Download or read book Incorporating Uncertainty Into Estimates of Atlantic Cod Gadus Morhua Capelin Mallotus Villosus and Arctic Cod Boreogadus Saida Consumption by Harp Seals Pagophilus Groenlandicus in NAFO Divisions 2J3KL written by Garry B. (Garry Bruce) Stenson 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 Ecosystem Based Fisheries Management written by Jason Link and published by Cambridge University Press. This book was released on 2010-10-07 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Responsible fisheries management is of increasing interest to the scientific community, resource managers, policy makers, stakeholders and the general public. Focusing solely on managing one species of fish stock at a time has become less of a viable option in addressing the problem. Incorporating more holistic considerations into fisheries management by addressing the trade-offs among the range of issues involved, such as ecological principles, legal mandates and the interests of stakeholders, will hopefully challenge and shift the perception that doing ecosystem-based fisheries management is unfeasible. Demonstrating that EBFM is in fact feasible will have widespread impact, both in US and international waters. Using case studies, underlying philosophies and analytical approaches, this book brings together a range of interdisciplinary topics surrounding EBFM and considers these simultaneously, with an aim to provide tools for successful implementation and to further the debate on EBFM, ultimately hoping to foster enhanced living marine resource management.

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 Roles of Capelin Climate Harp Seals and Fisheries in the Failure of 2J3KL northern Cod to Recover written by Alejandro Daniel Buren and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Atlantic cod (Gadus morhua) fishery sustained the way of life of Newfoundlanders during centuries. Its collapse in the early 1990s represented a socio-economic and cultural crisis. Despite the fishing moratorium imposed in 1992, the northern cod stock (NAFO Divs 2J3KL) is still a shadow of its former self. Several hypotheses have been offered to explain this lack of recovery, many involving ecological interactions between harp seals (Pagophilus groenlandicus) and cod. However, these contentions are based on indirect evidence, while formal assessments are lacking. Availing of long term data series, I addressed the two simplest ways in which harp seals might impede cod's recovery: predation and competition for food resources, particularly for the major forage fish in the system: capelin (Mallotus villosus). I found no supporting evidence for either hypothesis. The biomass dynamics of northern cod during the period 1985-2007 were driven by an interplay between fisheries removals and food (capelin) availability, and potentially affected by water temperature. Harp seal predation was not an important driver of the stock. I provide evidence that a regime shift occurred on the Newfoundland and Labrador Shelf ecosytem during the early 1990s, linking community reorganization to physical perturbations. The capelin stock is regulated by bottom-up processes: ocean climate adn the regime shift, acting via food availability. I found also that Atlantic cod did not change its diet following the regime shift. In addition, the diet of Atlantic cod overlapped to a greater extent with the diet of Greenland halibut than with harp seals' diet. These findings constitute mounting evidence against the consumptive competition hypothesis. The results presented in this thesis are important for the development of ecosystem approaches to fisheries management and raise questions as to the potential impacts of climate change on the structure and productivity of the Newfoundland and Labrador Shelf marine ecosystem. Also, this suggests that reductions in the harp seal population are unlikely to enhance the rebuilding of the northern cod stock; management efforts should be focused on protecting cod itself and the lower trophic levels.

Download or read book Quantifying Uncertainty in Estimates of Atlantic Cod Gadus Morhua Consumption by Harp Seals Phoca Groenlandica written by and published by . This book was released on 2004 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Estimates of consumption by predators form one piece of information required to determine the impact of predators on the recovery of cod stocks. The objective of this paper is to describe the model used to estimate prey consumption by harp seals and to assess the sensitivity of the estimate to model parameters. Consumption of Atlantic cod by harp seals in the northern Gulf of St. Lawrence was estimated for 1985-2003. Estimates were obtained by combining information on harp seal abundance, energy requirements, diet composition, and the distribution of animals. Current estimates differ from earlier studies by attempting to incorporate variability in population estimates, energy requirements, seal distribution, & diet composition.

