The Influence of Bending Stiffness on the Deformation of Axisymmetric Networks

2004 ◽  
Author(s):  
F. G. O’Neill
Keyword(s):  
Internal Pressure ◽  
Mesh Size ◽  
Upper Bounds ◽  
Bending Stiffness ◽  
Fishing Gear ◽  
Dimensional Parameter ◽  
Trawl Fishing

The aftmost part of a trawl fishing gear, the cod-end, has been successfully modelled as an axisymmetric network. Here we investigate the influence that the bending stiffness of the component twines has on the deformation of the network and accordingly on the degree to which the netting meshes open. A non-dimensional parameter EI/NM4P, where EI is the twine bending stiffness, N is the number of meshes around, M is the mesh size, and P is the internal pressure, is shown to characterize network deformation. We identify upper bounds on the network radius when subject to a constant internal pressure and demonstrate numerically how this varies as the value of this non-dimensional parameter increases. We also look at some specific examples and discuss how an increase in twine bending stiffness may affect fish escape from the cod-end.

scholarly journals Ancaman keanekaragaman hayati (Biodiversity) terhadap ekosistem daerah penangkapan pukat hela

2020 ◽  
Vol 7 (2) ◽  
pp. 129
Author(s):  
Fauzan Ramadan ◽  
Farhan Ramdhani ◽  
Deni Efizon ◽  
Nofrizal Nofrizal
Keyword(s):  
Coastal Waters ◽  
Negative Impact ◽  
Mesh Size ◽  
Survey Method ◽  
Fishing Gear ◽  
Fish Resources ◽  
Fisheries Resources ◽  
Trawl Fishing ◽  
Penaeus Indicus ◽  
By Catch

Trawl has the size a mesh size  a small size pockets of the cod end. This allows the trawl fishing gear to potentially be a fishing gear that is not selective about the size of the fish and the species that are targeted for its catch. If this fishing gear is left, its existence will eventually have a negative impact on the sustainability of fish resources, especially in coastal waters. The purpose of this study is to calculate the composition and proportion of main catches, bycatch and discarded catches. It is expected that knowing the composition and proportion of the main, by-product and discarded catches can provide an overview of the pressure on stocks and sustainability of fisheries resources in the waters where trawl is operated. The method used in this study is a survey method. A series of survey activities were carried out directly in the field to identify and count the types of species caught by trawlers. Based on the percentage of main catch, by-catch and discard per type, it Matuta planipes are the dominant species caught by trawlers (23.65%). The main catch Parapenaeus longirostris 15.92%. In addition, the main catch caught were Parapenaeopsis sculptilis (9.787%), Penaeus merguiensis (0.646%), Metapenaeus brevicornis (10.118%), Penaeus indicus (0.029%) and Squilla mantis (0.153%). Percentage of bycatch reaches 2.245% of 10 species caught and discarded catches reach 61.103% of 25 species caught.

scholarly journals ANALISIS ASPEK TEKNIS KAPAL PUKAT CINCIN (PURSE SEINE) DAN ALAT TANGKAP YANG DIGUNAKAN NELAYAN DI PERAIRAN TELUK BONE

2020 ◽  
Vol 3 (2) ◽  
pp. 226-238
Author(s):  
Hawati Hawati ◽  
Angkasa Putra
Keyword(s):  
Survey Methods ◽  
Secondary Data ◽  
Purse Seine ◽  
Primary Data ◽  
Fishing Gear ◽  
Technical Aspects ◽  
Fish Resources ◽  
Trawl Fishing ◽  
Fisheries Regulation ◽  
Fishing Area

