Download or read book The Effects of Trawl Performance and Fish Behaviour on Th Catching Efficiency of Sampling Trawls written by Arill Engås and published by . This book was released on 1991 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The effects of trawl performance and fish behaviour on the catching efficiency of sampling trawls written by Arill Engås and published by . This book was released on 1991 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Gear Modifications on the Trawl Performance and Catching Efficiency of the West Coast Upper Continental Slope Groundfish Survey Trawl written by Alaska Fisheries Science Center Nationa and published by BiblioGov. This book was released on 2013-06 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the 1970's the National Oceanic and Atmospheric Administration (NOAA) was made to manage our oceanic and atmospheric resources. The Alaska Fisheries Science Center is the research branch for marine life and coastal oceans off parts of the U.S. west coast and Alaska. This includes the Eastern Bering Sea where some the worlds most important commercial fishing takes place. Their mission is to develop and maintain scientific exploration to help understand and manage that region's environment. Over the years there have been many reports published which discuss their findings; this is one of them.
Download or read book Effects of Gear Modifications on the Trawl Performance and Catching Efficiency of the West Coast Upper Continental Slope Groundfish Survey Trawl written by Robert Russell Lauth and published by . This book was released on 1998 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Future of Fisheries Science in North America written by Richard J. Beamish and published by Springer Science & Business Media. This book was released on 2009-02-07 with total page 736 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fisheries science in North America is changing in response to a changing climate, new technologies, an ecosystem approach to management and new thinking about the processes affecting stock and recruitment. Authors of the 34 chapters review the science in their particular fields and use their experience to develop informed opinions about the future. Everyone associated with fish, fisheries and fisheries management will find material that will stimulate their thinking about the future. Readers will be impressed with the potential for new discoveries, but disturbed by how much needs to be done in fisheries science if we are to sustain North American fisheries in our changing climate. Officials that manage or fund fisheries science will appreciate the urgency for the new information needed for the stewardship of fish populations and their ecosystems. Research organizations may want to keep some extra copies for a future look back into the thoughts of a wide range of fisheries professionals. Fisheries science has been full of surprises with some of the surprises having major economic impacts. It is important to minimize these impacts as the demand for seafood increases and the complexities of fisheries management increase.
Download or read book Ecoacoustics written by Almo Farina and published by John Wiley & Sons. This book was released on 2017-05-22 with total page 425 pages. Available in PDF, EPUB and Kindle. Book excerpt: The sounds produced by geophonic, biophonic and technophonic sources are relevant to the function of natural and human modified ecosystems. Passive recording is one of the most non-invasive technologies as its use avoids human intrusion during acoustic surveys and facilitates the accumulation of huge amounts of acoustical data. For the first time, this book collates and reviews the science behind ecoaucostics; illustrating the principles, methods and applications of this exciting new field. Topics covered in this comprehensive volume include; the assessment of biodiversity based on sounds emanating from a variety of environments the best technologies and methods necessary to investigate environmental sounds implications for climate change and urban systems the relationship between landscape ecology and ecoacoustics the conservation of soundscapes and the social value of ecoacoustics areas of potential future research. An invaluable resource for scholars, researchers and students, Ecoacoustics: The Ecological Role of Sounds provides an unrivalled set of ideas, tools and references based on the current state of the field.
Download or read book Canadian Journal of Fisheries and Aquatic Sciences written by and published by . This book was released on 2013 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of Northwest Atlantic Fishery Science written by and published by . This book was released on 1998 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Estimating Confidence in Trawl Efficiency and Catch Quantification for the Eastern Bering Sea Shelf Survey written by Duane E. Stevenson and published by . This book was released on 2016 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Alaska Fisheries Science Center’s Resource Assessment and Conservation Engineering (RACE) Division has been conducting annual multispecies bottom trawl surveys of the eastern Bering Sea continental shelf using the same standardized gear and trawling procedures since 1982. The data and results from these surveys are available to the general public. However, because the use of these data and results by researchers outside RACE is not monitored, users should be aware of the limitations of this information and design their analyses accordingly. In particular, there are multiple sources of variability in the sampling efficiency of the trawl gear used for the survey, both species- and size-specific, that may affect inferences about the nature of the overall catches and relative animal densities. Furthermore, the quality and specificity of catch quantification (weighing and counting) at sea of many taxa can vary depending on the overall size of the catch and the species composition of the sample, particularly for non-commercial taxa of small size. This document is an assessment of the relative reliability of survey catch weights, numbers, and catch per unit effort estimates derived from the eastern Bering Sea shelf bottom trawl survey and is intended to serve as a guideline for researchers interested in using the survey data and results. Included within is a confidence matrix of sampling efficiency and catch quantification for all fishes and invertebrates identified during the shelf survey. [doi:10.7289/V5/TM-AFSC-335 (http://dx.doi.org/10.7289/V5/TM-AFSC-335)]
Download or read book Marine Fish Behaviour in Capture and Abundance Estimation written by A. Ferno and published by Wiley. This book was released on 1995-01-17 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this new book, experts from the Institute of Marine Research in Bergen synthesize our current understanding of both basic and applied fish behaviour and, in light of the many advances of recent years, examine the influence of fish behaviour on fish capture and abundance estimation. Marine Fish Behaviour is an essential source of up-to-date and topical information an practical, professional guidance for fisheries technologists, gear manufactureres fisheries researchers and fishermen.
