• 수산해양기술연구
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• 제45권4호
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• pp.211-222
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• 2009

The fisheries resources by a set net in the coastal waters off Neungpo, Goeje Island from 2003 to 2004 were studied to determine species composition and catch variation. The main fishing period by a set net were from April to December in 2003 and from May to December in 2004. A total weight of 48 species caught through the survey period was 540,688.0kg. Most of them were 44 species of fishes and a few were 4 species of cephalopods. Dominant species was Trachurus japonicus accounting to 57.5% in total catch. Sub-dominant species were Trichiurus lepturus(12.9%), Engraulis japonicus(10.6%), Scomber japonicus(6.9%), Clupea pallasii(4.5%), Todarodes pacificus(2.8%) and Parapristipoma trilineaturm(1.3%). The remnant species showed a low catch, indicating the catch had less than 1% in total, respectively. T. japonicus and T. lepturus were caught throughout the survey period, but C. pallasii, Gadus macrocephalus, Oncorhynchus keta in low temperature season and Thunnus obesus in high temperature season. The fishing ground temperature was 11.7-24.0${^{\circ}C}$ in range and the catch by a set net was higher in autumn than in spring and in summer with the variation of fishing ground temperature. The annual catch by a set net was much higher in 2004 than in 2003 due to high temperature(>17${^{\circ}C}$) and the recruitment of T. japonicus from offshore seas. Therefore we concluded that the catch of Neungpo fishing ground by a set net was highly related to the variation of T. japonicus catch with fishing ground temperature.

• 한국수산과학회지
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• 제37권1호
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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.

• 수산해양기술연구
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• 제35권3호
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• pp.227-236
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• 1999

Temperal and spacial analysis for catches have been drawing up a catch distribution chart and analysing catches and CPUE(Catch Per Unit Effort) using catch data with purpose of obtaining basic data to establish a selective method of effective fishing the tuna purse seine fishing ground.The temperature profile section and catch was surveyed to analyse the effect of catch in relation to the fishing ground environment.The results are as follows ;1. As for the catch variation between 1983 and 1984, the catch mainly took place on150^{\circ}E$, and after that it moved eastward enlarging the range of catch. In the monthly catch variation between January and February, the catches mainly happened on 135$^{\circ}$~ 150$^{\circ}$E, and then moved to the gradually westward. However, from July it moved to the South and from October Southeast.2. As to the eatch ratio for the school associated with the drifted object, the pelagic migrating school and the school associated with the biological objects, the catch ratio for the school associated with the drift objects was the highest. The catch ratio for the school associated with the drifted object was high in June, July and November whiles between January and March for the pelagic migrating school.3. SST(Sea Surface Temperature) was around 28~29^C$ on the observing line of 137^{\circ}E$ and the catches took place in the north equatorial counter-current situated on around $5^{\circ}~6^{\circ}N$. SST in the northern summer was 1^C$higher than winter and it was about 29~30^C$. The catch happened with the center of north equatorial counter-current. The reason why the catch mainly took place on the north equatorial counter-current is that main catch of tuna purse seine was the school associated with drift objects. It is thought that the fishing grounds are made in waters that have many drift objects like drift logs from the coast.

• 한국수산과학회지
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• 제41권4호
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• pp.272-281
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• 2008

Seasonal and annual variation in the species composition of bag-net catch in the coastal waters of Incheon, Korea were examined from April 2000 to November 2004. To analyze seasonal variation of the fisheries data, we implemented a self-organizing map(SOM), an unsupervised artificial neural network, with the catch amount of 97 species. Over 5 years, we caught 68 species of fish, 23 species of crustaceans and six species of cephalopods. The total number of fish species were gradually increased during the study period. The number of species was higher during the spring than the autumn. The SOM identified four groups of the sampling months based on seasonal changes in communities. In the spring, the dominant species were Leptochela gracilis and Pholis fangi; whereas, in the autumn, Engraulis japonicus and Portunus trituberculatus were dominant species in bag-net catch. Our results will be used to estimate seasonal and annual variation in fisheries resources of Korean coastal waters.

• 한국어류학회지
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• 제21권3호
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• pp.191-199
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• 2009

남해도 미조 정치망 어획물의 종 조성과 어획량 변동양상을 알아보기 위하여 2004년의 어기(3월 말부터 12월까지) 동안 매일 조사를 실시하였다. 조사기간 중 총 어종수 39종과 총 어획량 69,147.5 kg의 수산자원이 어획되었으며, 이중 어류가 33종 66,410.2 kg, 두족류가 5종 1,126.6 kg 그리고 갑각류가 1종, 1,610.7 kg을 차지하였다. 우점적으로 어획된 수산자원으로는 갈치, 까나리, 멸치, 삼치 등이며, 전체 어획량의 81.2%를 차지하였다. 이 외 정어리, 감성돔, 새우류, 살오징어 등이 소량 혼획되었으나, 전체 어획량에서 차지하는 비율은 낮았다. 우점어종 중에서 까나리는 봄철에 주로 어획되었고, 갈치와 삼치는 여름과 가을철에 그리고 멸치는 봄부터 가을철까지 계속 어획되었다. 미조 정치망의 어획량은 봄보다는 가을철 전후에 많이 어획되었는데, 이는 우점종인 갈치와 삼치의 어획량 증가에 따른 것이며, 이는 또한 $17^{\circ}C$ 이상의 어장 적수온과 관련이 있었다.