Download or read book Quantifying Uncertainity in Estimates of Atlantic Cod Gadus Morhua Consumption by Harp Seals Phoca Groenlandica written by G. B. Stenson and published by . This book was released on 2004 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Estimated Consumption of Atlantic Cod Gadus Morhua and Some Other Prey by Grey Seals Halichoerus Grypus and Harp Seals Phoca Groenlandica in the Southern Gulf of St Lawrence NAFO Division 4T written by Michael O. Hammill and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Estimated Consumption of Atlantic Cod Gadus Morhua and Some Other Prey by Grey Seals Halichoerus Grypus and Harp Seals Phoca Groenlandica in the Southern Gulf of St Lawrence NAFO Division 4T written by Michael O. Hammill and published by . This book was released on 2002 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Estimated Consumption of Atlantic Cod Gadus Morhua by Harp Seals Phoca Groenlandica in NAFO Zone 4RS written by Michael O. Hammill and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Estimated Consumption of Atlantic Cod Gadus Morhua by Harp Seals Phoca Groenlandica in NAFO Zone 4RS written by Michael O. Hammill and published by . This book was released on 2004 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Inter annual Variability in Predation by Atlantic Cod Gadus Morhua on Capelin Mallotus Villosus and Other Prey Off Southern Labrador and Northeastern Newfoundland in Autumn written by G. R. Lilly and published by . This book was released on 1989 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Estimated Consumption of Atlantic Cod Gadus Morhua and Some Other Prey by Grey Seals Halichoerus Grypus and Harp Seals Phoca Groenlandica in the Southern Gulf of St Lawrence NAFO Division 4T written by and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the 4R assessment this diet was separated into a high cod diet for the southern part of 4R(d) and a low cod diet for the northern part of 4R(abc). [...] With the exception of a few stomachs collected from grey seals from the Magdalen Islands in the early 1990s, Information is lacking on prey consumed by grey seals in the central or northern portion of NAFO zone 4T , around the regions of Gaspe and the Magdalen Islands, an area where cod are known to be more abundant. [...] Lawrence overwinter are limited and our estimates are based on assumptions concerning changes in population size and the component of 4T cod in the diet consumed in 4VN. [...] This sample likely underestimates cod consumption because cod leave the Gulf during the winter when sampling of seals in both the Estuary and the Magdalen Island area occurred. [...] The assessment of competition between seals and commercial fisheries in the North Sea and the Antarctic.

Download or read book Modelling the Growth of Northern Cod written by Zakiyah Mohammed and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We develop a body size growth model of Northern cod (Gadus morhua) in Northwest Atlantic Fisheries Organization (NAFO) Divisions 2J3KL during 2009-2013. We use individual length-at-age data from the bottom trawl survey in these divisions during 2009-2013. We use the Von Bertalanffy (VonB) model extended to account for between-individual variations in growth, and variations that may be caused by the methods which fish are caught and sampled for length and age measurements. We assume between-individual variation in growth appears because individuals grow at a different rate (k), and they achieve different maximum sizes (l∞). We also included measurement error in length and age in our model since ignoring these errors can lead to biased estimates of the growth parameters. We use the structural errors-invariables (SEV) approach to estimate individual variation in growth, ageing error variation, and the true age distribution of the fish. Our results shows the existence of individual variation in growth and ME in age. According to the negative log likelihood ratio (NLLR) test, the best model indicated: 1) different growth patterns across divisions and years. 2) Between individual variation in growth is the same for the same division across years. 3) The ME in age and true age distribution are different for each year and division.

Download or read book Stock Assessment of Atlantic Cod Gadus Morhua in NAFO Divisions 4X5Y written by Canadian Science Advisory Secretariat and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Whales Seals Fish and Man written by A. Schytte Blix and published by Elsevier. This book was released on 1995-10-06 with total page 735 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume outlines the major findings from the Norwegian research programme on whales and seals in Norwegian waters. A wide range of topics are covered, including physiological aspects, social organization, population dynamics, stock assessment and management. The book will be of great value to scientists and managers, as well as to members of the general public interested in environmental issues.

Download or read book Marine Fishes of Arctic Canada written by Brian W. Coad and published by University of Toronto Press. This book was released on 2018-01-01 with total page 633 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine Fishes of Arctic Canada is an accessible and up-to-date study on the diverse marine fish population existing in Canadian waters.

Download or read book SEA KNOWS NO BOUNDARIES cl written by and published by University of Washington Press. This book was released on with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 100-year story of the International Council for the Exploration of the Sea, a scientific collaboration originally formed by eight northern European nations to address problems of overfishing in the North Atlantic. The author uses archival research and interviews to profile key ICES members and to provide insight into the relationship between fisheries science and biological oceanography. Contains a small section of historical photographs.