• 수산경영론집
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• 제26권1호
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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.

• 수산해양교육연구
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• 제20권3호
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• pp.400-409
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• 2008

전북연안의 어업자원 생산량의 경년변화를 알아보기 위하여 시험조업과 어업생산량을 조사 분석하였다. 2002년도의 시험조업에 의해 어획된 어업생물의 종수는 23종 이었고 총개체수는 6,008개체, 총중량은 376.38kg 이었다. 2004년도에는 종수는 15종, 총개체수는 2,469개체, 총중량은 211.99kg으로 나타났다. 1990년부터 2007년사이의 전국해면어업 생산량은 약 140만톤에서 180만톤으로 비교적 안정된 모습을 보인 반면 전라북도는 1990년도에 133,997톤이던 생산량이 2007년도에는 44,695톤으로 67%가 감소되었다. 전라북도와 인접한 충청남도의 어업생산량은 전라북도와는 달리 1990년에 51,187톤이었던 생산량이 최근에는 85,637톤으로 증가 되었다. 경기도의 어업생산량은 1990년에 42,260톤이 2007년에는 6,770톤으로 무려 84%가 감소되었다. 이러한 결과를 초래한 원인은 여러 가지 들 수 있겠지만 가장 큰 원인은 각종 개발사업으로 인한 어장축소와 해양오염으로 인한 어업자원 감소를 들 수 있다. 같은 서해안에서도 개발이 비교적 더디게 진행되고 있는 충청남도는 어업생산량이 증가하고 있음이 이를 중명한다고 할 수 있다.

• 수산해양기술연구
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• 제53권3호
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• pp.246-255
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• 2017

The species composition and variation in abundance of fishery resources near Oenarodo, Go-heung Peninsula, Korea, were investigated by gill net, trap net, and longline in May, July, and October 2015 and 2016. During the study period, the total catch included 14 species in the gill net, 11 species in the trap net, and 4 species in the longline. The dominant species were Portunus trituberculatus and Raja pulchrain the gill net, Charybdis japonicaand and Octopus vulgarisin in the trap net, and Muraenesox cinereusin in the longline. The Catch Per Unit Effort (CPUE) per individual and per weight in the gill net were similar in May and July of 2015 and 2016. In October 2015, the CPUE per individual was 2.1 ind./h and the CPUE per weight was 505 g/h higher than the results in 2016, but there was no significant difference in the total CPUE between 2015 and 2016. In the trap net, the CPUE per weight was similar in both 2015 and 2016, but the CPUE per individual was 2.7 ind./h higher in October 2015 than in October 2016 and the total CPUE was not significantly different from 2015 to 2016. The CPUE per individual and weight in the longline were significantly higher in July and October 2015 than in the same months of 2016, but the total CPUE in 2015 and 2016 did not show a significant difference.

• 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.

• 수산경영론집
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• 제43권2호
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• pp.41-49
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• 2012

This study aimed to estimate the economic value of the recreational fishing in the Jeonnam marine ranching area as a part of the total socioeconomic evaluation of the Jeonnam marine ranching program. A travel cost method was applied to the estimation of economic value of the recreational fishing in the Jeonnam marine ranching area and input variables included annual fishing trip days, average travel cost per trip, average catch amount, monthly income, marriage, age, and personal perception on the marine ranching program. In the analysis, due to its characteristic of count data, both poisson model and negative binomial model were used. Model results indicated that a negative binomial model was statistically more suitable than the poisson model as the overdispersion problem occurred in the poisson model. All signs of the estimated parameters were estimated as previous studies showed. Based on the results, the economic value per trip of the recreational fishing in the Jeonnam marine ranching area was estimated to be 145,000 won and the annual total economic value of the recreational fishing in the Jeonnam marine ranching area was analyzed to be 2,514,000 won. In addition, the change of total value by catch rate showed that the economic value could be increased by 180,900 won as the catch increased by one kilogram.

