• Title/Summary/Keyword: By-catch

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Characteristics of Korean Coastal Fisheries (한국 연안어업의 실태)

  • Yoon, Sang Chul;Jeong, Yeon Kyu;Zhang, Chang Ik;Yang, Jae Hyeong;Choi, Kwang Ho;Lee, Dong Woo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.47 no.6
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    • pp.1037-1054
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    • 2014
  • In this study, the status of coastal fisheries was examined based on the catch and number of fishing vessels of coastal fisheries in Korea. Comparing the status on coastal fisheries of the East Sea, Yellow Sea and South Sea in Korea, scientific evidence was made for fisheries management on coastal fisheries based on characteristics of each sea area. From 1990 to 2011, the catch of coastal fisheries in Korean waters ranged from 150,000 mt to 230,000 mt, with an average of 190,000 mt, and it accounted for 15% in average of total catch fished in adjacent waters of Korea. In order of catch by coastal fisheries, gillnet (36.7%) was the primary fishery, followed by coastal complex (24.7%), stow net (18.3%), trap (12.9%), lift net (3.9%), purse seine (3.0%) and beam trawl (0.4%) fisheries. In order of catch by species, anchovy (15.0%) had the largest proportion of total catch, followed by common squid (10.3%), akiami paste shrimp (5.2%), blue crab (3.9%) and octopus (3.7%). Of the average catch by sea area from 1990 to 2011, Yellow Sea, South Sea and East Sea were 37.4%, 34.6% and 28.0%, respectively. Since 2000s, however, the average catch of South Sea has accounted for the largest proportion. The number of permitted fishing vessels involved in 8 coastal fisheries was 55,336 vessels in average from 1997 to 2011. The number of vessels was about 47,000 vessels in 1997, and increased to 61,300 vessels until 2000, then has decreased to 44,000 vessels operating in 2011. In order of the number of permitted fishing vessels by fisheries, complex (52.4%) took the first place, followed by gillnet (31.5%), trap (13.4%), stow net (0.8%), beam trawl (0.8%), purse seine (0.6%), lift net (0.4%) and seine net (0.0%). In order of the number of permitted fishing vessels by sea area, South Sea (29,994 vessels) took the first place, followed by Yellow Sea (18,185 vessels) and East Sea (7,158 vessels). In order of the catch per unit effort (CPUE, mt/vessels) which was analyzed using catch and number of vessels in average by fishery, stow net is the highest followed by lift net, trap, purse seine, gill net, beam trawl and complex fisheries. In particular, the CPUE of complex and gill net fisheries, which accounted for the largest number of vessels were 4.0 mt/vessels and 1.6 mt/vessels, respectively. Since those are too low relative to other fisheries, it was judged to need systematical management on both fisheries.

Development of a Catch Basin Sump Insert to Reduce Mosquitoes

  • Kim, Dong Gun
    • Korean Journal of Environmental Biology
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    • v.36 no.4
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    • pp.554-557
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    • 2018
  • A catch basin sump is one major habitat for mosquito larvae, especially in urban areas. This study developed a device for mosquito control, specifically for the catch basin sump. It consists of a housing, is a little smaller than the catch basin sump, numerous floating materials, which the key component for mosquito control, and mesh nets. The small balls or pyramid-shaped floating materials inhibit mosquito enclosures and spawning by significantly decreasing the surface area of the water, which is essential for the mosquito life cycle. These floating materials were designed to keep the water flowing. The mesh nets were installed to prevent the outflow of floating materials. The efficiency of the floating materials was tested with 3 conditions (1, 2, 3 layers of floating materials) and a control group. The emergence of mosquito adults decreased by 20% in one-layer, and 70-80% in second and third layers. Therefore, this device is expected to certainly contribute to mosquito population control in the catch basin sump.

