• Title/Summary/Keyword: Fisheries production statistics

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A New Statistical Approach for the Estimation of Range and Degree of Fisheries Damages Caused by Public Undertaking (공공사업으로 인한 어업피해 범위와 피해정도 추정의 새로운 통계학적 접근)

  • 강용주;김기수;장창익;박청길;이종섭
    • The Journal of Fisheries Business Administration
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    • v.35 no.1
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    • pp.117-132
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    • 2004
  • This study attempts to suggest a new approach of the estimation of range and degree of fisheries damages caused by a large scale of reclamation undertaken in coastal area using the central limit theorem(CLT) in statistics. The key result of the study is the introduction of the new concept of critical variation of environmental factor($d_{c}$). The study defines $d_{c}$ as a standard deviation of the sample mean($\bar{X}$) of environmental factor(X), in other words, $\frac{\sigma}{ \sqrt{n}}$. The inner bound of $d_{c}$ could be the area of fisheries damages caused by public coastal undertaking. The study also defines the decreasing rate of fisheries production$\delta_{\varepsilon}$, in other words, degree of fisheries damages, as the rate of change in the distribution of sample mean(($\bar{X}$), caused by the continuous and constant variation of environmental factor. Therefore $\delta_{\varepsilon}$ can be easily calculated by the use of table of the standardized normal distribution.

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The main factor and counterplan for marine casualties of fishing vessel according to the type of fishing gear in Korea (업종별 어선 해양사고의 원인과 대책)

  • PARK, Byung-Soo;KANG, Il-Kwon;HAM, Sang-Jun;PARK, Chi-Wan;KIM, Su-Hyeong;CHO, Hyun-Kuk
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.52 no.3
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    • pp.232-240
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    • 2016
  • Marine casualties originated from fishing vessels occupied about 71.2% of the whole marine casualties in Korea from 2008 to 2014, which has not changed much for a long time. Therefore, a pragmatic counterplan to decrease in casualties in fishing vessel is indispensable for reduction of marine casualties in Korea. Since the casualties occurred by fishing vessels may incline to a specific type of casualties according to the difference in the operating type; in this paper, 11 fishing types which occurred casualties frequently in numbers and occupied ratio were selected. Since the most frequent occurring casualties in fishing vessels were from collisions and fire explosion in statistics from KMST (2008~2014), the study focused on them. The collision is given a great deal of weight in all the casualties mostly due to the negligence of duty regardless of the job types. Gill netter, trap fishing boat, jig boat, multiple fishing boat and stow netter have their own specific causes of casualties in collision according to the operating types. The cause of fire explosion was mainly due to poor inspection and maintenance the electric cord. For this reason, it may be necessary for an operator to make strict precaution on the other vessels under way systematically, keep the regulation for preventing collisions, and for an engineer on watch to make a check the electricity periodically to reduce the fire explosion.

An analysis on marine casualties of fishing vessel by FTA method (결함수 분석 (FTA) 기법을 이용한 어선 해양 사고 분석)

  • KIM, Su-Hyung;KIM, Hyung-Suk;KANG, Il-Kwon;KIM, Wook-Sung
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.53 no.4
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    • pp.430-436
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    • 2017
  • The most frequent occurring and the serious marine casualties in fishing vessels are the collision in statistics from Korea Maritime Safety Tribunal (2008-2015). Collisions are is given a great deal of weight in all marine casualties, and the main cause of collisions is the negligence of watching. From this point of view, this study deals with the collision and its immediate cause, the negligence of watching which are main factors on the indirect causes. Basic analyzing data was gathered from the questionnaire made by experts of sea service part, and analyzed by using the fault tree analysis (FTA). From the result of the study, the occurrent probability of the negligence of watching in the collision due to the indirect causes occupied 64.9%, and its probability caused by the man factors was less than the other factors; i.e. the media factors and the management factors. For the reduction of the negligence of watching in the collision from this study, it needs an effort to remove not only the man factors, but also the media factors and management factors.

A Study of Fisheries' Competitiveness in Korea, China and Japan (한.중.일 수산업의 산업경쟁력 분석)

  • Hong, Hyun-Pya;Lee, Heon-Dong;Ma, Chang-Mo;Baek, Eun-Young
    • The Journal of Fisheries Business Administration
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    • v.40 no.2
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    • pp.127-148
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    • 2009
  • The objective of this paper is to evaluate of fisheries competitiveness in Korea, China and Japan. A joint research with researchers from Korea, China and Japan from 2007 to 2008 was conducted to analyze competitiveness of each respective fishery industry. An industry's competitiveness means the aggregated and potential abilities of the infrastructure, producers and other operators in the industry. The study improved the Norway-Iceland Model developed by the FCI Team(2005) and applied it to the fisheries of the 3 countries. To compare competitiveness of each fishery from the 3 countries, the study examined 87 items including 64 questions and 23 statistics items. Korea fisheries' competitive advantage over China is in marketing capability. Capabilities of fishing companies and fishing processors are also slightly over Japan's performance. However, Korea holds an absolute disadvantage over China and Japan when it comes to the macroeconomic environments and government support, industrial environments and infrastructure, and production and management. Korea's fishing companies and fishing processors especially are much weaker than those of China. In conclusion, Korea needs strategies to advance the industry's structure, China needs to expand the industry's base and Japan needs to differentiate the industry.

