ABSTRACT INTRODUCTION

Transcription

1 MODIFICATION OF PAYANG DESIGN FOR SUSTAINABLE CATCH OF SCAD FISHERIES IN SOUTH SULAWESI Najamuddin 1 1) Faculty of Marine Science and Fisheries Unhas, Makassar Accepted: 8 May 2005; Approved: 21 November 2005 ABSTRACT The design of fishing gear is the basic information study for improving fishing gear selectivity. This study was aimed to analyze payang design and to improve its design in response to scad fish sustainability. One payang unit was selected on purpose for collecting data on dimension, length and wide and number of meshes of all net parts, mesh sizes, twine notation and materials. Description analysis was showed, and calculation on TSA and weight of net on CADNET and NETCAGE softwares was performed. The existing design constructed of wing, belly and cod-end which each part consist of 4 subparts. There were no cutting rate apply in all parts of the net. The mesh size applied in irregular manner, in contrast to mesh sizes which regularly are reduced from wing up to cod-end. Some modifications are made in term of its performance and selectivity. Key words: design, fishing gear, payang, modification INTRODUCTION Small pelagic fish species were the main target for payang fishing in Makassar Strait. The total production was 15,870.4 ton in year 2001 and approximately 64.2% of South Sulawesi total production and increased year by year for about 10%. Some previous research indicated high exploitation level of those species occurred (Nessa et al., 1986; Gafa et al., 1993; Kamsur, 1993), however Widodo et al. (1998) found that exploitation levels reach 50%. The contradictive information is needed to clarify in response to responsible fisheries in this area. Payang is the traditional fishing gear dominated in Majene and Mamuju Districts. This gear relatively appropriate while modern fishing gears such as purse seine already adopted but developed very slowly. It is hipothesed that payang can compete with purse seine due to some unique either in its design or operation. The research on payang s design is very limited, none in the area. Payang is unique and up to date still survive among other modern gears. This research is very important as a basis data in applied Code of Conduct for Responsible Fisheries (FAO, 1995). The sustainable fisheries is also the main issue in developing and improving fishing gear technology (Arimoto et al., 1999; Charles, 2001). Lack information of fishing gear design for small pelagic fishes and contradictive information on fisheries resources were main points for this research. Hence, it is hypothesed that 1) Contact person: Dr. Najamuddin Fisheries Department, Faculty of Marine Science and Fisheries, Hasanuddin University Jl. Perintis Kemerdekaan Km 10 Tamalanrea, Makassar Indonesia Telp/fax ; nnajamuddin@lycos.com 336 Najamuddin

2 payang has a unique design and non-selective either to fish species or fish size. In responding to the Code of Conduct for Responsible Fisheries in this area, it is urgently required to evaluate the payang s design and modification made for improvement. The research aims were: (1) to analyze existing payang s design; and (2) to analyze payang s design for improvement. It is expected, this study can be applied as basis data for Code of Conduct for Responsible Fisheries. METHODS The research was conducted from May to August 2003 in Majene District, with the case study methods applied. It was selected 1 payang unit on purpose and then dimension of all part were measured i.e. length (in meter and number of meshes), deep (in meter and number of meshes), cutting rate, twine notation, twine materials and mesh sizes. Rope dimensions, length and diameters, and materials were also calculated, as well as float and sinker materials, dimension, and rigging. Payang s design was analyzed manually and compared by using CADNET and NETCAGE software. Modification on sustainable scad fishery was made refer to Najamuddin (2005). Twine surface area was calculated according to Clive formula (Najamuddin, 2005): N n TSA x H x 4ad x10 2 where: TSA = twine surface area (m 2 ); N = number of meshes on top panel; n = number of meshes on base panel; a = mesh bar; d = twine diameter. Twine diameter (D) was calculated according to the following formula: D 210 x twine number 5135 and net weight (Wt) was calculated according to Clive formula (Najamuddin, 2004): 6 N n x H x{(2 x S) K} 2 Wt 1000 x R where: S = net mesh size; K = knot content; R = runnage (m/kg). RESULTS AND DISCUSSION Payang Description Payang consists of wing, belly and pocket parts. The pelagic schooling fish species are the main target of this gear. Its specific character is the under leap more forward than upper leap, in order to protect fish escape downward. Polyamide net is used in all part of payang with different mesh and twine size. Wing part is the longest part of the payang since it acts to guide fish entering the belly and direct to the cod-end (Fig. 1 and 2). Polyamide materials 210D/9 is applying in all wings. The wings consist of 4 parts from the tip: wing 4, wing 3, wing 2, and wing 1, with respective lengths of 1.4, 5.6, 35 and 15.6 m. Length of the whole wing part is 57.6 m. Mesh size of each part is different, which are 75, 65, 40 and 20 cm from the wing tip. Modification of payang design for sustainable catch of scad fisheries in South Sulawesi 337

