• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.29 no.4
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• pp.260-271
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• 1993

Due to depletion of fish resources as time goes on, the trawl fishing industries which have caught the demersal fish is confronting with financial difficulties. For the purpose of breaking these difficulties, trawlers are expanding the fishing targets to the midwater from bottom stock. The trawlers become to be able to detect the fish schools not only vertical but also horizontal direction by equipping the sonar system on board. Even though the operator locates the fish school by sonar, it is not easy to make a desirable catch of the fish school which is detected, for the reason of the maneuverring characteristics of trawler. For the purpose of enhancing the efficiency of a fish catch, the auther performed a series of on board experiments to investigate the maneuverablilites of midwater trawaler. The obtained results are summerized as follows: 1. The higher the RPM of main engine, the smaller the magnitude of turning circle. And it is smaller in the right than in the left turning 2. Towing speed varies irregularly under turning novenment. When the RPM of main engine being 560, 680 the angular velocities are 11.3deg/min, 22.5deg/min respectively. 3. The difference of new course distance between calculated by maneuverring indices and measured by experimental ship is high when altering course being large and towing speed low. 4. The faster the towing speed is, the shorter the new course distance becomes. When towing speed is same in right and left turning movement, the now course distance is shorter in case of right turning movement than in left. 5. It is considered to be convenient for a navigator to utilize the curves for altering course in order to steer the ship rapidly and accurately.

• Journal of Nutrition and Health
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• v.3 no.2
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• pp.107-109
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• 1970

The authors carried our experiment based on Pseudociaena manchurica and Cololabis saira about what the fish muscle protein changed after being stocked. It resulted in the below and followed much improvement in medium of making polyacrylamide gel: After salting the Pseudosciaena manchurica and Coloabis saira, there after refrigerating and freezing of order it could be concluded by disc-electrophoresis that analystic pattern was most being in number by refrigerating at Pseudosciaena manchurica, the second by salting and freezing. As it were: refrigerating is most suitable for saving protein.

• Journal of Environmental Health Sciences
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• v.39 no.4
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• pp.369-375
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• 2013

Objectives: This study was conducted to identify factors determining the toxicity of manufactured silver nano-particles (AgNPs) on aquatic organisms. Methods: For this purpose, we prepared several AgNPs with varied characteristics, including hydrodynamic size (nano-$^{ABC}Ag^{Cit}\;vs$-sized-$^{ABC}Ag^{Cit}$), impurities ($^{ABC}Ag$ stock vs $^{ABC}Ag$), and citrate capping ($^{ABC}Ag^{Cit}$), using a commercially available manufactured AgNP ($^{ABC}Ag$ stock). Acute tests were conducted using larval zebrafish (Danio rerioI). In addition, in order to determine the ecotoxicological potentials of various capping agents, toxicity tests were conducted with microbes, waterfleas, and fish for eight different capping agents that are used for NPs. Results: The toxicity of AgNPs in terms of 96 h fish $LC_{50}$ increased in the following order: $^{ABC}Ag$ stock < $^{ABC}Ag=^{ABC}Ag^{Cit}=nano-^{ABC}Ag^{Cit}$ < ${\mu}$-sized-$^{ABC}Ag^{Cit}$ < $AgNO_3$. After removing impurities by dialysis, 96 h $LC_{50}$ value decreased significantly from $126.6{\mu}g/L$ (95% confidence intervals [CI]: 107.0-146.2) ($^{ABC}Ag$ stock) to $78.6{\mu}g/L$ (CI: 72.7-84.8) ($^{ABC}Ag$). For ${\mu}$-sized-$^{ABC}Ag^{Cit}$ (ranging between 3.9 and 40.6 nm) and $^{ABC}Ag^{Cit}$ (40.6 nm and $9.1{\mu}m$), the 96 h $LC_{50}$ of the former ($43.9{\mu}g/L$, CI: 36.0-51.7) was approximately two-fold lower than that of the latter ($87.0{\mu}g/L$, CI: 73.5-100.3). Conclusions: In this study, we found that for acute lethality, the contribution of impurities and particle size was significant, but that of citrate was negligible.

• The Journal of Fisheries Business Administration
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• v.40 no.1
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• pp.133-152
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• 2009

The purpose of this paper is to model price formation and analyze demand structures for fishes under the restriction of Korean fisheries regulations. This study suggests the model that the price of fish is formed by its quantity, expenditure, and habit persistence. In economic literature, such a fishery market demand is called the inverse demand with dynamic habit persistence. Based upon a static differential price formation model, the paper has generalized it dynamically incorporating habit persistence effects. The empirical results show that all the species have values less than one and (-) sign of price flexibilities, thus being price inflexible. The estimated habit adjustment coefficients are significant at the level of 1%. Especially, TAC species have the smaller values of them than those of other main fish species. The contribution and results are summarized as follows. First, the fishery market demand has a strong dynamic effects from habit persistence. Second, the fishery market demand structure could be analyzed in a way different from the ordinary demand analysis, which is based upon price flexibility, scale flexibility, and cross adjustment flexibility. Third, the limitation of this paper is that it ignores the increasing stock effects by catching restrictions, thus raising consumers' benefit in the future.

