• Title/Summary/Keyword: Over-fishing

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A Study on Behaviour of Giant Pacific Octopus, Parotopus dofleini to Single Line Hook for Hook Design (외줄낚시에 대한 대문어의 행동과 낚시형상 설계)

  • Park, Seong-Wook;Lee, Jeong-Woo;Yang, Yong-Su;Seo, Du-Ok
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.40 no.1
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    • pp.1-8
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    • 2004
  • The single line hook fishery for giant pacific octopus, Parotopus dofleini is one of the important in coastal Kangwon-do of Korea, where was caught an average of 4,000 ton during the period of 1996~2000. The fishing gear is consisted of a single buoy line, a buoy and a hook. In this study, the responses of giant pacific octopus to single line hook gear were examined in an experimental tank using a video camera in order to know hooking mechanism and improve hook. Giant pacific octopus tend to envelop the bait with their arms by rush or slowly swimming towards it. When they rush to the bait, they show much feeding behaviour as withdrawing after enveloping the bait using two arms. But when they approach with slowly swimming to bait, they show feeding behaviour as stopping after enveloping the bait using one arm. and then, the highly hooking rate appeared more often in the case of latter then former. The average feeding time on a sardine, giant pacific octopus and pork fat showed the range of 1 to 30 min, 10 to 50 min, and 50 min to over 1 hour, respectively. This indicates that it takes longer time for giant pacific octopus to eat the tough meat than the soft meat. The performance concerned with hooking showed that the 'B' type hook with a short shank was more favorable than the 'A' type hook with a long shank. However, the 'A' type hook has the advantage of easy dropping out caught octopus, compared to the 'B' type.

A Model Experiment on the Basic Efficiency of Midwater Rope Trawl Net (로프 트롤 그물의 기본성능에 관한 모형실험)

  • Yae, Young-Hee;Lee, Byong-Gee
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.29 no.3
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    • pp.200-213
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    • 1993
  • A model experiment on a midwater rope trawl net which is used in the North Pacific to catch alaska pollack is carried out in the circulating tank to examine the basic efficiency of the net. The prototype is the net used by M/S Hanil(1, 179GT, 2, 700PS), a Korean trawler. The model net was made according to the Tauti's Similarity Law of Fishing Gear in 1/100 scale by considering the condition of the tank. To measure the basic efficiency of the standard model net, the vertical opening and width between some points marked on the net were measured, and the hydrodynamic resistance were determined. Then the constructive conditions of the net were varied as follows and the factors were measured again to compare the efficiency of those nets with that of the standard net(A-1 type) front weight multiplied 1.5 times: A-2 type. buoyancy and depressing force multiplied 1.7 times: A-3 type. front weight multiplied 1.5 times on A-3 type: A-4 type. depressors rigged at ground rope: B type. cod-end stuffed with cashmylon wad: C type. The results obtained can be summarized as follows: 1. The vertical opening at the center of head rope was steeply decreased with the flow velocity increasing and the vertical opening H(m) can be expressed in H=1.2v super(-1.2)(v : flow velocity in m/sec). The width of the net varied a little when the flow velocity was over 0.4m/sec, and the width of net mouth showed about 37% of the distance between the fore tips of net pendant. The shape of net mouth was almost a circle at 0.2m/sec and then steeply flatted elliptically with the flow velocity increasing and the area of mouth S(m super(2)) can be expressed in S=(1.65-2.3v)$\times$10 super(-2). The hydrodynamic resistance of the net increased almost linearly with the flow velocity increasing and the resistance R(kg) can be expressed in R=3.2$\times$d/l$\times$abv. where d/l denotes the mean of d(diameter of netting twine) and l(length of a leg in a mesh) from wing tip to the end of bag-net except cod-end on the side pannel, and a denotes the strectched circumference of the net at the fore end of a meshed part and b the stretched length of the whole net from wing tip to the end of cod-end. 2. In the condition-varied nets, the vertical opening of head rope showed some increase in every type net except the C type, and the increase showed the greatest in the B type by 30~54%, whereas it showed decrease in the C type by 5~10%. Variation of the area of net mouth showed almost the same tendency as the vertical opening and the increase showed the greatest in the B type by 20%, whereas it showed decrease in the C type by 12%. Hydrodynamic resistance showed some increase in every type compared with the standard net, and the rate of increase indicated 5~10% in the A-2, A-3 and A-4 type, 22% in the B type and 3% in the C type.

