• 제목/요약/키워드: By-catch

검색결과 995건 처리시간 0.025초

도루묵 수산자원회복계획에서의 TAC정책 평가 (Evaluating the TAC Policy in the Sandfish Stock Rebuilding Plan)

  • 김도훈
    • 수산경영론집
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    • 제46권1호
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    • pp.29-39
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    • 2015
  • This study aimed to evaluate the TAC policy and to examine the effective annual TAC quota in the sandfish stock rebuilding plan using a bioeconomic modelling method. In the analysis, first, a sandfish bioeconomic model was developed by combining a sandfish stock population model and economic models by fishery and second, achieving stock rebuilding targets and changes of fishing revenues by the level of annual TAC quota were examined. Model results indicated that the TAC 1,500ton policy would have the greatest impact on the increase of sandfish stock biomass comparing to the status quo and other TAC policies. In addition, it was evaluated that the total fishing revenues of coastal gillnet and danish seine fisheries could be increased the most in the TAC 2,500ton policy. In both cases of TAC 3,500ton and 4,000ton, the fishing revenues of both fisheries were inversely reduced due to the decrease of catch by coastal gillnet and the decline of market prices by danish seine's excessive catch. Furthermore, they would have a negative impact on sandfish stock biomass.

가막만 멸치 들망 어장의 해역별 특성 (Environmental Condition of Sea Areas for Anchovy Lift Net in Kamak Bay)

  • 이인원;김동수
    • 수산해양기술연구
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    • 제34권1호
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    • pp.67-73
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    • 1998
  • In order to find out the environmental factors influencing the catch of anchovy lift nets in kamakbay, the three oceanographic factors, i. e., the water temperature, the salinity, the amount of chlorophyll-a were observed respectively from August 1 to 12, 1995 and from September 20 to 26, 1995, and each of them was compared with the catch of anchovy by the lift net. The results obtained are summerized as follow : 1) The water temperature was ranged from 17.3 to 29.6$^{\circ}C$ and its difference between the surface and bottom was 1 to 3$^{\circ}C$. In the three areas, A, B and C, the area A was the hightest in temperature, the area B being a second, and the area C being the lowest. 2) The salinity was ranged from 32.20 to 33.47$\textperthousand$ and its difference between the surface and bottom was not significant. In the three areas, the area A was the highest in salinity, the area B being a second, and the area C being the lowest. 3) The amount of chlorophyll-a was ranged from 0.19 to 5.30mg/m supper(3) and its difference among the three areas was not significant. Daily variation of the amount was very irregulated because the position operated was changed daily. 4) A comparison of the water temperature, the salinity and the amount of chlorophyll-a with the catch gave that the water temperature and the amount of chlorophyll-a had large influence on the catch and the salinity did not so. However, the influence of the amount of chlorophyll-a was larger than that of the water temperature. 5) The catch of anchovy was large respectively during two hours after sun set and during two hours before sun rise.

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Fisheries resources management of crucian carp based on assessment of fish stock and potential yield in the mid-upper system of Seomjin River

  • Ryu, Hui Seong;Jang, Sung Hyun;Lee, Jung Ho;Lee, Jung Joon
    • Journal of Ecology and Environment
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    • 제37권4호
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    • pp.209-216
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    • 2014
  • This study was undertaken to suggest an effective fisheries resources management system by using stock assessment and potential yield analyses of crucian carp population in the mid-upper system of the Seomjin River. Fieldwork was conducted seasonally from 2008 to 2009 in the mid-upper system of the Seomjin River. The stock assessment was carried out by the swept area method and the potential yield was estimated by improved fisheries resource potential estimation system based on the Allowable Biological Catch. Also, the yield-per-recruit analysis was used to review the efficient management implication of the resource, Carassius auratus. As a result, the age at first capture ($t_c$) was estimated as 1.468 year, converted body length (BL) was 10.8 cm. Meaning the current fishing intensities, the instantaneous coefficient of fishing mortality (F) was $0.067year^{-1}$, and the yield-per-recruit analysis showed that the current yield per recruit was estimated to be 15.999 g with F and $t_c$. The instantaneous rate of fishing mortality that provides for Allowable Biological Catch ($F_{ABC}$) based on the current $t_c$ and F was estimated as $0.618year^{-1}$. Therefore, the optimum fishing intensities could be achieved at the higher fishing intensity for Carassius auratus. The calculated annual stock of C. auratus was estimated as 7,608 kg, and the potential yield was estimated as 343 kg with $t_c$ and F at the fixed current level. Using yield-per-recruit analysis, if F and $t_c$ were set at $0.618year^{-1}$ and 2 year, the yield per recruit and total allowable catch would be predicted to increase to 62 g and 2,531 kg by about 3.9 times and 7.3 times, respectively.

