• 제목/요약/키워드: Over-fishing

검색결과 283건 처리시간 0.022초

광대역 수중 스피커 시스템의 설계 및 성능 특성 (Design and Performance Characteristics of a Broadband Underwater Speaker System)

  • 이대재
    • 한국수산과학회지
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    • 제44권5호
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    • pp.543-549
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    • 2011
  • An underwater speaker was developed for use as an acoustic deterrent device that transmits acoustic energy through the water omnidirectionally over a broadband frequency range to eliminate marine mammal attacks and to prevent physical damage to the inshore and coastal fishing grounds of Korea. The underwater speaker was constructed of two vibration caps machined from 6061-T6 aluminum alloy and a stack of PZ 26 piezoelectric ceramic rings (Ferroperm Piezoceramics A/S) connected mechanically in series and electrically in parallel. The performance characteristics of the underwater speaker were measured and analyzed in an experimental water tank of $5\;m{\times}5\;m{\times}6\;m$. The peak transmitting voltage response (TVR) was measured at 11.16 kHz with 163.45 dB re $1\;{\mu}Pa$/V at 1m. The underwater speaker showed a near omnidirectional beam pattern at the peak TVR resonance frequency. The usable frequency range was 4-25 kHz with a lower TVR limit of approximately 140 dB. We conclude that this underwater speaker could be satisfactorily used as an acoustic deterrent device against marine mammals, particularly the bottlenose dolphin, to protect catches and fishing grounds as well as the mammals themselves, for example, by keeping them away from fishing gear and/or vessels.

한일 어업질서의 이행 실태와 어업관계의 개선 과제 (A Study on the Transition Situation of Korean-Japan Fisheries Agreement and Improvement Issue of Bilateral Fisheries Relations)

  • 김대영
    • 수산경영론집
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    • 제47권1호
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    • pp.31-45
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    • 2016
  • This study aims to evaluate the status of implementation of bilateral-fishery order since the Korea-Japan Fisheries Agreement came into effect in 1999 in order to improve fisheries relationships between two countries. The agreement regulates bilateral-fishery order by the principle of the EEZ regime and mutual benefits among countries. (e.g. the mutual agreed fishing in EEZ and cooperation for resource management). However, the Korea-Japan Fisheries Agreement has some limitations such as reducing quotas of the mutual agreed fishing in EEZ, strengthening Japanese fisheries regulation, insufficient cooperation for fisheries management and joint countermeasures. In order to improve fisheries relationships between the two countries, it is imperative to rebalance quotas for the mutual agreed fishing in EEZ, to establish effective resource management systems in the Intermediate zone, to invigorate fisheries cooperation in the private sector, and to introduce new management systems by species over the all waters around East Asia. To accomplish such measures, it is necessary for Korean and Japanese governments to improve fisheries relationships based on trust and cooperation, achieving a win-win situation. Additionally, it is required to incorporate fisheries management among Korea, China, and Japan.

Current Status of Fishery Resources in Kenya

  • Ibuuri, Peter Kimathi
    • 한국해양바이오학회지
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    • 제3권1호
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    • pp.24-30
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    • 2008
  • Fishing in Kenya, until the discovery of Nile perch as an export commodity in the early 1990s, has basically a subsistence occupation for the lake and coastal communities. The government also did not recognize the importance of fisheries as a contributor to the macro-economy and therefore, did not pay much attention in terms of resource allocation for the development of the sector. Most fishing in Kenya is artisanal, with a little industrial fishing by prawn trawlers. The deep sea (EEZ) fishery resources are currently exploited by DWFNs through a licensing system. Only a small quantity of catch from the EEZ is landed in Kenya, primarily tuna loins for processing for export. Currently capture fisheries, mainly from Lake Victoria, earn local fishers over Kenya shillings (K Sh) 7 billion, while exports earn the country K Sh 5 billion (US$ 50 million) in foreign exchange annually. The government has been putting in place an enabling environment to promote investment activities in order to achieve economic recovery as well as for the development and sustainable use of fisheries resources in the country within the specified period. The Department's major roles are to ensure sustainable exploitation of fisheries resources; to promote aquaculture development; to assure quality and safety of fish and fishery products; and to facilitate fish marketing in order to maximize the benefits that can be derived from fisheries. The contribution of fisheries to local incomes, subsistence and food nutrition is significant, as this occurs in areas with the highest incidences of poverty in the country.

