• Animal Systematics, Evolution and Diversity
• /
• v.8 no.1
• /
• pp.133-140
• /
• 1992

The telestaceans were collected from Mip'o, Oryukto, CHngmu, Hongdo and Hodo in the Korea Strait, and Sgwip'o in the Cheju Island area from 1970 to 1986 . Pseudocladochonus hicksoni identified in the present study is new to the Korean fauna.

• Animal Systematics, Evolution and Diversity
• /
• v.12 no.4
• /
• pp.289-304
• /
• 1996

Notodelphyid copepods taken from Ascidians, Ascidia samea (Oka) and Ascidia sp. which had been collected in the East sea and the Korea Strait are reported. These copepods are Lonchidiopsis hartmeyeri Vanh ffen, 1917 and Pachypygus curvatus Ooishi 1961, and are redescribed as new records to the Korea fauna.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.24 no.6
• /
• pp.459-471
• /
• 1991

The community structure and micro-scale distribution of plankton in relation to hydrography were investigated in Masan Bay, Korea in October 1989. Warmer and less saline waters with stratification was located in the inner part of the Pudo Strait, and chlorophyll-a and nutrients were higher. Both phytoplankton biomass and nutrients was changed dramatically around the Strait. Offshore/oceanic species in phytoplankton i.e., Chaetoceres decipiens, Rhizosolenia stolterforthii, Rhizosolenia styliformis and Ceratium trichoceros and zooplankton i.e., Sagitta enflata, Oncaea uenusta and Oikopluera longicaudata occurred mainly in well mixed waters of the outer part. This suggests that discontinuous layer seems to play an important role as an approximate border for the plankton population. This layer was located between Station 3 and Station 4 near the Pudo Strait, since the layer consisted of a series of micro-scale discontinuties of salinity and dissolved inorganic nutrients gradient. Phytoplankton patchs of more than 801e1 were found only in the inner part of the bay. Depletion of silicate caused by a rapid assimilation of phytoplankton in the inner part of the bay seemed to be responsible for the decline of blooms.

• Korean Journal of Environmental Biology
• /
• v.32 no.4
• /
• pp.335-343
• /
• 2014

Several species of the genus Pseudo-nitzschia produce the neurotoxin domoic acid (DA) known to be responsible for amnesic shellfish poisoning. Recently off the coast of Geomundo and in Exclusive Economic Zone (EEZ) of Korea Strait, P. cf. brasiliana predominated in summer, 2010. As P. cf. brasiliana was new to Korea, we describe the morphological characteristics of the species. It was observed that cells were linear to lanceolate in valve and girdle view, $51{\sim}76{\mu}m$ long and $1.9{\sim}2.6{\mu}m$ wide. In the central part a large interspace was absent. The number of fibulae and striae in $10{\mu}m$ were 30~37 and 31~37. Each stria contained 2~3 rows of poroids, with 10 to 14 poroids in $1{\mu}m$ length. These morphological features of P. cf. brasiliana were found to be similar with the P. brasiliana, except with the fact that P. cf. brasiliana carred more numbers of fibulae/striae in $10{\mu}m$ and poroids in $1{\mu}m$. Based on our observation, we suggest that P. cf. brasiliana is a newly identified Pseudo-nitzschia species or a variety of P. brasiliana.

• Animal cells and systems
• /
• v.2 no.2
• /
• pp.195-201
• /
• 1998

The tube anemone, Cerianthus filiformis Carlgren, was collected from nine localities in the Yellow Sea and the Korea Strait (the South Sea). Populations at different localities showed color variations in tentacles from pale brown to violet. This species is redescribed here because it shows the color variation and the association with the phoronid, Phoronis australis, which was newly recorded from Korean waters. The phoronid has black to purple tentacles shaded with the same color as the cerianthid's tube for mimicking.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.18 no.2
• /
• pp.65-69
• /
• 2013

In situ measurement of a primary production in East Sea, a marginal sea with a fair accessibility, is nonetheless an arduous task because of dynamic variability. In this study, we estimated the mean value of background (gross) primary production over the warm region of the East Sea based on a biogeochemical hypothesis. We propose an immiscible-shoaling hypothesis for the estimation of primary production, which assumes that primary production in the warm region occurred only by the nutrient supply through the Korea Strait. Annual primary production thus estimated is $209\;gC\;m^{-2}\;y^{-1}$, which is comparable to the satellite-based estimates of net primary production in the region. However, since this hypothesis assumes that primary production is based on only the new nutrients supplied to the system, primary production would increase by 40% if we release the assumption, and assume f = 0.6. This suggests that nutrient influx through the Korea Strait alone is more than enough to support primary production previously reported. Primary production may increase as much as two times if we considered other external perturbations excluded intentionally to estimate the background level of primary production, such as coastal upwelling, submerged ground water discharge, aeolian input, ocean dumping, and mixing by typhoons as well as the contribution of cyanobacteria that has not been quantified in the region. This implies the primary production in the warm region of the East Sea would be comparable to that of the Peru upwelling region with f = 0.6.

