• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.3
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• pp.184-192
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• 1988

Anchovy, Engraulis Japonica were caught by scoop net with fishing lamp in the surrounding water of Cheju and Seogwipo, and their gathering depth, gathering effects, change of catch by the age of the moon and submarine illumination were investigated from May to August 1985. Fish finder (SR-385) and fishing lamp (1 Kw incandescent) were set up at one meter of starboard of scoop net and one meter ahead of the prow together with two meters above the water surface respectively. The submarine illumunation was measured at 2m interval to both vertical direction of 0~18m and horizontal direction of 0~12m form the standard point which is to be 0.1m depth right under the fishing lamp. The catch of anchovy by scoop net was almost $90\%$ of total amount during the early period and the late period in moon age while as low as $10\%$ only was cought during the middle period. The catching depth of anchovy shoals by scoop net with fishing lamp was approximately 2~5m and submarine illuminations were 20~42 Lux, 24~48 Lux in Cheju and Seogwipo respec lively. Submarine illumination which could be cought by scoop net with fishing lamp should be 7~12 times lighter than before gathering since the shoals swiming at 10~15m depth which is 1.7~7 Lux illumination made by 1 Kw. AC 100V incandescent lamp, a surface gathering lamp of 2m high above anchovy scoop net came up to 2~5m depth which is 20~42 Lux illumination. The catching depth of anchovy by scoop net was 2~3m and this could be increased to 4m even though the AC voltage was decreased from 100V to 80V at final fishing stage.

• Development and Reproduction
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• v.16 no.2
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• pp.87-93
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• 2012

Reproductive biology (maturation and spawning) of the female tongue sole Cynoglssus semilaevis were examined in 154 specimens caught from the west coast of Korea (between February and November 2010). Monthly changes of gonadosomatic index (GSI) and condition factor (CF) were peaked in September. Hepatosomatic index (HSI) showed a negative correlation with those of the GSI. Ovaries were classified into six stages based on the development of advanced oocyte and histological characteristics: virgin/immature, early developing, developing, late developing, ripe/spawning and spent/regressing stage. The relationship between fecundity (F) and total length (TL) of the fish was expressed as $F=251.43TL^{0.1264}$, and body weight (BW) was expressed as F=1130.4BW-880848. Biological minimum size of female was 46.87 cm (TL).

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.3
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• pp.348-354
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• 2015

Experiments for catch and cluster analysis on the catch by gillnet for the Pacific herring were conducted using traditional nylon net (PA) and developing biodegradable net (PBS) with different monofilaments of #2 (=0.23 mm) and #3 (=0.28 mm) in diameter between 2011 and 2012, and of #2, #2.5 and #3 in 2013 in the eastern coastal waters of Samcheok, Korea. The total catch during the experiments was 3,337kg in weight and 16,757 individuals in number. Though the catch ratio of the Pacific herring in 2011 and 2012 was 97.4% and 98.7%, respectively, that of the Pacific herring in 2013 was 73.6% as the biggest and followed by goldeye rockfish (8.6%), black edged sculpin (8.4%), atka mackerel (7.2%) and Alaska cod (1.0%). The ANOVA analysis on the total catch in relation to net material showed that there was not statistically significant difference at the 5% level between nylon net (PA) and biodegradable net (PBS) (p=0.91). With the cluster analysis on the catch in relation to net material (PA, PBS) and twine thick (#2, #3), it showed the influence of net material on the catch was greater than that of twine diameter in this experiment. From the test of homogeneity on the catch by the gillnet with PA and PBS in which several species were caught in 2013, there was not statistically significant homogeneity in relation to net material (p<0.005). That meant the traditional gillnet of nylon (PA) was more efficient than the biodegradable (PBS) gillnet to catch several kinds of fish, however the PBS gillnet was better than the PA gillnet to catch the target Pacific herring.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.2
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• pp.130-140
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• 2016

