• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.3
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• pp.208-215
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• 2000

The estimated total material transports through the Cheju Strait using all data which investigated in 1997 and 1999 are as follows; A large amount of suspended sediments and dissovted inorganic nutrients are carried tothe South Sea through the Cheju Strait by a persistent eastward flow (Cheju Current) from the Y311ow Sea andthe East China Sea. The annual material Oanspous by the Cheju Current are as follows; 22.9${\times}$10$^6$ ton yr$^{-1}$(SS), 0.52${\times}$10$^{10}$ mol yr$^{-1}$ (NH$_4\;^+$), 6.05${\times}$10$^{10}$ mol yr$^{-1}$ (NO$_3\;^-$), 0.36${\times}$10$^{10}$ mol yr$^{-1}$ (PO$_4\;^{3-}$), 10.27${\times}$10$^{10}$ mol yr$^{-1}$ (Si(OH)$_4$). The annual suspended sediment flux per water transport in the Cheju Strait (44.48${\times}$10$^6$ ton yr$^{-1}$ Sv$^{-1}$) is about 1.7 larger than that in the Korean Strait (26.08${\times}$10$^6$ ton yr$^{-1}$ Sv$^{-1}$). The annual nitrate flux per water transport (11.60${\times}$10$^{10}$ mol yr$^{-1}$ Sv$^{-1}$) is about 1.2 larger than that in the Korean Strait (9.72${\times}$10$^{10}$ mol yr$^{-1}$ Sv$^{-1}$) and 2/3 of that by Kuroshio in the East China Sea (18.55${\times}$10$^{10}$ ton yr$^{-1}$ Sv$^{-1}$). It suggests that chemical rich Cheju Current will play a significant role in the biogeochemical processes in the South Sea where the huge land-based waste are introduced.

• Journal of the Korean earth science society
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• v.27 no.4
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• pp.464-474
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• 2006

The paleoceanography since 14 ka was reconstructed based on the planktic foraminiferal assemblages of core sediments from the outer shelf of the Korea Strait. Planktic foraminifera in the core sediments can be divided into four assemblages: A, B, C, and D. Assemblage A consists mainly of Globigerinoides ruber group and Globigerinoides conglobatus with low abundance (less than 10%), indicating the tropical-subtropical water mass. Assemblage B is composed of Pulleniatina obliquiloculata and Neogloboquadrina dutertrei, the indicator of Kuroshio Current, and shows the aspect of the inflow of the Tsushima Current into the Korea Strait. Assemblage C yields polar-subpolar species, mainly Neogloboquadrina incompta and N. pachyderma. It decreases upward of the core. Assemblage D contains coastal water species such as Globigerina bulloides and G. quinqueloba. It is abundant in the lower to middle region of the core. From the analysis of distributions of each assemblage and the result of age datings in the core, it is suggested that the Korea Strait played a role of channelling the East China Sea and the East Sea after the LGM (ca. 14 ka). During this time, the coastal water, affected by fresh waters originated from the river systems of China and/ or the Korean Peninsula, flourished around the Korea Strait and theses coastal water might entered to the East Sea. Around 8.5 ka, the effect of the Tsushima Current started to strengthen in this region, and the present current system seems to be formed at about $7{\sim}6ka$.

• 한국해양학회지
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• v.28 no.4
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• pp.281-291
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• 1993

A time-dependent primitive two0dimensional calculation is conducted to investigate the variations of Vol. transport onto the Yellow Sea and the Korea Strait with real bathymetries and to tract the Lagrangian movement of water particles. A series of experiment of the barotropic Kuroshio intrusions shows that the eddy induced branching of Kuroshio has sufficient intensity as to modify the continental shelf circulation. This intrusion seems to be one of the important forcing terms such as winds. tides and buoyancy that can also affect the dynamics in the region of the continental shelf. Transport variations across the shelfbreak due to the branching of Kuroshio which come particularly from the southwest of the Kyushu Island, have a strong relationship with the transport variations across the Korea Strait and in the southern area of the Yellow sea. The particle trajectories of the model results are well agreed with the trajectories of satellite tracking drifters obtained by one of the WOCE/TOGA program except the longer travel time period in the present model.