여수연안 정치망 어장의 환경요인과 어황 변동에 관한 연구 (Environmental Factors and Catch Fluctuation of Set Net Grounds in the Coastal Waters of Yeosu)

  • 김동수
    • 수산해양기술연구
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    • 제29권2호
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    • pp.94-108
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    • 1993
  • In order to investigate the relation between the environmental properties and catch fluctuation of set net fishing ground located in the coastal waters of Yeosu, oceanographic observation and catches on the grounds were carried out from Jan. to Dec. in 1990 and 1992. The results obtained are summarized as follows; 1) Because of the surveyed area is a costal shallow water, the fishing ground was influenced largely by atmospheric phenomena such as air temperature. precipitation. etc. and so showed large variations in temperature and salinity yearly. The inner water flowed out mainly between Yeosu ad Namhe-do, and then through Kumo-do between Dolsan-do and Kumo-do. On the other hand, off shore water was supplied into the fishing ground from the vicinity of Sori-do and Yokchi-do. thus the fishing ground was occupied usually by various sources of water. 2) The water mass in the fishing ground were divided into the inner water(29.0~30.6$\textperthousand$) and the mixed water(31,7~32.2$\textperthousand$) and off shore water(32.3~32.8$\textperthousand$) accourding to the distribution of salinity from T-S diagram plotted all salinity data observed in 1990 and 1992. In summer the inner and mixing water which was formed by river flowed southerly and spread south-easterly in the vicinity of Kumo-do. The off shore water which supplied from the vicinity of Sori-do and Yokchi-do and inner water formed the thermal front and halo front in summer. 3) The fishes caught by the set net were arranged in the order of catch amounts as follows: Spanish mackerel>Horse mackerel >Hair tail>Common mackerel> Sardine> Anchovy. The Catches of anchovy and sardine were high in April to May and those of hair tail and horse mackerel in July to September, but spanish mackerel were caught during the whole period of fishing. When inner water and mixing water appeared respectively and inner water and mixing water speared together in the set net fishing ground, the set net showed a high catch.

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통영 바다목장에서 새우조망, 자망, 주낙에 어획된 수산생물의 자원량 추정 (The estimation of fishery resources collected by shrimp beam trawl, gill net and longline near marine ranching area, Tongyeong, Korea)

  • 조윤형;장충식;안영수;고은혜
    • 수산해양기술연구
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    • 제55권2호
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    • pp.105-120
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    • 2019
  • The species composition and abundance variations of fishery resources in the adjacent marine ranching area, Tongyeong, Korea, were investigated by shrimp trawl, gill net, and longline during the period of July, September, and October in 2016. During the study period, the total catch were 8,522.9 kg with 34 species from the shrimp trawl, 32 species from the gill net, and nine species from the longline. The dominant species were different by gear, which were Hypodytes rubripinnis and Parapercis sexfasciata in the shrimp trawl, Platycephalus indicus and Raja kenojei in the gill net, and Conger myriaster and Scomber Japonicus in the longline. In terms of spatial distribution, Yongchodo showed the highest total catch in number as well as of in weight while Jukdo showed the lowest total catch in number and Bijindo showed the lowest total catch in weight. The amount of demersal fish resources in the survey area estimated as 301 ha, was 99,396 individuals which was converted to be 8,552.9 kg. The amount of demersal fish resources by gear were of trawling area, which area is 127 ha, were 76,251 and 3,489.5 kg, 74 ha in the gill net and longline survey area was 16,213 and 3,457.3 kg, and the other 100 ha area was 6,932 and 1,606.1 kg. In this study, the minimum resources for demersal fish is 61,687 and 4,265.2 kg, and the maximum is 149,439 and 14,197.9 kg.

