• Title/Summary/Keyword: fishery condition

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Variation of fisheries conditions of mackerel (Scomber japonicus) fishing ground for large purse seine fisheries (대형선망어업에 있어서 고등어 (Scomber japonicus) 어장의 어황변동)

  • Lee, Haet-Nim;Kim, Hyung-Seok
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.47 no.2
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    • pp.108-117
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    • 2011
  • In order to offer data about fisheries resources management and prediction of catch on large purse seine fisheries, the fluctuation of the fisheries condition and distributions of fishing ground for mackerel were analysed with monthly catch data for 1990.2009. The overall catch has decreased to about 70% since 1997, with approximately 70% of the mackerel (Scomber japonicus) catch and monthly fluctuations showing a similar pattern. Monthly distribution of fishing ground is like distribution of mackerel in large purse seine fishery. The main fishing grounds are near Jeju Island and the Yellow sea with the main fishing season existing between October to December. The catches fluctuations and distribution of fishing ground were related to the effect of regime shifts. Therefore, in order to prediction of catch on large purse seine fisheries should be studied these relationships.

A Study on the Enhancement of the Quality of Pusan Port Traffic Management Service (부산항 해상교통관제 서비스의 품질개선에 관한 연구)

  • 이은방;윤정수
    • Proceedings of KOSOMES biannual meeting
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    • 2001.05a
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    • pp.105-133
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    • 2001
  • World trade has been increasing continuously in total volume, on the other hand, environmental protection on sea and conservation of fishery resources has been rising up the major issue. All of the world are pushing their efforts two major purposes to the full, one is taking competitive place in marine transportation throughout the world and another Is environment protection. Pusan Port as world leading Port put its all effort in bring more ocean going vessels and securing their traffic route by providing them more information related marine traffics through PTMS in port. During two years of operation, statistics of marine traffic accidents showed that many dynamic casualties such as collisions, groundings, and rammings has been decreased. However, due to increasing cargo volume, limited water area and unpredictable weather condition, potential risks still exist high. In this paper, in order to maximize the efficiency of PTMS and reduce various risks in the future, we examine risk factors over operational results and experience, and propose reasonable operational methods of PTMS.

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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.

The Analysis about Factors Affecting of Extinction Risk in Fishing Village (어촌 소멸위험의 영향 요인 분석)

  • Lee, Seo-Gu;Kim, Jung-Tae
    • The Journal of Fisheries Business Administration
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    • v.51 no.1
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    • pp.67-79
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    • 2020
  • The purpose of this study is to propose a policy improvement plan by analysis of the extinction risk factors reflecting the specificity of fishing villages, fishing village support policies, and settlement conditions of fishing villages as one of the solutions to the immediate problem of fishing village extinction. The results of the study show the higher the level of number of fishing ports, number of returning rural population, and housing diffusion rate, the dependent variable extinction risk index was a positive effect while vacant house ratio and aged house ratio was analyzed to be in was a negative (-) relationship with the dependent variable.The policy implications through this study were to prepare an effective policy to reduce the risk of extinction, to improve urgent settlement conditions, and to prepare a condition to convert returning rural population into fishery population.

A Study on the Automatic Counting Method of Number of Chlorella

  • Ota, Makoto;Sumi, Yasuaki;Yabuki, Noboru;Obote, Shigeki;Matsuda, Yoshitaka;Fukui, Yutaka
    • Proceedings of the IEEK Conference
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    • 2000.07b
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    • pp.789-792
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    • 2000
  • Marine chlorella (Nannochloropsis oculata) is cultivated at the fish farming association of experimental fishery laboratory. In the culture of the chlorella, it is necessary to count the number of chlorella in order to understand the condition of increase. For that purpose, we develop automatic chlorella counter using the image processing and the neural network. Its effectiveness is confirmed through the experiment.