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The Exploitation of World Fishery Resources for 10 Years under the New Regime in the Sea (신해양질서 10년후 세계어업자원 이용동향)

  • 이장욱;허영희
    • The Journal of Fisheries Business Administration
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    • v.23 no.1
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    • pp.43-87
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    • 1992
  • In this paper, state of exploitation of world fishery resources after 10 years under the new regime in the sea, called the era of exclusive economic zone (EEZ) expending up to a 200 nautical miles from coastal line, was reviewed to determine effect from establishing EEZ in the world fishery production and its export/import volume based on the fishery statistics annually published by the Food and Agriculture Organization (FAO) of United Nation. The world total production from marine living resources had a trend showing a waned increase during 1970's when most of coastal states were translated into the reality of EEZ. From mid-1980's onwards, it increased rapidly, reaching about 85 million tons . Such increase in production was basically from the Pacific Ocean, accounting for more than 60% of the world total production. Fishing areas where showed increase in the production after the new regime in the sea were the southwestern Atlantic (FAO area 41) , the eastern Indian (FAO area 57) and the whole fishing areas in the Pacific except the eastern central Pacific (FAO area 77). Increase in the production from distant-water fishing countries came from the regions of the southwest Atlantic (FAO area 41) and the southwest Pacific (FAO area 81) . The production from coastal states was up from the regions of the eastern Indian (FAO area 57) , the northwest and northeast Pacific (FAO areas 61 and 67) and the southeast Pacific (FAO area 87) . It was likely that the exploitation of the fishable stocks was well monitored in the areas of the northwest Atlantic (FAO area 21) , the eastern central Atlantic (FAO area 34) and the northeast Pacific (FAO area 67) through appropriate management measures such as annual harvest level, establishment of total allowable catch etc. The marine fisheries resources that have made contribution to the world production, despite expansion of 200 EEZ by coastal states, were sardinellas, Atlantic cod, blue whiting and squids in the Atlantic Ocean : tunas which mainly include skipjack, yellowfin and bigeye tuna, croakers and pony fishes in the Indian Ocean : and sardine, Chilean pilchard, Alaska pollock, tunas (skipjack and yellowfin tuna) , blue grenadier and blue whiting including anchoveta in the Pacific Ocean. It was identified that both fishery production and its export since introduction of the new regime in the sea were dominated by such coastal states as USA, Canada, Indonesia, Thailand, Mexico, South Africa and Newzealand. But difficulties have been experienced in the European countries including Norway, Spain, Japan and Rep. of Korea. Therefore, majority of coastal states are unlikely to have yet undertaken proper utilization as well as rational management of marine living resources in their jurisdiction during the last two decades. The main target species groups which led the world fishery production to go up were Alaska pollock, cods, tunas, sardinellas, chub and jack mackerel and anchoveta. These stocks are largely expected to continue to contribute to the production. The fisheries resources which are unexploited, underexploited and/or lightly exploited at present and which will be contributed to the world production in future are identified with cephalopods, Pacific jack mackerel and Atlantic mackerel, silver hake including anchovies. These resources mainly distribute in the Pacific regions, especially FAO statistical fishing areas 67, 77 and 87. It was likely to premature to conclude that the new regime in the sea was only in favour of coastal states in fishey production.

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Forecasting biomass and recruits by age-structured spawner-recruit model incorporating environmental variables (환경요인을 결합한 연령구조 재생산모델에 의한 자원량 및 가입량 예측)

  • Lee, Jae Bong;Lee, Dong Woo;Choi, Ilsu;Zhang, Chang Ik
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.48 no.4
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    • pp.445-451
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    • 2012
  • We developed an age-based spawner-recruit model incorporating environmental variables to forecast stock biomass and recruits of pelagic fish in this study. We applied the model to the Tsushima stock of jack mackerel, which is shared by Korea and Japan. The stock biomass of jack mackerel (Trachurus japonicus) around Korean waters ranged from 141 thousand metric tons (mt) and 728 thousand mt and recruits ranged from 27 thousand mt to 283 thousand mt. We hind-casted the stock biomass to evaluate the model performance and robustness for the period of 1987~2009. It was found that the model has been useful to forecast stock biomass and recruits for the period of the lifespan of fish species. The model is also capable of forecasting the long-term period, assuming a certain climatic regime.

