• Title, Summary, Keyword: Trammel nets

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Development of a Single Tangle Net for the Brown Shrimp by Observation of Entanglement Behaviour

  • Kim Yong-Hae
    • Fisheries and aquatic sciences
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    • v.6 no.1
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    • pp.34-40
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    • 2003
  • Three panel trammel nets were made illegal for the brown shrimp (Penaeus japonicus) or fishes by Korean fisheries law while trammel nets for fleshy prawn in the West sea remained legal. In this study a single panel tangle net with vertical loop lines rigged between the float line and sinker line was specially designed to catch brown shrimp. This net was developed for the first time after observation of the brown shrimp behaviour when reacting to a net in an observation tank. In field experiments these single tangle nets were compared with the traditional trammel nets in the coastal waters of the Keoje area. The mean number of the brown shrimp for 53 fishing operations was 1.13 per unit panel of the single tangle nets when fitted with the vertical loop lines. This was $84\%$ of the mean catch of 1.36 achieved with the trammel nets. These results of fishing experiments using single tangle nets in the field revealed a high fishing efficiency for the brown shrimp and showed little difference from trammel nets. The size of the brown shrimp or number of by-catch was not different between single tangle nets and trammel nets.

Catching efficiency of biodegradable trammel net for swimming crab (Portunus trituberculatus) in the Yeonpyeong fishing ground of Korea (연평어장에서 생분해성 꽃게 삼중자망의 어획성능)

  • Kim, In-Ok;Lee, Gun-Ho;Cho, Sam-Kwang;Cha, Bong-Jin;Sohn, Byung-Kyu
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.48 no.4
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    • pp.322-336
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    • 2012
  • To study the catching efficiency of biodegradable trammel net for swimming crab (Portunus trituberculatus), three types (biodegradable, monofilament and multifilament) of trammel nets were used in the field test, and the tests were carried out 16 times with two different mesh sizes (105mm and 160mm) in the Yeonpyeong fishing ground of Korea, 2009~2011. The catching efficiency of three type nets was analyzed by catch in number, catch in weight and average weight per individual of small and large size swimming crab by net types and mesh sizes. Statistical T-test was also carried out to verify the efficiency between the three types of nets. The results are as follows. The catch in number of swimming crab was 24,667 and formed about 81.0% of total catch. Of all swimming crab catch, small swimming crabs with less than 64mm in carapace length which is a prohibited landing size by law formed 48.1%, larger swimming crabs with more than 64mm in carapace length which is a landing size formed 51.9%. In 105mm mesh size trammel net test, the catch share in number of small size swimming crab by biodegradable trammel net was 47.5% in comparison with multifilament trammel net and 74.2% in comparison with monofilament trammel net, so biodegradable trammel net has more protective effects on small size swimming crab than other types of trammel nets. The protective effects for small size swimming crab by biodegradable trammel net was 25.8~52.5% in comparison with other types of trammel nets. The catch share in weight of large size swimming crab by biodegradable trammel net was 98.3% in comparison with multifilament trammel net and 92.3% in comparison with monofilament trammel net, so biodegradable trammel net has a similar catch efficiency to multifilament trammel net. The results of 160mm mesh size trammel net test have shown similar results of 105mm mesh size trammel net test. This study shows that biodegradable trammel net is a more useful fishing gear than multifilament and monofilament trammel net because biodegradable trammel net has lower catch rate than other types of nets in small size swimming crab and similar catch rate than multifilament trammel net which is a well used net by fishermen.