Download or read book Advances in Invertebrates and Fish Telemetry written by Jean Paul Lagardere and published by Springer Science & Business Media. This book was released on 1998-10-31 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the Second Conference of Fish Telemetry in Europe held in La Rochelle, April 5-9, 1997
Download or read book A Guide to Bycatch Reduction in Tropical Shrimp trawl Fisheries written by Steve Eayrs and published by Food & Agriculture Org.. This book was released on 2007 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bycatch is the unwanted or non-target part of the catch taken by fishermen. It is either discarded at sea or used for human or animal consumption. The capture of bycatch may pose a threat to species diversity and ecosystem health because this part of the catch is usually unregulated. In tropical shrimp-trawl fisheries, bycatch often consists of juvenile food-fish species and is therefore a threat to food security and sustainable fisheries production. Bycatch is a global problem that must be addressed. This Guide to Bycatch Reduction in Tropical Shrimp-Trawl Fisheries is designed for fishermen, net makers, fishing technologists and others interested in a practical guide to the design, use and operation of effective bycatch reduction devices. Fishery managers, policy-makers and legislators will find this guide useful to help develop specifications governing the design and application of these devices in a shrimptrawl fishery. The issue of bycatch is not going away and scrutiny of fishing activity is increasing. All fishermen are strongly urged to use appropriate bycatch reduction measures to help maintain the productivity of the fishery and the long term prosperity of the fishing industry. By responding appropriately, fishermen can help to protect the marine environment and assist global food security both now and in the future. Also published in French and Spanish.
Download or read book Fish Behaviour in Relation to Fishing Operations written by Clement S. Wardle and published by . This book was released on 1993 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fish Atlas of the Celtic Sea North Sea and Baltic Sea written by Henk J. L. Heessen and published by Brill Wageningen Academic. This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first complete survey of all marine fish species from the North Sea, Baltic Sea and Irish Sea. European research focuses on commercially interesting marine fish. This atlas presents the current data of all Western European species in the period 1977 to 2013.--
Download or read book Measuring the Ecosystem Impacts of Commercial Shrimp Trawling and Other Fishing Gear in Core Sound North Carolina Using Ecological Network Analysis written by Rebecca Anne Deehr and published by . This book was released on 2012 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt: The impacts of commercial trawling are well documented, especially alteration of benthic environments, removal of targeted and by-catch species, and alteration of food webs. I investigated and modeled the impacts of shrimp trawling on the estuarine ecosystem in Core Sound, North Carolina. Since 1978, the North Carolina Division of Marine Fisheries has enforced no-trawling rules in nursery areas, but most of Core Sound is open to trawling. This "natural experiment" allowed me to compare the ecosystem impacts trawling using ecological network models. I used field collections, fisheries data from the NC Trip Ticket program, and Ecopath network modeling software to create four network models of areas open and closed to shrimp trawling during spring (2007) and fall (2006 and 2007). Each model consisted of 65 compartments (including non-living detritus, by-catch, producers, and various invertebrate and vertebrate consumers), and harvests by different types of fishery gears (crab pots, gill nets, haul seines, and pound nets in closed areas; shrimp trawls, skimmer trawls were added to the models in areas open to trawling). Approximately 12,000 shrimp trawling trips occurred from 2001 - 2007 in areas open to trawling, suggesting the potential for large trawling impacts. Based on the benthic sampling, shrimp trawling had a major impact on the Core Sound ecosystem. Contrary to expectation, biomass (g C/m2) of infaunal benthic invertebrates, especially deposit-feeding polychaetes, was significantly greater in areas open to trawling. Meiofaunal biomass was significantly greater in the closed areas. Field collections of fish and invertebrates revealed that there was more biomass (g C/m2) of benthic-invertebrate feeders (such as spot, pinfish and blue crabs) in areas closed to trawling. These results suggest a trophic cascade due to trawling may have occurred in the open areas, whereby trawls removed benthic-feeding fishes and blue crabs, released their prey (benthic polychaetes) from predation pressure, and lowered the abundance of meiofauna (prey of the polychaetes). Alternatively, the dead biomass from by-catch could fuel the growth in polychaetes and other benthos due to a direct subsidy from trawling. Further experimental work is required to test these model-derived