• 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.

• Fisheries and Aquatic Sciences
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• 제5권2호
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• pp.114-121
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• 2002

A correction index of catchability (CIC) was derived using a 6 year research data set to examine the seasonal variation in catchability for the night time prawn fishery in Albatross Bay. CIC reflects the composite effect of the monthly variation in size selectivity, emergence­burying behaviour and population density variation of prawn populations. The values of CIC for four dominant species, Metapenaeus endeavouri, M. ensis, Penaeus semisulcatus and P. esculentus, were examined. The value of CIC for M. endeavouri varied substantially and was the highest in August. The values of CIC for M. ensis were high during November to March and the seasonality was weaker than that for M. endeavouri. The monthly variation in CIC for P. semisulcatus reflected the seasonal variation in population density, being high during November to February. These results suggest that the catch ability of P. esculentus is steady throughout the year but it varies greatly on a seasonal basis for M. endeavouri.

• 수산해양기술연구
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• 제47권2호
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• pp.108-117
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• 2011

In order to offer data about fisheries resources management and prediction of catch on large purse seine fisheries, the fluctuation of the fisheries condition and distributions of fishing ground for mackerel were analysed with monthly catch data for 1990.2009. The overall catch has decreased to about 70% since 1997, with approximately 70% of the mackerel (Scomber japonicus) catch and monthly fluctuations showing a similar pattern. Monthly distribution of fishing ground is like distribution of mackerel in large purse seine fishery. The main fishing grounds are near Jeju Island and the Yellow sea with the main fishing season existing between October to December. The catches fluctuations and distribution of fishing ground were related to the effect of regime shifts. Therefore, in order to prediction of catch on large purse seine fisheries should be studied these relationships.

• 한국어류학회지
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• 제13권3호
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• pp.210-219
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• 2001

제주 연안 4개 지역 정치망어획량 조사결과, 총 어획량은 153,862 kg으로 이중 전갱이가 89,530 kg으로 전체의 58.2%를 차지하였고, 그 다음으로 독가시치 (9.0%), 살오징어 (5.8%), 한치오징어 (2.9%), 부시리 (1.9%), 흰오징어 (1.8%), 방어 (1.6%) 등이 차지하고 있었다. 가장 많이 어획된 전갱이는 제주도 북쪽 구엄해역에서 88,710 kg이 어획되어 전갱이 전체어획량의 97%를 차지하였다. 이번 4개 해역 조사 결과, 제주연안의 어기는 보통 4월에 시작하여 12월까지 진행되나, 어획량은 봄에서 여름철로 갈수록 높아지고, 가을 및 겨울철로 갈수록 어획량은 낮아지는 현상을 나타내었다. 이와 같은 현상은 수온변화와 관련이 있었다. 정치망 어장별 수온범위는 평대가 $18{\sim}26^{\circ}C$, 두모가 $16{\sim}26^{\circ}C$, 구엄이 $15{\sim}26^{\circ}C$, 강정이 $15{\sim}26^{\circ}C$이었으나, 어획량은 각 어장별 수온범위내에서 수온이 증가할 수록 증가하는 경향에 있었다.

• 한국어류학회지
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• 제18권4호
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• pp.319-328
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• 2006

1971~2002년까지의 지난 32년간 장기간 시계열 자료를 통하여 겨울철 남해의 방어 어획량 변동양상을 계절별로 구분하여 조사하고, 이와 더불어 겨울철 한국 남부의 기상상황 및 남해의 해황 변화도 조사하여 장기간의 환경변화와 방어의 어획량 변동 사이의 대응관계에 대해서 살펴보았다. 겨울철 우리나라 남부의 기상변동을 살펴본 결과 1990년대에 들어서 기온이 상승하고 상대습도는 낮아지며 풍속이 많이 약화되는 특징들을 보이는 등 전체적으로 온난화 경향을 나타내고 있었고, 겨울철 남해의 50 m 수층 수온도 이 시기부터 뚜렷이 상승하고 있었다. 이와 관련하여 남해의 방어 어획량 변동양상을 계절별로 구분하여 조사한 결과 타 계절에 비해 특히 겨울철 생산량이 1990년대에 들어서부터 점차 증가하고 있었으며 방어의 주먹이원의 하나인 멸치의 어획량도 이 시기부터 증가하고 있었다. 이번 연구에서 조사한 기상 요인들을 포함한 환경 요인들과 겨울철 남해 방어 어획량 자료를 이용하여 상관분석을 실시한 결과 겨울철 방어 어획량의 증가는 겨울철 기온과 수온의 증가 그리고 멸치 어획량의 증가와 매우 밀접하게 연관되어 있다는 것을 알 수 있었다.