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Netting materials for fishing gear
228 NETTING
MATERIALS
Materials for Fishhg Gear, 2nd edn. Gerhard Klust. An FAO Fishing Manual. Fishing News Books Ltd., Farnham, Surrey, Gt. Britain, 1982, 192 pp., 61 illustrations, 68.00 plus 80 p post/packing. ISBN: O-85238118.2.
Netting
The first (1973) edition of this book has already become an appreciated and much used source of information on the subject, not only for fishermen and netmakers as sugges,ted by the author in the preface, but also for scientists dealing with development and construction of fishing gear. In this new edition, the basic content is not much changed. However,some corrections have been made, as well as “modifications and additions in order to update the text with particular regard to IS0 standards and developments in the terminology”. The manual is divided into three main chapters: (1) Raw materials for netting. (2) Netting yarns. (3) Choice of netting materials for fishing gear. Chapter 1 deals mainly with so-called synthetic fibres used for fishing gear, but some consideration is also given to natural (vegetable) fibres such as cotton, sisal, manila and hemp. In particular, the rotting problem and its prohibition by preservation is dealt with for the natural fibres. The most common synthetic fibres for fishing gear, such as polyamides, polyester, polyethylene and polypropylene (Europe) and polyvinyl chloride, polyvinylidene chloride and polyvinyl alcohol (Japan), are dealt with for their chemical classification, historical development, basic properties and also problems with the identification of the different classes. The manufacturing process of the polyamides is described thoroughly. A comprehensive trade-name table for the different classes of materials is also valuable for material identif!cation. More recently developed fibre materials for fishing gc_;, such as Aramid (Kevlar) and Karat, are not included in the manual, probably because these materials are for the time being only used for ropes. Chapter 1 also includes a description of the different basic fibre types for netting twines, such as continous filaments, stqle fibres, monofilaments and split fibres. Here the exclusion of the denomination “spun” fibre may cause some confusion to readers familiar with it. Chapter 2: Netting Yarns, constitutes the bulk of the manual with 110 pages. It contains a detailed description of the construction and designation of netting yarns, including an essential part on terms and definitions. Although this manual does not deal with netting and nets, it is a bit surprising that the author has totally excluded any description of, or reference to, hexagonal netting. This type of netting is now in heavy use, especially in (Norwegian type) purse seines, and as for the normal knotless netting that is included in the description, the construction of the meshes of such netting
has totally interfered with the netting yam construction. The sub-chapter, properties of netting yarns, includes a comprehensive description of equipment for testing of the breaking strength of netting twines and the parameters influencing it, such as twine construction, dimensions, twist hardness, knots, etc. The user can here, in several tables and d&rams, find useful information on the specific breaking strength as a function of twine thickness (no., tex, diameter) for different materials and twine constructions. Other important twine properties for fishing gear, such as fiextural stiffness, change of length in water, extensibility and elasticity, and abrasion and weathering resistance are also thoroughly dealt with in this chapter. Chapter 3: Choice of Materials for Fishing Gear, deals with netting materials for bottom and midwater trawls, purse seines and gill nets. Wisely enough, the author in this part of the manual does not pretend to be too conclusive in his statements, obviously being aware of the sometimes contradictory views on the subject among fishermen, netmakers and even fishing experts of different countries or fishing areas. However, some useful information is given on the applicability of the different materials for specific fishing purposes, and a lot of examples are given of materials actually used for specific gear which are valuable as guidance for any user of the manual. Netting Materials for Fishing Gear, by G. Klust is, to the knowledge of the reviewer, the most comprehensive work (available in .English) at present on this special subject. In addition to the extensive and detailed contents, the book is also well-edited which, together with a wealth of tables and wellprepared illustrations and diagrams, also makes it easy to use as a book of reference. LIJDVIG KARLSEN Institute of Fisheries. University of Tromso. Postboks 3033. Guleng, 9001 Tromso, Norway
TROPICAL
FISHERY
Theory and Management of Tropical Fishery, D. Pauly and G. Murphy (Editors). Proceedings of the ICLARMCSIRO Workshop on the Theory and Management of Tropica! Multispecies Stocks, 12-21 January 1981, Cronulla, Australia, published by ICLARM, Manila, Philippines, 1982, 360 pp., paperback price US$28.50, ISBN 971-04-0022-3. This book constitutes the proceedings of the ICLARM%SIRO workshop on theory and management of tropical multispecies stocks held in Cronulla, Australia, 12-21 January 1981, the objectives of which were to define the
MATERIALS
Materials for Fishhg Gear, 2nd edn. Gerhard Klust. An FAO Fishing Manual. Fishing News Books Ltd., Farnham, Surrey, Gt. Britain, 1982, 192 pp., 61 illustrations, 68.00 plus 80 p post/packing. ISBN: O-85238118.2.