• 한국해양학회지
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• v.30 no.5
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• pp.512-521
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• 1995

To investigate a short-term (from 2 hours to 24 hours) variability of a mixed layer, oceanographical data (water temperature, salinity, current) and meteorological data (wind, air temperature, solar radiation) were collected at a site in the Korea Strait at the interval of one hour for 48 hours from October 12 to 14, 1993. The average rates of temporal variations of the mixed layer depth (MLD) and temperature of the mixed layer (MLT), which are very weakly correlated with the wind stress and buoyancy flux at the sea surface, are about 5.2 m/hour and 0.2$^{\circ}C$/hour, respectively. The mixed layer is relatively shallow when both MLT and MLS (salinity of the mixed layer) are low, while MLD is relatively deep when they are high. MLT shows a sudden decrease or increase. Analysis of satellite infrared images and XBT data shows that sudden increase of MLT is caused by advection of warm water. These results suggest that the short-term variation of the mixed layer in the Korea Strait in autumn, in which surface current is relatively strong and different water masses exist, is mainly determined by advection rather than air0sea interaction such as wind stress or buoyancy flux.

• Parasites, Hosts and Diseases
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• v.52 no.1
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• pp.9-19
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• 2014

Anisakis spp. (Nematoda: Anisakidae) parasitize a wide range of marine animals, mammals serving as the definitive host and different fish species as intermediate or paratenic hosts. In this study, 18 fish species were investigated for Anisakis infection. Katsuwonus pelamis, Euthynnus affinis, Caranx sp., and Auxis thazard were infected with high prevalence of Anisakis type I, while Cephalopholis cyanostigma and Rastrelliger kanagurta revealed low prevalence. The mean intensity of Anisakis larvae in K. pelamis and A. thazard was 49.7 and 5.6, respectively. A total of 73 Anisakis type I larvae collected from K. pelamis and A. thazard were all identified as Anisakis typica by PCR-RFLP analysis. Five specimens of Anisakis from K. pelamis and 15 specimens from A. thazard were sequenced using ITS1-5.8S-ITS2 region and 6 specimens from A. thazard and 4 specimens from K. pelamis were sequenced in mtDNA cox2 region. Alignments of the samples in the ITS region showed 2 patterns of nucleotides. The first pattern (genotype) of Anisakis from A. thazard had 100% similarity with adult A. typica from dolphins from USA, whereas the second genotype from A. thazard and K. pelamis had 4 base pairs different in ITS1 region with adult A. typica from USA. In the mtDNA cox2 regions, Anisakis type I specimens from A. thazard and K. pelamis showed similarity range from 94% to 99% with A. typica AB517571/DQ116427. The difference of 4 bp nucleotides in ITS1 regions and divergence into 2 subgroups in mtDNA cox2 indicating the existence of A. typica sibling species in the Makassar Strait.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.3
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• pp.216-223
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• 2000

In order to study origin and mixing ratio of surface water masses in the East China Sea (ECS), the South Sea of Korea and the Korea Strait, we use three end-member mixing equation. We use $^{228}$Ra/$^{226}$Ra activity ratio and salinity as two conservative tracer and the Changjiang Water (CW), the Yellow Sea Water (YSW), and the Kuroshio Water (KW) as three end members, Results show that ECS surface water includes all the three end member water, in the order of KW (50-90%), YSW (20-40%) and CW (0-20%) in August 1997. Also, the amount of CW can be approximately estimated by salinity alone. Surface water of the South Sea and the Korea Strait includes very small or almost no CW (below 2% except station 9) in May 1998. Thus in the Korea Strait mixing ratio could be estimated by $^{228}$Ra/$^{226}$Ra activity ratio tracer alone between two end-members, KW and YSW. However, in order to Set more accurate results or in case of rainy season, a mixing equation based on two tracers and three end-members is required.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.9 no.3
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• pp.132-139
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• 1997