Analysis of Species Assemblages Caught by Large-pair-Trawler in Korean Waters (한국 근해 쌍끌이대형저인망어업의 어종군집 분석)

  • Lee, Dong-Woo;Lee, Jae-Bong;Kim, Yeong-Hye;Kang, Su-Kyung
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.44 no.5
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    • pp.499-505
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    • 2011
  • The fishing grounds of Korean large-pair trawlers have shifted since exclusive economic zones (EEZs) were established in a fisheries agreement involving countries neighboring Korean waters. The distributions of marine ecosystems and fisheries resources have been changing with environmental changes such as global warming and with the shift in species targeted as a result of changes in fishing technology and fishing gear. This study analyzed variation in the species assemblages caught in Korean waters by large-pair trawlers as a result of these geopolitical and environmental changes. The data used in this study were obtained from the Fishery Production Statistics of Korea and the Port Sample Survey of the National Fisheries Research and Development Institute (NFRDI) from 1990 to 2007. Hierarchical clustering analysis (HCA) and correspondence analysis (CA) were used to explore the characteristics of the catch-species composition. The overall variation in the species composition of the catch of Korean large-pair trawlers showed that the proportions of croaker Johnius grypotus, small yellow croaker Larimichthys polyactis, eel Anguilla japonica, and blue crab Portunus trituberculatus decreased, whereas those of hairtail Trichiurus lepturus, Spanish mackerel Scomberomorus niphonius, anchovy Engraulis japonicus, and common squid Todarodes pacificus increased in Korean waters over the 18-year period. The results of the HCA of the annual catch data by species showed four different distributions of fish species according to year. Results of the CA showed that the species assemblages differed between the 1990s and 2000s.

A study on the stability of a crab trap fishing boat with water tank experiment (수조 실험에 의한 게 통발 어선의 복원성에 관한 연구)

  • Lee, A-Reum;Kang, Il-Kwon;Jo, Hyo-Jae
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.45 no.4
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    • pp.267-275
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    • 2009
  • According to the recent statistics of marine casualties in Korea, fishing boats are more likely to be ended in the casualties, and small fishing boats especially cause much more accidents in sinking and capsizing than any other big vessels. These casualties were mainly produced from the ignorance on the lack of own ship stability. From this view, this study aims to analyze the characteristics of stability on the crab trap fishing boat receiving transverse wave by means of carrying out the water tank test. The rolling angle of the model ship was affected largely with the displacement and the wave period of it, and the trends were shown that the magnitude of the angle was proportional to the displacement, but inversely to the wave period. And the wave height had effect on the rolling angle just in the specific range of the wave period. The force of steady wind didn't have influence on the rolling variation significantly.

Characteristics on the rolling response of a small fishing boat according to the waves and the ship's speed (파랑의 조우각과 선속 변화에 따른 어선의 횡동요 특성)

  • Kang, Il-Kwon;Kim, Hyung-Seok;Kim, Min-Seok;Lee, Yoo-Won;Kim, Jung-Chang;Jo, Hyo-Jae;Lee, Chun-Ki
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.43 no.1
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    • pp.62-70
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    • 2007
  • Marine casualties of vessel are serious problems on social and national aspects, because it results in sacrifice of lives, a great lose of properties and marine pollution. According to recent statistics of marine casualties of vessel, fishing boats are more likely to be ended in the casualty, and especially, small fishing boats cause much more accidents than any other big vessels. Most of marine casualties were caused by the human factors such as poor watch keeping, inadequate manoeuvering and negligent action for engine, etc. This study is intended to provide navigator of small fishing boat with a specific information of necessary to assist both the manoeuvering and the avoidance of capsizing. The manoeuvering characteristics of ship can be adequately judged by the results of typical ship trials manoeuvres. For this purpose, the author measured the roll responses of a small fishing boat in waves using the real sea experimental measuring system, and analyzed the experimental data by the statistical and spectral analyzing methods to get the characteristics of the roll motion responses of the small boat through the wave directions and the ship's speed.

Size-class Estimation of the Number of Walleye Pollock Theragra chalcogramma Caught in the Southwestern East Sea during the 1970s-1990s (1970-1990년대 동해에서 어획된 명태(Theragra chalcogramma)의 체장에 따른 체급별 어획 마릿수 추정)

  • Kang, Sukyung;Park, Jung Ho;Kim, Suam
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.46 no.4
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    • pp.445-453
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    • 2013
  • Walleye pollock Theragra chalcogramma fisheries in Korean waters have changed dramatically during the last three decades: the highest catches occurred in 1981, followed by continuous decreases through the 1990s, ending with a complete collapse of the population in the 2000s. The major spawning ground of walleye pollock is located in North Korean waters, and some juveniles (called nogari in Korean, <300 mm) migrate to the south for feeding and growth. Since the 1960s, Korean fishermen have often caught juveniles, and the weight (metric tons) of juvenile catch was recorded from 1975-1997. However, because the walleye pollock were not aged, the population age structure was not delineated. We developed a model to estimate the number of walleye pollock of each size class based on catch statistics of adults and juveniles, the catch proportion of each size class, and length and weight information on specimens collected by Danish-seine and drift-gill-net fisheries. The model results demonstrated that the recruitment size of walleye pollock was consistently within the 200-250mm size class, and the highest number of this size class occurred in 1981, although values greatly fluctuated interannually. The number of juvenile pollock was 10.4 times higher than that of adult pollock during 1975-1997. The total yield of juvenile pollock was 0.95 million tons, which was equivalent to about 68.2% of total pollock production. The number of juvenile pollock caught during the same period, however, was 16 billion, comprising about 91.2% of the total number caught. Such high fishing pressure on juvenile pollock is considered one of the main factors causing the collapse of the pollock population.