• Title/Summary/Keyword: by-catch

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Influence of Sea Condition on Catch Fluctuation of Long Line for Common Octopus, Octopus Variddilis, in the Coastal Waters of Yosu (2) (여수연안 낙지주낙 어장의 해황과 어획 변동에 관한 연구(2))

  • 정정민;김동수
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.37 no.4
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    • pp.326-330
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    • 2001
  • In order to investigate the influence of sea condition on the catch fluctuation of long line for common octopus, octopus variabilis, the oceanographic factors, i. e., the wind direction, the wind speed, the age of moon and ebb tide and flood tide in the coastal waters of Yosu from Jan. 11 to Jul. 25 in 1997, and compared with the catches of common octopus, octopus variabilis, by long line. The results obtained summerized as follows; 1) The catch of common octopus was highest in wind direction from SE and lowest in that from NW. The catch was highest at the wind speed of 2m/sec and decreased with increasing speed, over 2m/sec. 2) The catch of common octopus was highest at the day of neap tide and lowest at the mid day, from neap tide to spring tide. More strictly the catch was higher during days at which the current became rapid than during days at which the current became slow. The catch was higher always at flood tide than at ebb tide in all the days investigated and highest with in one hour from ebb tide.

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Fishing characteristics of small yellow croaker drift gill net by net height (참조기 유자망의 설 높이에 따른 어획특성)

  • Oh, Taeg-Yun;Cho, Young-Bok;Seo, Young-Il;Kim, Byung-Yeob;Lee, Chang-Heon
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.50 no.3
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    • pp.368-377
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    • 2014
  • Small yellow croaker is one of the important stocks in Korean waters. In this study, we conducted sea trials to estimate optimum height of a drift gill net for effective fishing of small yellow croaker. In the trial using existing net which has 9.2m in height, there was 22 species (1,180 fishes, 99.9kg) caught. The catch (in individuals) of small yellow croaker, especially larger fishes (over 22cm in FL), was higher as part of net height is higher, while the number of species bycaught and the catch of those species were higher as part of net height is lower. In the trial using extension net which has 18.4m in height, there was 27 species (2,030 fishes, 151.7kg). It showed same pattern with existing net in the section I to III, however, in the section IV which is over 13.8m of net height, the catch sharply decreased. The number of species bycaught and the catch of those species using extension net were also same as results using existing net. It showed that section III (9.2-13.8m) where is upper-middle part of the net has caught most of catch and large fishes having over 22cm in length. Through these results, it is judged that the setting depth of the net where is 4.6-13.8m above the sea bottom is the best to reduce bycatch and catch much more large size fishes, and the catch per net is proportional to filtering area of net. Therefore the Fisheries Resource Management Act (the clause 1, article 10) on the amount of usage for offshore drift gill net need to be considered not only length of a net but also net height.

Catch-up growth and development of very low birth weight infants (극소저출생체중아의 따라잡기 성장 및 발달평가)

  • Ma, Tae Ho;Kim, Kyung Ah;Ko, Sun Young;Lee, Yeon Kyung;Shin, Son Moon
    • Clinical and Experimental Pediatrics
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    • v.49 no.1
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    • pp.29-33
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    • 2006
  • Purpose : The aim of this study was to analyze the results and contributing factors of catch-up growth in very low birth weight infants(VLBWI) at the corrected age of 2 years. In addition, we looked for a relationship between the catch-up growth and the development by the bayley scales of infant development II(BSID II). Methods : A retrospective analysis by evaluating medical records was done for the 76 VLBWI whose follow-up was possible up to a corrected age of 2 years, out of the 114 who had been treated in the neonatal intensive care unit during the January of 2000 to December of 2001 at Samsung Cheil Hospital. Based on the Standard Korean Infant's Growth Curve, the catch-up growth group was defined over the 10th percentile of weight at 2 years as the corrected age and the failed catch-up growth group was defined under the 10th percentile. We investigated the clinical factors and courses of each group and compared the scores of the BSID II. Results : The catch-up growth group of the VLBWI was 51 infants and the failed catch-up growth group was 25 infants. In comparison with maternal clinical factors, use of antenatal steroids was significantly higher in the catch-up growth group. In comparisn with clinical factors and courses of VLBWI, two clinical factors were significantly different between the two groups : birth weight and intrauterine growth retardation(IUGR). Numbers of delayed development were increased in the failed catch-up growth group but statistically significant differences could not be observed. Conclusion : The catch-up growth of the VLBWI was affected by the use of antenatal steroids, birth weight and IUGR. No significant differences regarding neurodevelopmental outcome were observed between the catch-up and failed catch-up growth groups.

