• Title/Summary/Keyword: Fish stock

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Effect of environmental conditions on the stock structure and abundance of the pacific saury, Cololabis saira in the Tsushima Warm Current region

  • Gong, Yeong;Suh, Young-Sang;Hur, Young-Hee
    • Proceedings of the Korean Aquaculture Society Conference
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    • 2004.05a
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    • pp.169-171
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    • 2004
  • Interannual and decadal scale body size of Pacific saury, catch and catch per unit effort were examined to investigate the environmental effects on the stock structure and abundance in the Tsushima Warm Current region. Interannual changes in thermal conditions are responsible for the different occurrence (catch) rates of sized group of the fish. Changes in body size due to environmental variables lead the stock to be homogeneous during the period of high abundance, while one of the reminder cohorts supports the stock during the period of low level of abundance. Migration circuits of two cohorts of saury stock are hypothesized on the basis of short life span and spatio-temporal changes in stock structure in normal environmental conditions. Changes in upper ocean structure and production cycles by the decadal scale climate changes lead changes in stock structure and recruitment, resulting in the fluctuation of saury abundance. Hypothesized mechanism of the effects of climate changes on the stock structure and abundance is illustrated on the basis of changes in thermal regime and production cycle.

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Use of Parasites for Stock Analysis of Salmonid Fishes (연어과 어류의 계군분석을 위한 기생충의 활용)

  • Kim, Jeong-Ho
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.12 no.2
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    • pp.112-120
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    • 2007
  • This paper reviews the use of parasites as 'biological tags' for studying stock analysis of salmonid fishes. Numerous definitions of stock concepts exist, but most of them essentially define a group of fish as having similar biological characteristics and being self-reproducing as stocks. It is important to manage fish stocks for human consumption and sustainable production and especially for salmonid fishes. Because these fry are considered as each country's property, it is necessary to identify and discriminate each fish stock in the open sea. Methods of separating fish stocks are very diverse. Artificial tags, parasites, otoliths scales and genetic characters have been used for stock analysis and each method has advantages and disadvantages. Of these parasites can be good biological tags because they are applied by nature at no cost. Parasites can be infected with susceptible host fishes when they enter into certain areas. Then if they move to the outside and are caught researchers can infer that the fish had been in the endemic area for a period of time during their life. Hence the host fish can be considered as naturally 'tagged' by parasites. However, if they do not pass the parasites-endemic. area, they will harbour no parasites. Therefore, researchers can discriminate each fish stocks and trace their migration routes with these biological tags. In this paper, several examples on the use of parasites as biological tags for studying salmonids, as well as other species, are listed. The advantages and limitations of parasites as biological tags are also discussed. Chum salmon (Oncorhynchus keta), the main salmonid species migrating to Korea, is distributed all around the North Pacific. Korean chum salmon are generally thought to move to the Sea of Okhotsk, the western North Pacific and the Bering Sea. However, there is no clear information on the distribution and migration pathways of Korean chum salmon, and no markers exist for separating them from others yet. Recent Korean chum salmon stock analysis including parasites information are mentioned.

A bibliographical Study on the Tojangguk in Korea (토장국의 문헌적 분석 고찰)

  • Lee, Yun-Kyung;Chun, Hui-Jung;Lee, Hyo-Gee
    • Journal of the Korean Society of Food Culture
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    • v.7 no.1
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    • pp.81-90
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    • 1992
  • The Guk had lessened to use Gang, Whak, Tang. The Guk was classified into cooking method as a soup stock, the used main substances, and the temperature of the Guk. According to the soup stock were divided clear soup, Tojangguk, and Gooumguk. Another classification of Guk by main substances were Yuktang (meat soup), Otang (fish soup), bongtang (poultry soup), Shotang (vegetable soup), Japtang (vary substance soup) and Yonpotang (soybean-curd soup), and by the temperature of the Guk were divided Doounguk (warm soup) and Naengguk (cold soup). In the thesis, according to the kinds of Tojangguk, the reference frequency to them, the adding foods in them, and the variety cooking method in the Tojangguk were analyzed by the cook books published from 1700 to 1988 in Korea. 1. There were 29 kinds of Tojangguk. 2. The main substances of Tojangguk were meat, poultry, fish, shellfish, vegetable, mushrooms and seasonings. 3. The Tojangguk was boiled with the rice water and fermented soybean paste and fermented soybean-pepper powder paste. For the development of taste were added beef, shellfish, dried anchovy, dried small prawn, and soup stock of beef bones in winter. Seasoning substances were green onion, garlic, black pepper, sesame powder and oil.

