• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.spc1
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• pp.231-235
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• 2006

Six echinoderm species were added to the echinoderm fauna of Dokdo, Korea based on the samples collected form inter - and subtidal areas of the Island on spring and autumn twice a year from 2002 to 2004. As result, sixteen echinoderm species were recorded from Dokdo.

• Fisheries and Aquatic Sciences
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• v.25 no.3
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• pp.187-187
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• 2022

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.4
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• pp.456-466
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• 2021

The distribution and abundance of euphausiids were investigated in Korean waters in 2016. Euphausiids were sampled with a Bongo net. A CTD (Sea Bird Electronics 9 plus) measured the water temperature and salinity while sampling. Mean water temperature ranged from 4.2-31.0℃. The highest temperatures occur in September and lowest temperatures in February. The mean water salinity ranged from 27.9-34.8 psu, with the highest salinities in March and lowest in September. Euphausiid species in group W consisted of four species. Among the euphausiid species, Euphausia pacifica was the dominant species with peak densities in September. The E. pacifica from group W was distributed in the bottom cold water during summer when a thermocline was formed. Five euphausiid species occurred in group S. E. pacifica and E. nana were the dominant species. In group S, E. nana was located in the warm and saline Tsushima Warm Current, a branch of the influential Kuroshio Current. Five euphausiid species occurred in group E. E. pacifica and T. longipes were the dominant species. In group E, E. pacifica and T. longipes were distributed in the deep and cold waters, these species prefer low water temperatures and perform vertical migration. The distribution of euphausiids in Korean waters were highly influenced by mass water characteristics, such as temperature and salinity.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.4
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• pp.500-504
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• 2013

A total of 24 juvenile specimens of Thunnus tonggol (5.45~7.26mm in total length) of the Sombridae were collected from the southeast sea of Jeju Island during 26~30 July, 2013. Twenty-four specimens identified T. tonggol have melanophores distributed on the 1st dorsal-fin rays, the dorsal of head and vetral side. Three individulas were identified using mitochondrial DNA cytochrome oxidase submit 1 (CO1) sequences (452 base pairs). All were identified as T. tonggol, their mtCO1 sequences being consistent with those of Thunnus tonggol (d=0.000), followed by Thunnus albacares (d=0.002) and Thunnus obesus (d=0.007).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.4
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• pp.344-348
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• 2006

The ecological characteristics and stock biomass of the Shiba shrimp, Metapenaeus joyneri, in Korean waters were determined, using fishery data from the Ministry of Maritime Affairs and Fisheries (MOMAF) and available length frequency data. The instantaneous coefficient of total mortality (Z) of M. joyneri was estimated to be 4.191year, and the annual survival rate (S) was 0.015. The estimated instantaneous coefficient of fishing mortality (F) for recent years was calculated to be 1.94/year. The age at first capture of M. joyneri was 0.71 years. Based on these parameters, the annual biomass of the M. joyneri stock was estimated using a biomass-based cohort analysis and data on the annual catch in weight at age for 1993-2004 in Korean waters. During the study period, the biomass of the shrimp peaked in 1994 at about 9,082 metric tons. Subsequently, it decreased to 500 metric tons in 1998.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.917-922
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• 2013

Changes in fishing ground of the large pair trawler were investigated by year, month and species off Korean waters. We used catch data by sea-block lat.${\times}$long.:$30^{\prime}{\times}30$) of the National Fisheries Research and Development Institute (NFRDI) and monthly fishing production statistics of Korean statistic information service from 1990 to 2007. In the 1990s, the demersal fish like Larimichthys polyactis, Collichthys sp, Portunus trituberculatus and Muraenesox cinereus were the dominant species, and in the 2000s, they were changed from demersal fish into pelagic fish like Scomberomorus niphonius, Scomber japonicus, Engraulis japonicus and Todarodes pacificus. Species composition of catch showed temporal variation by cluster analysis deviding into 4 period, 1990-1994, 1995-2000, 2001-2003 and 2004-2007. Fishing ground in the 2000s was decreased up to 2/3 in the 1990s, while the density of catch in the fishing ground in 2000s was higher than the 1990s.

• Ocean Science Journal
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• v.42 no.3
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• pp.179-192
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• 2007

Understanding in climate effects on marine ecosystem is essential to utilize, predict, and conserve marine living resources in the 21st century. In this review paper, we summarized the past history and current status of Korean fisheries as well as the changes in climate and oceanographic phenomena since the 1960s. Ocean ecosystems in Korean waters can be divided into three, based on the marine commercial fish catches; the demersal ecosystem in the Yellow Sea and the East China Sea, the pelagic ecosystem in the Tsushima Warm Current from the East China Sea to the East/Japan Sea, and the demersal ecosystem in the northern part of the East/Japan Sea. Through the interdisciplinary retrospective analysis using available fisheries, oceanographic, and meteorological information in three important fish communities, the trend patterns in major commercial catches and the relationship between climate/environmental variability and responses of fish populations were identified. Much evidence revealed that marine ecosystems, including the fish community in Korean waters, has been seriously affected by oceanographic changes, and each species has responded differently. In general, species diversity is lessening, and mean trophic level of each ecosystem has decreased during the last $3\sim4$ decades. Future changes in fisheries due to global warming are also considered for major fisheries and aquaculture in Korean waters.

