• Title/Summary/Keyword: Catch efficiency

Search Result 116, Processing Time 0.034 seconds

Scale Efficiency and Fishing Capacity Analysis for Large Pair-Trawl Vessels in Korean Waters (한국 근해 쌍끌이 대형기선저인망어선의 규모별 효율성과 어회능력 활용도 평가)

  • Lee, Dong-Woo;Lee, Jae-Bong;Jung, Suk-Geun;Kim, Yeong-Hye
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.41 no.6
    • /
    • pp.485-492
    • /
    • 2008
  • To propose proper vessel characteristics for sustainable fisheries in Korean waters, we analyzed the fishing capacity, scale efficiency and utilization of large pair-trawl vessels based on the database of catch, effort and vessel characteristics (gross tonnage and engine power) in 1990 by applying data envelopment analysis (DEA). The input factors were gross tonnage, horse power and days operated; whereas the output factor was expected catch by vessel characteristics. The optimal vessel types, selected based on the input-oriented technical efficiency and gross tonnages, was 100 GT with engine power <600 HP. The output-oriented unbiased estimate of capacity utilization (CD) decreased with increasing vessel tonnage. For the same tonnage vessels, the CD decreased with increasing engine power.

Octopus fisheries in the coastal waters of Gangneung - I - Pot fishery - (강릉시 연안 문어어업에 관한 연구- I - 통발어업 -)

  • An, Young-Il;Park, Jin-Young
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.41 no.4
    • /
    • pp.271-278
    • /
    • 2005
  • In order to study the catch situation of the octopus pot fishery in the coastal waters of Gangneung, catch quantities and weight per month and depth, the soaking time & loss of fishing gear were studied based on 62 fishing times (1 set consisted of 150 pots which is equivalent to 1 fishing time) over a period of 10 months from February to December 2003 using commercial fishing vessels and training ships. The monthly CPUE was generally high in the months of june - September, and during this period July showed the highest quantity (134g/pot, 19.21kg/haul). In consideration of the fact that octopus below the weight of 2kg is protected in foreign countries, the majority of the catch was small with 76% (486 octopuses) below 1kg. The octopus catch quantity was high in depth of more than 40m, and the average catch number per set of pots in depths of over 50m was the highest with 13 octopuses. CPUE(g/pot) was the highest at a depth of over 60m recording 101. In terms of catch quantity per soaking time (4-18 days) the highest was on the 7th day, and 13-18 days also recorded high catches, and this suggests the possibility of ghost - fishing with the loss of fishing gear. Loss of fishing gear was the highest in terms of loss frequency and amount at depths of 20-30m. Consequently, it seems that octopus pot fishing at depths of more than 30m would relieve friction with other types of fishing and increase fishing efficiency.

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
    • /
    • v.50 no.1
    • /
    • pp.1-11
    • /
    • 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.

Fishing efficiency by vessel capacity of Korean tuna purse seiners operating in the western and central Pacific Ocean (태평양 수역 우리나라 다랑어선망어업의 선박 역량에 따른 조업 효율성 분석)

  • LEE, Mi Kyung;LEE, Sung Il;KIM, Doo Nam;KU, Jeong Eun;KWON, Youjung
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.53 no.2
    • /
    • pp.169-176
    • /
    • 2017
  • Tuna purse seine fishery in the western and central Pacific Ocean (WCPO) has been rapidly developed since early 1980s due to massive investment of major distant water fishing nations, and catch by purse seine fishery operating in the WCPO accounts for nearly half of the world's tuna total catch. As fishing efficiency is reflected by not only improving of individual vessel's capacity but also increasing number of active vessel, it is essential to understand vessel capacity for reliable assessment result on how fishery affects stock status of target species. In this study, fishing efficiency was analyzed by main factors which are representative of vessel capacity using fishing data and vessel information related to Korean tuna purse seine fishery operating in the western and central Pacific Ocean from 1992 to 2014. It showed that fishing efficiency of vessel tends to be higher when having larger vessel tonnage, higher engine power, lower vessel age and larger length of vessel. As for fishing efficiency by set type, CPUE of associated set with floating objects was generally higher than that of free school set, and CPUE of free school set seemed to have a greater effect on engine power and vessel age compared to other factors.

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

  • Kim Yong-Hae
    • Fisheries and Aquatic Sciences
    • /
    • v.6 no.1
    • /
    • pp.34-40
    • /
    • 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.

Hydroacoustic Investigation of Demersal Fisheries Resources in the Southeastern Area of the Cheju Island , Korea - The Composition of Trawl Catches and the Influence of Net Efficiency on the Fish School Target Strength- (제주도 동남해역의 저서어업자원 조사연구 - 트롤 어획물의 조성과 어구 효율이 어군반사강도에 미치는 영향 -)

  • Lee, Dae-Jae;Lee, Won-Woo
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.32 no.3
    • /
    • pp.257-265
    • /
    • 1996
  • The combined hydroacoustic and bottom trawl surveys were conducted in the Cheju southeastern area by the training ship "KAYA" belong to Pukyong National University in July 1995 and the traning ship "NAGASAKI MARl]" belong to Nagasaki University in April 1994, respectively. The main purpose of the investigations was to provide the basic data for the management and the biomass estimation of commercially important demersal fish stocks in this area. Fish samples were collected by bottom trawling from 10 trawl stations randomly selected in the survey area, and the species and length compositions of trawl catches were examined. The fish school target strength for demersal fish aggregations was related to the catchability of trawl net with a 90 mm mesh codend. The most abundant species in the 1995 trawl stations were Japanese flying squid, sword tip squid and red horsehead and that of the 1994 trawl stations Japanese flying squid and blackmouth goosefish. The average weight per cubic meter of trawl catches collected by bottom trawling in the Cheju southeastern area were $1.0791{\times}lO^-4$kg/$m^3$ in the 1994 survey area and $1.3636{\times}lO^-4$kg/$m^3$ in the 1995 survey area, respectively. The catch data by cover net suggest that the efficiency of trawl net could affect the weight normalized target strength values for demersal fish aggregations. That is, the average target strength per unit of weight dropped from - 33.1 dB/kg using the total catch by codend and cover net to - 30.5 dB/kg using only the catch data by codend, and a change of2.6 dB/kg was observed.ange of2.6 dB/kg was observed.