한국 산업혁신연구의 현황과 과제 (Sectoral Innovation Studies: A Review of the Literature and Its Implications)

  • 정재용;황혜란
    • 기술혁신연구
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    • 제25권3호
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    • pp.115-154
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    • 2017
  • 한국이 산업혁신에 성공한 대표적인 국가의 하나로 주목받아 혁신연구의 사례로 연구되기 시작한 이래 30여 년이 되어 가고 있다. 그간 한국의 산업혁신에 관한 연구는 성공적 산업 추격을 진화적 관점에서 이해하는 데 초점이 맞추어져 왔다. 성공적 추격을 위한 진입전략, 추격을 가능하게 한 학습의 메커니즘 등에 관한 다양한 연구들이 수행되었다. 그러나 최근 추격체제의 성장 잠재성이 한계에 이른 여러 징후들이 나타남에 따라 새로운 관점의 산업혁신 연구의 필요성이 제기되고 있다. 본 논문은 이러한 문제의식 하에 이제까지의 한국 산업혁신 연구를 주요 연구주제별로 리뷰하고, 현재의 상황변화에 비추어 앞으로 요청되는 연구주제를 도출하는데 목적을 두고 있다. 특히 한국의 산업혁신 연구를 산업혁신시스템과 추격이라는 두 가지 관점을 기반으로 추격국 산업혁신의 특성 및 패턴, 기술능력 축적과 추격과정, 추격혁신과 제도, 성장동학의 형태 등을 중심으로 기존 연구성과를 리뷰했다. 또한 한국 산업혁신의 진화적 특성, 산업의 기술적 특성과 추격의 용이성, 산업혁신에서의 제도의 중요성, 산업혁신의 지향성 등의 논점을 중심으로 기존 연구성과를 비판적으로 검토하였다. 기존 연구성과의 검토와 현재 한국 산업혁신이 직면한 환경 변화를 고려하여 향후 국민경제 차원에서 산업혁신 고도화에 대한 고찰 필요성, 산업혁신 고도화와 전환 가능성, 추격의 그늘에 대한 검토 필요성, 산업혁신의 비기술적 요인에 대한 검토와 산업혁신연구에서의 다양한 가치의 통합 필요성 등을 중심으로 향후 연구과제를 도출하였다.

Fluttering Characteristics of the Ropes and Nets as an Active Stimulating Device inside the Cod End of a Trawl Net

  • Kim, Yong-Hae
    • Fisheries and Aquatic Sciences
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    • 제16권2호
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    • pp.101-108
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    • 2013
  • An active stimulating device (ASD) consisting of a net panel or ropes fluttering in the turbulence inside the cod end was effective in driving fish near the cod end to reduce juvenile by-catch. The fluttering characteristics of the rope and net panel were examined by video observations and analyzed for fluttering amplitude and period in a water channel and in field experiments with a bottom trawl. The amplitude ratio of the fluttering ropes or nets in the tank test increased with the fluttering index as the diameter of the twine, mesh size, flexibility, and flow velocity changed, whereas the period decreased with the above factors. In bottom trawl experiments, the range of mean depth difference in the fluttering net panel was 12-17% of the length of the fluttering net, and the period of depth difference or three-dimensional (3D) tilt was revealed, with shorter ones ranging from 2 to 6 s. The amplitude as depth difference and period from field measurements were similar to those of nets in tank experiments and also to the period of 3D flow velocity inside the cod end. These results could be used to design an ASD that could be used for to the cod end of actual towed fishing gear to reduce juvenile by-catch.