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Annual changes of fisheries production in the shore of Jeonbuk Province, Korea (전북연안 어업자원생산량의 경년변화)

  • Park, Jong-soo
    • Journal of Fisheries and Marine Sciences Education
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    • v.20 no.3
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    • pp.400-409
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    • 2008
  • The purpose of this study is to examine annual changes of coastal fisheries production in the shore of Jeonbuk Province in Korea. The catch data of an experimental vessel that used dredge nets were used to study fish species and catch per unit of fishing effort carried out from April 2002 to November 2004. The total number of fish species caught in 2002 was 23, and 15 in 2004. Total number of individuals were 6,008 and their total weight was 376.38 kg in 2002. In 2004, total number of fishes was 2,469, and their weight was 211.99 kg. The annual changes in fisheries production in the western coast of Korea were also analyzed from 1990 to 2007. The total near shore fisheries products in Korea has been relatively stable around 1,4000,000 metric tons to 1,8000,000 tons during this period. Similarly the Chungnam Province's annual fish catch had steadily risen from about 51,187 tons in 1990 to 85,637 tons in 2007. However, Jeonbuk Province's annual fish catch declined dramatically at around 133, 000 tons in 1990 to 45,000 tons in 2007. In summery, while the overall Korea's fisheries production has been stable over the past decade, that of Jeonbuk Province suffered drastic decline in the period. This decline was reflected in the decreased number of fish species, total individuals, and total catch in surverys performed with an experimental vessel.

Characteristics of Puffer Fish Poisoning Outbreaks in Korea (1991-2002) (대한민국에서 복어독에 의한 식중독 발생 특성)

  • Kim, Ji-Hoe;Gong, Qing-Li;Mok, Jong-Soo;Min, Jin-Gi;Lee, Tae-Seek;Park, Jeong-Heum
    • Journal of Food Hygiene and Safety
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    • v.18 no.3
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    • pp.133-138
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    • 2003
  • The data on outbreaks of puffer fish poisoning during 1991 to 2002 in Korea were gathered from press reports, and characterized information collected. During the period, a total of 32 outbreaks of puffer fish poisoning was reported. These outbreaks caused 111 persons to become poisoning, among the cases 30 persons were fatal. The mean case fatality rate was 27.0%, and most of deaths (93.3%) were the male of above 29 years old. Patient number of below 4 persons per a poisoning accident occupied 75.0% of total outbreaks; 65.8% of total cases; and 66.7% of total deaths) was occurred in the months, November through January. Most of puffer fish poisoning (75.0% of total outbreaks; 68.5% of total cases; and 73.3% of total deaths) were found along the south coastal area of Korea, including Busan, Gyeongsangnam-do, Jeollanam-do and Jeju-do. Over than 80% of puffer fish poisoning outbreaks occurred at fishing boat and home where privately made food was cause, and outbreaks in restaurants accounted for 15.6%. Most commonly implicated foods were Guk, boiled soup with puffer fish meat and spices.

Location Suitability Assessment on Marine Afforestation Using Habitat Evaluation Procedure(HEP) and 3D kriging: A Case Study on Jeju, Korea (서식지 평가법(HEP)과 3D 공간보간법(Kriging)을 이용한 제주도 바다숲 입지적합성 평가)

