• Title/Summary/Keyword: Costal fisheries

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Maturity and Spawning of the Chub Mackerel Scomber japonicus in the Korean Waters (한국 연근해 고등어(Scomber japonicus)의 성숙 및 산란 특성)

  • Kim, So Ra;Kim, Jung Jin;Park, Hee Won;Kang, Sukyung;Cha, Hyung Kee;Baek, Hea Ja
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.53 no.1
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    • pp.9-18
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    • 2020
  • We investigated the maturity and spawning dynamics of chub mackerel Scomber japonicus in Korean waters using samples collected by a large purse seine fishery from January 2013 to December 2017. We analyzed sex ratio, monthly maturity stage, gonadosomatic index (GSI), Fulton's condition factor (K), and fork length at 50% group maturity. Spawning occurred from March to June, with a peak in May. We detected a significant difference in sex ratio (χ2 test, P<0.05). The relationship between fork length and body weight was expressed as BW=0.0025FL3.4693. We estimated 50% group maturity at a female fork length of 29.3 cm.

Characteristics of the Eggs and Larval Distribution and Transport Process in the Early Life Stage of the Chub Mackerel Scomber japonicus Near Korean Waters (한국 연근해에 분포하는 고등어(Scomber japonicus) 난·자치어의 분포특성 및 초기 수송과정 연구)

  • Kim, So Ra;Kim, Jung Jin;Stockhausen, William T.;Kim, Chang-Sin;Kang, Sukyung;Cha, Hyung Kee;Ji, Hwan-Sung;Jang, Seo-Ha;Baek, Hea Ja
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.52 no.6
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    • pp.666-684
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    • 2019
  • The horizontal distributions of eggs and larvae of chub mackerel Scomber japonicus were extensively surveyed in the vicinity of Korean waters between 31°75'N and 36°50'N during May and June in 2016 and 2017 (total of four surveys). We used a coupled bio-physical model (DisMELS) that combines an individual-based model (IBM) incorporating vertical migration of larvae and temperature-dependent survival to understand transport processes in the early life stage. Using the distributions of eggs and larvae from surveys, the potential spawning grounds were estimated at the northwest and southeast of Jeju Island and the central East China Sea in May, and at the southwestern East Sea and southern West Sea in June by running the model backward in time. In forward experiments within 30 days from the backward results, most larvae were transported to both the Korean and Japanese sides of the East Sea through the Korea Strait. However, the larvae released in the central East China Sea were transported to the Japanese side only, while those released in the southern West Sea were retained within that region. The survival rates at 30 days after release based on the simulation incorporating temperature-dependent survival throughout May and June were 29.7% in 2016 and 28.8% in 2017.

An Empirical Analysis on the Productivity of Coastal Fishery (연안어업 생산성에 관한 실증연구)

  • Eh, Young-Yang;Song, Dong-Hyo;Hwang, Seon-Jae;Park, Bo-Gyeong
    • The Journal of Fisheries Business Administration
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    • v.51 no.1
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    • pp.19-36
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    • 2020
  • The purpose of this paper is to analyze the productivity of the costal fisheries in Jeonnam Province. In this study, the operational characteristics and Cobb-Douglas production function of coastal fisheries were examined based on a research on the actual condition of costal fisheries (RACF). The statistical analysis of RACF data reveals that Cobb-Douglas production function consists of the three variables: fishing quantity per ton-age, the number of fisherman per ton-age and fishing equipment cost per ton-age. The results of this study show us that the relation and productivity between labor and capital of the operational equipment in the coastal fisheries. If extensive comparable biological and market data become available, analysis model can be widely applied to yield more accurate results.

Study on Evaluation of Heat Demand and GIS Mapping in Costal Area (연안도시의 열 수요 추정 및 GIS Map 작성에 관한 연구)

  • Chung, Yong-Hyun
    • Journal of Fisheries and Marine Sciences Education
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    • v.25 no.1
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    • pp.192-197
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    • 2013
  • To overcome the mismatch of heat demand and heat supply is important as considering point on heat utilizing aspects in Urban area. At this point, It need to know the plan of heat networks on the heat balance aspects. The purpose of this study is to know the method of heat evaluation on heat network around costal area. It is need to building uses to calculate the amounts of heat demand. 25 different types of building uses were supplied, but it was reclassified 10 types and calculated the amounts of heat demand in the costal area. The results was described on the area with GIS mapping.