북서태평양 꽁치 자망의 망지 재료에 따른 어획성능 및 망목선택성 (Relative efficiency and mesh selectivity of monofilament and twisted multifilament nylon gill net for Pacific saury, Cololabis saira, in the Northwest Pacific Ocean)

  • 조현수;안두해;고정락;김영승;박창두
    • 수산해양기술연구
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    • 제42권4호
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    • pp.195-202
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    • 2006
  • To determine the relative efficiency and mesh selectivity of gill net for the Pacific saury, Cololabis saira, a series of fishing experiments was carried out in the Northwest Pacific Ocean from August 13 to October 13 in 2002, using gill nets of different mesh size(30, 33, 35, 37, 39 and 42mm) constructed from two kinds of twine material(monofilament, twisted multifilament nylon web). The relative efficiency of two material gears was expressed as the ratio obtained by dividing monofilament catch by multifilament catch in number. The master selection curve of each material gear was estimated by applying the extended Kitahara's method. The catch of experimental gears is mostly Pacific saury(98.6%), Cololabis saira. The kinds of bycatch are common squid(0.7%), Pacific mackerel(0.6%), etc. Catch comparisons in the two gears showed that monofilament nylon nets are 1.7 times more efficient. The optimum values in monofilament and multifilament gill net for Pacific saury are 8.28 and 8.23, respectively.

한국 근해 대형선망 어획물의 계절 및 연 변동 분석 (Seasonal and Annual Variations of Catch by Large Purse Seine off Korea)

  • 백철인;박종화;최광호;황선도
    • 한국해양학회지:바다
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    • 제6권3호
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    • pp.164-179
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    • 2001
  • 1991년부터 1994년 사이에 한국 근해에서 대형선망에 어획된 수산생물의 종조성, 어획량, 분포의 계절 및 연 변동 양상을 파악하였다. 조사 기간 중 전체의 0.1%이상을 차지하는 주요 종은 19종이 출현하였으며, 그중 고등어(Scomber japonicus)가 전체 생체량의 54.7%, 정어리 (Sardinops melanostictus) 20.4%, 전갱이 (Trachurus japonicus) 9.1% 그리고 삼치(Scomberomorus niphonius) 6.2%로 이들 부어류 4종이 전체의 90% 이상을 차지하였다. 어획노력량은 봄부터 높아져 여름에 최고였고 가을철까지 높았으나, 단위노력당 어획량은 가을부터 높아져 겨울에 최고를 보였고 봄까지 높게 나타났다. 이는 산란과 섭이를 위해 남북 이동을 하여 여름동안 분산되었던 부어류가 겨울철에는 월동장으로 회유하여 위집됨으로써 어획률이 높았기 때문으로 판단된다.

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고추포장에서 담배나방의 성충 발생소장과 약제방제 (Seasonal Occurrence of Oriental Tobacco Budworm (Lepidoptera: Noctuidae) Male and Chemical Control at Red Pepper Fields)

  • 양창열;전흥용;조명래;김동순;임명순
    • 한국응용곤충학회지
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    • 제43권1호
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    • pp.49-54
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    • 2004
  • 고추의 주요 해충인 담배나방은 유충이 과실 속에서 가해하기 때문에 방제가 어려운 해충이다. 수원지역의 고추 포장에서 페로몬 트랩을 이용하여 성충의 발생소장을 조사한 결과 전체 발생기간은 5월 하순부터 10월 상순까지였으며 각 세대의 발생 최성기는 6월 하순, 7월 하순 8월 상순, 8월 하순 9월 상순이었다. 월동세대와 1세대 성충 발생기간 중에 트랩유인 수준은 그 이후에 발생하는 유충에 의한 과실의 피해정도를 잘 반영하였다. 그러나 고추 생육후기에 발생하는 2세대의 경우 트랩에 유인되는 성충의 수는 매우 많았으나 유충에 의한 피해율은 그다지 높지 않았다. 페로몬 트랩으로 조사된 세대별 성충 발생시기에 관한 정보를 토대로 약제방제 시험을 수행한 결과, 각 세대별 성충 발생 최성기를 중심으로 연 5회에 걸쳐 살충제를 살포하면 유충에 의한 과실 피해를 효과적으로 줄일 수 있는 것으로 조사되었다.