Comparison of catches and species composition for flounders caught using gillnets, gillnets with supporting lines, and trammel nets

  • Park, Hae-Hoon;Millar, Russell B.;Park, Chang-Doo;Park, Seong-Wook;Lee, Sung Il;Bae, Bong-Seong;An, Heui-Chun;Cho, Sam-Kwang;Lee, Kyounghoon
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.50 no.1
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    • pp.1-11
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    • 2014
  • To compare the catches made using gillnets, trammel nets, and gillnets with supporting lines, several experiments were conducted with commercial vessels near Uljin and Pohang in Eastern Korea between July 2010 and May 2011. Two sets of 13 different nets were used, including 5 panels of gillnets and trammel nets each with stretched mesh sizes of 7.6, 9.1, 10.6, 12.1, and 13.6 cm and 3 panels of gillnets with a mesh size of 9.1 cm with supporting lines with different line spacing. The outer (stretched) mesh size of the trammel nets measured 51.5 cm. The target fishes of the fishing nets were various types of flounders. The catch rate of flounders was 50.7% of the total catch in weight. The total catch for all nets was 443.8 kg. The predominant species was pointhead flounder (Cleisthenes pinetorum). The total catch by trammel nets was 1.4 times that of the comparable gillnets. But more pointhead flounder were caught by gillnets than by trammel nets, though there was no significant difference. Fishermen catching the pointhead flounder in Korea said that there was no need to use trammel net to catch it; this was an unexpected finding compared to the findings of other flounder fisheries. The amounts of roughscale sole, brown sole, and blackfin flounder caught by trammel nets were greater than those caught by gillnets. The mean lengths (standard deviation) of blackfin flounder, pointhead flounder, brown sole, and roughscale sole were 21.0 (4.57), 22.9 (3.40), 24.7 (4.90), and 28.3 (5.43) cm, respectively; there were significant differences in mean length (p < 0.00001). Therefore, in order to catch flounder efficiently, the fishing nets and mesh size should be chosen according to the target species. One advantage of using supporting lines is that it prevents breakage by strengthening the material especially when utilized on a rough bottom. Catch by using gillnet with supporting lines was not greater than that by using trammel net for the conservation of fisheries resources.

Mesh Selectivity in Trammel Net for Flat Fish (가자미 삼중자망의 망목 선택성)

  • 김성훈;이주희
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.38 no.2
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    • pp.91-100
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    • 2002
  • The field experiments were carried out to examine for the mesh selectivity in trammel net and optimum mesh size, during Aug. 10~13, Non 9~13 2000 in Jumunjin, Kangwon-Do and during Jun. 1~27 2001 in Suyong-Bay, Busan. The experiments in Jumunjin area were conducted by using trammel nets with seven different mesh sizes (60, 75, 90, 105, 135, 150, 180mm) and those in Suyong-Bay were done by using trammel nets and gill nets with three different mesh sizes (60, 75, 90mm) in order to compare two types of nets of same structure. The mesh selectivity analysis was done mainly with flat fish(Eopsetta grigorjewi) that was occupied 60% out of total catches. And the mesh selectivity was written by extension of Kitahara's method included master curve with function type. The results obtained are summarized as follows 1. Total number of catch by, trammel net was 2,331 and that of gill net was 1,433, and flat fishes occupied 59.8 ~60% in total catches. 2. The value of optimum l/m by, trammel net was higher about 0.1 than that of gill net according as trammel net was 2.56, and gill net was 2.47. 3. The 50% selection range by, trammel net was wider about 1.5 time than that of gill net according as trammel net was 1.88~3.36(1.48) and gill net was 2.00~3.02(1.02). 4. The optimum mesh size(OMS) was estimated that trammel net was about 141mm and gill net was about 132mm on first maturity length(FML) 265mm of flat fish. 5. On the optimum mesh size based on the first maturity length of flat fish, The 50% range by, trammel net was wider about 76mm than that of gill net according as trammel net was 265 mm~474mm and gill net was 265mm~398mm.

Fishing investigation with trammel nets by mesh size in the Korean deep-water of the East Sea (삼중자망에 의한 동해 심해 수산자원의 망목별 어획특성)