A Study on International Disputes with Korean Distant-Water Sea Fisheries (한국의 원양어업관련 국제분쟁 사례연구)

  • 김민종
    • The Journal of Fisheries Business Administration
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    • v.34 no.1
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    • pp.69-85
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    • 2003
  • The primary objective of this thesis is to study, case by case, the international disputes for fishing rights between fishing nations and costal states never imagined till the introduction of the UN Convention on the Law of the Sea adopted in 1982 and came into effect in November 16, 1994, which governs the high seas and EEZ in a new manner. Such a study is to provide help in the understanding on this new marine system and how to deal with. This is addressed by the perspectives of disputes (a) in the high seas between fishing nations having traditionally enjoyed the principle of the freedom of the high seas and costal states, (b) in the EEZ between fishing nations and costal states possessing the exclusive jurisdiction over living marine resources and sovereign rights for determining allowable catch and the surplus in its EEZ. The article can be divided into four main parts. First, both the general principles of the settlement of international disputes, and the nature and procedures described in the UNCLOS are introduced. Second, it gives cases of tuna long-liner, North Pacific trawler and squid jigger occurred in the coastal states EEZ, and analyses the problem in both terms of its background and final judgment. It further describes the possible issues in case it depends on the International Tribunal for the Law of the Sea for its settlement. Third, closely tied to above, important points such as the right of hot pursuit, prompt release of vessel and crew, and the limits of cooperation with costal states inspector on board fishing vessels are considered mostly based on the UNCLOS, Bilateral Agreement and UNIA. Finally, the article concludes as follows ; The need for broad analyses on the nature of international suits and legal system for the settlement, to win the case before the International Tribunal for the Law of the Sea or coastal states court, is really acknowledged. However, considering the lack of previous studies about it, it is preferably recommended that governmental efforts for making legal standards to cover the judicial costs, for helping industry out of becoming bankrupt.

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Seasonal Change of RNA/DNA Ratio and Blood Characteristics of Black Sea Bream Acanthopagrus schlegeli Habituated in Geojae Costal Area, Kyungnam Province, Korea (경남 거제해역에 서식하는 감성돔(Acanthopagrus schlegeli)의 연간 RNA/DNA 및 혈액학적 특성 변화)

  • Kim, Su-Kyoung;Shim, Na-Young;Lee, Do-Hyun;Kim, Dae Hyun;Yoon, Seong-Jong
    • Journal of Environmental Science International
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    • v.22 no.1
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    • pp.37-45
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    • 2013
  • The monthly variations of blood characteristics and RNA/DNA of black sea bream, Acanthopagrus schlegeli, habituated in Geojae costal area were analysed to determine health condition of natural stocks in terms of gonad maturation and spawning season from March 2010 to February 2011. Spawning season determinated by gonadosomatic index is from June to August. RNA/DNA ratio of black sea bream muscle was strongly correlated with spawning season. During the gonad maturation RNA/DNA ratio in dorsal muscle tissue was decreased contrast to rapid increase during spawning season. Blood composition factors increased in terms of gonad maturation are aspartate aminotransferase, cholesterol, triglyceride, total protein, glucose, globulin, alkaline phosphatase and inorganic phosphate. Other blood factors increased during spawning season are alanine aminotransferase, blood urea nitrogen, uric acid and lactate dehydrogenase.

The Research on the Korean Distant Water Trawl Fisheries (한국 원양트롤어업의 경영실태에 관한 연구 : 기지식 트롤어업을 중심으로)

  • 성락곤;옥영수
    • The Journal of Fisheries Business Administration
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    • v.32 no.2
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    • pp.127-148
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    • 2001
  • Korean distant water trawl fisheries were sector of most important distant water fisheries with tuna long liner fisheries during the development age in Korea. Nevertheless Korean distant water trawl fisheries have suffered from catches and Income problem. It was caused to the strengthen regulation of costal countries, the rapid liberalization trend of trade on the fishing products and the shortage of cheap manpower, etc. In this situation, Korean government is inclined to convert big adjacent trawl fisheries of distant water trawl fisheries for structure adjustment In domestic fisheries. that is analyzed to incorrect method because the efficiency of management indicator in adjacent trawl fisheries was bad than distant water trawl fisheries. Then this policy of Korean government needs to convert anything else. Also it was compared with one of Japan to the efficiency of management indicator of Korean distant trawl fisheries. The result of analysis, Korea was better than Japan in some factor, especially labor cost Then if Korean government will put weighted policy on this viewpoint, Korean distant water trawl can more grow.

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