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양식어업 어장관리선에 승선하는 어선원의 안전사고 위험요인 분석 (Analysis of risk factors for safety accidents for fisher onboard aquaculture fisheries management vessel)

  • 이승현;김수형;류경진;이유원
    • 수산해양기술연구
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    • 제60권2호
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    • pp.170-178
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    • 2024
  • This study aimed to quantitatively analyze the risk using data from 329 safety accidents that occurred in aquaculture fisheries management vessels over the recent five years (2018-2022). For quantitative risk analysis, the Bayesian network proposed by the International Maritime Organization (IMO) was used to analyze the risk level according to the fishing process and cause of safety accidents. Among the work processes, the fishing process was analyzed to have the highest risk, being 12.5 times that of the navigation, 2.7 times that of the maintenance, and 8.8 times that of the loading and unloading. Among the causes of accidents, the hull and working environment showed the highest risk, being 1.7 times that of fishing gear and equipment, 4.7 times that of machinery and equipment, and 9.4 times that of external environment. By quantitatively analyzing the safety accident risks for 64 combinations of these four work processes and four accident causes, this study provided fundamental data to reduce safety accidents occurring in aquaculture fisheries management vessels.

어촌지역(漁村地域)의 영양조사(營養調査) - 특(特)히 40세(歲) 이상(以上)의 남자(男子)를 대상(對象)으로 - (Nutrition Survey in a Korean Fishing Area - Especially on Male Subjects of more than 40 years old -)

  • 이기열;함정례;김영후;김형수
    • Journal of Nutrition and Health
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    • 제8권3호
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    • pp.9-17
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    • 1975
  • The purpose of this survey was to study the nutritional status for over 40 years old, related to the dietary pattern of fishing area. The nutrition survey was conducted in a fishing area located in Chilpo-dong, Euchang-myon, Youngil-gun, Kyungbuk province. The precise weighing method was used in evaluating the foods intake for 40 households during a 7 days period. Physical examination, detailed biochemical test on both blood and urine and stool tests were performed by physians on 45 persons over 40 years old man. The result obtained are summarized as follows: (1) Average nutrients intake of an adult per day: calorie intake was 2,883 Cal and its components-Protein (76.3 g) was 10.6%, fat (13.7 g) was 4.2% and carbohydrate (521 g) contributed 85.2% of the total calories. Other nutrients were higher than any other survey data. (2) To evaluate the nutritional deficiencies, clinical examinations were conducted. Hepatomegaly was present 25.3% of these examiners. (3) By stool test most of the examiners were infested in ascareis and infestation rate of stool was 87.5%. (4) The following chemical components of blood serum were analyzed and found to be within the normal range: glucose, blood urea nitrogen, uric acid, total cholesterol, inorganic phosphate, alkaline phosphatase, and electrolytes. (5) Content of electrolytes, glucose, pH, specific gravity in urine were normal range.

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굴(Crassostrea gigas)양식 중단 이후 퇴적물 질 회복에 관한 지화학적 지표 탐색 (Geochemical Indicators for the Recovery of Sediment Quality after the Abandonment of Oyster Crassostrea gigas Farming in South Korea)