  • Park, Hae-Hoon
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.49 no.1
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    • pp.1-17
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    • 2013
  • The investigation for species composition and catch in the Korean deep-water of the East Sea (also known as Sea of Japan) was carried out with trammel nets of 7 mesh sizes (6.1~24.2cm) offshore Donghae (2006) and Yangyang (2007) of Korea. The catches were 1,268kg and composed of 37 species between 200m and 1,200m in depth. The principal species caught were Taknka's snailfish, salmon snailfish, red snow crab, hunchback sculpin, snow crab, spinyhead sculpin, Tanaka's eelpout, Alaska cod and so on. Those were target fish for commercial value except salmon snailfish. The mesh sizes for the largest catch were 10.6cm and 15.2cm in the fishing ground of Donghae and Yangyang, respectively. The habitat of snow crab was shallower than that of red snow crab in both areas. Trammel net enabled to investigate fish in deep-water with small fishing vessel and rather cheap expenses in contrast to bottom trawl that required too much of it. With increasing inner mesh size of trammel net the mean size of some principal species such as Taknka's snailfish, spinyhead sculpin, hunchback sculpin, Pacific cod, snow crab, red snow crab and hybrid between snow crab and red snow crab tended to be large in certain range of mesh size.

An analysis on catch and fishing power of trammel nets by fishing ground (삼중자망에 의한 해역별 어획량 및 어획성능 비교)

  • Bae, Bong-Seong;Park, Hae-Hoon;Jeong, Eui-Cheol;An, Heui-Chun;Yang, Yong-Su;Chun, Young-Yull
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.45 no.2
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    • pp.96-105
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    • 2009
  • For an effective management of fisheries resources, we need fisheries informations necessary for the establishment of reasonable fishing effort and TAC distribution. We carried out fishing research using trammel nets in the coastal sea of Susan-port(Yangyang, Gangwondo, Korea) and Hupo-port(Uljin, Gyeongbukdo, Korea) and analyzed fishing power variation of the fishing gear in terms of species composition, condition and so on for both sites. A total of 29 species were caught with most dominant species of Hippoglossoides dubius followed by Pseudopleuronectes herzensteini, Lophius litulon and Alcichthys elongatus in Susan. The total number of species caught in Hupo was 37 species with most dominant species of Todarodes pacifius followed by Lophius litulon, Hexagrammos agrammus and Pseudopleuronectes herzensteini. CPUE of Susan fishing area per trammel net was 12.74 fish and 2.00kg on average, while it was 6.80 fish and 2.27kg on average for Hupo. The fishing power index for both sites was 1, placing the two fishing grounds in a same level.

Mesh selectivity of the bottom trammel net for spinyhead sculpin Dasycottus setiger in the eastern coastal sea of Korea (저층 삼중자망에 대한 동해안산 고무꺽정이 (Dasycottus setiger)의 망목 선택성)

  • PARK, Chang-Doo;BAE, Jae-Hyun
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.53 no.4
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    • pp.317-326
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    • 2017
  • Comparative fishing experiments were conducted in the eastern coastal waters near Uljin, Korea from 2002 to 2004, using the experimental trammel nets to estimate the selectivity for spinyhead sculpin Dasycottus setiger. The inner panels of the nets were made of nylon monofilament with four mesh sizes (82.2, 89.4, 104.8, and 120.2 mm) while its two outer panels were made of twisted nylon multifilament with a mesh size of 510 mm. The SELECT (Share Each Length's Catch Total) procedure with maximum likelihood method was applied to obtain a master selection curve. The different functional models (normal, lognormal, bi-normal, and logistic model) were fitted to the catch data. The lognormal model with the fixed relative fishing intensity was chosen as the best-fitted selection curve through comparison of model deviance and AIC (Akaike's Information Criterion). The optimum relative length (the ratio of fish total length to mesh size) with the maximum relative efficiency was obtained as 2.492.

Catch characteristic and present condition of by-catch & discard of trammel nets fishery in the East Sea (동해 삼중자망어업의 해역별 어획 특성과 혼획·투기 현황)