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A Study on the Horizontal Management of the Fisheries in the Northeastern Pacific (북태평양 어업의 호리존탈.매니저먼트에 관한 연구)

  • 이재후
    • The Journal of Fisheries Business Administration
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    • v.17 no.1
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    • pp.41-76
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    • 1986
  • The northeastern Pacific and eastern Bering Sea supports large and divers finfish and shellfish compelxes. The North Pacific fishing grounds are largest fish production total 30.89 percent of the world in 1983. Recent action by the around countries extending their fisheies jurisdiction to 200 mile has provided a new environment. The new approch to fisheries management has resulted in an arormous expansion in tile demand for scientific information. These are no longer limited to biological concerns. Emphasis has been focused recently on the need to understand the economic, social, politics and philosophy characteristics of a fishing and how they will be affected by management decisions. The horizontal management and portfolio management for fisheries has increased interest in complex biological models and the coupling of these models with economic, politics and phyisophy components. Successful completion of this task will require and expanded understanding of oceanographic, biological, economic, social, politics and philosophic process associated with fisheries. Particular attention should be devoted to acquiring information an data processing for Korean trawl fishery, stock assessment in the areas. The need for international collaboration in management must be stressed. Some northeast Pacific and eastern Bering Sea fish stock migrate over long distances and political boundaries. Further, nearly all the fish stocks are harvested by several nations. The features require cooperation and coordination of research activities. The horizontal management will be made a way these activities for the around countries in the sea. Strongly, tile proposed again, Pacific International Council for Exploration of the Seas, PICES will interest between all users of the area's fisheries.

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Quality Characteristics of Mussel Stock with Different Heating Times (가열시간을 달리하여 제조한 홍합육수의 품질특성)

  • You, Soo-Hyun;Shin, Kyung-Eun;Choi, Soo-Keun;Seo, Yoon-Weon
    • Culinary science and hospitality research
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    • v.19 no.3
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    • pp.209-217
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    • 2013
  • This study aims to develop mussel stock, which is the base of sauce, soup, etc., using various nourishing elements in mussels. In mussel stock with different heating times, the moisture content was significantly different according to heating times(p < 0.05). For the color value of mussel stock, L value was highest in MS1(35.48), a value in MS1(-2.39), and b value in MS5(-9.49). pH was lowest as 6.56 in MS5, and with increased heating time, pH decreased significantly (p < 0.001). With increased heating time, the sugar content was highest as $4.03^{\circ}Brix$ in MS3 and lowest as $3.37^{\circ}Brix$ in MS1. The salinity content was lowest as 0.71% in MS1, and with increased heating time, the salinity content increased significantly (p < 0.001). The test for characteristic differences of mussel stock showed that its color intensity, transparency, fish flavor, fish taste, and salty taste increased with increased heating time. Savory taste of mussel stock was highest in MS4 with 4.33% According to the results of acceptance test, taste, and overall acceptance test, MS3 showed the best results. In conclusion, mussel stock showed great preference with increased heating time, and the preference has increased when it was heated for 15 min.

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Detection of fish pathogens in cultured juveniles for stock enhancement in 2010 (2010년 방류용 수산종묘에 대한 병원체 검출)