hypotheses. Ecopath outputs were validated using stable isotopes and examined for system-wide impacts. The concentrations of stable isotopes of [delta]15N and [delta]13C were compared to Ecopath effective trophic levels. Trophic fractionation occurred across trophic levels, and results were comparable to published studies (for each unit effective trophic level increase there was a fractionation of +2.637% for [delta]15N and +1.084% for [delta]13C). Ecopath whole-ecosystem metrics indicated that net primary productivity, trophic efficiency, ascendency, and net primary production: respiration ratios were greater in the areas open to trawling; total system throughput and Finn Cycling Index were greater in the areas closed to trawling. Additional compartment-level comparisons were made using mixed trophic impacts (MTI) and keystoneness index (KSI). The MTI analysis indicated that shrimp trawling in Core Sound caused large negative impacts only on jellyfish, a bycatch species. The KSI indicated that sea turtles and brown pelicans were keystone groups (large influence relative to their biomass) overall in Core Sound. Spot, bluefish and Atlantic croaker also had high KSI in closed areas. Pink shrimp, white shrimp and bluefish all had high KSIs in the open areas, suggesting that they played a key role in the ecosystem's trophic structure where trawling was allowed. These Ecopath models can be useful tools for resource managers to better understand the direct and indirect impacts of (shrimp trawl) fishing in Core Sound. Future work should include the creation of annualized models and simulation modeling using Ecosim to explore different management scenarios.
Download or read book Biological Sampling in the Deep Sea written by Malcolm R. Clark and published by John Wiley & Sons. This book was released on 2016-03-16 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: The deep sea covers over 60% of the surface of the earth, yet less than 1% has been scientifically investigated. There is growing pressure on deep-sea resources and on researchers to deliver information on biodiversity and the effects of human impacts on deep-sea ecosystems. Although scientific knowledge has increased rapidly in recent decades, there exist large gaps in global sampling coverage of the deep sea, and major efforts continue to be directed into offshore research. Biological Sampling in the Deep Sea represents the first comprehensive compilation of deep-sea sampling methodologies for a range of habitats. It reviews the real life applications of current, and in some instances developing, deep-sea sampling tools and techniques. In creating this book the authors have been able to draw upon the experiences of those at the coal face of deep-sea sampling, expanding on the existing methodological texts whilst encompassing a level of technical detail often omitted from journal publications. Ultimately the book will promote international consistency in sampling approaches and data collection, advance the integration of information into global databases, and facilitate improved data analyses and consequently uptake of science results for the management and conservation of the deep-sea environment. The book will appeal to a range of readers, including students, early-career through to seasoned researchers, as well as environmental managers and policy makers wishing to understand how the deep-sea is sampled, the challenges associated with deep survey work, and the type of information that can be obtained.
Download or read book Behavior of Marine Fishes written by Pingguo He and published by John Wiley & Sons. This book was released on 2011-06-09 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt: BEHAVIOR OF MARINE FISHES BEHAVIOR OF MARINE FISHES: Capture Processes and Conservation Challenges Understanding fish behavior in relation to capture processes in marine fisheries is of fundamental importance to reducing bycatch and discards, and to enhancing marine fisheries conservation efforts. A thorough understanding of this allows commercial fishers to more effectively capture target species while reducing the catch of unwanted species. Behavior of Marine Fishes: Capture Processes and Conservation Challenges provides the reader with principles, patterns, and characteristics on fish behavior and fish capture processes using several types of important commercial fishing gears. The book also highlights conservation challenges facing the marine capture fisheries in efforts to maintain sustainable use of marine resources and to reduce negative impacts to the marine ecosystem. This volume, with contributions from leading applied fish behaviorists and fishing gear technologists from around the world, will be a valuable reference for researchers, fishing gear technologists, fisheries managers, students, and conservationists. SPECIAL FEATURES: Synthesis of current research and valuable knowledge that will help reduce bycatch and discards in commercial fisheries Review of basic fish behavioral principles and patterns and their relation to capture methods and conservation efforts Contributions from leading international applied fish behaviorists and fishing gear technologists
