• 제목/요약/키워드: Growth function of fish

검색결과 48건 처리시간 0.025초

레포츠피싱을 통한 어가소득 증대에 관한 연구 (Feasibility of Enhancing Fishing Household Income Through Leports-fishing Development)

  • 박성쾌;김수진;김영자
    • 수산해양교육연구
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    • 제19권2호
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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).

볼락, Sebastes inermis 산출 후 초기 성장 및 눈의 조직학적 발달 특성 (Early Growth and Characteristic of Histological Eye Development in Post Parturition Dark banded Rockfish, Sebastes inermis)

  • 박인석;박혜정;길현우;구인본
    • 한국발생생물학회지:발생과생식
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    • 제16권2호
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    • pp.101-106
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    • 2012
  • 어류의 시각 구조와 시각 기능 연구에 있어서 행동적 요인이나 환경적 요인의 중요성은 시각생태학에서 매우 중요하게 다루어지고 있으며, 볼락, Sebastes inermis에 관하여는 아직까지 초기 눈의 성장 및 발달에 관한 발생생물학적 연구가 이루어진 바가 없음을 고려하여 이에 대한 연구를 수행하였다. 볼락의 전장, 두장, 두고, 눈의 직경과 수정체 직경은 산출 직후부터 산출 후 60일까지의 단계에서 양성의 상관관계(positive allometry)를 보여주었다. 전장과 관련된 두장과 두고에서의 증가와, 두고와 관련된 눈의 직경과 수정체 직경의 성장은 거의 동형(isometric)성장을 나타내었다. 눈은 산출단계에 완전히 형성되었다. 산출 단계의 눈은 시신경 섬유층, 신경절 세포층, 내망상층, 내과립층, 외망상층, 외과립층, 외경계막, 간체, 추체층 및 상피층을 가지며, 산출 후 60일의 망막 두께는 산출 직후의 망막 두께보다 더 크다. 본 실험기간 동안, 망막의 간체와 추체층의 비율 및 외과립층과 시신경의 비율은 상당히 증가한 반면, 망막의 외망상층과 내과립층, 신경절 세포층의 비율은 현저하게 감소하였다(P<0.05). 차후, 본 연구에 사용된 볼락 망막에 대한 빛 민감성과 공간 해상력에 관한 부수 연구가 필요하리라 사료된다.

한국수산업의 해외진출전략에 관한 연구 (Foreign Entry Strategies for Korean Fishery Firms)

  • 김회천
    • 수산경영론집
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    • 제15권1호
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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.

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CLA 첨가사료가 감성돔(Acanthopagrus schlegeli) 성장과 지방산 조성 및 내장 추출지방이 지방세포 3T3-L1에 미치는 영향 (Influence of Dietary Conjugated Linoleic Acid (CLA) and Carotenoids on Growth, Fatty Acid Composition, and 3T3-L1 Cells in Black Seabream (Acanthopagrus schlegeli))

  • 곽뢰;쥴리야티 로마;최광수;박시향;하영래;강석중;최병대
    • 생명과학회지
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    • 제25권5호
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    • pp.548-556
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    • 2015
  • 공액리놀레산(CLA)과 카로테노이드 일정량을 함유하는 두 가지 사료구와 대조구를 감성돔(Acanthopagrus schlegeli)에 급여하였다. 대조구에는 CLA와 카로테노이드가 포함되지 않았고, CP10구에는 CLA 1%와 카로테노이드 0.1%가 포함되었고, CP25구에는 CLA 2.5%와 카로테노이드 0.1%가 포함되었다. 대조구, CP10 및 CP25구의 일일성장률(SGR)은 0.74, 0.81, 0.97이었고, 사료요구율은 2.65, 2.46 및 2.04이었다. 사육 후 근육 내에 축적된 CLA 함량은 CP10 및 CP25구에서 각각 2.8% 및 5.6%였으며, 내장에 축적된 CLA 함량은 4.0% 및 8.3%였다. 한편, CP25구의 에서 추출된 지용성 물질(VLE)을 첨가한 3T3-L1 지방세포 생존율은 대조구와 비교하였을 때 처리량에 따라 영향을 받는 것으로 나타났다. 따라서 CP25구의 VLE 추출물 농도를 1, 10, 50 및 $100{\mu}g/ml$으로 처리하였을때 각각 $85.9{\pm}0.8%$, $74.8{\pm}0.9%$, $75.5{\pm}0.6%$$72.1{\pm}0.7%$ 감소시켰다. 이와 같은 사료로 감성돔을 사육하는 경우 CP10 및 CP25구의 내장에서 추출한 지질함량 중 CLA함량은 각각 4.0% 및 8.5%, 카로테노이드는 각각 0.62 mg/g 및 0.56 mg/g, EPA 및 DHA는 각각 11.7%와 10.8% 및 11.8%와 12.7%로 증가하였고, 총 PUFA 함량도 각각 48.4% 및 50.5%로 증가하여 인체에 긍정적인 영향을 미치는 성분을 동시에 섭취할 수 있어 기능성 어류의 생산이 가능한 것으로 나타났다.

