• Journal of Fisheries and Marine Sciences Education
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• v.19 no.2
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• pp.180-196
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• 2007

This study aims at analyzing the potential of leports-fishing for improving fishing household income. Leports-fishing is a composite concept which is combined with those of leisure, sports and fishing. Korean on-shore resources have also a composite characteristic. The properties of the east, west and south coastal waters are quite different in geography, biology and ecology. There is a array of leports-fishing development potentials of utilizing their characteristics. At present, angling forms a main activity of leports-fishing, but coastal seas would be an emerging space for the public. In order for them to be a ground of fun, enjoyment and festivals, it would be necessary to supply a wide range of activities and facilities including angling, scuba diving, fish barbecue, ecological experience, fishing experience, cruise, and so forth. As seen in the survey results, the participants have strong desire for fun and enjoyment through leports-fishing activities. The proportion of people participating in one or two times a year amounts to 40 percent. Most coastal places visited are close to medium/large cities and two-days leports-fishing/tourism accounts for some 77 percent. However, it turned out that conflicts between leports-fishing participants and fishermen are not serious. The results of expenditure function estimation appear that the elasticity of per capita income is very high with 1.2660 and that there are negative relationships between leports-fishing expenditure and transportation/food/lodging costs. Assuming the annual national economic growth rate of 4 percent, it is anticipated that Korean leports-fishing population will increase to 3.18 million in 2010 and 4.07 million in 2015. Korean leports-fishing market potential in 2015, which is calculated based on per capita expenditure on leports-fishing, appears to amount to 1,400 billion won~1,600 billion won. The contribution of such market potential to the fishing households is expected to be 62.3~74.2 percent(934.5 billion won~111.3 billion won).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.3
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• pp.313-320
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• 2018

Chub mackerel Scomber japonicus is an economically important pelagic species in the western North Pacific. In the last 50 years, the annual total catch in Korean waters showed large fluctuations, ranging from 100 to $420{\times}10^3tons$. To provide a biological reference point for management of chub mackerel, we applied a simulation-based yield-per-recruit (Y/R) model that considered both temperature-dependent growth and size-dependent mortality. We estimated the fisheries yield with respect to varying biological reference points and environmental conditions, including 1) the instantaneous rate of fishing mortality (F), 2) length of fish at first capture ($L_c$), and 3) water temperature. The result of our analysis showed that the Y/R could be greatest when the $L_c$ ranges from 19-27 cm and F ranges from $1.48-2.00yr^{-1}$. Y/R increases with increased water temperature between 15 and $23^{\circ}C$. We suggest targeting an $L_c$ of 17 cm (age=0.6 years) under the assumed current of $F=0.48yr^{-1}$ for maximizing the chub mackerel harvest. Further analysis considering spawning and recruitment processes are required to provide biological reference points to ensure the sustainability of chub mackerel fisheries in Korean waters.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.2
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• pp.153-159
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• 2017

We examined changes in the physiological responses of gray mullet Mugil cephalus exposed to acidic seawater (pH 6.0, 6.5, 7.0) and normal seawater (pH 8.0, control) for 15 days. As pH decreased, survival rate and body weight also decreased. Levels of aminotransferase, total protein and triglycerides also differed significantly with changes in pH, presumably due to stress caused by exposure to acidic water. The level of osmotic pressure was significantly higher in the pH 6.0 group than in other groups. Superoxide dismutase was significantly higher in the pH 6.5 and 7.0 groups than in the pH 8.0 group, and glutathione level was lowest in the pH 6.0 group. We conclude that decreasing the pH level of seawater induces a stress response in fish, damaging their ability to control their hematological and osmotic pressure. Antioxidant enzymes are generally sensitive to osmotic stress; in this study, antioxidant activity significantly changed with pH level. These results indicate that physiological stress induced by exposure to acidification reduces survival rates and inhibits growth in M. cephalus.

• Fisheries and Aquatic Sciences
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• v.24 no.2
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• pp.99-107
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• 2021

