• Title/Summary/Keyword: Oceanographic factors

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Factors Affecting the Wintering Habitat of Major Fishery Resources in Southwestern Korean Waters

  • Kim, Jin-Yeong;Choi, Il-Su;Kim, Joo-Il;Choi, Seok-Gwan;Chun, Young-Yull
    • Ocean Science Journal
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    • v.42 no.1
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    • pp.41-48
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    • 2007
  • We investigated the temperature and salinity effects on the major fish species in the wintering grounds based on trawl surveys and oceanographic observations in the southwestern waters of Korea during March-early April in 2002-2003. The influence area of warm Kuroshio water was limited to the southwestern area of Korea in 2003 with a range of $7.7-16.3^{\circ}C$, 32.54-34.70 of salinity, wider than that of 2002. The number of fish species and density of major fish species in 2003 were higher than in 2002. Geographical estimation showed high proportions of species number and catches in the areas around Jeju Islands, southwestern waters and the southeastern coast of Korea. Five species; silver pomfret (Pam pus echinogaster), hairtail (Trichiurus lepturus), anchovy (Engraulis japonicus), Small yellow croaker (Larimichthys polyactis) and yellow goosefish (Lophius litulon) were most abundant, composing above 60% of the total catch in 2002 and 2003. More than 50% of catch in the major fish species were mostly distributed in the range of $9.5-11.0^{\circ}C$ of temperature and 33.1-33.9 of salinity. Non-parametric estimation for the major species showed the 1st mode around $10^{\circ}C$ and the 2nd mode at $8-9^{\circ}C$ in 2002 and $11-14^{\circ}C$ in 2003. Among major fish species, hairtail was principally composed of juveniles, and larger individuals were caught in southeastern waters. These results are considered to be helpful for the area-based fishery management strategy for the wintering grounds of the Yellow Sea and coastal waters of Korea.

Influence of Sea Condition on Catch Fluctuation of Long Line for Common Octopus, Octopus Variddilis, in the Coastal Waters of Yosu (1) (여수연안 낙지주낙 어장의 해황과 어획 변동에 관한 연구 (1))

  • 정정민;김동수
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.37 no.3
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    • pp.155-158
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    • 2001
  • In order to investigate the influence of sea condition on the catch fluctuation of long line for common octopus, octopus variabilis. the oceanographic factors. I .e., the water temperature, the salinity and the density in the coastal waters of Yosu from Jan 11 to Jul. 25 in 1997 and compared with the catches of common octopus, octopus variabilis by long line. The results obtained summerized as follows ; 1) The range of water temperature, salinity and density from Jan. to Jul. at the sea area were 4.1∼23.6℃. 31.7∼34.5‰ and 21.30∼27.81. respectively, and the catch of common octopus, octopus variabilis was high respectively at the temperature of 17∼20℃ at the salinity of 33.0∼33.5‰ and at the density of σ/sub t/ 22.5∼24.0. 2) The catch of common octopus. octopus variabilis was lowest from Jan. to Feb. and highest from May to June.

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Influence of Sea Condition on Catch Fluctuation of Long Line for Common Octopus, Octopus Variddilis, in the Coastal Waters of Yosu (2) (여수연안 낙지주낙 어장의 해황과 어획 변동에 관한 연구 (2))

  • 정정민;김동수
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.37 no.3
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    • pp.159-162
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    • 2001
  • In order to investigate the influence of sea condition on the catch fluctuation of long line for common octopus, octopus variabilis, the oceanographic factors. I. e., the wind direction, the wind speed, the age of moon and ebb tide and flood tide in the coastal waters of Yosu from Jan. 11 to Jul. 25 in 1997, and compared with the catches of common octopus, octopus variabilis by long line. The results obtained summerized as follows: 1) The catch of common octopus was highest in wind direction from SE and lowest in that from NW. The catch was highest at the wind speed of 2m/sec and decreased with increasing speed, over 2m/sec. 2) The catch of common octopus was highest at the day of neap tide and lowest at the mid day, from neap tide to spring tide. More strictly the catch was higher during days at which the current became rapid than during days at which the current became slow. The catch was higher always at flood tide than at ebb tide in all the days investigated and highest with in one hour from ebb tide.