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Korean Drift Gillnet Fishery For Flying Squid , Ommastrephes bartrami ( Lesueur ) , and the Variation of Oceanographic Conditions in the North Western Pacific Ocean (한국의 빨간 오징어 유자망 어업과 북서태평양의 해황 변동)

  • 임기봉
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.22 no.3
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    • pp.8-16
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    • 1986
  • The fishing conditions of flying squid, ommastrePhes barsram(Lesueur), in the North Pacific Ocean was studied based on the horizontal water temperature data, satellite data from NOAA and statistical data of flying squid fisheries which were collected from 1980 to 1984. The obtained results were as follows; 1. Since 1979, the Korean drift giIlnet fishery for flying squid was launched in North Pacific. Number of operating vessel and catch of flying squid increased gradually every year. The number of vessels were 111 and their annual catches were 42, 977 M/T in 1984. Therefore, Korean drift giIlnet fishery for this species has played an important role in the products of Korean high-sea fisheries. 2. In the beginning of the fisheries, fishing grounds was formed in the west of long. 1800E. In 1982, in consequence of the center which extended eastward, the fishing ground was formed long. 166$^{\circ}$W in the central North Pacific Ocean. Since 1983, the fishing grounds were formed as far as long. 161$^{\circ}$W. The range of general fishing season in the central North Pacific was from June to August. After september, fishing ground was shifted to the west, in the Northwestern Pacific. 3. The Predominant fishing season for the flying squid was August through January of the coming year. Optimum water temperature for flying sguid at surface layer in the Pacific Ocean ranged from 11 $^{\circ}$e to 17$^{\circ}$e in winter, 13$^{\circ}$e to 17$^{\circ}$e in spring, 12. 8$^{\circ}$C to 19.7$^{\circ}$e in summer and 1O.6$^{\circ}$e -18.7$^{\circ}$e in fall. 4. In summer, the Oceanographic condition in the North Pacific Ocean showed that the water temperature at surface layer was lower in 1980, 1983 and higher in 1981, 1982 and 1984 as compared with mean annual water temperature. 5. The characteristics df oceanographic conditions in the fluation, disformation, mixing and other factors of the Kuroshio and Oyashio currents, which have considerably influenced upon the water masses of the areas. 6. The data and information on surface thermal Structure interpreted from Infrared Satellite Imaginary from NOAA-7 and NOAA-8 are very available in estimating water temperature on the areas and investigating the major fishing grounds. 7. According to the fisheries statics of Japanese drift gilInet, the annual catches of flying squid considerably decreased from 225, 942 M/T in 1983 to 133, 217 M/T in 1984. 8. The fishing grounds in the central North Pacific in several fishing seasons were formed as follows: In June, the initial fishing season, the fishing grounds were formed in the vicinity of lat. 35 - 40oN, the central North Pacific east of 179$^{\circ}$E. In July, the fishing ground were formed in the wide arEa of the central North Pacific north of 400N and long. 174$^{\circ}$E-145$^{\circ}$W In Auguest, concentrative fishing operation carried out in :he central North Pacific north of 43$^{\circ}$N and East of 165$^{\circ}$W. On the other hand, in September, main fishing grounds were disappeared and moved to the west.

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Environmental Character and Catch Fluctuation of Set Net Ground in the Coastal Water of Hanlim in Cheju Island III. Environmental Character and Catch Fluctuation (제주도 한림 연안 정치망 어장의 환경특성과 어획량 변동에 관한 연구 III. 어획량변동과 환경요인)

  • KIM Jun-Teck;JEONG Dong-Gun;RHO Hong-Kil
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.32 no.1
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    • pp.105-111
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    • 1999
  • To investigate the relationships between ocean environmental characteristics and thechange of the catch, we analyzed various environmental factors such as mean temperature, salinity, current vectors, lunar day and wind vectors from 1995 to 1996 and the catch fluctuation of Hanlim set net from 1994 to 1996. The results are as follow ; 1) The proportion of fishes caught in Hanlim set net is highest for horse mackere1 ($69.2\%$) and is followed by common mackerel ($18.4\%$), hair tail ($5.6\%$), squid ($2.7\%$) and rabbit fish ($1.4\%$) in order. Two peaks in the monthly catch appeared in June and October in the operation period of May- December. 2) The flow direction was northward in flood time and southeastward in ebb time around the Hanlim set net. Thus, the vortical mixing of sea water was active and continued for more than 3 hours. In addition, mean daily temperature was low due to the presence of middle and bottom water in offshore. Increase in salinity or high salinity of sea water provides a favorable condition for catches of fishes. Catches in the first quarter and the last quarter of the moon were larger than that in full moon and the last of the month. In particular, when south or southeasterly wind velocity reaches about 3$\~$6.5 m/s, the possibility of catches increases.

