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 Canadian Journal of Fisheries and Aquatic Sciences written by and published by . This book was released on 1998 with total page 824 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Distribution of Cod gadus Morhua L in Relation to Oxygen Level and Temperature in the Northern Gulf of St Lawrence written by Denis d'Amours and published by . This book was released on 1992 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Animal Behaviour Abstracts written by and published by . This book was released on 1996 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atlantic Cod written by George A. Rose and published by John Wiley & Sons. This book was released on 2019-02-26 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive handbook, covering all aspects of the Atlantic cod including the biology, ecology, life histories, behaviour, commercial exploitation and conservation Not only is Atlantic cod one of the most valuable food fish in the world’s oceans, it is an important component of North Atlantic ecosystems and has been subject to much research into its biology, ecology and exploitation. After hundreds of years of exploitation, overfishing in the last half of the 20th Century caused many stocks to collapse, most famously the Northern cod stock off Newfoundland and Labrador, Canada. Since then, most cod stocks have been better researched and managed, but remain in a variety of states, from fully recovered to continued decline. This book, written by world experts, describes that research and management, and the importance of cod and its fisheries on North Atlantic cultures and economies, with impacts well beyond the range of the species. Atlantic Cod: Bio-Ecology of the Fish offers insightful chapter coverage of cod nomenclature, taxonomy, phylogeny and morphology; physiology and ecophysiology; reproduction and spawning behavior; early life history and pre-recruitment processes; migrations, movements and stock identity; feeding, growth and energetics; the place of cod in the ecosystem; the exploitation of cod through history and present day commercial fisheries and precautionary management for sustainable fisheries; impacts of climate change on cod biology and ecology; and the future of the species and its fisheries. Discusses the major commercial importance of Atlantic cod through history Provides a comprehensive treatment of the bio-ecology of the most researched and highly exploited fully marine species Examines how the decline (and recovery) of cod stocks is of great political and scientific interest An essential purchase for marine fisheries scientists Atlantic Cod: Bio-Ecology of the Fish is a vital book for all fisheries scientists, managers and fish biologists.
Download or read book A Study of Northern Atlantic Cod Gadus Morhua of Eastern Newfoundland and Labrador as a Metapopulation written by R. Kent Smedbol and published by . This book was released on 1999 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Oceanic Abstracts written by and published by . This book was released on 1996 with total page 802 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Main Prey and Predators and Estimates of Mortality of Atlantic Cod Gadus Morhua in the Northern Gulf of St Lawrence During the Mid 1980s Mid 1990s and Early 2000s written by C. Savenkoff and published by . This book was released on 2006 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Interactions in the Marine Benthos written by Stephen J. Hawkins and published by Cambridge University Press. This book was released on 2019-08-29 with total page 535 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive account of how abiotic and biotic interactions shape patterns of coastal marine biodiversity and ecosystem processes globally.
Download or read book Incorporating Depth dependent Differences in Fishing Efficiency Among Vessels in the Research Survey Time Series for Atlantic Cod Gadus Morhua in the Southern Gulf of St Lawrence written by Canada. Department of Fisheries and Oceans. Gulf Region. Science Branch and published by Moncton, N.B. : Fisheries and Oceans Canada. This book was released on 1995 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fish Reproductive Biology written by Tore Jakobsen and published by John Wiley & Sons. This book was released on 2016-03-21 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fish recruitment is a key process for maintaining sustainable fish populations. In the marine environment, fish recruitment is carried out in many different ways, all of which have different life history strategies. The objective of this book is to argue for greater linkages between basic and applied research on fisheries recruitment, and assessment and management of exploited fish stocks. Following an introductory chapter, this second edition of Fish Reproductive Biology is organized into 3 main sections: Biology, Population Dynamics and Recruitment Information Critical to Successful Assessment and Management Incorporation of Reproductive Biology and Recruitment Considerations into Management Advice and Strategies The authors collectively bring a wide range of diverse experience in areas of reproductive biology, fisheries oceanography, stock assessment, and management. Fully updated throughout, the book will be of great interest to a wide audience. It is useful as a textbook in graduate and undergraduate courses in fisheries biology, fisheries science, and fisheries resource management and will provide vital information for fish biologists, fisheries scientists and managers.