  • Cho, Mi-Young;Park, Su-Young;Won, Kyoung-Mi;Han, Hyun-Ja;Lee, Soon-Jeong;Cho, Young-A;Kim, Jin-Woo
    • Journal of fish pathology
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    • v.24 no.2
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    • pp.121-129
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    • 2011
  • Aquatic animal raised in hatcheries play an important role in supplying seedling to stock enhancement and seed quality, especially, seed health is the key factor for survival in the field after release and for stocking effectiveness. We have inspected the hatchery-reared seeds of 33 marine species and 12 freshwater species for legally designated diseases in stock enhancement program in 2010. Results showed that abalone was the most abundant as 20.0% in the marine species group and then sea cucumber (15.6%), olive flounder (8.4%), rockfish (6.7%), black sea bream (6.3%) and swimming crab (6.1%) were followed. Crucian carp was the most abundant as 19.4%, and then eel (11.8%), Korean bullhead (10.9%), mandarin fish (10.8%), melanian snail (8.4%), catfish (7.7%) were followed in the freshwater species group. The total number of inspection cases for eight pathogens in this study were 2,105 and disqualification cases were 30 by detection of aquatic animals pathogens such as koi herpesvirus (KHV), red sea bream iridovirus (RSIV), white spot syndrome virus (WSSV) or viral haemorrhagic septicemia virus (VHSV).

STUDIES ON THE FISHERY BIOLOGY OF THE PACIFIC SAURY, COLOLABIS SAIRA OF THE EAST COAST OF KOREA 3. Quantitative Variations (꽁치의 어업생물학적 연구 3. 수량변동)

  • KIM Ki-Joo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.6 no.1_2
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    • pp.58-64
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    • 1973
  • Changes in stock size of the Pacific saury, Cololabis saira, were studied on the basis of fishery statistics compiled from 1964 to 1972 and body size composition of the fish collected from 1968 to 1972. During the period from 1964 to 1972 there was a direct correlation between the stocks of fall (september-february of the following year) and spring (March-August) season. The sizes of stocks in both seasons showed a three-year cyclic change, and the mode of stock in the fall always proceeded one year that in the spring. Exceedingly high fishing effort was observed in the spring as well as the fall of 1967. But very low fishing effort was noticed in the spring of 1969. In spring a large stock size has a high proportion of large sized group. On the other hand, in fall a large stock size tends to have a high proportion of medium sized group instead. When the medium sized group outnumbers the large sized group, stock size becomes larger. In contrast, it tends to be smaller when the large sized group exceeds the medium sized group. The patterns of distribution centroid seems to be related to the amount of fish landings. Northward moving trend of the centroid was accompanied by a large amount of landing, while westward (or north-westward) moving trend was followed by a poor landing of the fish.

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A Political-Economic Study on Cooperative Squid Fishing East to the $E128^{\circ}$ (동경 128도 이동 오징어 공조조업에 관한 정치경제학적 연구)

  • Park Seong-Kwae
    • The Journal of Fisheries Business Administration
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    • v.35 no.2
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    • pp.91-115
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    • 2004
  • The main purpose of this study is to analyze the cooperative squid fisheries problems surrounding the $E128^{\circ}$, established by the 1965 Korea - Japan Fisheries Agreement which banned Korean large trawlers' fishing east to the $E128^{\circ}$ In fact, the moratorium was put on by Japans request. However, such issue did not occur until the filefish stock in the southern Korean sea, which was a major target fish species of the large trawl fisheries, The filefish stock collapsed completely around 1991 and at the same time most of bottom fish stocks in the East China Sea began to show a symptom of over - exploitation. Thus, the off - shore large trawlers learned to have a little opportunity of finding out alternative fish stocks as well as fishing grounds. Fortunately, at that time squid resource stock and consumption were on the increasing trend. The large trawl fisheries were able to economically exploit squid stock east to the $E128^{\circ}$ through cooperative fishing with squid angling light boats in the East and East - South Sea, even though such cooperative fishing activities violate the existing fishery laws apparently. Some important reasons that the large trawlers have continued the cooperative fishing seem to be because (ⅰ) squid resource stock has been on the increasing state over time, (ⅱ) the trawl fisheries have made a significant contribution to meeting domestic and export demands and stabilizing squid prices, and (ⅲ) they have kept domestic squid market from foreign competition. However, the new Korea - Japan fisheries agreement in 1998 provided a momentum of questioning the effectiveness of the $E128^{\circ}$ by the squid - related fisheries other than the squid angling. Serious conflicts between squid - related fisheries began to emerge and to be much intensified. Squid angling industries in the East opposed to large trawlers's efforts to formalize such illegal cooperative squid fishing activities. Their main argument was that such formalizing would definitely make the East coast squid prices lower and in turn their business performance would be worse off. The results of quantitative analysis suggest that the trawlers' massive landing may have a significant influence on lowering the east coast squid prices. Now, an important issue that the squid - related fisheries and the government are facing is to solve such complex squid fishing problems through a multi - participatory negotiation process, including price stabilization, total allowable catch level and its operation schemes, $E128^{\circ}$ rearrangement, and so on.