This study analyzed annual catch trend during 45 years and monthly catch of the least 10 years (2005~2014) for chub mackerel caught in the Korean coastal waters. To determine fishing status of chub mackerel, fork length measurements were conducted at least twice every week for 100 individuals randomly selected at the Busan Cooperative Fish Market from January of 2012 to December of 2014; and biological characteristics and proximate composition (moisture, protein, fat, ash) were analyzed by length class (I~IV) on a monthly basis from January to December of 2014. Monthly catch trend showed low level below 5,000 mt from February to July, whereas high level above 15,000 mt from October to December. For the period between 2012 and 2014, annual average catch proportion of juvenile were relatively high at 68.1%, 53.1% and 53.2% from January to April, before spawning season, while those were low at 21.5%, 20.7% and 29.12% from June to November. As for the change in the proximate composition per 100 g of muscle, protein and ash did not change much by seasons and length class, whereas fat and moisture contents showed large fluctuations and complementary relationship between the two factors. Regardless of length class, monthly average fat content, containing Omega-3, showed the lowest at 7.18 g in April and highest at 19.27 g in December, which exhibited 2.6 times difference from one another. Regardless of fishing seasons, fat content by length class were 19.06 g for the class I and 6.43 g for the class IV, which showed three times difference. Fat contents of the class I were high at 26.97 g and 27.19 g in November and December, while low at 8.37 g and 9.99 g in April and May. Especially, fat contents from January to May were 5.0 g, which was the lowest. Therefore, it is expected that consumer could indirectly contribute fisheries management through their understanding and wise consumption based on fishing status and fluctuation of proximate composition.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.3
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• pp.238-249
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• 2013

Species composition and seasonal variation of aquatic organism in the marine ranchig ground of Taean, Korea were investigated using shrimp beam trawl from January to December 2010. A total of 99 species, $5,355,816ind./km^2$ and $84,697kg/km^2$ of aquatic organism were collected. Among them, fish include 9 orders 33 families 54 species, crustaceans include 2 orders 15 families 30 species, cephalopods consist of 3 orders 4 families 5 species, gastropods include 2 orders 3 families 4 species, echinoidea sp. include 1 order 2 families 2 species, bivalves were composed of 2 orders 2 families 2 species, and holothuroids include 1 family 1 order. According to the dominants by month, Palaemon gravieri was dominant in January, Cynoglossus joyneri was dominant in February, March, and June, and Hexagrammos otakii was dominant, in July. And Oratosquilla oratoria was dominant echinoidea sp. was dominant in April, May, and August and in September, October, November, and December. Cluster analysis based on species composition of the 38 most common species showed that the species were separated into 5 different groups. Group A was composed of species which were abundant in spring and summer, group B was composed of year-round residents, and group C was composed of species which were abundant in autumn.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.5
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• pp.306-316
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• 1989

We examined the state of Korean pomfret(Pampus echinogaster) in Korean waters and considered the management strategy of the stock based on the theory yield Per recruit. It is not facile to discriminate Korean pomfret distributed in Korean waters from silver pomfret (p. argenteus) due to the similarities in their external morphologies. For this rea- son, Korean pomfret has been treated in silver pomfret in fisheries statistics of Korea. In this study, we asserted Korean pomfret from pomfrets caught commercially by the morphology, from which we recognized that Korean pomfret took $60\~70\%$ in catch(in weight) and that the smaller the body length, the higher the proportion of Korean pomfret. Parameters estimated for Korean pomfret were as follows: natural mortality(M) = 0.6, fishing mortality(F) =0.924(mean value for $1986\~1988$), age at recruit to fishery($t_r$) =0.19 yrs, age at first capture($t_c$) : 0.49 yrs, and the rate of recruit of age-0 fish to fishery(Q) = 0.29. The results obtained from the theory of yield per recruit indicated that the present state of stock was below the optimum level of exploitation and that the control of fishing intensity rarely had an effect on the increasing of yield. Accordingly, we conclude that proper management can be made by increasing the current age of 0.49 yrs at first capture to 1.5 yrs.

