The purse seine has been in operation commercially

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1 The Asian Journal of Animal Science (December, 2010), Vol. 5 Issue 2 : RESEARCH ARTICLE Design aspects of small meshed purse seine nets without pocket R.R. JADHAV, A.S. MOHITE AND T.G. KAZI Received : July, 2010; Accepted : Aug., 2010 See end of the article for authors affiliations ASHISH S. MOHITE Department of Fisheries Engineering, College of Fisheries, (Dr. B. S. Konkan Krishi Vidyapeeth), Shirgaon, RATNAGIRI (M.S.) INDIA. ashishmohite@yahoo.com ABSTRACT The small meshed purse seine net without pocket was locally called ghan in Ratnagiri because of smaller mesh size of the main webbing of the net. The study deals specifically with the design, construction and operational details of the small meshed purse seine nets (ghan) without pocket operated from Ratnagiri. The nets were made of polyamide (PA) with knotted netting having small mesh size of 30 mm. The total length and stretched depth of purse seines in Ratnagiri was to m and 33 to m, respectively. The hanging coefficient along the floatline was 0.52 to 0.88 while along the lead line was 0.59 to The gear was operated using the single boat with the aid of an unpowered skiff. The depth of operation was always less than the depth of the net. The time required for setting, pursing, hauling and brailing varied from two to two and half hours. Key words : Design, Small meshed purse seines, Purse seines without pocket. The purse seine has been in operation commercially for more than two decades in Ratnagiri. The purse seine was basically designed and operated for sardine and mackerels, other fishes like ghol, shrimps, cat fishes, pomfrets, ribbon fishes etc., are also often caught by the net. Aspects of classification, structure and operation of purse seine nets have been discussed by, Ben-Yami (1987, 1994), Sainsbury (1996) and others. The design, construction and operational details of purse seines have been reported by many authors (Sedanandan et al., 1975; Verghese, 1976; Mukundan et al., 1980; Iitaka, 1971). The purse seine operation for sardine and mackerel on the Indian coast was first attempted by the FAO experts working on the Malabar (Kerala) coast and Mangalore (Karnataka) coast during the year 1970 s to 1980 s (Sadanandan et al., 1975). In Maharashtra, this type of fishery was initiated in the year 1983 along the coast of Ratnagiri. The total marine fish production of Ratnagiri district was 1,03,184 metric tonnes (Anonymous, 2007). Purse seine fishing accounts for 25 to 30% to the total world marine catch (Ben Yami, 1994). This communication presents the design, technical specifications and rigging of the small meshed purse seine net without pocket operated from Ratnagiri. Jadhav, R.R., Mohite, A.S. and Kazi, T.G. (2010). Design aspects of small meshed purse seine nets without pocket. Asian J. Animal Sci., 5(2): MATERIALS AND METHODS The total number of purse-seiners in Maharashtra was 288, out of which 167 were operated from Ratnagiri (Anonymous, 2007). The present investigation was undertaken during the period August, 2009 to May, The detail information regarding design and construction of purse seine nets was undertaken by physically sampling the unit and recording the data according to Sadanandan et al. (1975) and Hellevang (1971) whereas, the particulars of the purse seine net operators of Ratnagiri and the vessel details were recorded according to Sreekrishna and Shenoy (2001). The design of the gear was documented according to Nedelec (1975). Data were analyzed with the appropriate statistical procedures wherever required. RESULTS AND DISCUSSION The technical specifications of the small meshed purse seine net without pocket operated from Ratnagiri are presented in Table 1 and its design is presented in Fig.1 and 2. The net was locally known by the name, Ghan because of smaller mesh size of the main webbing of the net. The main parts of the net were the bunt (Mand), shoulder, main webbing and wing (Kan). A total 32 to 55 number of rectangular sections of webbing were joined vertically to form a full length net. The stretched height of all the sections of main webbing was same in the purse seine without pocket. The bunt part was located at one end of the net and wing at the other end. At the both end of the net choke with bridles were provided with thicker twines. The depth of bunt and wing was less than the