  • 심보람;김형철;강성찬;이대인;홍석진;이상헌;김예진
    • 한국수산과학회지
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    • 제53권5호
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    • pp.773-783
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    • 2020
  • In order to evaluate the recovery of fishing ground environment after the cessation of aquaculture farming, we examined the variation in sediment quality over time using different geochemical factors and investigated whether these factors are indicators of sediment quality recovery. The study area was an oyster Crassostrea gigas, farm in Tongyeong, Geyongsangnam-do, South Korea, where aquaculture activities had been carried out for 20 years, and the changes in water and sediment environment were monitored for 14 months after the abandonment of the farm. The mean water depth was 14 m, with a tidal range of 3 m, and seawater current velocity ranged from 4.7 to 7.0 cm/s. After the abandonment of the farm, total organic carbon and total nitrogen concentrations in the surface sediments decreased significantly over time compared to those in the control site; in particular, immediately after farm abandonment, acid-volatile sulfide concentrations decreased relatively rapidly. Carbohydrate and protein concentrations in the sediments showed no significant changes; however, lipid concentrations markedly decreased. Further studies on other aquaculture taxa and various aquaculture areas are needed to establish new policies for environmental management of fishing grounds, such as relocation of fishing grounds and determination of optimal fallowing periods.

한국(韓國) 연근해어선(沿近海漁船)에 대(對)한 전개가능곡면(展開可能曲面) 선형(船型)의 응용(應用) (An Application of the Developable Hull Surface to Korean Inshore Fishing Boats)

  • 김극천
    • 대한조선학회지
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    • 제7권1호
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    • pp.57-78
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    • 1970
  • The Korea inshore fishing boats are the size up to 30G.T., and their construction commonly employs the traditional wide wooden planking. Nevertheless, the hull forms have been developed with chine-type straight-framed sections which give developable surface party, but not on the whole: especially not on the whole portion of the hull are preferable for them. Considering many merits in the boat construction, the author, excluding cases of the FRP construction by hand lay-up or spray-up method and of the ferro-cement construction, finds out no reasons to depart from the chine-type hull forms of a developable surface in future development of their hull forms, too. In this report, the author proposed new designs of the developable hull surface for four typical boats forming the main structure of Korean inshore fishing fleets; 5G.T.-class multi-purpose boat, 10G.T.-class angling and longlining boat, 20G.T.-class drift and gill netters, and 27G.T.-class stow netters, and presented the tank test results on their propulsion resistance. The tank test had two purposes; one is to present the powering schedule of the new designs and the other to investigate the resistance characteristics of this kinds of boat in comparision with those of equivalent round-type boats at operational speed ranges. Between the both types of the boat no material differences in powering are expected. Hence, the author is confident of that saving in the construction cost of the developable hull over that of the round-type boat may result in considerable contribution to the over-all boat economy.

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전남지역 낭장망의 어구 및 어획물 비교 (Comparison of fishing gears and catches by areas in the Gape net with wings in Jeonnam, Korea)

  • 조삼광;송대호;유준택;최문성;차봉진
    • 수산해양기술연구
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    • 제50권3호
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    • pp.301-309
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    • 2014
  • This study was carried out to compare the regional fishing gears and catches of the gape net with wings used in Jeonnam, Korea. The total length of the gear used in Yeosu, Wando and Jindo was 107.0m, 64.0m, 52.8m, and the size of codend was 4.3mm. 7.8mm. 9.8mm, respectively. The total number of bycatch species from anchovy (Engraulis japonicus) catches in Yeosu, Wando, and Jindo during the survey period were 21, 13, and 13 species. A total of individuals of anchovy accounted for over 90% out of total catches in all survey areas. The proportion of anchovy individuals was constantly high up to October in Yeosu, but it showed a sharp reduction to 18% in October in Wando with the increase of the individuals of Kammal thryssa (Thryssa kammalensis) and Big eyed herring (Sardinella zunasi). In Jindo, individuals of anchovy occupied over 99.8% out of total catches up to August. Since August, the number of individuals of Big eyed herring (Sardinella zunasi), Kammal thryssa (Thryssa kammalensis), and Slimy (Leiognathus nuchalis) has increased while the number of anchovy individuals were decreased.

