• Journal of Plant Biology
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• v.34 no.2
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• pp.165-173
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• 1991

Subtidal algal communities of lnchon Dock, an enclosed artificial dock in the western coast of Korea, were investigated qualitatively and quntitatively. Assessments of species composition, biomass rlominant species, and vertical distribution were conducted from January to December, 1990. Duf"16 the study, benthic marine algal community was disturbed completely by water blooming in June, and was recolonized from July. Forty-five species of marine algae, 18 blue green. 13 green. 6 brown, and 8 red algae, were identified as results. Mean biomass was in ranges of $53.50-118.00\;g-dry\;wt/m^2$ in community before disturbance and $0.57-2.62\;g-dry\;wt/m^2$ after it. Dominant species determined by biomass and frequency were Polysiphonia m0\ulcorner7owii and Ceramium fastigiramosum before disturbance, while Lyngbya semiplena, Lyngbya lutea and Lyngbya rivulariarum after disturbance as pioneer colonizers.nizers.

• Journal of the korean society of oceanography
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• v.39 no.1
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• pp.46-56
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• 2004

Spectral attenuation of light and upwelling radiance were measured in the western coast of Korea on board the R/V Inchon 888 of the Korean National Fisheries Research and Development Institute(NFRDI) during four seasons. The goal of these efforts was to determine the spatial and temporal distribution of the inherent and apparent optical properties of the water, and the factors that control their distribution. Our data indicate that while stratification of the water column, phytoplankton, and wind stress determined the vertical distribution of the optical parameters offshore, it was the tidal current and sediment type that controlled both the vertical and horizontal distribution in the coastal areas. These findings led to the development of a model that estimates the spectral attenuation of light with respect to depth and time for the Yellow Sea. The model integrates water leaving radiance from satellites, sediment types, current vectors, sigma-t, bathymetry, and in situ optical measurements in a learning algorithm capable of extracting optical properties with only knowledge of the environmental conditions of the Yellow Sea. The performance of the model decreases with increase in depth. The mean absolute percentage error (MAPE) of the model is 2% for the upper five meters, 8-10% between 6 and 50 meters, and 15% below 51 meters.

• Journal of the Korean Geotechnical Society
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• v.28 no.10
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• pp.55-68
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• 2012

The west seacoast has approximately 83% of tidal flat in Korea. Gyeonggi-do and Inchon has 35.1%. This study was carried out to understand depositional environment and properties of tidal deposits that distributed in the Gyeonggi bay. On the basis of observation and description on mineralogical, geochemical, physical properties, detailed sedimentary unit has been respectively distinguished Based on. stratigraphic position, facies and unconformity, the intertidal zones are classified into four sedimentary units, and bedrock over the units has been developed in the order of Unit 4${\rightarrow}$Unit 3${\rightarrow}$Unit 2${\rightarrow}$Unit 1. The intertidal sediment deposits of Gyeonggi Bay were compared with those of west coast. In Cheongra area all strata of Unit 4-Unit 3-Unit 2-Unit 1 appear. In Yeongjong-do Unit 2-Unit 1, in Incheon Bridge and Songdo area Unit 4-Unit 3-Unit 1 are observed. In Daesan area Unit 4-Unit 3-Unit 1 are observed. Average clay mineral content ratio is 8.2% in Cheongra area, 2.9% in Yeongjong Island, 18.4% in Incheon Bridge, 24.6% in Songdo area.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.6 no.1_2
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• pp.76-80
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• 1973

Cyclina sinensis is an edible bivalve inhabiting wide tidal flats which are exposed to the air at ebb tide along the western coast of Korea. Over the period of June to September 1971, some specimens from a tidal flat near Inchon were submerged in sea water with various concentrations of ammonium hydroxide added and careful observations were made on their fertilization, early development, and metamorphosis of the larvae. The highest rate of fertilization was demonstrated by individuals treated with 1/1000 normal solution of ammonium hydroxide and their fertilized eggs followed normal development, i.e., two cell stage 1.5 hours after fertilization, blastular stage after 4 hours, and trochophore stage after 6 hours. Within 24 hrs after fertilization C. sinensis larvae have acquired the form of early straight-hinge veliger with the mean prodissoconch I with the length of $110\mu$. It takes seven days to get the umbo stage with the mean shell length of $190\mu$ and twenty days to get the morphosing stage with the mean shell length of $260\mu$. The larvae were cultured to the metamorphosing stage with the shell length of $270\mu$ in the laboratory condition.

• Journal of Veterinary Clinics
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• v.26 no.3
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• pp.226-230
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• 2009

We evaluated the efficacy of $\beta$-hemolytic Streptococcus(S.) iniae vaccine on cultured olive flounder. Three hundred flounders(weight $50{\pm}5$ g) were obtained from two farm at Wando and Taean in the southern and western coast of Korea at May and June 2007, respectively. Twenty of flounders moved in 0.5 tons aquaria in land-marine tank system of National Veterinary Research and Quarantine Service. Seawater was transported from the sea of Inchon in western Korea, and water temperature maintained to $22^{\circ}C$ and $25^{\circ}C$ during the vaccination and challenge test, respectively. We used the formalin-inactivated $\beta$-hemolytic S. iniae vaccine produced by domestic manufacturers. The vaccine was intraperitoneally administered to fish. The vaccinated and control group were challenged with intraperitoneal injection by virulent S. iniae SI-36 isolates with $5.0{\times}10^8$ CFU/fish at 3 weeks after vaccination. We evaluated the vaccine efficacy by calculating numbers of dead fish, and observing of clinical signs, exterior and gross lesions, and examining bacteria isolation and identification. Thirty-four(25.2%) of 135 control and vaccinated group fish were dead with serious anemia, abdominal extension, and hernia of intestine during 3 weeks post vaccination. We isolated Neoheterobothrium hirame from the buccal cavity and Edwardsiella tarda from kidney of dead and diseased fish. When infected fish with these agents were challenged with S. iniae SI-36 isolates, the cumulative mortality of control and vaccinated group were 86.7, and 46.7%, respectively. However, significant differences(p<0.05) were observed on cumulative mortality between control(20.0%) and vaccinated group(95.0%) at second trials with 40 healthy, and relative percent survival(RPS) was 78.0%. We confirmed that the efficacy of $\beta$-hemolytic S. iniae vaccine on olive flounder were impacted by health condition such as bacterial and parasitic diseases.