The utilization of fish resources by fishermen in the waters of Bone Bay uses different fishing gear and patterns as well as different utilization and management policies. This can affect the sustainability of existing fish resources, one of which is in the Bone Regency area. This study aims to analyze the technical aspects of purse seine and fishing gear used by fishermen in the waters of Bone Bay, especially in Bone Regency. Furthermore, the technical aspects of the vessel and fishing gear as a result of the calculation are compared with the provisions stipulated in the PERMEN-KP Number 71 of 2016 to determine the zone of the fishing area. This research was conducted in Panyula Village, which is the fishing base area of purse seine fishermen and the waters of Teluk Bone, starting from November 2016 to March 2017. This research uses a combination of survey methods and case studies. The type of data used consists of primary data and secondary data. Based on the technical aspects of purse seine vessels, ring trawl fishing gear and FAD fishing tools, purse seine units should be operated on Fishing Route II and Fishing Route III in accordance with Minister of Marine Affairs and Fisheries Regulation Number 71 of 2016.

OPERATION STUDY AND CONSTRUCTION OF PURSE SEINE AT KM MARWAH LAMPULO ACEH UTARA

2020 ◽  
Vol 4 (1) ◽  
pp. 47-56
Author(s):  
Roma Yuli F Hutapea ◽  
Ratu Sari Mardiah ◽  
M. Nur Arkham ◽  
Ratih Purnama Sari ◽  
Wewen Nassa Syaputra
Keyword(s):  
Pelagic Fish ◽  
Purse Seine ◽  
Fishing Gear ◽  
Trawl Fishing ◽  
Construction Operation

Aceh is a province located at the western tip of Indonesia. Aceh's territorial waters are very strategic waters. The dominant fishing gear used by fishermen in Aceh is the purse seine. The reason many fishermen use purse seines in Aceh is because the waters of Aceh have a lot of pelagic fish potential, where the target of purse seines is pelagic fish. The purpose of this research is to know and understand the construction of purse seines in KM Marwah Lampulo Aceh Utara; as well as knowing and understanding the operation of purse seine fishing gear in Lampulo, North Aceh. The type of purse seine used by KM Marwah is trapezoid. Ring seine construction with PE (Polyethylene) nets with mesh sizes of 1-3 inches. The upper ris rope is 600 m long and 10 mm in diameter, while the lower ris rope is 12 mm in diameter, with a length of 600 m. Selvedge is used for net protection so that it is not easily torn. PE (Polyethylene) rope with a length of 650 meters. PE (polyethylene) based weight rope. Ring strap with a diameter of 10 mm and made from PE (polyethylene). 6000 pieces of PVC-based buoys and 4800 lead-based weights. The operation of the purse seine consists of a setting, namely the process of preparing and lowering the trawl fishing gear into the water, after the catch is collected and the nets have formed a bowl, then proceed with hauling, which is the activity of raising fishing gear onto the ship. Keywords Aceh, construction, operation, purse seine

scholarly journals Understanding the release efficiency of Atlantic cod (Gadus morhua) from trawls with a square mesh panel: effects of panel area, panel position, and stimulation of escape response

2014 ◽  
Vol 72 (2) ◽  
pp. 686-696 ◽  
Author(s):  
Bent Herrmann ◽  
Harald Wienbeck ◽  
Junita Diana Karlsen ◽  
Daniel Stepputtis ◽  
Erdmann Dahm ◽  
...  
Keyword(s):  
Escape Response ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Mesh Size ◽  
Accumulation Zone ◽  
Trawl Fishery ◽  
Trawl Fishing ◽  
Panel Effects ◽  
The Baltic ◽  
Stimulation Of

Abstract Based on size selectivity data for more than 25 000 cod (Gadus morhua) collected during experimental trawl fishing with six different codends, all of which included a square mesh panel, we investigated the effect on cod-release efficiency based on the size of the square mesh panel area, position of the square mesh panel, and stimulation of the escape response. Based on the results, we were able to explain why the BACOMA codend, applied in the Baltic Sea cod directed trawl fishery, releases juvenile cod efficiently, whereas other designs, including a square mesh panel with similar mesh size, are less efficient. Our main findings reveal that the release efficiency of the square mesh panel in the BACOMA codend depends largely on the overlap of the square mesh panel and the catch-accumulation zone in the codend, where cod do not have the option of just drifting further back in the trawl when proximate to the panel. On the contrary, the reduction in panel size by 50% did not significantly affect the release efficiency when the panel overlapped with the catch-accumulation zone. It was possible to stimulate an escape response for cod to achieve a release through a square mesh panel positioned away from the catch-accumulation zone. Our findings demonstrated that this release was as efficient as for a panel mounted in the catch-accumulation zone of the codend. Devices that stimulate behaviour may improve the release efficiency of cod through square mesh panels in other fisheries where this is a problem.