Spatial Variations in the Catch of Billfishes in the Pacific Ocean and Factors Affecting Annual Changes in the Catch (태평양 새치류의 어장분포와 어획량 경년 변동에 영향을 미치는 요인)

  • Yoo, Joon-Taek;Hwang, Seon-Jae;An, Doo-Hae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.42 no.6
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    • pp.695-702
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    • 2009
  • This study includes spatial variations in the catch of billfishes in the Pacific Ocean and examines factors affecting interannual changes in the catch. Main billfish species caught by Korean tuna longline fishery were blue marlin and swordfish. A main fishing ground of the species was the tropical Pacific Ocean, while additional fishing ground of billfishes tended to be formed in the Pacific coast of Mexico in the El Nino periods. Further, the catch of billfishes was significantly related to CPUE (tons/average of the used hooks/vessel) in the entire Pacific Ocean as an index of stock abundance and equatorial SOI (EQSOI) as an index of El Nino event. Annual changes in the catch of billfishes in the Pacific Ocean could be regulated mainly by variations of stock abundance. In addition, increase of the density of billfishes in the tropical Pacific and additional formation of fishing ground by El Nino event possibly contribute to increase of the catch of billfishes in the Pacific Ocean. On the other hand, linear regression model may be more adequate in the analysis of relationships between fisheries data and indices made from using some environmental factors.

Fishing Characteristics of Pacific Herring Clupea pallasii and Relationship between Its Catch and Sea Temperature during the Past 50 Years in Korean Waters (50년간 우리나라 청어(Clupea pallasii)의 어획 특성 및 어획량과 수온과의 관계)

  • Yoo, Joon-Taek;Kim, Jung Jin
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.54 no.2
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    • pp.208-217
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    • 2021
  • This study described the fishing characteristics of Pacific herring Clupea pallasii and examined the relationship between its catch and sea temperature in Korean waters from 1970 to 2019. Although the herring catch in Korean waters stayed below 1,000 tons per year from the mid-1970s to mid-1980s, the catch in the winters in the East Sea of Korea started to increase markedly after 1987-1988, when the sea surface temperature (SST) seemed to shift to a warmer regime. Since the mid-2000s, overall, herring was caught throughout the year in the East Sea and eastern South Sea of Korea, and its catch significantly increased by around 30,000 tons per year. The main fishing grounds of herring in the poor fishing years until the mid-1980s were possibly formed in the western offshore of Korea, and subsequently the fishing grounds were distributed in the eastern coast of Korea. While the standardized catch per unit effort (CPUE) for two main fisheries of herring catch was significantly correlated with the herring catch since the 2000s, there was a gradual decline since the 2010s. The herring catch in the East Sea had significant positive correlations with SSTs, but that in the West Sea had a significant negative correlation.

An Analysis of Changes in Catch Amount of Offshore and Coastal Fisheries by Climate Change in Korea (기후변화에 따른 한국 연근해 어업생산량 변화 분석)

  • Eom, Ki-Hyuk;Kim, Hong-Sik;Han, In-Seong;Kim, Do-Hoon
    • The Journal of Fisheries Business Administration
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    • v.46 no.2
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    • pp.31-41
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    • 2015
  • This study aimed to analyze the relationship between sea surface temperature as a climatic element and catch amount of offshore and coastal fisheries in Korea using annual time series data from 1970 to 2013. It also tried to predict the future changes in catch amount of fisheries by climate change. Time series data on variables were estimated to be non-stationary from unit root tests, but one long-term equilibrium relation between variables was found from a cointegration test. The result of Granger causality test indicated that the sea surface temperature would cause directly changes in catch amount of offshore and coastal fisheries. The result of regression analysis on sea surface temperature and catch amount showed that the sea surface temperature would have negative impacts on the catch amount of offshore and coastal fisheries. Therefore, if the sea surface temperature would increase, all other things including the current level of fishing effort being equal, the catch amount of offshore and coastal fisheries was predicted to decrease.