The Role of Immunostimulants in Monogastric Animal and Fish - Review -

  • Sohn, K.S.;Kim, M.K.;Kim, J.D.;Han, In K.
    • Asian-Australasian Journal of Animal Sciences
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    • 제13권8호
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    • pp.1178-1187
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    • 2000
  • Many immunostimulating substances have been developed to improve immunity of domestic animals, although their exact mode of action and effects are not clearly defined, and they are now widely used in feed industry. Bacterial lipopolysaccharides, called endotoxin, in particular may have a profound effect not only on the immune system but also on macrophages of the reticuloendothelial system. Glucans from a variety of yeast cell wall have been shown to stimulate both specific and non-specific immune responses and to increase growth performance in pigs. Recently, there has been great interest in the role of complex carbohydrates in disease prevention and treatment. Mannanoligosaccharide is a glucomannoprotein complex derived from the cell wall of yeast. Generally, it was also known that the deficiencies of some major vitamins (vitamin A, E and C) and minerals (chromium and selenium) lead to impaired immune system and, as a result, immune function is depressed and recovery delayed. On the other hand, many researchers suggested that one possible reason for the superior performance observed in pigs fed plasma protein may be because of the presence of biologically active plasma proteins (e.g., immunoglobulins) which are known to contribute to the health of the starter pig. And, immunoglobulins present in plasma protein have been implicated as contributing to the overall immunocompetence of the newborn pig. Other immunostimulants, lactoferrin and lysozyme, mainly found in milk and egg white, have been known as having bacteriocidal and bacteriolytic effect. When considering practical use of immunostimulants, the concept of using immunostimulants is new to many people and, in most cases, it is poorly understood how and why such compounds act, and how they should be used in practice. Therefore, in order to clarify the reason for discrepancies in results, special attention should be paid to the dose/response relationship of immunostimulants and the duration of the effect.

구조 생물학을 이용한 Antifreeze protein의 최근 연구동향 (Recent Advances in Structural Studies of Antifreeze Proteins)

  • 이준혁;이성구;김학준
    • Ocean and Polar Research
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    • 제33권2호
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    • pp.159-169
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    • 2011
  • Antifreeze proteins (AFPs) have ice binding affinity, depress freezing temperature and inhibit ice recystallization which protect cellular membranes in polar organisms. Recent structural studies of antifreeze proteins have significantly expanded our understanding of the structure-function relationship and ice crystal growth inhibition. Although AFPs (Type I-IV AFP from fish, insect AFP and Plant AFP) have completely different fold and no sequence homology, they share a common feature of their surface area for ice binding property. The conserved ice-binding sites are relatively flat and hydrophobic. For example, Type I AFP has an amphipathic, single ${\alpha}$-helix and has regularly spaced Thr-Ala residues which make direct interaction with oxygen atoms of ice crystals. Unlike Type I AFP, Type II and III AFP are compact globular proteins that contain a flat ice-binding patch on the surface. Type II and Type III AFP show a remarkable structural similarity with the sugar binding lectin protein and C-terminal domain of sialic acid synthase, respectively. Type IV is assumed to form a four-helix bundle which has sequence similarity with apolipoprotein. The results of our modeling suggest an ice-binding induced structural change of Type IV AFP. Insect AFP has ${\beta}$-helical structure with a regular array of Thr-X-Thr motif. Threonine residues of each Thr-X-Thr motif fit well into the ice crystal lattice and provide a good surface-surface complementarity. This review focuses on the structural characteristics and details of the ice-binding mechanism of antifreeze proteins.