• The Journal of Fisheries Business Administration
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• v.38 no.3
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• pp.89-108
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• 2007

The purpose of the study are summarized as follows: First, it has researched the new functions of middleman in Fisheries Port Market. Second, the new functions which middleman have to perform in Fisheries Port Market consist of the origin function, marketing function, logistics function. The origin function consists of the discrimination of fish species and freshness, making the price by auction, financing, etc. Marketing function consists of various species assortment from not only fisheries port market but also non fisheries port market as frozen and import fish markets, finding the new selling markets as not broker but wholesaler, making the price and margin non through the action, processing, etc. Logistics function consist of fish stock, delivery Third, it has recognized the upcoming important problems by building up the new functions as middleman in Fisheries port Market. This study has used a questionnaire to verify 3 hypotheses. Research model, factor analysis, regression analysis. The result of this study are summarized as follows: The origin function influences positively on the effectiveness of middleman's performance in Fisheries port Market. Marketing function influences positively on the effectiveness of middleman's performance. However, logistics function did not directly influences on the effectiveness of middleman's performance.

• 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.

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.82-82
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• 2017

Chum salmon, Oncorhynchus keta, has received considerable attention in recent years for population genetic studies due to its broad geographic distribution and high commercial importance in North Pacific fisheries. The Bering Sea and North Pacific Ocean provide major feeding habitats for various salmon stocks originating from Japan, Russia and North America. Chum salmon are a dominant pelagic fish in the Bering Sea during summer and their numbers fall when they moved in coastal areas to spawn. Population genetic data for chum salmon that can serve as a baseline for stock identification studies are scarce. In this review, we describe recently developed molecular markers and discuss their use in the study of genetic population structure of chum salmon in the Pacific Rim. In addition, we review previous genetic studies focused on the assessment of stock compositions in mixed chum salmon aggregations in the Bering Sea and North Pacific Ocean.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.46 no.4
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• pp.392-405
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• 2010

The population of small yellow croaker, Larimichthys polyactis, in the Yellow and East China Seas has decreased significantly since the mid 1970s. Several management measures have been introduced to conserve it, but population size remains low. To rebuild this population, it is now necessary to consider more effective management methods based on the stock assessment. To determine long-term population changes, fishery and biological data collected over 34 years (1969-2002) were analysed. Yearly fish length compositions were analysed for the time periods 1968 through 1970, 1978 through 1982, and 1993 through 2002; and catch data was available from 1969 to 2002. Annual population sizes were calculated based on length composition, the relationship between total length and body weight, and total landings. Analyses showed that since the 1970s, average size of harvested fish decreased; the proportion of less mature fish (smaller than the 50% maturity length, 19cm) in catches has increased and the estimated biomass has decreased significantly. Consequently, the main management recommendation is that juvenile fish need to be better protected to allow the rebuilding of resources to a more sustainable population level. This will require fish size limit, permissible mesh size, and closed area and season regulations.

• Korean Journal of Ichthyology
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• v.36 no.1
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• pp.58-67
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• 2024

The purpose of this study was to find out the fish species that appeared monthly through the fish stock survey of Minyang eelgrass beds in Tongyeong and compare them with the results of previous studies in the same area. This survey confirmed the species compositional characteristics of fish using surf net from March 2021 to February 2022. During the survey period, a total of 24 species, 8,679 individuals, and 3,714.42 g of the total fish were collected. The dominant species were Gymnogobius castaneus, G. heptacanthus, Chaenogobius gulosus, Pholis nebulosa, Rudarius ercodes which accounted for 95.9% of a total number of individuals collected. Similar to previous studies, most of the fish species that appeared were gobiidae, and in this study. Leiognathus nuchalis, which was selected as pollution indicator species, appeared for the first time.

• Culinary science and hospitality research
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• v.20 no.2
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• pp.89-99
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• 2014

This study aims to make stock using cod bones with the hot water extraction method. Moisture content, chromaticity, pH, salinity, sugar content, mineral contents, quantitative analysis, and overall acceptance were studied to determine the standard formula. The results are as follows. The moisture content decreased (p < 0.001) and color value increased as heating time increased. The pH was highest in CS5 which was heated for 30 minutes and lowest in CS1. The salinity and sugar content significantly increased with more heating time (p < 0.001). In terms of mineral contents, sodium was highest in 138.87~154.17 mg, magnesium and iron showed proportion difference with increased heating time. The mineral analysis test result revealed that sodium, magnesium and iron showed proportional difference with increased heating time, while potassium and calcium did not change. The result of quantitative analysis test showed transparency, fishy smell, delicate flavor, savory flavor, salt taste and umami taste became stronger as high-pressure heating time increased. From these result, CS4 was evaluated to be the best in appearance, flavor, taste, aftertest and overall acceptance. Also, 60 minute high-pressure heating time is the most desirable to produce stock using cod bones as a main ingredient.