3 Figure 1. General view of payang fishing gear. Remarks: (1) floats; (2) sinkers; (3) main float; (4) upper lip (upper caka); (5) lower lip (lower caka); (6) fishing line; (7) head line; (8) belly; (9) cod-end. Figure 2. The original payang s design. 338 Najamuddin

4 Belly Belly is the middle part of the net; consists of four parts: belly 1, 2, 3 and 4. Each belly is applying different mesh sizes which getting smaller as approaching to the cod-end. Polyamide materials 210D/9 applies in the belly with mesh sizes of 75, 60, 30 and 20 cm respectively. In the first belly, the upper lip (local name: caka toppo) and lower lip (local name: caka kayyang) are placed. The caka has a specific construction that could not be found in any other of fishing gears (Fig. 3). Figure 3.. The caka construction. The 60 cm caka is constructed from solid horn material and twisted with polyamide twine in rounded form. Caka is needed since the taper can not be applied in the bosom. The construction of upper and lower caka is same, but the float is replaced with an addition sinker in the lower caka. Some part of the net in the belly and wing are tightening to the caka with addition of half mesh. Caka end is tighten with swivel and connected to head line. The main regulator for opening payang is located in the caka, therefore the floats and sinkers should have an appropriate force in this part. The payang s mouth is aimed as an entrance for fish and frightens fish that swim in the surface. When fishes touch to the headline, they tend to escape downward, however they are blocked by lower leap that constructed upward. Cod-end Cod-end is the last part of the payang as a place to collect fish. This part consists of 4 subparts: cod-end 1, 2, 3 and 4 with mesh sizes 8.8, 4, 2.5 and 2 cm respectively. The mesh size in the cod-end 4 is the smallest and reflects to the fish size caught. PA 210D/12 materials applied in this part with 16.3 m of total length. Fig. 4 showed the new payang s design as a CADNET software output. The figure shows the left hand side as a half lower part and right hand side as a half upper part. Net mesh sizes indicated in mm and shown in the first row under mesh size legend, and the second row indicated twine number in denier system. Mesh deep indicated as the total mesh number in each part of the net as refer to the figure. Number shown in the figure indicated the total mesh number in that part of the net. Some value in the Fig. 4 can be crossed check with Table 1 as the original design. The main critical point of wing part is too many parts of the net that seem unnecessary due to small mesh deep number. This is just making time consume during construction. This condition characterized as the traditional design as seen in Java Island (Mangunsukarto et al., 1985). The only modification was in net materials, the synthetic fibers, due to unavailability of natural fibers anymore. Payang can compete with modern fishing gears such as purse seine because of the fishing ground condition of open sea with high current speed (Najamuddin et al., 2004a). It only has 3 parts of???? in order to reduce net joining. Wing 1, the lower part, should be constructed as a Modification of payang design for sustainable catch of scad fisheries in South Sulawesi 339

5 square in the trawl, to protect fish escaping downward, so the mesh deep reduced to 20 and the rest was add to the wing 2 (Fig. 2). Figure 4. Modification of payang s design. Table 1. Data sheet of original payang fishing gear. Name of fishing gear DATA SHEET : Payang (Bag Seine Net) Fish yield : Scad, Baby Tuna Location : Majene District Fishing ground Country : Indonesia characteristic : sand, mud Netting W4 W3 W2 W1 B1 B2 B3 B4 C1 C2 C3 C4 Material Knot type Maintenance Colour Polyamide English knot drying without direct sun light Brown Twine size D/9 D/12 Mesh size (mm) Mesh number (#) Deep (#) Joining type Take up 340 Najamuddin