• Journal of Fisheries and Marine Sciences Education
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• v.14 no.2
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• pp.213-228
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• 2002

This study is aimed to analysis the fishery consciousness of the fishermen in Kyungbuk province. an issue for the study may be used on activating device of fisheries high school. So, the data were collected from a fishermen living at the city of Pohang in Kyungbuk province. The treatment of materials are classified by age, level of a school career and by working career. This research evaluated percentage to the frequency of responses to each question and carried out $\chi^2$. The statistically signigicant level account for p<.05 and made use of SPSS 10.0. The conclusion of study were as follows; First, fishermen have little understanding for fishery consciousness, therefore there was needed public activities and life long education. Second, in order to solve the difficulties of fisheries villages, governmental financial support have to be presented, It is showed that economically, culturally, and financially, govermental policy should be devised for the purpose of emerging from backwardness of fisheries villages. Third, large portions of economic value should be allocated to fisheries villages by improving fisheries structure. Actually, lower incomes haves have burdened fisheries villagers with more debts. More years of being engaged in fisheries have resulted in more debts. People in fisheries villages regarded incomes as the most important among factors in their selecting fisheries as a job. If they earned more money in fisheries village than in metropolises, people on fisheries villages would choose the fisheries an their jobs. Naturally, there will prove to be an increase of number of persons engaged in fisheries. Also, thinking of fisheries as dangerous and heavy should be corrected into the new image by improving work environments and mechanization.

• The Journal of Fisheries Business Administration
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• v.16 no.2
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• pp.1-18
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• 1985

The dispute on the object of study in the business management have been carried out since 1912 in Germany, and then it is the situation of "business management" academic world there is no the confirmed object. But P. F. Drucker has prescribed the large enterprise as the object of his study of management, because the large enterprise it the decisive, the representative, and constitutive in modern industrial country. And it is usual that we would consider the large manufacturing enterprise as the object of study. But, in fisheries management, because large fisheries enterprises are almost attached too much to the pelagic fisheries, it is judged that they are not "decisive". And it is judged that they are not "representative", because the large fisheries enterprises can not sufficiently symbolize the managerial characteristic of fisheries industry. The coastal and inshore fisheries which constitute th real part of fishing industry have been operating by private enterprises which are small business in scale, so the large fisheries enterprises could not be considered "constitutive " Therefore, the private fisheries enterprises is "decisive" because it is distributed in all most fisheries management, "representative" because it is exceedingly symbolize the managerial characteristic of fishing industry, and constitutive because it constitute the real part of fisheries industry. From the above-mentioned, it could be concluded that the object of study is regarded the private fisheries enterprise as appropriate as long as it is engaging in producing fisheries product as good and conducts the pursuit of principle of profit maximization. Because the object of study can not include all the thing which has to be observed in order to study, the materialization of the object is actually necessary. And then as aforesaid we intend to realize the materialization through taking the private fisheries enterprise as the object in fisheries management theory. And the materialization does mean a necessary process in choosing the object of analysis, but not the entity itself.choosing the object of analysis, but not the entity itself.

• The Journal of Fisheries Business Administration
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• v.33 no.2
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• pp.31-48
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• 2002

This paper is aimed to analyze how to evaluate the choice of optimal management measures and level of control in fisheries management under the costly and imperfect management system by comparing with costless and perfect management system that is commonly assumed in the analysis of fisheries regulations. Fishermen would set the level of fishing efforts at the point where the marginal fishing profit for fishing effort is equal to the marginal level of fine under costly and imperfect management system. Therefore, under the case where the marginal fishing profit is higher than the marginal level of fine, the level of fishing efforts would be made at the point which is higher than the level of fishing efforts made under costless and perfect management system and is not a point where the economic profit is maximized in regulated fisheries. From this conclusion, the fishermens avoidance activities against regulations as well as the level of control in fisheries management substantially have an influence on the choice of fisheries management instruments. According to the analysis of optimal fisheries management policy, the economic profits in regulated fisheries are determined by the level of fisheries enforcement costs and total fishing profits, in which as enforcement costs increase the economic profits decrease. In addition, the economic profits vary in response to the level of control in avoidance activities. That is, as avoidance costs decrease, the economic profits increase. The determination of optimal level of control in fisheries management should be made at the point where the marginal regulation costs are equal to the marginal profits from regulated fisheries, in which marginal regulation costs are different according to the type of management measures. And the level of profits changes in response to different levels of avoidance activities. The management measure that can maximize the difference between the marginal regulation costs and marginal profits from regulated fisheries should be chosen as an optimal fisheries management instrument.