Catch characteristics of the biodegradable gill net for flounder (생분해성 가자미 자망어업의 어획 특성)

  • Bae, Bong-Seong;Cho, Sam-Kwang;Park, Seong-Wook;Kim, Seong-Hun
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.48 no.4
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    • pp.310-321
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    • 2012
  • There are many studies of the biodegradable net for fishing to prevent marine pollution in Korea and the snow crab gill nets is developed effectively. Recently, the biodegradable gill net for fishes is being developed. This study is the experiment of the catch characteristics for the biodegradable flounder gill net. The 8 experiments were carried out using the nylon gill net and the biodegradable gill net in from August to October, 2011 in the southern East Sea. The results obtained from the above approaches are summarized as follows; A total of 16 species was caught with most dominant species of Cleisthenes pinetorum followed by Liparis tanakai, Glyptocephalus stelleri, Buccinum striatissimum and Dasycottus setiger. A total of catch of the nylon net was 342,885g and that of the biodegradable net was 236,857g. Thus catch of the nylon net was 1.45 times more than that of the biodegradable net. The length composition of Cleisthenes pinetorum, caught by the biodegradable net was very similar to that of nylon. As a result of analysis on the effect of submerged time, small fish escaped more easily than large fish as the submerged time is getting longer. And catches of the biodegradable net was less than the nylon net's as higher as wave height. Wave height was more influential factor for fishing capacity than submerged time based on the results of a comparison between catch difference of two kinds of gill nets and catch characteristics.

Influence on the catch of shellfish by offshore dredge fishery according to change fishing area to the construction of the Samangeum Dike in Jeollabuk-do, Korea (새만금방조제 건설로 인한 조업구역의 변경이 전라북도 근해형망어업의 패류어획량에 미치는 영향)

  • CHOI, Jong-deok;RYU, Dong-ki;LEE, Mi-Hee
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.53 no.3
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    • pp.266-275
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    • 2017
  • The maximum sustained yield (MSY) of shellfish caught through dredge fishery was 7,250 to 7,490 MT from 1990 to 1999, which was not affected by the construction of the Saemangeum Dike. The MSY from 2000 to 2016, under the influence of the dike, was 1,716 to 1,776 MT when the total annual fish catch was 1,000 MT or more, and 289 to 336 MT when it was less than 1,000 MT. The construction of the Saemangeum Dike led to a decrease in the catch volume of the offshore dredge fishery in Jeollabuk-do, to 4.2 to 23.7% of that before its construction. The allowable biological catch (ABC) was estimated to be 313 to 1,532 MT per year, which was about 72.3 to 94.3% less than before the construction of Saemangeum Dike. Currently, the dredge fishery in Jeollabuk-do relies on comb pen shells. For fishery management, the catch per vessel should be set at 51.0 MT/year or less, and the number of fishing vessels should be reduced to 22 as quickly as possible. Besides, in the long term, the number of current fishing vessels should be reduced to less than half in consideration of the comb pen shell collecting period in Jeollabuk-do.

An analysis of the fishing characteristics of Korean large purse seine fisheries in Japanese waters (우리나라 대형선망어업의 일본수역 조업특성 분석)

  • YU, Gwang-Min;RYU, Kyung-Jin;KIM, Hyung-Seok;LEE, Chun-Woo
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.57 no.2
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    • pp.107-116
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    • 2021
  • The breakdown of the Korea-Japan fishing negotiations since 2016 has made it impossible for many domestic fishing vessels to operate in the Japanese EEZ water, and large purse seine fishing vessels are one of them. Mackerel is a highly migratory fish species, circulating in the East China Sea, South Sea, West Sea and East Coast throughout the year, and goes through a period of wintering, spawning, growth and feeding migration. In this study, in order to find out the dependence of large purse seine fishing vessels on mackerel fishing in the Japanese EEZ waters, we analyzed the characteristics of mackerel by large purse seine fisheries in the Japanese EEZ waters from 2010 to 2016. The catch and fishing details were investigated. The total catch of mackerel by large purse seine fishery, the average catch rate of mackerel in Japanese EEZ is 4 percent per year. The amount is estimated at 10.2 billion won per year. Although there was an effect, it was not judged to be a significant factor, and it was found that the amount of catch and fish price in the domestic waters had a greater influence on the total catch than the Japanese EEZ waters.

A Study On The Optimization of Java Class File under Java Card Platform (자바카드 플랫폼상에서 자바 클래스 파일의 최적화 연구)

  • 김도우;정민수
    • Journal of Korea Multimedia Society
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    • v.6 no.7
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    • pp.1200-1208
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    • 2003
  • Java Card technology allows us to run Java applications on smart cards and other memory-constrained devices. Java Card technology supports high security, portability and ability of storing and managing multiple applications. However, constrained memory resources of the Java Card Platform hinder wide deployment of the Java Card applications. Therefore, in this paper we propose a bytecode optimization algorithm to use the memory of a Java Card efficiently. Our algorithm can reduce the size of the bytecode by sharing the memory of the parameters of the catch clause in the try-catch-finally sentence.