Water temperature (WT) is a major environmental factor of metabolic rate in fish; it directly affects food intake, ammonia excretion, oxygen consumption (OC), growth, and survival. Thus, the purpose of this study was to investigate changes in the OC and the hematological response of olive flounder Paralichthys olivaceus because of WT changes. In Exp. I, WT was increased from 20℃ to 29℃ within 18 h and maintained at 29℃ for 96 h. Then, WT was decreased from 29℃ to 20℃ within 18 h and maintained at 20℃ for 24 h. In Exp. II, WT was decreased from 20℃ to 11℃ within 18 h and maintained at 11℃ for 96 h. Then, WT was increased from 11℃ to 20℃ within 18 h and maintained at 20℃ for 24 h. The Exp. III maintained that the Exp. I and II was consecutively. In Exp. I, the OC increased from 116.7 mg O₂ kg^-1 hr^-1 to 317.5 mg O₂ kg^-1 hr^-1 with increasing WT. In Exp. II, the OC decreased from 96.5 mg O₂ kg^-1 hr^-1 to 71.3 mg O₂ kg^-1 hr^-1 with decreasing WT. In Exp. III, OC tended to increase or decrease in inverse proportion to temperature. In Exp. I, cortisol, glucose, and aspartate aminotransferase (AST) values increased with increasing WT. In Exp. II, Cl^-, osmolality, AST, and alanine aminotransferase (ALT) values significantly changed during the experimental period: glucose values increased, whereas cortisol values decreased with decreasing WT. Exp. III was shown to be a more stressful environment to olive flounder than Exp. I and Exp. II. The results of our study will be useful for evaluating current aquaculture procedures of olive flounder and developing techniques to minimize stress in aquaculture farms.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.5
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• pp.1491-1498
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• 2015

In this study we investigated the effect of vaccine efficacy and immune activities by feeding additives several natural herbal remedies extracts of Sweet Wormwood (Artemisia annua), Galla Rhois, Oriental raisin tree (Havenia Dulicis) and 6-mixed herb to Oilve flounder, Paralichthys olivaceus. Each group of fish fed with the herbal remedies added feed and basic formula during the seven weeks and vaccinated with Edwardsiella tarda Formalin killed vaccine after 4 weeks feeding. Relative Percentage Survival values (RPS) in the group was assessed by the challenge with E.tarda. All groups with the herbal remedies added feed enhanced growth rate, but there were not significantly different in lysozyme activity and agglutination titer. In a challenge experiment with E.tarda, RPS in the all groups feeding additives natural herbal remedies was higher than that of the control group. These results suggest that the natural herbal remedies extracts of Sweet Wormwood (Artemisia annua), Galla Rhois, Oriental raisin tree (Havenia Dulicis) and 6-mixed herb would be effective to enhance efficacy of vaccination to Olive flounder.

• Microbiology and Biotechnology Letters
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• v.31 no.1
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• pp.46-50
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• 2003

Lactococcus lactis SA72 from Jeot-gal (Korean traditional fermented fish foods) produces lacticin SA72. The influence of several parameters on the fermentative production of lacticin SA72 by Lactococcus lactis SA72 was studied. MRS medium among several media was selected for enhanced bacteriocin production. The mean growth rate and bacteriocin productivity of L. lactis SA72 increased as the initial pH of the media increases. The highest lacticin SA72 activity was detected 3,200 AU/ml at pH 6.0, $32^{\circ}C$, and 1% (inoculum size, v/v) in the jar fermenter. Enhanced production of lacticin SA72 was investigated by a fed-batch cultivation with the intermittent feeding of the concentrated glucose solution. Under the optimized conditions, lacticin SA72 activity finally reached to 6,400 AU/ml.

• The Journal of Fisheries Business Administration
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• v.15 no.1
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• pp.131-153
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• 1984

