Design Construction and Uses of Trawal Fishing Gear

by K P Biswas

ISBN: 9789351307723
View Ebook
Imprint : Daya Publishing House
Year : 2021
Price : Rs. 8995.00
Biblio : xv+238p., figs., tabls., ind., 25 cm

Author Profile

Dr. K.P. Biswas, M.Sc., Ph.D., D.F.Sc. (Bombay), E.F. (West Germany), F.Z.S., F.A.B.S. (Kolkata), Former Joint Director Fisheries (LI), Government of Orissa, Director Fisheries, A&N Islands, Government of India, Principal, Fisheries Training Institute, Fishery Technologist (ICAR), and at present Faculty Member of Marine Science Department, University of Calcutta and West Bengal University of Animal and Fishery Sciences. <BR> The author operated 28 wooden fishing trawlers (32 - 48 feet LOA) from Paradeep Orissa during 1968-69 and four 57 feet steel polish trawlers during 1971-72 in Odisha coast of Bay of Bengal and is conversent with trawl fishery in Indian coast.

About The Book

The net, among the fishing gear occupies the prime position in catching fish commercially for mass production. Among the net, trawl net chase the fish to be caught, as such, has established itself as the most important gear throughout the world oceans. With these objectives, the book in its nineteen chapters, not only, outlined the features of the trawl net, but described the operational characteristics of the net in different operating conditions.. Starting with the principles of the design and construction of the net, the evolution of various trawl fishing gears, tested on trials over time series, from the conventional two seam trawl to four and six seam trawls with overhang, bulged belly, long wing, large mesh, tested for operation at different depths were elaborately described in different chapters of the book. <BR> The incorporation of By catch Reduction Devices, a new innovation adopted as conservation measures together with the common by catch species encountered in Indian Seas have also find place in the book. The engineering performance of trawl net in operation towards perfection was elaborately discussed in flume tank test. The reaction and behavior of fish school towards approaching trawl was vividly observed under water and narrated in the book. The possibility of introducing electrical trawl in sea fishing with technical back-up was discussed in details. The construction details and diagrams of different types of trawl presented in the book will be useful to the students, teachers, net-makers and net manufacturers.

Table of Contents

1. Evolution of Trawl Fishing Gear 1 <BR> Parts of trawl net, Webbings, Square, Bosom, Jibs, Quarters, Side panels. Bellies, Throat, Cod end, Flapper, Apron, Lines and ropes. Foot rope, Bolch line, Details of construction-Baiting and creasing. Point and Bar cutting. Mesh and bar cutting, Joining of panels and take up ratio, Joining ratio, Mounting of netting. Hanging coefficient. <BR> Description of trawl gear: Conventions adopted in data sheets. Webbing, Material, Type of knot, Preservation, Color, Twine size, Breaking strength. Twine surface area. Stretched mesh, Upper edge, Lower edge. Depth, Baiting rate. Take up. Quantity, Hanging, Lines and rope-Material, Construction, Diameter, Breaking strength, conventions adopted in drawings. <BR> Data and construction details: 12 m two seam fish trawl, 14 m two seam fish trawl, 15 m two seam fish trawl, 16.5 m two seam fish trawl, 20 m two seam fish trawl, 24 m two seam fish trawl, 24 m modified two seam fish trawl, 30 m two seam fish trawl, 35 m two seam fish trawl, 45 m two seam fish trawl, 17 m four seam shrimp trawl, 18 m four seam shrimp trawl, 27 m four seam shrimp trawl, 28 m four seam shrimp trawl, 43.6m four seam shrimp trawl. <BR> Otter boards: Flat otter board 120 kg for 28 m shrimp trawl. Oval flat otter board 50-55 kg for 42-56 HP trawlers. Oval flat otter board 150 kg for 153-200 HP trawlers, Oval flat otter board 180-190 kg for 200 HP trawlers. Oval flat otter board 250 kg for 240-300 HP trawlers, Otter trawl accessories- Floats, Sinkers, Pennants, Bridles, Trawl warps, Bobbins, Tickler chain, Knotless webbing, Preservation of nets. <BR> 2. General Principles of the Design of the Trawl Gear 51 <BR> Classification of trawl net. Parts of trawl Net, Trawl net design and development, Developing conventional otter trawl net Size of trawl gear matching to engine horse power, Design features of trawl operating in Gulf of Mannar-Fish trawl and Coastal shrimp trawl. <BR> 3. Working Principles and Performances of Trawl Nets 82 <BR> Instrumentation, Telemetering instruments. Continuous multi-channel data acquisition system. Data processing with the help of computer. <BR> 4. Trawl Net Design and Development 85 <BR> Development and trial of bulged belly and Six seam trawl net. Details of 25 m bulged belly trawl. Large mesh high opening fish trawl. Belly depth studies of shrimp trawl, Six seam otter trawl, Three panel double trawl net, Overhang for trawls. <BR> 5. Mid Water Trawl One Boat Mid Water Trawl 97 <BR> One boat mid-water trawl. Features, Babylon, Construction, Hanging, Rectangular mid-water trawl, Oneboat mid water trawling trials in SW coast of India, One boat trawl for pelagic stocks, 10.5 m mid-water trawl, Pair trawling-fishing gear, rigging, operation. <BR> 6. Bottom Trawl Large Meshed Bottom Trawl 111 <BR> Large mesh bottom trawl, Design criteria of bottom trawl for 16.5 m steel trawlers. Bottom trawl trials off Tamil Nadu, Design diagram and Bottom