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Relationship between Weather factors and Water Temperatures, Salinities in the West Sea of Korea (한국 서해에서 기상인자와 수온, 염분과의 관계)

  • Lee Jong Hee;Kim Dong Sun
    • Proceedings of KOSOMES biannual meeting
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    • 2003.11a
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    • pp.181-185
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    • 2003
  • the effect if atmosphere is more important in the West sea of Korea than in other seas because of shallow water and heat storage if the water. The serial oceanographic observation data and coastal station data from NFRID, and the atmosphere data from KMA were used in order to find out the relationship between them The highest water temperature, salinity and weather factor were recorded in Aug, and the lowest of them in Feb. As the water deepens, the maximum time leg in water temperature and the minimum time leg in salinity. Water temperature have the maximum in Oct, the minimum in Apr at 75m of the 311-07 station with 100m depth water temperature (WT)-air temperature, WT-precipitation (Preci.) and salinity (Sal)-wind speed (WS) were in direct proportion, but WT-WS, Sal-AT and Sal-Preci in inverse proportion Water temperature and salinity I-ave time leg at the same depth the maximum had more the delay of $2\~4$ months at a depth if 20 meters than at the surface in all stations except for salinity at 307-05.

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Influence of Sea Condition on Catch Fluctuation of Long Line for Common Octopus, Octopus Variddilis, in the Coastal Waters of Yosu (1) (여수연안 낙지주낙 어장의 해황과 어획 변동에 관한 연구(1))

  • 정정민;김동수
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.37 no.4
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    • pp.321-325
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    • 2001
  • In order to investigate the influence of sea condition on the catch fluctuation of long line for common octopus, octopus variabilis, the oceanographic factors, i. e., the water temperature, the salinity and the density in the coastal waters of Yosu from Jan. 11 to Jul. 25 in 1997, and compared with the catches of common octopus, octopus variabilis by long line. The results obtained summerized as follows; 1) The range of water temperature, salinity and density from Jan. to Jul. at the sea area were 4.1~$23.6^{\circ}C$, 31.7~34.5$\textperthousand$ and 21.30~27.81, respectively, and the catch of common octopus, octopus variabilis was high respectively at the temperature of 17~$-20^{\circ}C$, at the salinity of 33.0~33.5$\textperthousand$ and at the density of $\sigma$t 22.5~24.0. 2) The catch of common octopus, octopus variabilis was lowest from Jan. to Feb. and highest from May to June.

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Influence of Sea Condition on Catch Fluctuation of Long Line for Common Octopus, Octopus Variddilis, in the Coastal Waters of Yosu (2) (여수연안 낙지주낙 어장의 해황과 어획 변동에 관한 연구(2))

  • 정정민;김동수
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.37 no.4
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    • pp.326-330
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    • 2001
  • In order to investigate the influence of sea condition on the catch fluctuation of long line for common octopus, octopus variabilis, the oceanographic factors, i. e., the wind direction, the wind speed, the age of moon and ebb tide and flood tide in the coastal waters of Yosu from Jan. 11 to Jul. 25 in 1997, and compared with the catches of common octopus, octopus variabilis, by long line. The results obtained summerized as follows; 1) The catch of common octopus was highest in wind direction from SE and lowest in that from NW. The catch was highest at the wind speed of 2m/sec and decreased with increasing speed, over 2m/sec. 2) The catch of common octopus was highest at the day of neap tide and lowest at the mid day, from neap tide to spring tide. More strictly the catch was higher during days at which the current became rapid than during days at which the current became slow. The catch was higher always at flood tide than at ebb tide in all the days investigated and highest with in one hour from ebb tide.

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Environmental Factors and Catch Fluctuation of Set Net Grounds in the Coastal Waters of Yosu - 4 . Water Temperature and Salinity and Fluctuation of Catch - (여수연안 정치망어장의 환경요인과 어황변동에 관한 연구 - 4 . 수온 염분과 어획량 변동 -)

  • Kim, Dong-Su;Rho, Hong-Gil
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.32 no.2
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    • pp.125-131
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    • 1996
  • In order to investigate the relation between the environmental properties and the catch fluctuation of set net fishing grounds located in the coastal waters of Yosu, oceanographic observations on the fishing grounds were carried out by the training ship ofYosu Fisheries University from January, 1990 to September, 1992, and the data obtained were compared with the catch data from the joint market ofYosu fisheries cooperative society from 1984 to 1993. The resuItes obtained are summerized as follows : 1. The ranges of water temperature and salinity in the fishing ground was 7.0 to $27^{\circ}C.$and 26.6 to 33.2${\textperthousand}$, and water temperature increased from March to August and decreased from September to February of following year. 2. The salinity in the fishing grounds was relatively high without significant changes from November to June of the following year. From July, however, the salinity decreased to continue a low value till September and then increased. The salinity in the fishing ground was dominated mainly by the precipitation and its variation was large at the north entrance of set net fishing ground, influenced greatly by the land waters from the river of Somjin, but small in the offshore of the fishing grounds. 3. The fishes caught by the set nets were arranged in order of catch as follows; Spanish mackerel> Horse mackerel > Sardine > Anchovy > Hair tail. The catches of Anchovy and Sardine were high in April to May and those of Hair tail in June to July, but Spanish mackerel and Horse mackerel were caught for whole period of fishing. Spanish mackerel was caught most in September and least in April and their means were largest in August and smallest in June. 4. The ranges of optimum water temperature for fishing by the set nets was 13.5 to $25^{\circ}C.$, and in the ranges the catches increased with increasing temperature. The ranges of optimum salinity for fishing varied between 25.0 and 32.0${\textperthousand}$.