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Environment of the Purse-seiner Fishing Ground in the Tsushima a Current (쓰시마 난류역에서의 선망 어장 환경)

  • Cho, Kyu-Dae;Yang, Yong-Rhim
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.21 no.1
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    • pp.41-61
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    • 1985
  • The purse-seine fishery is very important in the coastal fishery of Korea and the main fish species of this fishery are mackerals and also the main fishing grounds are Tushima Current region, To investigate the relationship between the fishing grounds of mackerels and oceanographic condition, the distribution of mean catches of mackerals of each size (1974~1982) was firstly examined and the oceanographic observation carried out in eastern and western area of Cheju island, being main fishing grounds, in July and October, 1983. The results are as follows: The main fishing grounds of mackerals were also in the Tsushima Current region in southern sea of Korea and the season of the good catches are in May and September to October. The small and medium size of mackerals of which the body lengths are 27 cm to 31 cm, about 2-3 ages, occupied about 90% but the smaller size mackerals of which body lenth is 22 cm (1 age)were about 40 to 70% in February to March. The locations of seasonal fishing grounds could founded by 15$^{\circ}C$ isotherm which indicates the Tsushima Current Water. With trace of this isotherm it was founded that the fishing grounds near the Korean Strait than that of south of Cheju island moves faster northward and/or later southward. The main fishing grounds eastward and westward of Cheju island were the front areas formed between the Tsushima Current Water and the southern coastal water of Korea or Yellow Sea Bottom Cold Water. And also the distributions of transparences, water colors and the penetration of sun light of this fishing grounds were similar to that of the temperature, the salinity or volume of planktonic organism.

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Studies on Thermal Resistance of Selected Yeast Strain for Pasteurization of Solid Packed Peach (복숭아 Solid Pack 적정(適定) 살균조건(殺菌條件) 구명(究明)을 위(爲)한 선발(選拔) 효모(酵母)의 열저항성(熱抵抗性)에 관(關)한 연구(硏究))

  • Koo, Young-Jo;Lee, Dong-Sun;Shin, Dong-Hwa;Yu, Tae-Jong
    • Korean Journal of Food Science and Technology
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    • v.13 no.1
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    • pp.43-52
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    • 1981
  • A series of thermal destruction studies of the most heat resistant yeast strain No. 15 among 61 isolates were conducted in order to establish the optimum pasteurization condition of peach solid pack. The results obtained are summarized as follows: 1. A survival curve of the selected yeast strain No. 15 at $58^{\circ}C$ consisted of heat labile and heat stable fraction, showing broken curve. 2. The actively growing cell showed less recovery rate than 10 day rested cell after agitation-growing for 90 hr. For heating menstrua, peptone solution gave higher recovery rate than peach juice. For recovery medium, YM agar gave higher recovery rate than peach juice agar. The selected yeast was more resistant to heat at pH 4.0 than at pH 3.5 in both heating menstrua and recovery medium. 3. Z value of TDT curve of the selected yeast (heating : at pH 3.5 in peach juice. recovery: at pH 3.5 in peach juice agar) was $4.8^{\circ}C$. 4. The selected yeast No. 15 was identified as Torulopsis candida. 5. In the inoculated pack test of 4 oz can, it was concluded that the optimum P.U. 70/5 was 168 (center temp; $78.5^{\circ}C$, initial temp; $18^{\circ}C$, processing time; 18 min, initial yeast count; $1.0{\times}10^7$ per can).

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A Study on the Telemetry system for the Inhabitant Environments and Distribution of Fish-I - Sea Temperature , Salinity and Distribution of Fish - (어류의 서식환경과 분포생태의 원격계측에 관한 연구-I - 수온, 염분과 어류의 분포생태 -)

  • Sin, Hyeong-Il;An, Yeong-Hwa;Sin, Hyeon-Ok
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.33 no.4
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    • pp.321-333
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    • 1997
  • This paper describe on the transmitting/receiving functions and the monitoring effects for the telemetry system which is designed to monitor the environmental condition of a culturing fishery ground inside a bay. The telemetry experiments were carried out by the telemetry system which constructed with the sea water temperature/salinity measuring sensor and telesounder at culturing fishery ground located in the coast of Sangyang-Myon, Kyongsangnam-Do province from October, 1995 to May, 1996. The results of this experiment showed that the developed telemetry system could be used for monitoring the sea water temperature/salinity and the distribution of fish in culturing fishery ground.

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