6 The mesh numbers of top and base panels are same, which mean the cutting rate of the net side part is all N (Table 1). Normally, wing panel taper is all B inside, and combined 1N2B 1N8B in outside part. The range of cutting rate were selected, depend on the opening height requirement, which the lowest is at taper 1N2B and the highest at 1N8N. Good taper will make meshes open proportionally during fishing operation and tend to reduce water-resistant of the net (Fridman, 1986; Najamuddin, 2005). Normally, fishermen construct the wing net and modified the taper. The joining system between two net parts is taken up, since the mesh numbers of two joining part are different. Nomura (1981) and Mangunsukarto et al. (1985) mentioned that take up is applying in joining of two net parts with different mesh numbers. Net belly consists of 4 parts from the top of belly: belly 1, belly 2, belly 3 and belly 4, with mesh size of 75, 60, 30 and 20 cm and lengths 9.75, 3.5, 1.8 and 1.2 m. Selection of mesh sizes from wing to belly seems to be misleading, since in normal design, mesh sizes tend to reduce proportionally as it is away from the wing and getting smaller as it is closed to the cod-end. According to the data, the mesh sizes configuration is almost the same. This modification suggests the wing parts apply mesh size of 75 and 65 cm while in the belly 60, 40, 30 and 20 cm. The length of each part is still maintained as its original, however the number of mesh will change as mesh sizes change (Fig. 4). The mesh numbers in the top and base of each part are the same, which mean no cutting rate in the side part of the net. Since the net shape required smaller away from belly 1, it is necessary to apply cutting rate as normally occurs in the trawl design, where normally taper 1N2B is 30% of the belly and the rest just arranged to fit the net size (Najamuddin, 2005). In the new design, it is still maintained the dimension of old design, just modified some parts and mesh sizes. Therefore, the cutting rate apply are 2M1B to 3M1B and fat shape as seen in Fig. 4. In the new design, caka is not required since the bosom, bunt and wing tapered all bars inside and making a good shape. Floats are tightened to the headline and sinkers to the fishing line. Modification with consideration only on selectivity can be done through applying square meshes as window in the belly part, since net meshes seem can not open properly in traditional design. Although the mesh sizes in the belly are big enough, it is still possible for fish not able to escape through the net. The square mesh net, as a window for escaping untargeted fish, may be apply in the belly 2 to belly 3, with mesh sizes depend upon fish species target. For example, for scad fish, the payang mesh size is 3.2 cm refer to the first maturity size (Najamuddin et al., 2004b). In the new design, the minimum mesh size was proposed, so the mesh size in the cod-end is 3.2 cm. In compare to the budget of construction, in old design modification, applying square meshes will be the cheapest way, however for the new construction, the best way will be to apply both, square meshes and minimum mesh size. Fonteyne and M Rabet (1992), Robertson and Stewart (1988), Walsh et al. (1992) found the square meshes applied in the cod-end have successfully increased trawl selectivity for fishes. The square meshes are relatively rigid, so difficult to gill fish. It is also very suitable to convince the worrying of most fisher to gill fish if they change to bigger mesh size. The twine surface area of net in the new design is about 5 m 2 less compare to the old design (Table 2). The TSA indicate the tension of net in the water due to water move toward gear or gear move toward water or both (Fridman, 1986; Najamuddin, 2005). So, the higher TSA tend to be heavier and require more fisher to full the net during the hauling. Modification of payang design for sustainable catch of scad fisheries in South Sulawesi 341