  • Bae, Bong-Seong;An, Heui-Chun;Park, Hae-Hoon;Park, Chang-Doo;Yang, Yong-Su
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.46 no.2
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    • pp.103-114
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    • 2010
  • For an effective management of fisheries resources, we need fisheries informations necessary for the establishment of reasonable fishing effort and TAC distribution. To study the present state of by-catch and discard of gill-net fishery in the East Sea, we carried out fishing research using trammel nets in the coastal sea of Susan-port (Yangyang), Jangho-port (Samcheok) and Hupo-port (Uljin). As a result, a total of catch of Susan was 259,172g and that of Hopo was 577,638g. Thus Catch of Susan was 1.49 times more than that of Hupo considering the number of used fishing gear. And catch of Janho was 7.4 times more than that of Susan considering the number of experiment. Two methods of by-catch analysis in this study were used, one method is standardizing of listed species catching possible in fishing license, another method is regarding catch species under 1% of total catch as by-catch. As a result of by-catch analysis of two method, by-catch rate of Susan was 6.55% and 5.87% respectively, that of Hupo was 44.70% and 5.24% and that of Jangho was 0.96% and 2.31%. Discard rate of fish in Susan, Hupo and Jangho were 1.59%, 3.42%, 2.23% respectively.

Seasonal Variations in the Species Composition of Fisheries Resources Caught by Trammel Net in the Uljin Marine Ranching Area, East Sea (울진바다목장에서 자망으로 어획된 수산자원의 종조성과 계절변동)

  • Yoon, Byoung Sun;Park, Jeong-Ho;Yoon, Sang Chul;Yang, Jae Hyeong;Lee, Sung-Il;Kim, Jong-Bin;Choi, Young-Min;Sohn, Myoung Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.48 no.6
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    • pp.947-959
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    • 2015
  • Variations in the species composition, biomass and size distribution of fisheries resources in the Uljin marine ranching area were investigated using trammel nets at two stations (artificial reef and natural rocky area) from 2009 to 2010. During the survey, a total of 74 species were sampled with a mean density of 132 ind./net and mean biomass of 21.56 kg/net. In the natural rocky area, a total of 45 species were sampled at a mean density of 202 ind./net and mean biomass of 28.81 kg/net, while in the artificial reef area, samples included a total of 56 species, with means of 62 ind./net and 14.30 kg/net. The dominant species, comprising over 3% of the total number of individuals, were Suberites ficus (30.8%), Ovalipes punctatus (19.2%), Paralichthys olivaceus (11.7%), Pleuronectes herzensteini (4.7%), Kareius bicoloratus (3.5%), Pseudopleuronectes yokohamae (3.5%) and Eopsetta grigorjewi (3.0%). The dominant species, in terms of biomass, comprising over 5% of the total biomass, were P. olivaceus (22.1%), S. ficus (18.7%), O. punctatus (7.2%), Hexagrammos otakii (6.6%), P. yokohamae (5.7%), K. bicoloratus and P. herzensteini (5.3%). A cluster analysis and non-metric multidimensional scaling (nMDS) analysis based on the Bray-Curtis similarity of fourth root transformed data for number of species and individuals, was divided into two groups: the artificial reef area (group A) and the natural rocky area (group B).

Fish Assemblages Collected by Bottom Trammel Gill Net around Gampo in the East Sea of Korea (동해 감포 주변해역에서 저층삼중자망에 어획된 어류 군집)

  • Kang, Pil Jun;Kim, Chong Kwan;Hwang, Sun Wan
    • Korean Journal of Environmental Biology
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    • v.33 no.1
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    • pp.27-33
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    • 2015
  • Fish assemblages in the coastal waters off Gampo in the East Sea of Korea were analyzed using the samples of fishes collected with bottom trammel gill nets June, September, and December 2005 and, March 2006. During the study period, a total of 32 fish species, 695 individuals, and 180,012.0 g representing 21 families were collected. The fish assemblages predominantly consisted of Ditrema temminckii, which accounted for 52.4% of the number of individuals and 40.4% in the biomass. The next major specimens were Hexagrammos otakii, Sebastes schlegelii, Stephanolepis cirrhifer, Sebastes taczanowskii, Halichoeres poecilopterus. These six fishes accounted 77.6% of total number of individuals and 77.5% of total biomass. The number of fish species, the number of individuals and biomass were fluctuated with month. The number of species was highest in June 2005 and lowest in March 2006. The number of individuals and biomass was highest in September 2005 and lowest in June 2005.