  • PDF

Catching efficiency of a shrimp beam trawl according to the length of beam and wing net and its influence on the hauling work (새우조망 어구의 막대 (빔)와 날개그물 길이에 따른 어획성능과 양망 작업에의 영향)

  • Park, Hae-Hoon
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.50 no.3
    • /
    • pp.396-406
    • /
    • 2014
  • Shrimp beam trawl fishery is one of the important coastal fisheries in Korea. It has a regulation to the length of beam (8m) and wing net (7m) of shrimp beam trawl that has been used in the district of Junlanam-do and Gyungsangnam-do. This regulation was made in relation to the size of shrimp beam trawler of 3-ton class at that time. Now the shrimp beam fishing vessel has a limit not greater than 5 tons in gross ton. Recently, with improvement of fishing industry and fishing vessel fishermen asked the expansion of the length of beam and wing net, therefore it is necessary to investigate the effect of lengthening the beam and wing net length. Three different beams (8m, 10m and 12m in length) and three different wing net (7m, 10m and 13m in length) were made and the experiment was conducted near Narodo of Goheng by two fishing vessels of 4.98 and 4.88 tons in gross ton between June 2011 and October 2012. When the length of wing net was increased from 7m to 10m and 13m, the relative catch ratio in total biomass was increased 25% and 79% for shrimp, (17% and 22% in total), respectively. And when the beam length was increased from 8m to 10m and 12m, the relative catch ratio was increased 35% and 84% for shrimp, (21% and 37% in total), respectively. The force exerted to the iron guide of inhauler's with the beam length of 8m was about 30% greater than that with the beam length of 10m when hauling the shrimp beam trawl net.

Adoption of Foreign Technologies in Korean Manufacturing Firms: Characteristics and Microfoundations

  • SUH, JOONGHAE
    • KDI Journal of Economic Policy
    • /
    • v.37 no.3
    • /
    • pp.75-106
    • /
    • 2015
  • The primary goal of this paper is to explore the microeconomic foundation of Korean firms' adoption of foreign technologies. The paper also reviews the overall trend of international technology transfers to Korea. The period covered in this paper is Korea's high growth era, from the 1960s to the 1990s. The works of this paper center on the two questions of what characterizes foreign technologies which had been imported through licensing contracts, and which driving forces expedite technology adoption by firms. The Korean experience provides the context of success in the catch-up growth. The co-movement of technology imports with capital goods imports manifests Korea's effort to improve the technical efficiency toward the world frontier. Underlying this trend are firms' decisions to adopt new technologies. The paper shows that firms respond proactively to wage increases by adopting newer technologies and thus, in turn, increasing employment, which implies the existence of a virtuous interactive mechanism among these factors.

  • PDF

Dynamic Efficiency Analysis of Korean HRD Programs using Data Envelopment Analysis (DEA 방법론 활용을 통한 국가 HRD사업에 대한 동태적 효율성 분석)

  • Lee, Jung-Mann
    • Journal of Digital Convergence
    • /
    • v.10 no.2
    • /
    • pp.63-71
    • /
    • 2012
  • This paper investigates efficiency analysis to IT HRD programs in the dynamic perspective. First, empirical result shows that government fund of IT research center is significantly associated with SCI thesis and the more trial goods and SW development is connected with the more patent and technology transfer. Second, ITRC program has been operated efficiently since 2000. Finally, dynamic efficiency analysis implicates that ITRC program is more efficient than other IT SoC program and foreign student support program. The reason why ITRC program is more efficient is generated not from the effect of imitation by catch-up strategy to developed HRD programs, but new operation system introducing and utilizing HRD performance system.

Fishing performance of hull form renovated tuna purse seiner (선형개조 다랑어 선망선의 조업성능)

  • HONG, Jin-Keun;KANG, Il-Kwon;JEONG, Seong-Jae
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.51 no.3
    • /
    • pp.321-332
    • /
    • 2015
  • In an attempt to find the improvement of the fishing efficiency according to the hull form remodeling for the 3 tuna purse seiner, the Catch-Per-Unit-Effort (CPUE) for that undertaken before (2008) and after (2010) was analyzed. In addition, the CPUE of 6 similar ships operated same period and same fishing ground. As result, it came to verify that the three modified ships had a significant value on the CPUE. An another index for the improvement of fishing efficiency is the rate of reduction of fuel oil consumption for the modified ships. Fuel oil consumption per day in service speed as comparing with the original ships were reduced 2.1%, 4.0% and 5.1% on the modified ship A, B, and C respectively. And each ship's service speed was increased 1.0 kt, 0.6 kt, and 0.4 kt according to the modified ship A, B, and C in due order. In the conclusion, the remodeling job with newly equipped bulbous bow, lengthened slipway and enlarged rudder area were improved fairly much on fuel oil efficiency, the ship's speed, and in the end, that led to the improving fishing efficiency. Hence, the remodeling of tuna purse seiner come to improve not only the fishing performance, but contribute to the reduction of operating cost by saving energy for the fisheries industry.