• 수산해양교육연구
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• 제24권2호
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• pp.137-145
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• 2012

In order to survey the conditions of bycatch and discards for a gape net, a series of filed surveys was carried out total 10 surveys on two gape nets operated in the coastal area of Jindo during July to November 2008. The all catches in each survey were measured the body length, weight after sorted species. The analysis of catch data was conducted to separate 'first operation' and 'general operation'. In this study, the first operation defined as hauling the fishing gears that soaked over 10 hours because of setting on the previous day. The general operation means the haul of fishing gears conducted at intervals of one of or two hours after first operation. The bycatch in this study is defined as the other species except for anchovy, and bycatch rate refers to the proportion of bycatch to total catch. From the survey results, the average bycatch rates on first operations were 50% and 51% for Masa-ri and Supum-ri areas in Jindo, respectively. Also, the average bycatch rates on general operation were 2% and 3% for Masa-ri and Supum-ri areas in Jindo, respectively. The proportion of anchovy to total catch caught represented 75.5%. It needs the research on the selective fishing technology to reduce the bycatch on the gape net fishery.

• 수산해양기술연구
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• 제47권2호
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• pp.99-107
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• 2011

The relationships among long-term variation in catches of Spanish mackerel (Scomberomorus niphonius) and main food organism such as common mackerel (Scomber japonicus), anchovy (Engraulis japonicus), and oceanic condition in Korean waters were analyzed using 40 years of time-series data from 1971－2010. In the 1990s, oceanic conditions around the Korean peninsula shifted to a warmer regime with higher SST (sea surface temperature). The total catch of Spanish mackerel in Korean waters increased dramatically since the early 2000s, and main fishing ground form into South Sea in winter season from December to January. From the results of correlation analysis, we found a significant relationship between the Spanish mackerel catch and environmental factor such as SST, common mackerel and anchovy catch in Korean waters.

• 수산해양기술연구
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• 제59권4호
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• pp.315-327
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• 2023

In the last five decades, there has been a consistent decline in the total catch of fisheries in the Korean jurisdiction since the peak in 1986. The decline in catch slowed and slightly rebounded in the 2000s, but changed back to a decline in the 2010s. As indicators that can identify changes in the marine ecosystem, trophic level (TL), biodiversity index (H'), and the ratio between pelagic fish and demersal fish (P/D) were analyzed by each local marine ecosystem. There were some different changes in each local marine ecosystem, but the mean TL and H' decreased and P/D increased in general in Korean waters. Demersal fish, which were dominant in the 1970s and 1980s, declined, and small pelagic fish and cephalopods have dominantly changed since the 1990s. However, these changes are not simple, and they are fluctuating in complex ways relating to each marine ecosystem and the timing. It is believed that changes in marine ecosystems in Korean waters are likely caused by a combination of fisheries and climate change. The ecosystem indicators reflected a change in the total catch, a sharp drop in catch of demersal fish, and increasing catch of pelagic fish since the mid-1980s.

• 수산해양기술연구
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• 제53권1호
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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.

• 수산해양기술연구
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• 제49권4호
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• pp.352-359
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• 2013

To estimate the mesh selectivity of gillnet for ocellate spot skate (Okamejei kenojei), the field tests were carried out 12 times with six different mesh sizes (121.2mm, 137.7mm, 151.5mm, 168.3mm, 178.2mm, 189.4mm) in the coastal waters of Taean, Chungcheongnamdo of Korea, 2010~2011. In the field tests, the total number of species was 31, and that of catch was 1,410 and the total weight was 618,006g. The number and weight of ocellate spot skate which is main target in this study were 1,004 and 434,592g, respectively. The catch in number of ocellate spot skate occupied about 71.2% in total catch. The others of catch species were marbled sole (8.4%), sea raven (4.4%), japanese swimming crab (4.2%) and flatfish (4.1%) and so on. The range of body disk width (DW) of ocellate spot skates which were caught in this study was 15.2~35cm and the mode was 27~29cm. The estimation equation of mesh selectivity using the extended Kitahara's method was expressed as s $(R)=s(DW/m)={\exp}\{(-0.56R^3-1.80R^2+12.96R-9.99)-4.26\}$. The optimum value of DW/m for 1.0 of retention probability in this estimation equation was estimated 1.899 and DW/m was estimated to be 1.194, 1.314, 1.395, 1.461 and 1.520 when the retention probability were 0.1, 0.2, 0.3, 0.4 and 0.5, respectively. When applied to the retention probability of 0.5, the optimum mesh size was estimated to be 177.0mm on first maturity disk width 26.9cm of ocellate spot skate.