여성 독거노인의 건강, 경제상태, 사회적 관계의 지역적 차이에 관한 연구 - 도시, 농촌, 어촌, 도서지역의 비교 - (Differences in Health, Economic Status, and Social Relations of Female Elderly Living Alone - A Comparative Analysis of Residental Areas including Urban, Rural, Fishing, and Island Communities in Chungcheong Province -)

  • 김윤정
    • 한국지역사회생활과학회지
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    • 제18권3호
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    • pp.417-431
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    • 2007
  • This study investigates the differences among residental areas in the health, standard of living, and social relationships of female elderly living alone. The total of 501 subjects(185 from rural areas, 159 from fishing communities, 77 from the islands, and 80 from urban areas) were questioned from May to July, 2006. The research area was confined to Chungcheong Province. The female elderly living alone of this study were an average of seventy-three years old, had a low cost of living, and received little formal school education. Over sixty percent(60.3) of them lived on less than thirty dollars a month which was the recognized Korean poverty level in 2006. The female elderly living alone were evaluated as being in good health, but they themselves perceived their health as being poor. Observed by residential areas, the subjects in urban areas were lower in ADL, and both the urban dwellers and the islanders appeared to be higher in their satisfaction with medical services as compared to those in rural areas and fishing communities. The fishing villagers showed the lowest standard of living for female elderly living alone. The analysis of social relationships as seen in the different residental areas revealed that the female elderly living alone g in urban areas tended to be receiving social supports rather than providing for others, and subjects living in fishing areas and the islands proved to be relatively higher in the exchange of social supports. In relation to offspring, the female elderly living alone in urban areas had a lower frequency of meeting with their children and also a lesser degree of intimacy with them because they lived at a distance. On the other hand, subjects living in rural areas and fishing communities had a higher frequency of meeting with their children and a greater degree of intimacy with them even if they lived at a distance. The study also showed that the female elderly living alone in the islands had a higher frequency of once meeting per three week with their offspring and a higher degree of intimacy with them because they all live in the same islands. In conclusion, the subject living in urban areas appeared to be isolated from their offspring as compared to the other seniors in the study. The female elderly living alone in urban areas suffered from an insufficient network of relatives and neighbors, and they experienced a poor quality of relationships to their offspring. Almost all of the lone seniors in the study had a low score in social activities; however, the female elderly living alone in urban areas revealed a higher level of participation in volunteer activities, group activities, and educational activities. Nevertheless, the lone seniors living in urban areas were not satisfied with their participation in social activities. The subjects living in rural in fishing communities and the islands showed more participation in money-making activities. This study suggests that the policies for female elderly living alone should reflect the differences of regional characteristics.

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상매선 운영에 관한 일고찰 (A Study on the Management Status of Sanggoson)

  • 김수관
    • 수산경영론집
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    • 제24권1호
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    • pp.29-44
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    • 1993
  • The Purpose of this study is to consolidate the management status of Saggoson in the Choson period by literature research, and examined latest status by field investigation. During the Choson period, there were fish distributors such as Saggoson and Kakju. Saggoson took charge of fish distribution from the fishing ground to the land, and handed over the fish to Kakju who sold over them to the whole country: This distibution system of fish was started from and adapted to the yellow-corvenia fishery of Westhern Sea. There were two resons far this. One was that these fish were. caught much from vast fishing grounds and had a very strong demand, for which professional disributors were needed. The thor was that because fishermen had very limited capital, they had to supply the money for fish production from capitalists like Kakju whom they agreed to sell fish directly to. By this time, it was thought that the fish distibution system for the Westhern Sea fishery was determined by the background and tradition. Meanwile, Saggoson, which has been working far a long time in Westhern Sea, is placed in changing circumstances. That is, small scale fishery Saggoson deals with will be getting fewer, because the big scale reclamation projects in this area threatens the fishery's existence. Also, Saggoson, presently, might be forced to become more efficient in its distribution in the future. In this situation, the management status of a Sggoson in the past and present needs to be consolidated and investigated through this study.

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