scholarly journals A study of approach to assessing a functional relationship between solidity ratios for the rope/net part of midwater trawl

2020 ◽  
Vol 200 (3) ◽  
pp. 656-670
Author(s):  
L. M. Simkin
Keyword(s):  
Functional Relationship ◽  
Fishing Gear ◽  
Mathematical Relationship ◽  
Midwater Trawl ◽  
Existing Structures ◽  
Trawl Fishing ◽  
Relationship Of ◽  
Mathematical Relationships ◽  
The Relationship

In this paper we have analyzed an approach to assessing the relationship between some characteristics of the net panels forming the rope/net cone of a fishing trawl. Using the mathematical relationship of solidity ratios for the rope/net panels, it is possible to analyze existing structures and, furthermore, reduce the time for selecting the prototype trawl. Such mathematical relationship allows faster calculation of new trawl designs which takes into account the production specifics of an enterprise manufacturing the trawl fishing gear. The use of mathematical relationships provides the opportunity to accelerate the process of trawl construction.

scholarly journals Selectivity of Gillnet to Catch Silver Pomfret (Pampus argenteus) in Pangandaran Waters, Indonesia

2021 ◽  
pp. 7-14
Author(s):  
Izza Mahdiana Apriliani ◽  
Herman Hamdani ◽  
Yuniar Mulyani ◽  
Heti Herawati ◽  
Dear Frans Lyandre Simanjorang
Keyword(s):  
Coastal Waters ◽  
Length Distribution ◽  
Fork Length ◽  
Mesh Size ◽  
Primary Data ◽  
Fishing Gear ◽  
West Java ◽  
Class Interval ◽  
Pampus Argenteus ◽  
Silver Pomfret

The purpose of this research was to determine the most selective mesh size of gillnet fishing gear for Pampus argenteus in coastal waters of Pangandaran Regency, West Java. Research on the selectivity of gillnet fishing gear was carried out in the coastal waters of Pangandaran, West Java Province, from August 2018 to January 2019. The method used in this research is experimental fishing, namely operating gillnet fishing gear directly in the fishing area with fishermen. The primary data collected was the measurement of the catch (fish weight, number, fork length, how the fish was caught, circumference (girth opercullum, maximum body girth). Meanwhile, the secondary data collected were supporting data from the Pangandaran District Fisheries and Marine Service, and literature study. In determining the sampling, the method used is the purposive sampling method. The operation of gillnets using 4.5 inches obtained a higher proportion of main catch (75%) than gillnets with a mesh size of 5 inches (44%). Gillnet with a mesh size of 4.5 inches, the silver pomfret caught was distributed between 17-22 cm in size with the highest mode in the 19 cm fork length. Unlike the gillnet fishing gear with a mesh size of 5 inches, the silver pomfret caught was distributed in the fork length range of 17-25 cm with the highest mode in the length class 19 cm fork length. mesh size 4.5 inches has a hanging ratio value of 0.51. Meanwhile, the 5 inch mesh size has a hanging ratio value of 0.54. Based on the length distribution, gillnets with a mesh size of 5 inches were more dominant in catching silver pomfret in a larger size class interval than gillnets with a mesh size of 4,5 inches. Based on the L50 value, both selective gillnets caught more fish at 50% second chance. The selectivity curve shows that gillnet fishing gear with a mesh size of 5 inches has more selective results than gillnets with a mesh size of 4.5 inches. 

scholarly journals KARAKTERISTIK PERIKANAN PUKAT CINCIN PELAGIS BESAR DI PERAIRAN SAMUDRA HINDIA (WPPNRI 572 DAN 573)