Fishery resources are still abundant compared with other resources and the possibility of exploitation is probably great. The Korean fishery industry has grown remarkably since 1957, and Korea is ranked as one of the major fishery countries. Its of fishery products reached the 9th in the world and the value of exports was 5th in 1982. But recently a growth rate has slowed down, due to the enlargement of territorial seas by the declaration of the 200 mile, Exclusive Economic Zone, the tendency to develop fishery resources strate-gically in international bargaining, the change in function of the international organizations, the expansion of regulated waters, the illegal arrest of our fishing boats, the rapid rise in oil prices, and the fall in fish prices, the development of fishery resources as a symbol of nationalism, the fishing boats decreptitude, the rise of crew wages, regulations on fishing methods, fish species, fishing season, size of fish, and mesh size, fishing quotas and the demand of excessive fishing royalties. Besides the the obligation of coastal countries, employing crews of their host countries is also an example of the change in the international environment which causes the aggravation of foreign profit of fishing firms. To ameliorate the situation, our Korean fishery firms must prepare efficient plans and study systematically to internationalize themselves because such existing methods as conventional fishing entry and licence fishing entry are likely to be unable to cope with international environmental change. Thus, after the systematic analysis of the problem, some new combined alternatives might be proposed. These are some of the new schemes to support this plan showing the orientation of our national policy: 1. Most of the coastal states, to cope with rapid international environmental change and to survive in the new era of ocean order, have rationalized their higher governmental structure concerning the fishery industries. And the coastal countries which are the objectives of our expecting entry, demand excessive economic and technical aid, limit the number of fishing boats’entry and the use of our foreign fishing bases, and regulate the membership of the international fishery commissions. Especially, most of the coastal or island countries are recently independent states, which are poorer in national budget, depend largely on fishing royalties and licence entry fees as their main resources of national finance. 2. Alternatives to our entry to deep sea fishing, as internationalization strategies, are by direct foreign investment method. About 30 firms have already invested approximately US $ 8 million in 9 coastal countries. Areas of investment comprise the southern part of the Atlantic Ocean, the Moroccan sea and five other sea areas. Trawling, tuna purse seining and five other fields are covered by the investment. Joint-venture is the most prominent method of this direct investment. If we consider the number of entry firms, the host countries, the number of seas available and the size of investment, this method of cooperation is perhaps insufficient so far. Our fishery firms suffer from a weakness in international competitive ability, an insufficiency of information, of short funds, incompetency in the market, the unfriendliness of host coastal countries, the incapability of partners in joint-ventures and the political instability of the host countries. To enlarge our foreign fishing grounds, we are to actively adopt the direct investment entry method and to diversity our collaboraboration with partner countries. Consequently, besides proper fishing, we might utilize forward integration strategies, including the processing fied. a. The enterprise emigration method is likely to be successful in Argentina. It includes the development of Argentinian fishing grounds which are still not exploited in spite of abundant resources. Besides, Arentina could also be developed as a base for the exploitation of the krill resources and for further entries into collaboration with other Latin American countries. b. The co-business contract fishing method works in American territorial seas where American fishermen sell their fishery products to our factory ships at sea. This method contributes greatly to obtaining more fishing quotas and in innovation bottom fishing operation. Therefore we may apply this method to other countres to diffuse our foreign fishing entry. c. The new fishing ground development method was begun in 1957 by tuna long-line experimental fishing in the Indian Ocean. It has five fields, trawling, skipjack pole fishing and shrimp trawling, and so on. Recently, Korean fisheries were successful in the development of the Antarctic Ocean krill and tuna purse seining. 3. The acceleration of the internationalization of deep sea fishing; a. Intense information exchange activities and commission participation are likely to be continues as our contributions to the international fishery organizations. We should try to enter international fishery commissions in which we are not so far participating. And we have to reform adequately to meet the changes of the function of the international commissions. With our partner countries, we ought to conclude bilateral fishery agreements, thus enlarging our collaboration. b. Our government should offer economic and technical aids to host countries to facilitate our firms’fishery entry and activities. c. To accelerate technical innovation, our fishery firms must invest greater amount in technical innovation, at the same time be more discriminatory in importing exogeneous fishery technologies. As for fishing methods; expanded use of multi-purpose fishing boats and introduction of automation should be encuraged to prevent seasonal fluctuations in fishery outputs. d. The government should increases financial and tax aid to Korean firms in order to elevate already weak financial structure of Korean fishery firms. e. Finally, the government ought to revise foreign exchange regulations being applied to deep sea fishery firms. Furthermore, dutes levied on foreign purchaed equipments and supplies used by our deep sea fishing boats thould be reduced or exempted. when the fish caught by Korean partner of joint-venture firms is sold at the home port, pusan, import duty should be exempted.

• Journal of Nutrition and Health
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• v.18 no.4
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• pp.259-271
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• 1985

The purpose of this study was to develop supplementary foods for infants and young children in order to improve their nutritional status. Three formulas composed of rice, soybeans, fish, dry skim milk and sesame in varying proportions were studied. The three formulas, $RS_{1}S_{2}$, $RFS_{1}S_{2}$, and $RMS_{1}S_{2}$, were consisted of Rice(R), Soybean$(S_{1})$, Sesame$(S_{2})$ (60 : 35 : 5) , Rice, Fish(F), Soybean, Sesame (60 : 10 : 25 : 5) , and Rice, Dry Skin Milk (M), Soybean, Sesame (60 : 10 : 25 : 5), respectively. A proximate analysis and amino acid determination were made on the developed formulas. In the animal assay, growth rate, PER and FER were evaluated and biochemical analyses were also carried out. A storage test and the cost evaluation were also conducted. The summarized results are as follows : 1) The proximate composition of the three formulas were 7.3-7.4% of moisture, 15.9-21.5% of crude protein, 7.8-9.6% of crude fat and 2.5-2.8% ash. 2) The result of amino acid analysis showed that the 1st limiting amino acids of $RS_{1}S_{2}$ and $RFS_{1}S_{2}$ were lysine (amino acid score, 76.6) and threonine (amino acid score, 93.3), and that of $RMS_{1}S_{2}$ and the commercially prepared formula were sulfur containing amino acids (amino acid score, 82.0 and 54.4). When the contents of the amino acids of the three formulas were compared with mother's milk and cow's milk, the balance of the amino acid of each formula was superior to mother's milk but inferior to cow's milk. 3) In the animal assay, the growth rate of all groups increased gradually during the experimental period. 4) The C- PER, which was corrected on the basis of the casein PER of 2.5 was 2.99, 3.38 and 3.10 in the $RS_{1}S_{2}$, $RFS_{1}S_{2}$ and $RMS_{1}S_{2}$ respectively. The C- PER of $RFS_{1}S_{2}$ and $RMS_{1}S_{2}$ were Significantly (P<.05) higher than that of the casein. 5) The FER of the casein, $RS_{1}S_{2}$, $RFS_{1}S_{2}$, and $RMS_{1}S_{2}$ were 0.37, 0.39, 0.43 and 0.39, respectively. The FER of $RFS_{1}S_{2}$ and $RMS_{1}S_{2}$ were also significantly (P<.05) higher than that of the casein. 6) The concentrations of hematocrit, hemoglobin, total protein and albumin in the serum of the rats of all groups were not significantly different among groups. 7) The storage stability test showed that the total plate count (TPC), the coliforms count and the bacterial spore count in the ingredients were quiet low. However, after 30 and 60 days storage, the count in $RFS_{1}S_{2}$ increased and were higher at room temperature than refrigerated temperature. 8) In the cost evaluation, the cost of the developed formulas was \1,826-2,626 / kg. This was less than that of the commercially prepared formula (\3,300-4,073 / kg) and that of the imported formula (\4,250-8,720 / kg).