2 R.R. JADHAV, A.S. MOHITE AND T. G. KAZI [Asian. J. Animal Sci. (Dec., 2010) Vol. 5 (2) ] 154

3 DESIGN ASPECTS OF SMALL MESHED PURSE SEINE NETS WITHOUT POCKET [Asian. J. Animal Sci. (Dec., 2010) Vol. 5 (2) ] 155

4 R.R. JADHAV, A.S. MOHITE AND T. G. KAZI Hanging coefficient (E) No. of mesh in length Material Mesh size (mm) No. of mesh in depth PA 14mm m PP 10mm PB 220 g m PA 12mm BR 2.5 kg PP 10mm m PP 24mm Fig. 1: Design the small meshed purse seine net without pocket operated from Ratnagiri depth of main body. The strips of selvedge with rigged floats and leads were attached to each sections of webbing at top and bottom, respectively. The total length and stretched depth of the small meshed purse seine nets without pocket in Ratnagiri was to m and 41.4 to 68.4 m, respectively. Sadanandan et al. (1975) observed that the length and stretched depth of the purse seines of Goa was 176 to 223 m and 40 to 44 m, respectively. Varghese (1976) stated the details of purse seines in which the length of the head rope was 292 m and the depth was 27 m. The length and depth of the purse seine recorded by Sadanandan et al. (1975) and Verghese (1976) was smaller than the observation recorded during the present study in Ratnagiri. The main webbing of purse seines used in Ratnagiri was made of polyamide (PA) multifilament. The webbing was fabricated by using single trawl knots. Sadanandan et al. (1975) also recorded the similar observation that the trawl knot was used for the webbing of purse seines in Goa. Mukundan et al. (1980) studied the design of the purse seine of Cochin. The material used for the purse seine studied by them was nylon 210D/3/3 for bunt and knotless nylon 210D/2/3 for main body. On the contrary, the purse seines used in Ratnagiri were made of PA multifilament of 210D/6/3 for main webbing and 210D/8/ 3 for bunt while polyethylene (PE) multifilament of diameter 1.25 mm was used for wing section. The mesh size varied in different parts of the net. The mesh size used for main webbing was 30 mm and for bunt section was 16 to 18 mm. Sadanandan et al. (1975) presented the design details of purse seines of Goa which had 18 to 20 mm mesh size of all the sections. Mukundan et al. (1980) stated the mesh size of purse seines of Cochin region was 15 mm for bunt and main body. The mesh size stated by Sadanandan et al. (1975) and Mukundan et al. (1980) was smaller than the mesh size of purse seines observed during the present study in Ratnagiri. Prado (1990) stated the actual height of a mounted (rigged or hung) net depends on the stretched height and the hanging ratio. He further stated that the actual depth or height should be equal to 50% of the stretched depth [Asian. J. Animal Sci. (Dec., 2010) Vol. 5 (2) ] 156

5 DESIGN ASPECTS OF SMALL MESHED PURSE SEINE NETS WITHOUT POCKET Mounted height as a percentage of stretched height Fig. 2: Bunt Main webbing Wing Hanging ratio of the net (E) Mounted height of small meshed purse seine net without pocket of the seine at its extremities, and 60% near the centre of the net. The mounted height or working depth of the bunt of purse seines of Ratnagiri was in the range of 76% of the stretched netting, main webbing was 75% of stretched netting and wing was 63% of stretched netting. The mounted height of the purse seine observed during the present study in Ratnagiri was on a higher side than that recommended by Prado (1990). In the present study, the hanging coefficient was greater on the leadline than on the floatline. The hanging coefficient varied along the length of the floatline and leadline, and was lower in the bunt section. The hanging coefficient along the floatline was 0.64 to 0.77 while along the lead line was 0.68 to Iitaka (1971) suggested horizontal hanging coefficient (E) along the floatline should be 0.7 to 0.8 and along the leadline should be 0.8 to 0.9. He observed that with Norwegian and Icelandic purse seines E was 0.45 to 0.65 and in the Mediterranian it was 0.8 to 0.9. He stated that in order to avoid entangling at the bottom of the seine, a smaller ratio of hanging of the webbing to the leadline was preferred. Average surface area covered (Prado, 1990) by the small meshed purse seine net without pocket of Ratnagiri was m 2 and the approximate volume (Ben-Yami, 1994) surrounded by the net at the end of the set, when the leadline reaches the full working depth of the net was 20,46, m 3. The average depth of the purse seines of Ratnagiri was 6.42% of the average length of the net i.e. depth to length ratio was 0.064:1 and length to depth ratio was 15:1. In practice, according to Donald (1930), the stretched net depth of purse seine in California was only 10 to 13% of the net length. Iitaka (1971) suggested to have a deeper net as deep as 30 to 50% of the total net length, for deep swimming fishes like sardines and mackerel. He recorded different length to depth ratios existed for different purse seines. In the U.S. tuna purse seines the length : depth ratio was 22:1, for Norwegian herring seine it was 9:1 and Japanese tuna purse seine it was 8:1. Prado (1990) stated that the length of the purse seine was greater than or equal to 15 times the length of seiner and minimum length and depth of bunt was equal to the length of seiner from which the net was operated. The average length of the purse seines observed in Ratnagiri during the present study was greater than the 15 times the average length of seiner, whereas the average length and depth of bunt was greater than the average length of the vessel used to operate the net. Polypropylene (PP) single floatline of diameter 12 mm with floats of ethylene vinyl acetate (EVA), expanded polyvinyle chloride (PVC) and plastic were used. The single leadline of PP of diameter 12 mm with lead sinkers of 220 g was used. The purse line of PP of diameter 24 mm was used to pass through the rings. The closed type of brass rings of 2.5 kg were attached to the ring bridle. Sadanandan et al. (1975) observed that ring bridles were attached to the leadline in purse seines of Goa. Only PVC floats were used for buoyancy where as the leads of 250 g each was attached to the leadline. The lead line was usually thinner than the headline. On contrary, in Ratnagiri, the ring bridles were not attached to the leadline. A separate line for ring bridle attachment was running through the bottom selvedges through the fifth or sixth mesh from the leadline. The wooden purse seiners were operated from Ratnagiri which had an overall length of 13.5 to 16.7 m where as the depth was 1.82 to 3.03 m. Similar observations were recorded by Boopendranath and Hameed (2007) that the purse seiners operated from Cochin were either of wood or steel hull and the most abundant length class of purse seiners was in the range of 13.1 to 17.0 m. The range of dimensions of the purse seiner s operated from Ratnagiri match with the dimensions reported from Cochin (Boopendranath and Hameed, 2007). Purse seiners operating from Ratnagiri were fitted [Asian. J. Animal Sci. (Dec., 2010) Vol. 5 (2) ] 157