  • Lee, Jinhyung;Kim, Youngho
    • Journal of the Economic Geographical Society of Korea
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    • v.17 no.4
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    • pp.771-785
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    • 2014
  • As marine desertification and chlorosis in Korean coast have been intensified over time, Korean government is promoting marine afforestation projects. However, marine afforestation location is mainly decided by administrative convenience. Also, there is limited literature on location suitability about the marine afforestation. This study aims to assess location suitability of marine afforestation considering 3 significant criteria: ecological, submarine topographical, and human-social environment. Jeju, the study area of this study, first observed chlorosis in Korean coast at the small fishery town in Seogwipo. Jeju is currently suffering from chlorosis all around the island. Habitat Evaluation Procedure (HEP), 3D kriging, Analytic Hierarchy Process (AHP) is applied as analysis methods. Especially, 3D kriging is utilized for modeling 3D ocean space reflecting ocean environment appropriately. The result shows that Jocheon coast has better location suitability than Seogwipo Pyoseon coast. Jocheon coast has the maximum 61% suitability as the habitat of Ecklonia cava Kjellman, and is highly evaluated in other criteria. The results of this study are expected to find optimal marine afforestation location, and to contribute to the restoration of the Jeju coastal ecosystem and the revitalization of Jeju fishing village societies.

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Measurement of the Public Value of Conserving Green Turtles (푸른바다거북 보전의 공익적 가치 추정)

  • Lim, Seul-Ye;Kim, Min-Seop;Cho, In-Young;Lee, Chang-Su;Kwon, Suk-Jae;Yoo, Seung-Hoon
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.2
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    • pp.177-186
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    • 2017
  • This paper attempts to quantitatively assess the public value that has been assigned to this government plan by employing a contingent valuation technique. Data gathering performed that professional research firm administrated a face-to-face national survey of 1,000 randomly-selected households. A one-and-one-half-bound model was adopted to elicit willingness to pay (WTP) responses, and the payment vehicle used was income tax. The WTP model used in this study is based on a utility difference approach and the spike model. The results showed that the public value of conserving green turtles was estimated to be 2,570 Korean Won per household over the next 10 years as of 2016, statistically significant at the 1% level. Expanding the values considered to include the national population gives a public value of 48.7 billion Korean Won. Thus, the public value of rescuing, rehabilitating, and releasing green turtles that have been caught by fishermen, collided with fishing boats, and died in nets through the government program is not small.

The Condition of Controlling Blood-pressure and the Use of Oriental Medical Services in Hypertensive Patients (고혈압(高血壓) 환자(患者)의 혈압관리실태(血壓管理實態)와 한방이용(韓方利用) 현황(現況))

  • Shin, Taek-Su;Yoo, Seong-Gi;Chong, Myong-Soo;Lee, Ki-Nam
    • The Journal of Traditional Korean Medicine
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    • v.15 no.1
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    • pp.128-144
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    • 2006
  • This Study aims at looking into the use of oriental medical services in treating hypertension. The first objective to be explored through this study is the morbidity caused by the disease, classifying them by age, gender, and occupation. The second is to determine the regular use of anti-hypertensive medicine and their efficacy in controlling blood-pressure. The third is to investigate the use-rate and satisfaction of oriental medical service. 838 households across the country, were asked to answer questionnaires for the period of time from Apr. to Jun. 2005. The conclusion from the survey can be summarized as following. The age of which the first medical diagnosis of hypertension were made showed lower in males, those with higher education and income. The study showed females were more active in blood-pressure control, with their frequent monitoring of blood-pressure for the past year. With age, people in under 50 age group proved to be less active. The management of high blood pressure was more effective in group with regular dosage compared to group with irregular use of anti-hypertensive medication, but their difference was minimal. Also, group with no medication showed signs of blood-pressure control. The use of oriental medical service for the past year, were more frequent in groups with lower education, either low or high income, old age, females and occupations in agriculture, forestry and fishing industry. Results were similar in both general population and high blood-pressure patient group. Females, people over 51 years old and with lower education showed more intentions in utilizing oriental medical services in the future. Results were similar in both general population and high blood-pressure patient group. It is necessary to offer a more accurate information on oriental medical treatments. Also, a systematic reform to reduce the patient's share of the treatment cost, as well as, heightening public awareness on the infirmity of present blood-pressure management system is crucial.

