Download or read book Design and Testing of Trawls written by Aleksandr Lʹvovich Fridman and published by . This book was released on 1979 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Design and Testing of a Divided Trawl for Comparative Fishing Experiments written by J. H. B. Robertson and published by . This book was released on 1990 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Design and Testing of a Divided Trawl for Comparative tfishing Experiments written by J Robertson and published by . This book was released on 1990 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Suggested Design Modifications to the URI 340 Series Trawl Following Tank Testing written by Geoffrey A. Motte and published by . This book was released on 1979 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Design and Testing of a Prototype Electrified Nephrops Trawl written by P. A. M. Stewart and published by . This book was released on 1971 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The design and field testing of an electro shrimp trawling system written by Norman L. Pease and published by . This book was released on 1967 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of Seabed Friendly Bottom Trawls written by Truong X. Nguyen and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Concerns over the impacts of fishing practices, especially bottom trawling, on the ocean environment have been expressed at the local, national and international scale. While physical alterations of the seabed by bottom trawling are known to occur, the biological effects on benthic communities and their recovery rates depend on substrate types, depth, and natural disturbance in the fishing area, as well as how trawl gears are designed and operated. In this thesis, I investigate different key research aspects regarding the subject of development of seabed friendly bottom trawls, in particular shrimp trawling in Newfoundland and Labrador, Canada. The complementary use of different research approaches (e.g., underwater video observations, numerical modeling and simulation, flume tank testing, and at-sea experiments) were applied for each of the research questions. First, I investigated the behavioural interactions of individual snow crab in response to the rockhopper footgear of a traditional inshore shrimp trawl used in Newfoundland and Labrador, Canada. I found that snow crab were quickly overtaken under the footgear of the approaching trawl and over half of the snow crab (i.e., 54%) observed experienced an encounter with the rockhopper footgear components. The majority of the snow crab observed appeared to be aware of the trawl and were actively responding and/or reacting to the approaching threat. Second, the strengths and limitations of different commercially available trawl simulation software (i.e., DynamiT, SimuTrawl, and Trawl Vision PRO) in terms of design capability, simulation capability, and reliability of results, were investigated and interpreted. The study provides valuable knowledge and reference for stakeholders (e.g., gear designers, researchers, and educators) who are considering using numerical simulation methods to optimize their gear design concepts during the early stages of development of seabed friendly bottom trawls (e.g., predict expected mechanical stresses of trawl components on the seabed). Next, I addressed the question of how well computer simulation and flume tank testing of scale engineering models actually predict full-scale at-sea performance of bottom trawls. The results demonstrated that the complementary use of two or three methods should be encouraged for assisting the gear development cycle given their own weakness and merits. For instance, the flume tank testing method was successfully utilized to estimate the percentage of contact area made by trawl footgear with the seabed, while at-sea experiments were not designed to measure such impacts. Moreover, I clarified that the precision and accuracy of the predictions depends on many factors. Thus, thoroughness and care must be emphasized in order to reduce bias in predicted performance. Finally, I examined the effectiveness of a reduced seabed impact footgear (i.e., drop chain) over a traditional rockhopper footgear on identical bottom trawls targeting northern shrimp (Pandalus borealis) in Newfoundland and Labrador, Canada. The results demonstrated that seabed impacts of shrimp trawling can be reduced if the trawl footgear is made lighter and/or designed to have less contact with the seabed. In particular, it was revealed that with the experimental drop chain footgear trawl we are able to reduce the interaction or encounter of snow crab. In summary, the knowledge presented in this thesis is believed to significantly contribute to the research and development of low-impact bottom trawls both in theoretical and practical aspects. While the potential impact of bottom trawling activities on habitats and benthic communities is not easy to predict and characterize for various reasons, I do believe that further development and application of fishing gears and techniques that reduce impacts on seabed habitats and associated benthic communities will be essential to achieve ecosystem objectives.
Download or read book Fishery Leaflet written by and published by . This book was released on 1967 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Commercial Fisheries Review written by and published by . This book was released on 1965 with total page 800 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Otter Board Design and Performance written by Food and Agriculture Organization of the United Nations and published by . This book was released on 1974 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Marine Research written by and published by . This book was released on 1969 with total page 764 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Further Testing of Cod Avoiding Trawl Net Designs written by David Chosid and published by . This book was released on 2008 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design Construction and Uses of Trawl Fishing Gear written by Kamakhya Pada Biswas and published by . This book was released on 2015 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Development of Fishing Trawl Testing Capabilities at NSRDC written by Clifford A. Goudey and published by . This book was released on 1984* with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings written by Institute of Fisheries and Marine Technology and published by St. John's, Nfld. : Marine Institute. This book was released on 1989 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theory and Design of Commercial Fishing Gear written by Aleksandr Lʹvovich Fridman and published by . This book was released on 1973 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt:
