• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.2
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• pp.70-77
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• 2003

From March 1998 to August 2000, the phenological and morphometric changes of Zostera marina L. were examined at the Duksan Port in the eastern coast of Korea. Morphometric characteristics, phenological stage, shoot density, biomass of Z. marina population and environmental parameters were also measured. Nutrient levels in water column varied over the season. Morphometric characteristics of vegetative shoot changed with season; shoot heights ranged from 54.2 cm (March) to 100.0 cm (October). Reproductive shoots appeared from mid-March to early September of which the height was ranged from 97.8 cm (March) to 213.0 cm (July). The flowering phase started at 12$^{\circ}C$ and the fruit development was resulted up to 21$^{\circ}C$. The seed maturing was developed at 22$^{\circ}C$-$25^{\circ}C$. Shoot density and biomass in permanent quadrate (0.25 m$^2$) were significantly different among seasons ranging from 38 to 136 shoots (mean 80.3$\pm$6.5) for shoot density, and 190 g dry wt m$^{-2}$ in October 1998 to 922 g dry wt m$^{-2}$ in June 1998 for biomass respectively. Relationships between shoot morphometrics and physico-chemical parameters were not significantly correlated. Seasonal changes in water temperature seemed responsible for the replacement of reproductive phases and the annual changes of shoot morphometrics in Z. marina populations.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.5
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• pp.435-444
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• 2001

Daily time series of longshore wind at 8 stations, sea surface temperature (SST) at 11 stations in the eastern coast of the Korean peninsula during $1983\~1997$ and the NOAA/AVHRR satellite data during $1990\~1998$ were used in order to study the temporal and spatial variations of the upwelling cold water which occurred in the summer season. The cold water occurred frequently in the eastern coastal waters of Korea such as Soimal, Kijang, Ulgi, Kampo, Pohang, Youngduk, Chukbyun, Chumunjin and Sokcho, During the upwelling cold water phenomenon, SST came down more than $-5^{\circ}C$ in a day. The maximum of the averaged RMS amplitude of daily SST was $5.8^{\circ}C$ along the eastern coast of Korea on Julian day 212 from $1983\~1997$. The cross correlation coefficients were higher than 0.5 between Sokcho and Chumunjin in the northern part of the East Sea, and along Soimal, Kijang, Ulgi, Kampo and Pohang in the southern part of the East Sea. In late July, 1995 the cold water occurred at Ulgi coastal area and extended to Ullung island which is located 250 km off the Ulgi coast. Even though the distance between Soimal and the Ulgi coast area is more than 120 km, the cross correlation coefficient related to the anomalies of SST due to upwelling cold water was the highest (0.7) in the southeastern coastal area of the Korean peninsula. This connection may be due to the cyclonic circulation of the Tsushima Current in this area and the topography of the ocean rather than the local south wind which induced the coastal upwelling.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.3
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• pp.396-404
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• 2015

Morotoge shrimp Pandalopsis japonica is caught by pot and others in the eastern coastal waters of Korea. Comparative fishing experiments were carried out in the eastern coast of Korea, using the dome-shaped pots with different five mesh sizes (17.1, 24.8, 35.3, 39.8, and 48.3 mm) in order to estimate the mesh selectivity of the pot for the morotoge shrimp, Pandalopsis japonica. The SELECT (Share Each Length's Catch Total) analysis method was applied to the catch data. The master selection curve of the pot for the shrimp was estimated to be s(R) = exp(15.770R-10.573)/[1+exp(15.770R-10.753)], where R is the ratio of carapace length to mesh size. From the selection curves, the carapace lengths of 50% retention were 11.6, 17.0, 23.9, and 34.1 mm for 17, 25, 35, and 50 mm mesh-size pot, respectively. It means that the pots of larger mesh size allow more shrimp of small size to escape.

• Journal of Positioning, Navigation, and Timing
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• v.4 no.2
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• pp.87-95
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• 2015

In this study, the temporal and spatial variation in precipitable water vapor (PWV) was analyzed for typhoon Ewiniar which had made landfall in the Korean peninsula in 2006. To make a contour map of PWV, zenith total delay (ZTD) was calculated using about 60 GPS permanent stations in Korea, and the pressure and temperature data of nearby AWS stations were interpolated and applied to the equation for calculating the PWV. While Typhoon Ewiniar was migrating north from the southern coast to the eastern coast of Korea, the PWV migrated showing a spatial distribution similar to that of rainfall. Also, the fluctuating pattern of the normalized PWV was analyzed, and the moving speed of the PWV was estimated using the delay time of the increase/decrease pattern in the eight-test stations. The result indicated that the moving speed of the PWV was about 35 km/h, which was similar to the average moving speed of the typhoon (38.9 km/h).