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Analyzing the Effect of COVID-19 on the Operational Efficiency of Asia's Major Container Ports: A Data Envelopment Analysis (COVID-19 위기가 아시아 주요 컨테이너항만의 운영효율성에 미치는 영향)

  • KIM, Tae-Hyung;CHOI, Sang-Duk
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.27 no.6
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    • pp.763-774
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    • 2021
  • The COVID-19 virus has generated major shockwaves in all spheres of human life since its outbreak. Maritime transport (both cargo and passenger) is one of the industries most heavily affected, yet over 80% of the world cargo is transported by sea. This study analyzes maritime port operational efficiencies before and after the start of the COVID-19 pandemic to determine whether the pandemic has caused major differences in the operational efficiencies of many leading Asian maritime container ports via data envelopment analysis (DEA). The results of both the CCR and BCC models reveal that overall, efficiency during the COVID-19 pandemic has been higher than before the pandemic despite a few inefficiencies. This implies that the pandemic has so far not has major consequences for the operational efficiency of maritime ports. However, two ports (Busan and Guangzhou) should adjust the scale sizes and technical capacities of their operations to improve performance.

A Study on Factors that Trigger Human Errors Related to Causes of Ship Collisions (선박충돌사고 원인과 관련된 인적과실 유발요인에 관한 연구)

  • Kim, Dae-Sik
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.7
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    • pp.801-809
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    • 2017
  • The purpose of this study is to contribute to the prevention of ship collisions by investigating real ship collision cases and statistically analyzing causes of human error for captains and Officers of the Watch (OOW). This study encompassed a total of 109 cases for 218 vessels, which were suitable for the analysis of ship accidents between merchant ships or merchant ships and fishing boats over the 7 years from 2010 to 2016. Data was collected while classifying vessels according to type, Give-way and Stand-on vessels, along with the cause of human error. Factors causing human error were identified after focusing on the cause of each collision given by the OOW ; frequency and cross tabulation analyses were conducted using SPSS, a statistical analysis tool. As a result, the main causes of human error by an OOW in a ship collision situation were that lookout was neglected in a Give-way vessel including radar surveillance (74.3 %) or continuous observation of an opponent vessel was carried out (17.4 %). A major factor for Stand-on vessels was failure to act to avoid collision with another vessel (63.3 %). In particular, most neglect for lookout type merchant ships occurred after the opponent ship was first observed, and a common cause of lookout neglect and neglect of duty was a focus on other tasks during navigational watch time.

A Historical Literature Review on the Records of Korean Anchovies (우리나라 멸치의 기록에 관한 연구)

  • Lee, Kyung-Joo;Kwon, Hojong;Jeong, Dae-Yul
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.9 no.12
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    • pp.439-451
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    • 2019
  • This study is about the historical records of anchovy which has fluent nutritions as well as the representative side dish in Korean food culture and life. The formal first record about anchovy is in the Uhaeieobo written by Damjeung in 1803. Another important historical record about anchovy are Hyeonsaneobo(Jasaneobo) written by Jeong Yak-jeon in 1814, and Eomyeonggo(Fish name list) of Nanhoeomogji written by Seo Yu-gu in 1820. The anchovies were used for food in Korea even before the Chosun Dynasty, but they were not noticed by people. Because at that time, fishing tools and instruments such as nets were not developed enough to raise enough catches and food processing technology were not developed. Since then, in the Japanese colonial era, it has been actively developing agricultural fertilizers using anchovies. In addition, the processing technology that can be used as an edible food using anchovy has been rapidly developed. Now, the anchovy industry has very important position in Korea's fisheries industry. Among them, 'Jukbangryum anchovy' catching bamboo weir tool which has been existed for over five hundred years in Namhae province, not only creates great high economic value, but also has cultural value. Therefore, the historical literature study on anchovy can be used as an invaluable resource not only for the study of fishery from an industrial point of view, but also for the registration of world cultural heritage and GIAHS (Globally Important Agricultural Heritage System) of 'Jukbangryum' which is traditional fishery catching instrument in Korea.