• Korean Journal of Ichthyology
• /
• v.18 no.1
• /
• pp.36-44
• /
• 2006

The distribution patterns of anchovy eggs and larvae and environmental characteristics such as oceanographic conditions and meteorological factors in the eastern part of Jeju Strait, Korea from June to October 2003 were investigated. During the sampling periods, the anchovy spawned on the coastal area mainly and approximately 85% of total egg abundance occurred in only two months, from July to August, suggesting that the main spawning season of anchovies is considered in summer from July and August in the study area. Relatively high proportions of the anchovy larvae larger than 20 mm TL observed in the eastern part area. These facts suggest that anchovy larvae gradually moved out to the eastern part of study area. Most wind speeds were markedly reduced to below 10 m/s with the exception of a few days and the precipitation was concentrated (37%) from July to August when the anchovy eggs and larvae occurred abundantly. Results of correlation analysis showed that the anchovy egg abundance correlated with the increasing chlorophyll a and copepod biomass. It is considered that the plankton biomass in the sea area would have significant effects on the anchovy spawning. In addition, salinity variations also had significant effects on the abundance of anchovy larvae, with increasing water temperature.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.34 no.6
• /
• pp.198-210
• /
• 2022

The southern strait of Jeju is a divergence point of the Tsushima Warm Current (TWC), and it is the starting point of the thermohaline circulation in the waters of the Korean Peninsula, affecting the size and frequency of marine disasters such as typhoons and tsunamis, and has a very important oceanographic impact, such as becoming a source of harmful organisms and radioactively contaminated water. Therefore, for an immediate response to these maritime disasters, real-time ocean observation is required. However, compared to other straits, in the case of southern Jeju, such wide area marine observations are insufficient. Therefore, in this study, surface current field of the southern strait of Jeju was calculated using High-Frequency radar (HF radar). the large surface current field is calculated, and post-processing and data improvement are carried out through APM (Antenna Pattern Measurement) and FOL (First Order Line), and comparative analysis is conducted using actual data. As a result, the correlation shows improvement of 0.4~0.7 and RMSE of about 1~19 cm/s. These high-frequency radar observation results will help solve domestic issues such as response to typhoons, verification of numerical models, utilization of wide area wave data, and ocean search and rescue in the future through the establishment of an open data network.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.15 no.4
• /
• pp.176-183
• /
• 2010

In order to understand the temporal variations and species composition of tintinnids, at two stations of the Korea Strait, this study was carried out from January to December 2007 (n=17). Fifty-one species from 22 genera were encountered: 27 neritic species (9 genera) and 24 oceanic species (14 genera). The species composition was different between two stations, and neritic species frequently appeared at St. 1, while oceanic species more frequently appeared at St. 2. According to the frequency in appearance of species, the most dominant species were neritic species such as Stenosemella nivalis and S. pacifica, that appeared in all seasons. Also, Acanthostomella norvegica, Amphorellopsis acuta, Epilpocyloides ralumensis, Protorhabdonella curta and other many oceanic species appeared intensively during the low salinity (${\leqq}33\;psu$) and high water temperature (${\geqq}24^{\circ}C$) period (July~October). The abundance of tintinnids ranged from 0 to 1,845 cells $L^{-1}$. It was higher in the seasons (summer and autumn) of low salinity and high water temperature than in other seasons. The abundance was relatively higher at St. 1 than at St. 2. On the basis of correlation and multiple regression analyses, the tintinnid abundance was not correlated with chi-a, but significantly correlated with water temperature and salinity, suggesting to be the primary abiotic factors influencing the abundance. This study suggests that the complex hydrographic conditions of the study area might influence the temporal distribution and species composition of tintinnids.

• Korean Journal of Ichthyology
• /
• v.8 no.2
• /
• pp.47-56
• /
• 1996

Hydrography of the Korea Strait was influenced by the various water masses such as Korean coastal water, East Sea cold water, and Tsushima Current. Anchovy larvae were frequently found in the area influenced by the Tsushima Current. Anchovy appeared in all seasons and were most abundant in summer. Anchovy was more abundant in the middle layer(30~70m) than the surface layer in spring and summer and was little in the deeper layer beyond the depth of 100m. It was most abundant in the surface layer in autumn, and decreased toward the deeper layer. They were more abundant in the middle layer(30~50m) than in the surface layer and the bottom layer in winter. Anchovy was most abundant in the depth of 30m to 70m during the day time, however it was more abundant in the surface layer during the night time. Although vertical distribution patterns of abundance varied seasonally and diurnally, most of the larval anchovy distributed in the upper layer within the depth of 100m and in the upper layer above the thermocline in summer and autumn.