CTD and current observation were taken to investigate the structure of the cold water in the Western Channel of the Korea Strait in October 1993. Thickness of the cold water in the deep trough of the strait changes from 20 m to 70 m according to the water depth. Thermocline between the Tsushima Warm Water and the cold water deepens from north to south with 0.00057 in slope. Temporal variation of the thickness appears to be related with the tidal current. The maximum variation is 20 m for 48 hours. Mean velocity of the cold water for 72 hours is 17 cm/sec southward. A simple model was used to understand dynamically the southward flow of the cold water and the return flow at the upper part in the lower layer. Calculated maximum southward flow and eddy viscosity coefficient are 7 cm/sec and 0.038 $m^2$/sec respectively in the model. Southward transport is $0.032$\times$10^6㎥/sec$ at the northern part in the trough and decreases from north to south due to the presence of the return flow. Southward transport increases with the increase in the upper layer transport but is not affected by the density of the upper layer or the interface slope.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.982-990
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• 2019

The interest of researchers and governments in exploiting tidal energy resources is increasing. Jangjuk strait is a place with high tidal energy density potential and is therefore appropriate for the constructing of a tidal turbine farm. In this study, a numerical approach is presented to evaluate the current flow and power potential in Jangjuk strait with an ADCIRC model. Then, the tidal field characteristics are utilized as input parameters for tidal resource calculation with an in-house program. The 1 MW scale tidal energy converter devices are employed and arranged in 4 layouts to investigate the annual energy yield as well as flow deficit due to the wake ef ect at the surveyed area. The best-performed array generates an annual energy yield up to 12.96 GWh/year (without considering the wake effect); this value is reduced by 0.16 GWh/year when accounting for the energy loss caused by the flow deficit. Moreover, by altering the turbine yaw angle during the flood and ebb tides, the impacts of this factor on the energy extraction are analyzed. This indicates that the turbine array attains the maximum tidal power when the turbine yaw angle is at 346° and 164° (clockwise, to the North) for the spring and neap tide in turns.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.6
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• pp.775-782
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• 2021

The Myodo-Strait at Yeosu Port is normally used as a major vessel passage for dangerous cargo carriers that carry regular products of dangerous goods. Currently, the Myodo-Strait allows only single passage, and the speed of passage is also limited to 8 knots. As a result, demurrage at the wharf of hazardous goods are also on the rise. It is expected that the development of a number of dangerous commodity wharf in the future will increase the volume of vessel traffic and increase the number of vessels used in the project area. Therefore, it is urgent to improve the waterway in order to secure the safety of ships using the waterway and improve the demurrage. This study proposed an improvement plan for the waterway through the analysis of the marine environment of the waterway and the process of collecting opinions from users in the sea area. and it was finally proposed to expend the width of the strait to 300m and secure a depth of 9.50m through Guidelines of Port and Harbor Design review and ship handling simulation evaluation. In addition it was evaluated that the vessel traffic congestions at peak-time in the situation of solo passage was greatly improved from 71.01% to 47.3% even when it was allowed to ship's crossing passage, as a result of vessel traffic congestions evaluation. According to the proposed improvement plan, the safety of ships' passage in the project area can be secured, and the issue of demurrage was also considered to be improved.

• Korean Journal of Ichthyology
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• v.19 no.4
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• pp.378-386
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• 2007

To study the composition of the developmental stages of Maurolicus japonicus eggs distributed in the western Korea Strait, we investigated the water temperature, salinity, eggs and larvae in December 2002. The Korea Strait Bottom Cold Water (KSBCW) lower than $10^{\circ}C$ was found in off the Ulsan and Busan where M. japonicus eggs were the most abundant. The composition of the developmental stages of M. japonicus eggs at each station were composed of 37.7~89.5% in the first stage, 8.5~37.8% in the middle stage and 0.0~24.7% in the last stage respectively. In the southern area where the KSBCW appeared, the first stage eggs occupied 73.3~89.5%. The high percentage of the first stage eggs indicated that the eggs should be transported by the cold water lower than $10^{\circ}C$ from the Ulleung Basin in the East Sea. In the northern area where the KSBCW was not found, the first, middle and last stage eggs were composed of 37.5%, 37.8% and 24.7% respectively. The ratios of middle and last stage eggs were much higher than those in the southern area with the KSBCW, which implies that the eggs are recruited into the northern area from the southern area with the KSBCW by the Tsushima Warm Current. The pre-larvae found only in the middle and northern part of the study area would be hatched during the transport of eggs from the southern area with the KSBCW by the Tsushima Warm Current.