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.2
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• pp.19-30
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• 2019

Objective of this study was to develop an organic fertilizer utilizing domestic livestock horn meal and to investigate the application effect of rice and eggplant. The possibility of utilization of livestock horn meal as an organic resource to replace imported expeller cake fertilizer was examined. In order to select domestic organic resources with high nitrogen content, 8 kinds of organic matter such as chicken manure, fish meal, soybean meal, sesame meal, perilla meal, blood meal, livestock horn meal, and beer sludge were analyzed and organic resources with high nitrogen content were selected. In addition, the conditions for the production of organic fertilizers that can be used in organic agriculture were established by mixing of the rice husk biochar and the rice bran as the supplements with the raw materials for mixing ratios. The content of total nitrogen (T-N) in the livestock horn meal was 12.0 %, which was the next low in 13.5 % blood meal. The content of total nitrogen was 5.9 ~ 7.9 % in fish meal and oil cakes. Total nitrogen content of non-antibiotic chicken manure for organic farming was 3 % and nitrogen content in beer sludge was 3.5 %. Organic fertilizer was produced by using biochar, rice bran as a main ingredient of non-antibiotic chicken manure, livestock horn meal and beer sludge. Compared to nitrogen content (4.0 to 4.2 %) of imported expeller cake fertilizer (ECF), the nitrogen content of organic fertilizer utilizing domestic livestock horn meal is as high as 7.5 %. The developed organic fertilizer is met as Zn 400 mg/kg, Cu 120 mg/kg the quality of organic agricultural materials such as or less. To investigate the effect of fertilizer application on the crops, prototypes of developed organic fertilizer were used for the experiment under selected conditions. As a result of application the developed organic livestock horn meal fertilizer (LHMF) for cultivation of the rice and eggplant, the application quantity of the developed organic LHMF 100 % was decreased by 40 % compared to that of the mixed expeller cake fertilizer (MECF). The application of LHMF, which refers to the application rate corresponding to the nitrogen fertilization recommended by the soil test, was reduced by 40% compared to the application rate of MECF, but the same results were obtained in crop growth and yield. The selection of a new high concentration nitrogen source utilizing domestic organic resources and the development of organic fertilizer is the starting point of the research for substitution of imported ECF using domestic local resources at the present time that the spread of eco-friendly agriculture is becoming increasingly important. If it is expanded in the future, it is expected to contribute to the stable production of eco-friendly agricultural products.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.5
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• pp.669-673
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• 1999

The effect of delayed initial feeding (1, 3, 5, 7 days) and starvation on morphological change, mortality and cannibalism on larvae of Siniperca scherzeri was examined by laboratory rearing. The larvae of S. scherzeri began to feed on Artemia nauplii at 4 days after hatching. In case of unfed and 7-days delayed groups, all of the larvae died at 12 days after hatching. The larvae of 1 day delayed feeding survived and grew as almost same as the control group, and 3-days delayed groups showed $33\%$ survival rate at the end of experiment (12 days after hatching). In case of the unfed group, total length of the starved larvae showed lower growth rate than the control group, and they did not reached at the same size of the larvae of the control group. Cannibalism were more common in the unfed group and the delayed fed group than the control group. The highest rate of daily mortality caused by cannibalism in the delayed fed group was $23\%$ at 8 days after hatching.