Netting
The first (1973) edition of this book has already become an appreciated and much used source of information on the subject, not only for fishermen and netmakers as sugges,ted by the author in the preface, but also for scientists dealing with development and construction of fishing gear. In this new edition, the basic content is not much changed. However,some corrections have been made, as well as “modifications and additions in order to update the text with particular regard to IS0 standards and developments in the terminology”. The manual is divided into three main chapters: (1) Raw materials for netting. (2) Netting yarns. (3) Choice of netting materials for fishing gear. Chapter 1 deals mainly with so-called synthetic fibres used for fishing gear, but some consideration is also given to natural (vegetable) fibres such as cotton, sisal, manila and hemp. In particular, the rotting problem and its prohibition by preservation is dealt with for the natural fibres. The most common synthetic fibres for fishing gear, such as polyamides, polyester, polyethylene and polypropylene (Europe) and polyvinyl chloride, polyvinylidene chloride and polyvinyl alcohol (Japan), are dealt with for their chemical classification, historical development, basic properties and also problems with the identification of the different classes. The manufacturing process of the polyamides is described thoroughly. A comprehensive trade-name table for the different classes of materials is also valuable for material identif!cation. More recently developed fibre materials for fishing gc_;, such as Aramid (Kevlar) and Karat, are not included in the manual, probably because these materials are for the time being only used for ropes. Chapter 1 also includes a description of the different basic fibre types for netting twines, such as continous filaments, stqle fibres, monofilaments and split fibres. Here the exclusion of the denomination “spun” fibre may cause some confusion to readers familiar with it. Chapter 2: Netting Yarns, constitutes the bulk of the manual with 110 pages. It contains a detailed description of the construction and designation of netting yarns, including an essential part on terms and definitions. Although this manual does not deal with netting and nets, it is a bit surprising that the author has totally excluded any description of, or reference to, hexagonal netting. This type of netting is now in heavy use, especially in (Norwegian type) purse seines, and as for the normal knotless netting that is included in the description, the construction of the meshes of such netting
has totally interfered with the netting yam construction. The sub-chapter, properties of netting yarns, includes a comprehensive description of equipment for testing of the breaking strength of netting twines and the parameters influencing it, such as twine construction, dimensions, twist hardness, knots, etc. The user can here, in several tables and d&rams, find useful information on the specific breaking strength as a function of twine thickness (no., tex, diameter) for different materials and twine constructions. Other important twine properties for fishing gear, such as fiextural stiffness, change of length in water, extensibility and elasticity, and abrasion and weathering resistance are also thoroughly dealt with in this chapter. Chapter 3: Choice of Materials for Fishing Gear, deals with netting materials for bottom and midwater trawls, purse seines and gill nets. Wisely enough, the author in this part of the manual does not pretend to be too conclusive in his statements, obviously being aware of the sometimes contradictory views on the subject among fishermen, netmakers and even fishing experts of different countries or fishing areas. However, some useful information is given on the applicability of the different materials for specific fishing purposes, and a lot of examples are given of materials actually used for specific gear which are valuable as guidance for any user of the manual. Netting Materials for Fishing Gear, by G. Klust is, to the knowledge of the reviewer, the most comprehensive work (available in .English) at present on this special subject. In addition to the extensive and detailed contents, the book is also well-edited which, together with a wealth of tables and wellprepared illustrations and diagrams, also makes it easy to use as a book of reference. LIJDVIG KARLSEN Institute of Fisheries. University of Tromso. Postboks 3033. Guleng, 9001 Tromso, Norway
TROPICAL
FISHERY
Theory and Management of Tropical Fishery, D. Pauly and G. Murphy (Editors). Proceedings of the ICLARMCSIRO Workshop on the Theory and Management of Tropica! Multispecies Stocks, 12-21 January 1981, Cronulla, Australia, published by ICLARM, Manila, Philippines, 1982, 360 pp., paperback price US$28.50, ISBN 971-04-0022-3. This book constitutes the proceedings of the ICLARM%SIRO workshop on theory and management of tropical multispecies stocks held in Cronulla, Australia, 12-21 January 1981, the objectives of which were to define the