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Generation Human -like Arm Motion to Catch a Moving Object

  • Kwon, Oh-Kyu;Park, Poo-Gyeon
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.161.5-161
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    • 2001
  • Robots are required to assist our activities in daily life. In this paper, we focus on arm movement to catch moving object as one of important tasks frequently performed by human. We propose an algorithm which enables a robot to perform human-like arm motion to catch a moving object. First we analyze human hand trajectories and velocity profiles to catch an object. From the experimental results, we extract some characteristics in the process of approaching and following a moving object and confirm that these are necessary to realize human-like motion. We then adopt an instantaneous optimal control method which evaluates the error and energy cost at each sampling step, and design two time-varying weight matrices to introduce human characteristic into robot motion. The matrix concerning the error is defined as a time-increasing ...

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Catch per Unit Effort and Size Composition of Crayfish, Astacus leptodactylus Eschscholtz 1823, in Lake İznik

  • Balik, Ismet;Ozkok, Ergun;Ozkok, Remziye
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.6
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    • pp.884-889
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    • 2002
  • This paper was carried out from 15 June to 24 December in 2000 in Lake İznik of Turkey, to determine catch per unit effort (CPUE) and size composition of crayfish, Astacus leptodactylus Eschscholtz 1823, captured by fyke-nets of local fishermen. The average CPUE of all size groups was found as 1.65 crayfish/fyke-net/night for fishing season in 2000, but 26.4% of which was below the legal minimum size (crayfish<90 mm). The average CPUE of legal-sized (crayfish$\geq$90 mm) crayfish was 1.10 crayfish/fykenet/night. The annual catch of crayfish was estimated as 2990 tonnes. The length and weight compositions of crayfish captured in the fyke-nets have varied between 60 and 130 mm, and 6 and 71 g, respectively. The mean length and weight were found as 95.5 mm and 28.8 g for all size groups and 100.1 mm and 33.0 g for legal-sized individuals.

Catching efficiency of the whelk pot in accordance with the pot materials in the Uljin waters, East sea (동해안 울진해역 원통형 고둥 통발의 재질별 어획 성능)

  • AN, Heui-Chun;BAE, Jae-Hyun;PARK, Chang-Doo;PARK, Jong-Myung;HONG, Sung-Eic;YOON, Byung-Sun;KIM, Pyungkwan;KIM, Seong-Hun
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.53 no.1
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    • pp.1-11
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    • 2017
  • Fishing pots are one of the important fishing gears in our coastal and offshore fisheries. In terms of a sustainable use of marine resources, there are concerns about the ghost fishing by lost pots. It is reported that 10 to 70% of the pots are abandoned or lost annually. This study is to compare the catching efficiency of drum type whelk pots that are made of biodegradable nets to those made of the ordinary nets, in the eastern coast of Korea. Five types of drum pots were used with combination of biodegradable nets and ordinary (PA, PE) nets applied to the main and funnel parts of the pots: pots with biodegradable nets (Bio+Bio); pots with PE net (PE+PE); pots with body and funnel made of biodegradable nets and PE nets respectively (Bio+PE); pots with body and funnel made of PE nets and PA nets respectively (PE+PA); pots with body and funnel made of PE nets and biodegradable net respectively (PE+Bio). Field experiments were conducted from June $18^{th}$, 2015 to August $7^{th}$, 2015 using a commercial fishing vessel in the Uljin waters on the eastern coast of Korea. Two fleets of pots with one hundred in each, 20 pots of each type, were casted for 8 to 15 days to analyze their catching efficiency. The catch of target species, whelks, was 202,563.0 g with catch rate of 38.7% of the total catch, while the bycatch was 320,709.7 g with the rate of 61.3% of the total catch. The catch of whelks was the highest in the Bio+PE pots (46,020.3 g), followed by the Bio+Bio pots (42,027.5 g), the PE+Bio pots (41,849.9 g) and the lowest being PE+PE pots (38,054.2 g). Compared to the conventional pots, the pots with biodegradable nets on the body or entrance part had slightly higher catch rate for both the target species and the bycatch. The PE+PE had the lowest catch rate. There is no significant difference in catch between the pots with biodegradable nets and the ordinary nets for the target species such as Buccinum opisthoplectum, Neptunea eulimata, Buccinum striatissimum. Consequently, using biodegradable nets for the conventional whelk pots can reduce ghost fishing by lost gears while keeping the performance of the pots.