6 R.R. JADHAV, A.S. MOHITE AND T. G. KAZI with 6 cylinders inboard engine of 95 to 156 horse power. Hellevang (1971) reported the Peruvian purse seine vessels were maneuverable and with engines ranging from 250 hp to 850 hp which had very high power than the purse seiners used in Ratnagiri. Sadanandan et al. (1975) observed the power of the engine of the vessels of Goa from which purse seining was conducted, ranged from 67 to 100 hp. The purse seine of Ratnagiri was operated mainly to catch oil sardine, mackerel and seer fish shoals moving in the surface and column waters. Single boat type purse seining with the aid of an unpowered skiff were practiced from Ratnagiri. The gear was operated using the basic principle of encircling the shoal. The shooting and hauling operations were done over the port side of the vessel with floatline. The bottom rope always touches the ground. The fishes collected at the bunt end, were brailed in by brail net. The time required for setting, pursing, hauling and brailing varied from two to two and half hours. Similar observations were reported by Sadanandan et al. (1975) where they observed the method of operation of purse seines of Goa and Boopendranath and Hameed (2007) described the single vessel purse seining operations conducted from Cochin. Purse seines were operated in the depth of less than 40 m from Ratnagiri. Purse seiners of Goa were generally limited to the fishing grounds having depth less than 20 m (Sadanandan et al., 1975) which was less than half the depth of operation of purse seines in Ratnagiri. However the depth of operation was always less than the depth of the net at both the places. Acknowledgement: The authors wish to thank the authorities of College of Fisheries, Ratnagiri (Dr. Balasaheb Sawant Konkan Krishi Vidyapeeth, Dapoli) for providing the necessary facilities, their kind encouragement and guidance during the course of the investigation. Authors affiliations: R.R. JADHAV AND T.G. KAZI, College of Fisheries, (Dr. B. S. Konkan Krishi Vidhyapeeth, Dapoli), Shirgaon, RATNAGIRI (M.S.) INDIA. rakeshcof169@gmail.com ; tashookazi@gmail.com LITERATURE CITED Anonymous (2007). Fish production report, Department of Fisheries, Govt. of Maharashtra, Mumbai, 161 pp. Ben Yami (1987). Purse-seining with small boats. FAO training series 13, Food and Agriculture Organisation of the United Nations, Rome, 97 pp. Ben Yami (1994). Purse seining manual. Fishing News Books, London, England, 404 pp. Boopendranath, M.R. and Hameed, M.S. (2007). A profile of mechanized fishing activities based at Cochin fisheries harbour Kerala, India. Fish. Technol., 44(2): Donald, H.F. (1930). The ring net, half ring net or purse lampara in the fisheries of California. Division of fish and game of California, Fish. Bulletin, 27: 65. Hellevang, N. (1971). Recent developments in the Peruvian anchoveta fishery. Modern Fishing Gear of the World: 3, Fishing News (books) Ltd., Farnham, Surrey, England, pp Iitaka, Y. (1971). Purse seine design and construction in relation to fish behaviours and fishing conditions. Modern Fishing Gear of the World: 3, Fishing News (books) Ltd., Farnham, Surrey, England, pp Mukundan, M. Radhakrishnan, N.P., Narayanan, K.P. and Jebapalan T.L. (1980). Results of purse-seining from 13.27M vessels. Seafood Export J., 12(5): Nedelec, C. (1975). FAO Catalogue of small scale fishing gear. Fishing News (books) Ltd., Farnham, Surrey, England, 191pp. Prado, J. (1990). Fisherman s workbook. Fishing News Books, Oxford, 180 pp. Sadanandan, K.A., Kunjipalu, K.K., George, N.A. and Joseph, T. (1975). Purse-seines off Goa. Fish. Technol., 12(1): Sainsbury, J.C. (1996). Commercial fishing methods - An indroduction to vessels and gear. Fishing News Books (Ltd), Farnham, 352 pp. Sreekrishna, Y. and Shenoy, L. (2001). Fishing gear and craft technology. Directorate of Information and Publication of Agriculture. Indian Council of Agricultural Research, New Delhi, 242 pp. Verghese, C.P. (1976). Introduction of purse seine fishing in Indian coasts-operations from 36 and 57 vessels for Sardine and Mackerel. Seafood Export J., Nov., ********* ***** [Asian. J. Animal Sci. (Dec., 2010) Vol. 5 (2) ] 158