• Korean Journal of Human Ecology
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• v.15 no.2
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• pp.327-339
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• 2006

We have investigated the distribution of major local foods cultivated in Gwangju City and Jeollanam-Do in order to understand the food culture of Honam region. The local foods were divided into 4 classes: agricultural, aquatic, animal and other products. 124 species of local foods, including 51 agricultural products, 50 aquatic products, 6 animal products and 17 others, were identified from this region. In Jeollanam-Do area, the agricultural products have a variety of fruits and vegetables, and aquatic products have fishes. In particular, rice, cucumber, pear, anchovy, oyster, laver, oyster mushroom, shiitake mushroom, and honey were determined as major local foods in Jeollanam-Do area. Note that Mudeungsan watermelon is cultivated in Gwangju, and sweet smelt and cat fish caught only in Sumjin river and Tamjin river area. In recent years, pumpkin (Cucurbita maxima Duchesne), paprika, kiwi and melon were determined as major local foods in Jeollanam-Do. Furthermore, branding strategy of agricultural and animal products can be said to improve. Wild types of aquatic productions, mushrooms and wild edible greens have been decreasing, whereas cultivated production increasing. The kinds of special local foods in Gwangju City and Jeollanamdo area were influenced by geographical, religious and social factors.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.1
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• pp.105-111
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• 1999

To investigate the relationships between ocean environmental characteristics and thechange of the catch, we analyzed various environmental factors such as mean temperature, salinity, current vectors, lunar day and wind vectors from 1995 to 1996 and the catch fluctuation of Hanlim set net from 1994 to 1996. The results are as follow ; 1) The proportion of fishes caught in Hanlim set net is highest for horse mackere1 ($69.2\%$) and is followed by common mackerel ($18.4\%$), hair tail ($5.6\%$), squid ($2.7\%$) and rabbit fish ($1.4\%$) in order. Two peaks in the monthly catch appeared in June and October in the operation period of May- December. 2) The flow direction was northward in flood time and southeastward in ebb time around the Hanlim set net. Thus, the vortical mixing of sea water was active and continued for more than 3 hours. In addition, mean daily temperature was low due to the presence of middle and bottom water in offshore. Increase in salinity or high salinity of sea water provides a favorable condition for catches of fishes. Catches in the first quarter and the last quarter of the moon were larger than that in full moon and the last of the month. In particular, when south or southeasterly wind velocity reaches about 3$\~$6.5 m/s, the possibility of catches increases.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.2
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• pp.133-139
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• 2001

In order to obtain fundamental data for estimation of fisheries resource by echo sounder, we carried out the measuring of dorsal aspect Target strengths for rock bream and dusky spinefoot fishes that were caught much around the Jeju Island and in South Sea of Korea. The appropriate equations share the common form. TS=A+20 log L, where TS is the average dorsal aspect target strength in decibels, L is the fish total length in centimeters, and the coefficient A is determined by a least mean squares regression analysis. For rock bream, the result is TS=-72.97+20 log L and, for dusky spinefoot it is TS=-63.16+20 log L And, we have investigated the bearing range of maximum dorsal aspect target strength for all of rock bream and dusky spinefoot by the echo sounder with transducer of which frequency is 200kHz. They are $-12^\circ$-$-21^\circ$and $-1^\circ$--8 espectively, when the fishes is swimming down to the bottom. The maximum dorsal target strengths are -41.50dB at -18 or rock bream and -30.69dB at $-6^\circ$for dusky spinefoot.

• Korean Journal of Ichthyology
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• v.20 no.1
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• pp.28-35
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• 2008

Fishes by a set net in the coastal waters off Gwideuk, Jeju Island were studied to determine species composition and catch variation, 2004. The fishing period conducted by a set net in Gwideuk fishing ground were from April to December. A total of 45,473.2 kg including 21 species was caught during the survey period. Most of them consisted of fishes of 17 species and a few were cephalopods of 4 species. Dominant species were Trachurus japonicus and Siganus fuscescens, 44.3% in the total. And sub-dominant species were Sepioteuthis lessoniana, Seriola dumerili, Seriola quinqueradiata, Loligo bleekeri, Seriola lalandi accounting for 54.4%. Although the number of species had a tendency to decreased from July to December, the catch by a set net was higher in summer and autumn than in spring. Such catch variations were closely related to recruitment of dominant species and also the seasonal variation of fishing ground temperature.