An Innovation Path of Catch-up by Semiconductor Latecomers: The Semiconductor Manufacturing International Corporation Case

  • Qing, Lingli;Ma, Xiang;Zhang, Xuming;Chun, Dongphil
    • Journal of East Asia Management
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    • v.3 no.2
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    • pp.43-64
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    • 2022
  • Exploring innovations for latecomers to catch up has been a popular concern in industry and academia. Over the last decade, more and more East Asian latecomer firms have moved beyond imitation and are delivering innovative products and services to the market. However, the semiconductor latecomers from China have limited success in catching up with more mature semiconductor firms. Our study examines how semiconductor latecomers to break through the latecomer's dilemma by innovation and achieve catch-up. We use a single-case approach for the Semiconductor Manufacturing International Corporation (SMIC) vertical development process to analysis its innovation path of catching up. The study's results showed that SMIC relied on the government's policy and funding support, and based on the strategic endurance of entrepreneurs, it persisted in technology R&D investment and independent innovation for 20 years. SMIC finally smashed the dilemma of latecomers and successfully achieved catch-up. With these findings, we believe that the path of catching up innovation for semiconductor latecomers should be equipped with independent innovation of technology, strategic leadership of entrepreneurs and support of government policies. As these factors are combined, latecomer firms' position is expected to rise and catch-up will become visible. Our study contributes to some enlightenment on the innovation path for latecomers in China and global semiconductors to achieve their catch-up.

Seasonal Variation of Fish Catch by a Set Net in Hamdeuk Fishing Ground off Jeju Island (제주도 함덕 연안의 정치망 어획량 변동)

  • CHA Byung-Yul;CHANG Dae-Soo;KIM Byung-Yeob
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.37 no.1
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    • pp.65-72
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    • 2004
  • Fish catch by a set net in Hamdeuk fishing ground off Jeju Island were studied to determine seasonal variation of species composition and catch from 1998 to 2000. A total 72,022.9 kg was caught during the survey period, including Scomber japonicus and Trachurus japonicus of $76.4\%$ in the total. The other dominant species were Siganus fuscescens, Loligo chinesis, Seriola dumerili, Sepioteuthis lessoniana, Sardinops melanostictus, and Seriola lalandi accounting to $20.0\%$ of the total. The fishing period conducted by a set net in Hamdeuk fishing ground were from May to November. The catch by a set net were higher in summer than in spring and autumn and closely related with the seasonal variation of sea water temperature. The catch was higher in 1998 than In 1999 and 2000, which was related to the sea water temperature in fishing ground.

The Analysis of the post Catch-up Research in the Public Sector (탈(脫)추격형 공공부문 연구활동의 특성 분석)

  • Song, Wi-Chin
    • Journal of Technology Innovation
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    • v.16 no.1
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    • pp.239-259
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    • 2008
  • Korea is in the middle of a transition from the catch-up stage to the post catch-up stage. This requires a new approach, a new perspective, and a new strategy to survive in the new environment. This research investigates the post catch-up research activities in the public sector, including universities and national research institutes. In this case study, the experts and research teams at the highest level in the world are introduced, and research environments and know-how possessed by the experts and research teams are analyzed. The cases shows that the post catch-up research teams have research patterns to open new research field and integrate prior knowledge base with new knowledges from other research field. They succeed in producing highly regarded research results and making research platform for further advanced research.

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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.

A Study on the Introduction of Allocated Catch quota System (쿼타관리제도의 국내 여행에 관한 연구)

  • 박장일
    • The Journal of Fisheries Business Administration
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    • v.26 no.1
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    • pp.41-54
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    • 1995
  • Recently our government intended to change the present fisheries management system into the allocated catch quota system, which is to increase the income of fishermen and to recover the depleted resources up to a desirable level. This paper is to find out the difficulties of introducing the allocated catch quota system into our fisheries mangement system and to reduce the possible errors for the enforcement of this system. The allocated catch quota system can be devided by two kinds, the one is to allocate among industries or fisheries with total allowable catch(TAC) and the other is to allocate among fishermen or individual vessels with individual fish quota(ITQ). The latter is a much advanced control system compared with the former and is what this study treats. This paper reviewed the case of Newzealand and Canada where the ITQ system is introduced earlier and classified the problems by two parts for successful introduction into Korea as follows : (1) allocation method problems, (2) enforcement problems. For the first part the problems to be considered are 1) a scientific oath qouta calculation system is necessary, 2) the quota must be opened, 3) by-catch problems. 4) interactions with adjoining countries. For the second part the problems to be considered are 1) monitoring system, 2) quota transferability, 3) quota flexibility, 4) the enforcement of the system must be connected with the reduction of fishing power, 5) a mass communication and decision making system between government and fishermen is essential.

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