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A Study on Establishing the Performance Evaluation System of the Fish Stock Rebuilding Plans (수산자원회복계획의 성과평가 개선방향에 관한 연구)

  • Kim, Dae-Young;Lee, Jung-Sam;Kim, Do-Hoon
    • The Journal of Fisheries Business Administration
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    • v.42 no.3
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    • pp.15-29
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    • 2011
  • The Fish Stock Rebuilding Plan (FSRP) is evaluated as one of the most effective fisheries policies domestically and internationally. FSRP is a comprehensive fisheries policy, including target stock size, rebuilding period, application of management measures, and participation of fishermen. The performance outcomes of FSRPs have been partially evaluated for recommendation for stock rebuilding in Korea, while they are fully evaluated in other countries that have implemented FSRPs. The performance evaluation system for FSRP is very needed to enhance its effectiveness as one of fisheries policies. That is, the system where problems can be reconsidered, achieving targets can be evaluated, and the plan can be modified should be implemented. This study classified the performance evaluation of FSRP into the economic evaluation as a quantitative analysis and the policy evaluation as a qualitative analysis. In the economic evaluation, the sustainability of fishery resources, the stability of fishing business, the efficiency of fishery production, and efficient utilization of fishery resources can be considered. As analytical methods for the economic evaluation, the bioeconomic model, efficiency estimation model, the dynamic MEY model can be utilized. The qualitative evaluation is to assess the qualitative performances of FSRPs, including interviews and surveys with fishermen and fisheries experts. In the survey, many different items can be included by evaluation factors which are related to policies such as timeliness, transparency, effectiveness, etc. In addition, the study suggested the performance evaluation system and procedures for objective and efficient evaluation of FSRPs. In order to practically apply the developed performance evaluation model, the pilot project is needed. That is, from the application of pilot project, detailed research methods, effective procedures, and evaluation factors can be investigated.

Investigation of Genetic Diversity between Wild-caught and Hatchery-reared Rock Bream (Oplegnathus fasciatus) Using Microsatellite DNA Analysis

  • Kim, Mi-Jung;An, Hye-Suck;Hong, Seong-Wan;Park, Jung-Youn
    • Fisheries and Aquatic Sciences
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    • v.11 no.2
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    • pp.82-87
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    • 2008
  • Marine fisheries are important natural resources and must be maintained, especially fish species that are important sources of food. Despite the increase in stocking programs to maintain fisheries with artificially raised fish, the genetic impact stocking has on the wild fry population has not been addressed. Genetic variation in rock bream, Oplegnathus fasciatus, within and between wild-caught parents and the $F_1$ generation produced by them in 1 day was assayed using nine highly variable micro satellite markers. The nine micro satellite loci used in this study displayed diverse polymorphisms, and in total, 98 different alleles were observed over all loci. Differences in genetic variability of the $F_1$ offspring compared to their wild-caught parents (brood stock) were observed in terms of allele frequency, gene diversity, and heterozygosity. Although the $F_1$ generation of rock bream was missing 16% of the micro satellite alleles, no significant reduction was found in mean heterozygosity of the $F_1$ population compared to the brood stock. Eight of nine loci showed significant Hardy-Weinberg equilibrium (HWE) deviations in the $F_1$ population, while the brood stock deviated from HWE at three micro satellite loci (KOF85, KOF360 and KOF374). These deviations showed mostly a deficit of heterozygotes. Our results provide evidence for genetic differences in the $F_1$ hatchery offspring compared to their wild-caught parents and reinforce the need for a series of consecutive egg collections to avoid the loss of genetic variability. This also further underscores the importance of monitoring genetic variability of hatchery populations for the conservation of natural rock bream resources.