2020 ◽  
Vol 26 (1) ◽  
pp. 37
Author(s):  
Irwan Jatmiko ◽  
Suciadi Catur Nugroho ◽  
Zulkarnaen Fahmi
Keyword(s):  
Mesh Size ◽  
Yellowfin Tuna ◽  
Purse Seine ◽  
Fish Length ◽  
Fishing Gear ◽  
Skipjack Tuna ◽  
Commercial Species ◽  
First Maturity ◽  
Immature Fish ◽  
Purse Seine Fishery

Pukat cincin merupakan salah satu jenis alat penangkapan ikan yang digunakan oleh nelayan di Indonesia untuk menangkap ikan pelagis termasuk tuna dan cakalang. Cakalang dan madidihang/tuna sirip kuning merupakan komoditas perikanan penting di Indonesia untuk kebutuhan pasar domistik dan ekspor. Penelitian ini bertujuan untuk mengetahui karakteristik alat tangkap pukat cincin pelagis besar terutama yang menangkap cakalang dan madidihang di perairan WPPNRI 572 dan 573 (Samudra Hindia). Pengumpulan data dilakukan selama tiga tahun dari 2016-2018 di 18 pelabuhan perikanan yang armadanya melakukan aktivitas penangkapan di perairan WPPNRI 572 dan 573. Indikasi proporsi ikan yang sudah dan belum matang gonad dihitung dengan membandingkan ukuran ikan dengan ukuran pertama kali matang gonad (Lm). Hasil penelitian menunjukkan bahwa alat tangkap pukat cincin sangat dominan dalam mengeksploitasi sumber daya cakalang dan madidihang dengan proporsi mencapai 95% di WPPNRI 572 dan 66% di WPPNRI 573. Kebanyakan ikan yang tertangkap didominasi oleh ikan yang belum matang gonad dengan proporsi sebesar 67% untuk cakalang dan 94% untuk madidihang. Hasil analisis menunjukkan bahwa pukat cincin tidak termasuk alat yang selektif untuk menangkap ikan madidihang. Selanjutnya untuk target ikan cakalang, ukuran mata jaring harus diperbesar untuk mencegah tertangkapnya ikan yang belum matang gonad.Purse seine is one of dominant fishing gear used to catch pelagic species include skipjack and yellowfin tuna, two commercial species in Indonesia’s marine waters. This research aimed to analyze characteristic of purse seine fishery focusing on skipjack and yellowfin tuna within FMA 572 and 573. All the catch-effort data was collected from 18 fishing ports during the period of 2016-2018. All the vessels (purse seiners) were known to be actively fished within FMA 572 and 573. Proportion of mature and immature fish were calculated by comparing the fish length with its length at first maturity (Lm). The results showed that purse seine was a significantly gear to catch skipjack tuna and yellowfin tuna with proportion of 95% in FMA 572, and 66% in FMA 573, respectively. Most of the catch were dominated by immature fish with proportion of 67% for skipjack tuna and 94% for yellowfin tuna. The study concluded that purse seine is not recommended to exploit yellowfin tuna. Futhermore for targeting skipjack tuna, mesh-size of the net need to be in creased, allowing immature fish to escape from the gear that maintain sustainability.

scholarly journals Fishermen Social Movements in West Sumatra: Issues, Actors, and Tactics of the Movement

2020 ◽  
Vol 8 (1) ◽  
pp. 14-29
Author(s):  
Dwi Retno Hapsari ◽  
Rilus A Kinseng ◽  
Sarwititi Sarwoprasodjo ◽  
Asnika Putri Simanjuntak ◽  
Khairil Anam ◽  
...  
Keyword(s):  
Social Movements ◽  
Social Movement ◽  
Mesh Size ◽  
Qualitative Approach ◽  
The Other ◽  
Main Issue ◽  
Fishing Gear ◽  
West Sumatra ◽  
The City

