This book was released on 2001 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lower Bounds on the Exploitation of Cod Gadus Morhua in NAFO Divs 3KL and Subdiv 3Ps During 1997 99 from Tagging Experiments written by and published by . This book was released on 2000 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes & presents results from a model developed to estimate exploitation rates (fraction of stock removed by the fishery) using tags returned from the commercial fisheries for Atlantic cod in NAFO Divisions 3KL & Subdivision 3Ps & adjacent areas during 1997-99. The model involves length- and gear-based exploitation rates and incorporates methods to estimate tagging mortality, tag loss, tag reporting rates, and fish growth. This model is used to estimate weekly exploitation rates in 3KL & 3Ps, but the focus is on exploitation in 3KL during the two time periods in which most of the commercial catch in 1999 was taken. The model's estimates represent the fraction of the tagged population exploited by the fishery if there was no migration. Using the reported landings for the two periods, the biomass of fish in 3KL is also estimated.
Download or read book Spawning Dynamics Seasonal Movements and Population Structure of Atlantic Cod Gadus Morhua in the Gulf of Maine written by Douglas Robert Zemeckis and published by . This book was released on 2016 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atlantic cod (Gadus morhua) have been a principal target species in New England's ground fish fishery since the 17th century. In recent decades, the Gulf of Maine cod stock has experienced substantial declines in abundance, and many historical spawning components have been depleted, reducing stock productivity and stability. Managing stock rebuilding has been difficult because of many uncertainties in population dynamics. Therefore, to support stock rebuilding efforts, the objective of this dissertation was to improve our understanding of the spawning dynamics, seasonal movements, and population structure of Atlantic cod in the Gulf of Maine. An interdisciplinary review of the scientific literature demonstrated that the cod population off New England can be described as a metapopulation that includes genetically-distinct spring- and winter spawning subpopulations which are comprised of many finer-scale spawning components. Available information indicates that current management unit boundaries do not accurately represent the biological population structure. Therefore, a modification of current management units is recommended to provide a more accurate representation of the underlying biological population processes. Review of the cod spawning literature indicated that cod spawn in multiple locations and seasons, and the complex cod mating system can be described as a "lek". The aspects of cod spawning dynamics most important for consideration by fishery managers are the spatial and temporal extent ofspawning, the behavior of spawners, and the reproductive contributions of older age-classes. The application of spawning closures as part of a multidisciplinary approach to fisheries management is recommended to prevent disruption of spawning and extirpation of semi-discrete spawning components. Spawning site fidelity contributes to the formation and maintenance of the observed metapopulation structure and delays the recolonization of abandoned spawning sites by limiting reproductive connectivity. Acoustic telemetry was used to document prevalent, fine-scale spawning site fidelity with respect to an inshore spawning site in the western Gulf of Maine. Movements away from the inshore spawning site were studied using conventional tags, acoustic telemetry, and geolocation utilizing data from archival data storage tags. Connectivity was documented among multiple inshore spawning sites, which is apparently sufficient to promote gene flow within the western subpopulation. Cod were primarily residential within the western Gulf of Maine. After spawning inshore, cod moved to offshore feeding grounds from summer to early winter. Deep offshore basins served as overwintering habitat before initiation of an inshore spring spawning migration. Results from this dissertation have been valuable for informing fishery managers in the development of regulations to protect cod spawning aggregations. Findings are contributing to ongoing processes to investigate cod population structure and reevaluate current management units. This dissertation provides a more holistic understanding of cod population dynamics, which is expected to contribute to the development of future fishery management plans and stock assessment models that work towards achieving stock rebuilding.
Download or read book Overview of Atlantic Cod Gadus Morhua Stock Structure in NAFO Subdivision 3Ps Inferred from Tagging Studies written by John Brattey and published by . This book was released on 1996 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Exploitation and Movements of Atlantic Cod Gadus Morhua in NAFO Divs 3KL Further Updates Based on Tag Returns During 1995 2004 written by John Brattey and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Movements of Atlantic Cod Gadus Morhua in NAFO Subdiv 3Ps and Updated Estimates of Exploitation from Tagging Experiments in 1997 2002 written by and published by . This book was released on 2002 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: A mark-recapture study of Atlantic cod, initiated off southern Newfoundland in 1997, was continued in 2002. The purpose of the study was to provide information on movement patterns of inshore & offshore cod and to obtain estimates of exploitation rates on different components of the stock. This report presents annual estimates of exploitation for each tagging experiment during 1997-2002 and summarizes the spatial & temporal distribution of recaptures of tagged cod released in various regions of the south coast during 1997-2002 and reported as recaptured up to the end of September 2002. The report also illustrates the distribution of recaptures from tagging.
Download or read book Lower Bounds on the Exploitation of Cod Gadus Morhua in NAFO Divs 3KL and Subdiv 3Ps During 1997 1999 from Tagging Experiments written by Cadigan, Noel G and published by . This book was released on 2000 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Estimation of Cod Gadus Morhua Growth in NAFO Subdiv 3Ps and Divs 3KL in 1997 1999 from Tagging Experiments written by Noel G. Cadigan and published by . This book was released on 2000 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mechanisms and Consequences of Variation in the Migratory Behaviour of Atlantic Cod Gadus Morhua L in the Northern Gulf of St Lawrence written by Arnault Le Bris and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis aimed to characterize individual variation in the migratory behaviour of Atlantic cod (Gadus morhua) in the northern Gulf of St. Lawrence, and to assess the consequences of this variation on the structure and management of the population. First, I reviewed interplays between genetic, environmental, and social factors in the evolution and maintenance of individual variation in the migratory behaviour of marine fishes, with an emphasis on Atlantic cod. Evidence of fine-grained responses to environmental changes suggested that phenotypic plasticity is a substantial source of variation in migratory behaviours. However, because the genetic basis of migratory traits has been overlooked, the relative contributions of genetic, environment, and genetic by environment interactions have not been quantified for any marine fishes. Within the cod population from northern the Gulf of St. Lawrence, reconstruction of migration routes of cod equipped with data-storage tags revealed undocumented concurrent presence of resident and migratory individuals. Depth time-series analyses revealed high individual variability in vertical patterns of migration. Consequences of the observed individual variation in migration propensity on the structure of the population were then evaluated. Focusing on the fjord of Bonne Bay where I previously identified resident and homing cod, I assessed the degree of demographic dependency of Bonne Bay cod with Gulf cod. Although local recruitment occurs, Bonne Bay does not harbour an abundance of adult cod and external sources of recruitment are substantial. The bay however provides a nursery and a spawning area for Atlantic cod. Finally, I quantified effects of variation in adult migratory behaviour and population density distribution on the performance of a fishery closed area designed to protect a spawning aggregation. Closed area usage by free-ranging individuals revealed disproportional levels of protection between migratory groups. Estimated population density distributions during two periods of contrasted abundance level suggested that, when a closed area is located on the core of a population distribution, density-dependent contraction of population range increases closed area performance. Both individual closed area usage and population density distribution indicated that a displacement south and a reduction of the enforcement period would improve the performance of the study closed area.
Download or read book Homing Population Structure and Management of Atlantic Cod Gadus Morhua with Emphasis on Spawning at Bar Haven in Placentia Bay Newfoundland written by Dave Robichaud and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spawning and Life History Information for North Atlantic Cod Stocks written by K. M. Brander and published by . This book was released on 2005 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