Effects of $\omega$6 and $\omega$3 Fatty Acid Diets on the Fatty Acid Composition of the Mesenteric and Subcutaneous Fat of Lactating Rats

  • Chung, Hae-Yun;Chung, Eun-Jung;Lee, Yang-Cha-Kim
    • Nutritional Sciences
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    • 제4권1호
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    • pp.3-12
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    • 2001
  • Long chain polyunsaturated fatty acids (LCPUFA) are important components of brain phospholipds and play important role (s) in brain function. In rats, the maximum brain growth occurs during the period of lactation even though it happens during the third trimester of gestation in human. Since milk contained docosahexaenoic acid (DHA) even through the maternal diet had no DHA and/or a very small amount of its precursor, $\alpha$-linolenic acid ($\alpha$-LnA), an emphasis was given to maternal adipose tissue as a reservoir of this fatty acid. We, therefore, investigated the mesenteric and subcutaneous adipose tissues for their fatty acid composition in dams reared with different fat diets. Diets containing various amounts of $\omega$6 and $\omega$3 fatty acids were given to adult female rats (200-250g) throughout the pregnancy and lactation periods. Diets were composed of 10% (wt/wt) corn oil (CO), soybean oil (SO), perilla seed oil (PO) containing about 60% $\alpha$-LnA, or fish oil (FO) rich in eicosapentaenoic acid (EPA) and DHA. The fatty acid ompositions of mesenteric and subcutaneous fat were measured and evaluated at Day-2 and Day-15 after parturition. In general, major characteristics of dietary fatty acid composition was reflected on the fatty acid composition of adipose tissues. Dietary fatty acid composition was reflected more on mesenteric fat as compared to subcutaneous fat. Mesenteric fat was found to contain less arachidonic acid (AA) and mesenteric fats of CO, SO and PO groups contained less DHA than did the subcutaneous fat. The P/M/S ratios of adipose tissues were similar between experimental groups while dietary P/M/S ratios differed significantly. It was noticeable that a small proportion of DHA was found in the adipose tissues of animals of CO, SO and PO groups (Day-2) and in SO and PO groups (Day-15), the groups which do not contain DHA in their diets. The percentage of DHA in mesenteric fat o CO, SO and PO groups decreased as lactation continues, while the proportion of DHA in FO group increased. Adipose tissues of FO group had higher DHA/EPA ratio as compared to the diet. Considering the fact that the body contains a large amount of adipose tissues, our present finding suggests that the adipose tissue can serve as a reservoir of DHA for pregnant and lactating rats.

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도시하천 수질개선을 위한 시민의 지불의사액 추정 연구 (Estimation of citizen's willingness to pay for water quality improvement on urban rivers)

  • 강지윤;양진우;황영순;김기욱
    • 한국수자원학회논문집
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    • 제56권3호
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    • pp.225-233
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    • 2023
  • 도시하천은 급속한 경제성장과 개발 등 여건변화로 본연의 모습과 가치를 잃고 인공적인 모습으로 변해왔다. 이로 인해 도시민의 삶의 질과 만족도 또한 하락되고 있다. 본 연구에서는 부산의 대표적 도시하천인 수영강을 대상으로 도시하천 수질 개선을 위한 도시민의 지불의사액을 추정하였다. 비시장가치 추정을 위해 조건부가치측정법(Contingent Valuation Method, CVM)을 적용하여 수질개선을 위한 지불의사액(Willingness To Pay, WTP)를 파악하고 경제적 가치를 추정하였다. 가상시나리오는 EPA, 수질사다리(waterquality ladder)의 개념을 이용하여 현재 수영강 수질이 오염된 물(4등급)이라고 가상시장을 설정하고 낚시가 가능한 수준(2등급)까지 개선을 시키고자 할 때의 지불의사를 조사하였다. 이때 지불수단은 기부금의 형태로 지불기간은 연 1회 향후 5년간으로 설정하였다. WTP는 한국개발연구원(Korea Development Institute, KDI)에서 제시하고 있는 로지스틱 분포와 스파이크 모형을 사용하여 추정하였다. 지불의사 추정결과 수영강 인접 지역주민의 지불의사가 상대적으로 높게 추정되었다. 또한 부산시민의 절반 이상(56.5%)이 '자연 및 생태보전'을 수영강의 주요 기능으로 인지하고 있음을 고려할 때, 하천환경개선을 위한 지불의사의 상승은 도시하천의 가치 향상을 위한 정책적 의사결정 기준으로 작용할 것으로 판단된다. 또한 도시민의 삶의 질 향상 기대수준 충족과 더불어 도시하천 경제적 가치상승을 위한 재원 조달 방안을 마련할 수 있을 것이다.