• ALGAE
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• v.20 no.1
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• pp.53-59
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• 2005

The objective of this study was to clarify marine algal flora and community structure of 16 uninhabited islands in Sinangun area, south western coast of Korea. As a result, a total of 63 species - 11 greens, 16 browns and 36 reds - was identified. The functional groups of marine algal species were filamentous 14.3%, foliose 20.5%, corticated 45.3%, leathery 13.7%, and articulated calcareous algae 6.2%. The (R+C)/P value was calculated as 2.9 showed temperate flora. The result of DCA showed that 16 uninhabitated islands tend to be distributed eastern and western parts. The dominant species was Ulva pertusa, while the subdominats were Gelidium divaricatum, Myelophycus simplex. The vertical distribution pattern of intertidal marine algae represented three distinct zones; Gloiopeltis furcata, Myelophycus simplex, Gelidium divaricatum - Ulva pertusa, Enteromorpha spp., Ishige okamurae - Ulva pertusa, Sargassum thunbergii, Symphyocladia latiuscula.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.9-12
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• 2002

The purpose of this study is to understand the high saline water phenomenon of Handong-ri area in the eastern coast of Jeju Island, were investigate the tidal effect of groundwater level, variation of electric conductivity and temperature, geological logging on the monitoring wells, chemical water quality, and ratios of oxygen istope of groundwater and seawater Results in investigating variation of interface zone of freshwater and saline water represented that the hyaloclastites formed at below groundwater table is developing toward the coast; this area consisted of stratum of good permeability. Hyaloclastites is presumed the main path of the high salinity water There are a lot of movement by the tide at upper layer. Salinity of lower layer spreads to upper up step in proportion to tidal energy. Because of hydrogeological characteristics, Interface zone of freshwater and saline water is made, High salinity of groundwater occur in east coastal area of Jeju Island. Therefore, I think that high saline groundwater phenomenon is natural condition by simple mixing.

• Ocean and Polar Research
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• v.23 no.2
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• pp.133-139
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• 2001

Ocean currents estimated from sea height anomalies derived from inter-calibrated TP/ERS are compared with daily mean currents measured with satellite-tracked drifters. The correlation coefficient between the geostrophic current from TP/ERS and surface current at 15 m depth from drifter tracks was found to be about 0.5. Due to the limitation of satellite ground tracks, small scale eddies less than 80 km are poorly resolved from TP/ERS. One of the interesting results of this study is that coastal currents along the eastern coast of Korea were well reproduced from sea height anomalies when the coastal currents were developed in association with eddies near the South Korean coast. The eddy kinetic energy (EKE) estimated from drifters, TP/ERS, and a numerical model are also compared. The EKE estimated from drifters was about 22 % higher than EKE calculated from TP/ERS. The pattern of low EKE level in the northern basin and high EKE level in the southern East Sea is shown in the EKE estimates derived from both the drifters and TP/ERS.

• Fisheries and Aquatic Sciences
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• v.21 no.9
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• pp.20.1-20.3
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• 2018

Hypoptychus dybowskii, the Korean sandlance, is widespread in cold areas of the North Pacific. Although H. dybowskii has been considered to occur on the coast of Hamgyeongnam-do in Korea, the species is also distributed along the coast of Goseong-gun, Gangwon-do, south of Hamgyeongnam-do in the eastern part of the Korean Peninsula on the basis of newly collected specimens. In addition, many Koreans confuse H. dybowskii and Ammodytes japonicus (= A. personatus for Korean specimens) because the Korean common name or dialect of both species is "Yang-mi-ri", yet the two species differ in their external morphology. Hypoptychus dybowskii differs from A. japonicus in the location of the origin of the dorsal fin and the number of dorsal and anal fin rays.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.609-612
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• 2006

Concrete structures in the seashore are greatly affected by salt attack primarily due to airborne chlorides like it can be seen through the corrosion of rebar. This study intends to investigate characteristics on the salinity of the airborne chlorides in terms of areas. Salinity measurement devices were installed at 27 areas along with seashore throughout the country. The area index for airborne chlorides were established according to the measurements. In Gochang and Taean area showed higher value of area index over 10. In addition, the Eastern coast showed higher index compared to the Western and Southern coast.

• ALGAE
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• v.17 no.3
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• pp.145-151
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• 2002

Three species of marine algae, two browns and one red were newly reported from the eastern and the southern coast of Korea including Cheju Island. their vegetative and reproductive structures were described. Colpomenia phaeodactyla Wynne et J.N. Norris (Scytosiphonaceae, Phaeophyceae) commonly occured in middle to lower intertidal zone of southern coast. Plants consisted of clusters of elongated and hollow sacs arising from an adherent colpomenioid base. Plurilocular sporangia were multiseriate, forming dense, extensive sori over the erect sacs. Cutleria adspersa (Mertens ex Roth) De Notaris (Cutleriaceae, Phaeophyceae) was collected from subtidal region of Cheju Island. It was characterized by broadly fan-shaped habits with golden brown colour and hair-fringed margines, attached by rhizoids along undersurface. Halarachnion latissimum Okamura (Furcellariaceae, Rhodophyceae) was found adrift from several areas of southern coast. Plants were brownish red, filmy and dlicate, membranaceous roundish fronds. Cystocarps were globular and formed under the cortical layer. Tetrasporangia were oblong and zonately divided.