• Journal of Navigation and Port Research
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• v.47 no.6
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• pp.350-357
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• 2023

Marine accidents frequently occur due to the unreasonable operation of ships excluded from ship departure control during marine special weather warnings within smooth water areas. Coastal wave buoys installed in smooth water areas are major reference indicators for ship departure control and can be seen as being directly connected to the safety of ships navigating smooth water areas and the coast. In this study, the location appropriateness of currently operating coastal wave buoys and additional installation in the smooth water areas were assessed by analyzing coastal marine accidents over the past 30 years (1991-2020), the main wind direction and wind speed of each major trading port, and the GICOMS ship track data in 2018. The study results showed that an additional coastal wave buoy should be installed at each of the major trading ports(Inchon Port, Pohang Port, Ulsan Port, and Busan Port) and that the location of the coastal wave buoy needs to be moved in the case of Busan Port. Based on various data analysis in this study, the suggestion for an additional installation and movement of the coastal wave buoy presented in this study is expected to contribute to improving the reliability of ship departure control and resolving safety blind spots.

• 한국해양학회지
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• v.30 no.5
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• pp.403-412
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• 1995

The present study was performed to determine th growth and production of Mactra veneriformis on the Songdo tidal flat off Inchon. west coast of Korea. Monthly samples were collected from Marc 1989 to September 1990. The size distributions of shell length showed unimodal patterns from March to August 1989. The binodal pattern after September 1989 indicated a recruitment of young clams during this period. The density fluctuated irregularly, but showed a decreasing pattern over time on the whole. The density of the year class 1989 increased markedly after February 1990. The growth in shell length showed three phases during a year, a fast growth phase in spring, a slow growth phase in summer and autumn, and a lag phase in winter. The annual increment in shell length reduced with age. The flesh dry weight showed a peak in late spring just before the spawning period, and another peak in autumn. The length of annuli and the back-calculated flesh dry weight were used to describe the annual growth. The growth in shell length fitted to the von Bertalanffy model and the flesh dry weight to the Gompertz model. The absolute growth rate of the shell length reduced gradually with age. The year class 1985 had the highest L, and the yeat class 1986 the lowest L. The annual growth in weight showed a typical sigmoid curve. The growth rate was maximum at the age of 2 to 3. Year classes of 1984 and 1985 had higher values of W and higher absolute growth rates than those of 1986 and 1987. Maximum absolute growth rates of 1986 and 1987 year classes were recorded at younger ages than 1984 and 1985 year classes. The annual relative growth rates of length and weight decreased exponentially with age. Biomass in flesh dry weight increased till spring and thereafter decreased progressively. Maximum biomass was 134.6g m/SUP -2/ in August 1990. The biomass of 1989 yeat class occupied highest proportion in total biomass. Annual production in flesh dry weight from March 1989 to March 1990 was 67.9 g m/SUP -2/ year/SUP -1/. Cumulative production of 1989 year class was highest among all year classes, and that of year class 1984 was lowest. The production is high in spring and autumn, and very low in summer and winter.

• Journal of the Korean association of regional geographers
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• v.4 no.2
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• pp.151-164
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• 1998

I analyzed the correlation between El-Nino phenomenon and our country's temperature and precipitation laying the stress on the anomaly, and the result of this analysis is as follows: (1) The extraction of the occurrences of El-Nino at the place of sea surface around Nino.3 which was known as the sea area under observation for El-Nino reveals that there are 9 years (1969, 1970, 1973, 1977, 1987, 1992, 1995, 1998) when the temperature anomaly in January is more than 1.0 during the period of research years ($1969{\sim}1998$). (2) The tendency of change of sea surface temperature around Nino.3 and that of our country are about the same, but the anomaly of Pusan and Inchon was much greater than that of Jangki in the East Coast. (3) The anomaly of sea surface temperature around Nino.3 and that of the ground temperature showed the similar changing tendency, the temperature of our country has something to do with that of sea surface as the correlation of ground temperature with the temperature of sea surface showed 0.31. Anomaly warm winter has something to do with El-Nino because the temperature of our country was high when El-Nino phenomenon appeared. (4) As for the precipitation, we can see that it has generally increased after 1989 when the phenomenon of warm climate was intense than before that year. But as we study the change of anomaly, the precipitation has less correlation in comparison with the ground temperature. The precipitation in 1973, 1983 and 1987 which were El-Nino years was correlated with El-Nino. While the change of sea surface temperature has showed a tendency of plus(+)increase since 1990, the precipitation has showed a tendency of minus (-)decrease. Therefore it seems that the temperature of sea surface has little correlation with the amount of rainfall.