Download or read book Revised Population Model for Atlantic Cod Gadus Morhua in the Southern Gulf of St Lawrence written by D. P. Swain and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Homing Mechanisms and Mating Systems of Atlantic Cod written by Matthew J. S. Windle and published by . This book was released on 2006 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Risk Evaluation and Biological Reference Points for Fisheries Management written by National Research Council Canada and published by NRC Research Press. This book was released on 1993 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Papers presented: 1) Reference points for fisheries management: the western Canadian experience; 2) Reference points for fisheries management: the eastern Canadian experience; 3) Reference points for fisheries management: the ICES experience; 4) Spawning stock biomass per recruit in fisheries management: foundation and current use; 5) The development of a management procedure for the South African anchovy resource; 6) How much spawning per recruit is enough?; 7) The behaviour of Flow, Fmed and Fhigh in response to variation in parameters used for their estimation; 8) The Barents Sea capelin stock collapse: a lesson to learn; 9) Variance estimates for fisheries assessment: their importance and how best to evaluate them; 10) Evaluating the accuracy of projected catch estimates from sequential population analysis and trawl survey abundance estimates; 11) Bootstrap estimates of ADAPT parameters, their projection in risk analysis and their retrospective patterns; 12) Analytical estimates of reliability for the projected yield from commercial fisheries; 13) Risk evaluation of the 10% harvest rate procedure for capelin in NAFO Division 3L; 14) Using jackknife and Monte Carlo simulation techniques to evaluate forecast models for Atlantic salmon; 15) Monte Carlo evaluation of risks for biological reference points used in New Zealand fishery assessments; 16) A comparison of event free risk analysis to Ricker spawner-recruit simulation: an example with Atlantic menhaden; 17) Choosing a management strategy for stock rebuilding when control is uncertain; 18) Risks and uncertainties in the management of a single-cohort squid fishery: the Falkland Islands Illex fishery as an example; 19) Risks of over- and under-fishing new resources; 20) Estimation of density-dependent natural mortality in British Columbia herring stocks through SSPA and its impact on sustainable harvesting strategies; 21) The comparative performance of production-model and ad hoc tuned VPA based feedback-control management procedures for the stock of Cape hake off the west coast of Africa; 22) A proposal for a threshold stock size and maximum fishing mortality rate; 23) Biological reference points for Canadian Atlantic gadoid stocks; 24) Stochastic locally-optimal harvesting; 25) ITQ based fisheries management; 26) Bioeconomic methods for determining TACs; 27) Management strategies: fixed or variable catch quotas; 28) Bioeconomic impacts of TAC adjustment strategies: a model applied to northern cod; 29) Experimental management programs for two rockfish stocks off British Columbia; 30)A brief overview of the experimental approach to reducing uncertainty in fisheries management; 31) Fisheries management organizations: a study of uncertainty.
Download or read book Resiliency of Gadid Stocks to Fishing and Climate Change written by Gordon H. Kruse and published by University of Alaska Press. This book was released on 2008 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Behaviors Habitat Preferences and Ecology of Distinct Atlantic Cod Phenotypes in the Gulf of Maine written by Christian W. Conroy and published by . This book was released on 2016 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diversity in spatial behaviors and associated divergence of phenotypes are common across fish taxa. Behavior and phenotype are shaped by geology, oceanography, climate, prey availability, predation, competition, and the cumulative effects of these factors on past generations. In stochastic natural systems, diversity may enhance stability, resilience, and even productivity of populations and population complexes. Among the behaviors of fish that vary between and within populations is migration. Migration is most often related to travel between spawning and feeding grounds and is integral to population productivity. However, members of the same species and even population may adopt vastly different migratory strategies, including long-distance migration and strict site residence. Across taxa, these strategies are often correlated with metabolism, growth, fecundity, and productivity. In the context of fisheries management, the spatial and physiological variance associated with different migratory strategies may lead to complicated or unexpected responses by managed stocks to disturbance. Understanding the processes that lead to the adoption and maintenance of migratory strategies, how these behaviors affect habitat use, and how behavior and habitat are related to phenotype, are necessary to the development of effective fisheries management policies and regulations. Atlantic cod (Gadus morhua) adopt a range of spatial behaviors across the North Atlantic, with effects on productivity and growth. As in other fish taxa, resident cod have lower growth rates and fecundity than conspecific migrants. Many identified groups of cod residents are physically isolated from nearby migrants, offering little insight to many of the important questions surrounding these behavioral strategies. In the Gulf of Maine, sympatric resident and migrant cod have been identified from a number of locations. This research focused on the interactions between behavior, habitat use, and phenotype of cod in the Gulf of Maine. A visually distinct cod phenotype found at several locations throughout the region features red pigmentation and a deeper body than the familiar form of cod. As is observed elsewhere in the species range, this red phenotype remains in relatively shallow, structured habitats and grows at lower rates compared to the familiar migrant olive phenotype. The connection between low growth, resident behavioral strategy, and body morphology (deep vs. fusiform) has been observed in a number of salmonids and may be common among fishes that occupy diverse environments. Red phenotypes were highly selective of certain habitats, and the spatial behaviors of all cod regardless of phenotype changed seasonally, possibly due to the influence of seasonal changes in environmental conditions like temperature. Phenotype-specific behaviors were consistent both inshore and offshore, generally following resident and migrant strategies. Offshore red phenotypes expressed strict site fidelity, but this may in part be due to habitat limitation, as nearshore red phenotypes adhered to shallow depths but moved up and down the coast. Regardless of phenotype, cod utilize shallow, structured habitats at an offshore site, Cashes Ledge, during the warm periods of the summer and fall. Habitat use is focused on the most complex habitats in the shallowest peaks of the ledge, which often are covered in thick macroalgal stands. The shallow structured habitats preferred by red phenotypes and utilized by all cod are not available to widely used groundfishing gear, thus limiting fishing pressure on these important habitats. At the same time, shallow coasts and ledges will be affected by warming surface waters and increased storm activities associated with ongoing climate change. The importance of these habitats and their utilization by cod relative to their adopted migratory strategies may impact population-scale responses of cod to future management activities.
Download or read book Seasonal Biological Cycles in Atlantic Cod Gadus Morhua and Implications for Fisheries and Management written by Luiz Gonzaga Silveira Mello and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