7 Table 2. Comparison of calculation results between existing design (Fig. 2) and new design (Fig. 4). Calculation Component Existing Design New Design TSA (m 2 ) Weight (kg) The weight of net figures out how much netting material is required, and reflects the cost of netting materials (Najamuddin, 2005). In the new design, it is lighter approximately 5 kg compare to the old one; hence the new design is cheaper than the old design. CONCLUSION Payang is still a traditional design with modification only on netting materials. Some modification made in term of performance and selectivity. The new payang design is lighter and lower twine surface area. In order to get more selective payang gear, it is recommended to apply the new payang design, by modification on belly 2 with square net mesh. ACKNOWLEDGEMENT I would like to express my thanks to Nurheriyah and Iqbal for their help in collecting field data, and thanks to staff of fisheries service in both Mamuju and Majene for providing secondary data. Special thanks to Mr. Palo Ali s family for providing accommodation and facilitating access to the payang s fishermen. REFERENCES Arimoto, T., S. J. Choi & Y. G. Choi Trends and perspectives for fishing technology research towards the sustainable development. Proceeding of 5 th International Symposium on Efficient Application and Preservation of Marine Biological Resources. OSU National University, Japan. Pp Charles, A. T Sustainable Fishery Systems. Blackwell Science, London. 370p. FAO Code of Conduct for Responsible Fisheries. FAO Fisheries Department. 24p. (Accessed: 9 July 2002). Fridman, A. L Calculation for Fishing Gear Designs. Fishing News Books Ltd., England. 241p. Fonteyne, R. & R. M Rabet Selectivity experiments on sole with diamond and square mesh cod-ends in the Belgian coastal beam trawl fishery. Fish. Res., 13: Gafa, B., S. Bahar & Karyana Potensi sumberdaya perikanan di perairan Laut Flores dan Selat Makassar. Jurnal Pen. Perikanan Laut, 72: Kamsur, W Potensi dan tingkat eksploitasi serta beberapa parameter dinamika populasi ikan layang (Decapterus spp) di perairan sekitar Kabupaten Majene. Jurusan Perikanan, Fakultas Peternakan, Ujung Pandang. 43h. Mangunsukarto, K., B. Murdiyanto, & T. Hestirianto Disain Alat-alat Penangkap Ikan. Proyek SISDIKSAT, BKS PTN INTIM IPB USAID/AED, Jakarta. Najamuddin Kajian pemanfaatan sumberdaya ikan layang (Decapterus spp) yang berkelanjutan di perairan Selat Makassar. Disertasi. Program Pascasarjana UNHAS, Makassar. 342 Najamuddin

8 Najamuddin, A. Asni & B. L. Roswaty. 2004a. Perikanan payang di perairan Kabupaten Mamuju, Sulawesi Selatan. BIPP, 8(1): Najamuddin, A. Mallawa, Budimawan & M. Y. N. Indar. 2004b. Pendugaan ukuran pertama kali matang gonad ikan layang (Decapterus macrosoma Bleeker). Bulletin Sains & Teknologi, 4(1): 1 8. Najamuddin Fishing Gear Design. Lecture Note. Fisheries Resources Utilization Study Program, Hasanuddin University, Makassar. Nessa, M. N., S. A. Ali, A. Salam, A. R. Mappangaja, R. A. Sumah & F. A. Ali Survei potensi sumberdaya hayati dan non hayati di perairan Selat Makassar. Lembaga Penelitian Universitas Hasanuddin, Ujung Pandang. 180h. Nomura, M Fishing Techniques (2). Japan International Cooperation Agency, Tokyo. 183p. Robertson, J. H. B. & P. A. M. Stewart A comparison of size selection of haddock and plaice by square and diamond mesh cod-ends. J. Constr. Int. Explor. Mer. 44: Walsh, S. J., R. B. Millar, C. G. Cooper & W. M. Hickey Cod-end selection in American plaice: diamond versus square mesh. Fish. Res., 13: Widodo, J., K. A. Aziz, B. E. Priyono, G. H. Tampubolon, N. Naamin & A. Djamali Potensi dan Penyebaran Sumber Daya Ikan Laut di Perairan Indonesia. Komisi Nasional Pengkajian Stok Sumber Daya Ikan Laut, LIPI, Jakarta. 251h. Modification of payang design for sustainable catch of scad fisheries in South Sulawesi 343