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A Study on Standardization of Marine Geographical Names in Korea (우리나라 해양지명 표준화에 관한 연구 - 해양지명 명명 사례조사를 중심으로 -)

  • Lim, Young-Tae;Choi, Yun-Soo;Yoon, Ha-Su
    • Spatial Information Research
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    • v.19 no.6
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    • pp.55-65
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    • 2011
  • All of area we live in has its own geographic names. Even small size of rock under the water has its own name. They are called "marine geographic names". Marine geographic names can be classified two categories. One is a proper name; the other is an attribute name. Rocks, reefs and banks referred in the introduction, belong to the category of the attribute name. And there are certain standards to name marine geographic things. In this study, we conducted a case research with the aims to figure out how we name and use those three features that we consider dangerous factors for marine navigation. This study also focused on differences between the methods used to classify attributes of marine geographic names in the past and today. In addition, it reviewed and analyzed marine geographic names used by Korea Hydrographic and Oceanographic Administration (KHOA) on its own Nautical charts and conducted a case research on marine geographic names notified by Korean Committee on Marine Geographic Names. Based on research and analysis, this study presents future methods regarding marine geographic names standardization.

Environmental Factors and Catch Fluctuation of Set Net Grounds in the Coastal Waters of Yeosu (여수연안 정치망 어장의 환경요인과 어황 변동에 관한 연구)

  • 김동수
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.29 no.2
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    • pp.94-108
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    • 1993
  • In order to investigate the relation between the environmental properties and catch fluctuation of set net fishing ground located in the coastal waters of Yeosu, oceanographic observation and catches on the grounds were carried out from Jan. to Dec. in 1990 and 1992. The results obtained are summarized as follows; 1) Because of the surveyed area is a costal shallow water, the fishing ground was influenced largely by atmospheric phenomena such as air temperature. precipitation. etc. and so showed large variations in temperature and salinity yearly. The inner water flowed out mainly between Yeosu ad Namhe-do, and then through Kumo-do between Dolsan-do and Kumo-do. On the other hand, off shore water was supplied into the fishing ground from the vicinity of Sori-do and Yokchi-do. thus the fishing ground was occupied usually by various sources of water. 2) The water mass in the fishing ground were divided into the inner water(29.0~30.6$\textperthousand$) and the mixed water(31,7~32.2$\textperthousand$) and off shore water(32.3~32.8$\textperthousand$) accourding to the distribution of salinity from T-S diagram plotted all salinity data observed in 1990 and 1992. In summer the inner and mixing water which was formed by river flowed southerly and spread south-easterly in the vicinity of Kumo-do. The off shore water which supplied from the vicinity of Sori-do and Yokchi-do and inner water formed the thermal front and halo front in summer. 3) The fishes caught by the set net were arranged in the order of catch amounts as follows: Spanish mackerel>Horse mackerel >Hair tail>Common mackerel> Sardine> Anchovy. The Catches of anchovy and sardine were high in April to May and those of hair tail and horse mackerel in July to September, but spanish mackerel were caught during the whole period of fishing. When inner water and mixing water appeared respectively and inner water and mixing water speared together in the set net fishing ground, the set net showed a high catch.

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Oceanographic Conditions in Relation to Laver Production in Kwangyang Bay, Korea (광양만의 김 생산과 양식장환경과의 관계에 대하여)

  • HONG Jae-Sang;SONG Choon Bok;KIM Nam-Gil;KIM Jong Man;HUH Hyung Tack
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.20 no.3
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    • pp.237-247
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    • 1987
  • The present study deals with the physico-chemical and meteorological conditions in Porphyra-cultivation ground to determine the relationship between laver production and its environmental factors in Kwangyang Bay from January to April in 1986. As a result, major environmental factors which are thought to have a great influence upon the poor harvest during the cultivation period are as follows; 1) the excessive rainfall in the beginning of cultivation period 2) the accumulation of suspended matters on the thallus of laver 3) the decrease of current velocity and the stagnation of the water in the cultivation ground.

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