The objectives of this study are to examine the main issue that provoke social movement of fishermen in West Sumatra, to identify the related actors, and to analyze the advocacy strategy carried out by fishermen. This research was conducted in July 2019 and took place in two locations, namely the City of Padang and West Pasaman Regency. The study used qualitative approach. From this study, it is revealed that the main issue that provoke social movements in West Sumatra was the issue of Regulation No. 71 of 2016 by the Minister of Maritime Affairs and Fisheries related to the prohibition of certain fishing gear. This regulation prohibits the use of 4 mm mesh size of the net and the use of lamps in operating the liftnet which reaches up to 25-30 thousand watts of power. This regulation has created a huge burden to fisherman’s work. The Other issue that is also triggering the movement was the arrestment of 6 fishing boats on June 11, 2016. Meanwhile, the main actors who are directly related to this movement are fishermen who are using liftnet (bagan). These actors can be divided into two main categories, namely movers and "participants". The main tactic used in social movements was demonstration.

scholarly journals Catching Technology of Fish Maw Snapper’s: Case Study of the KMN Nur Aqila07 Fishing Boat in Kumbe Village, Malind District, Merauke Regency, Papua

2021 ◽  
Vol 328 ◽  
pp. 08011
Author(s):  
Sajriawati Sajriawati
Keyword(s):  
Data Collection ◽  
Mesh Size ◽  
Fishing Gear ◽  
The Sun ◽  
Running Water ◽  
Gill Nets ◽  
Weight Range ◽  
Fishing Boat ◽  
Gill Net

The purpose of this study was to determine the fishing technology used by fishermen in Merauke to catch snapper and post-harvest handling of fish maw snapper. This research was conducted in January 2021 in Kumbe Village, Malind District. Data collection was carried out by interviewing fishermen on the fishing boat KMN Nur Aqila07. The results showed that the fishing boat KMN Nur Aqila07 has a weight specification of 30 GT. The main fishing gear is a drift gill net with a length of 50 meters with a width of 2 meters with a mesh size of 7.5 inches. The pulley machine is used to help pull the gill nets when they want to pull fishing gear (hauling). Fish maw of snapper is removed manually using a knife, then cleaned with running water and then dried in the sun to dry. Fish maw is sold dry. The highest price for fish maw is in the weight range of 150 grams which can reach Rp. 22,500,000 per kg, while the lowest price is in the weight range of less than 50 grams, which is Rp. 4,500,000 per kg.

scholarly journals Relativerigidity of twisted fishing gear

2020 ◽  
Vol 0 (1) ◽  
pp. 46-60
Author(s):  
Alexander Alekseevich Nedostup ◽  
Karina Konovalova ◽  
Pavel Nasenkov ◽  
Alexey Olegovich Razhev ◽  
Boris Altschul ◽  
...  
Keyword(s):  
Physical Modeling ◽  
Bending Stiffness ◽  
Full Scale ◽  
Torsional Stiffness ◽  
Dynamic Processes ◽  
Fishing Gear ◽  
Model Experiments ◽  
Longitudinal Stiffness ◽  
Longitudinal Bending ◽  
Dimensionless Combination

The article touches upon the problem of physical modeling of fishing twisted filamentary materials, in particular, the justification of the rules of similarity of relative longitudinal, bending and torsional stiffness of filamentary parts. The formulation of the problem is associated with the difficulties of conducting full-scale experiments for designing new fishing gear, as well as with the lack of systematic experiments on measuring the stiffness of synthetic cordage. In connection with this, it becomes necessary to conduct model experiments related to physical modeling of dynamic processes occurring with the cordage under load. There has been calculated the coefficient of proportionality of bending stiffness that determines the ability of filamentary parts and cordage to resist bending. There have been given the formulas that determine the combination of the ratio of bending stiffness to longitudinal stiffness and the dimensionless combination of the ratio of bend-ing stiffness to torsional stiffness. The study allows to predict the behavior and basic properties (di-ameter, density, strength, elongation, etc.) of modern synthetic filamentous fishing gear at the stage of their creation (design).

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