• Korean Journal of Ichthyology
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• v.26 no.4
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• pp.295-302
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• 2014

Mottled skates, Beringraja pulchra, mainly found in the Yellow Sea were caught by otter trawl at 30 stations from 2002 to 2013 to identify the distribution patterns and ecology of the fish in the eastern Yellow Sea. A total of 442 individuals of mottled skate were caught at the 112 hauls of the total 892 hauls. The fish was widely distributed in the entire survey area in spring and autumn, and mainly caught in the northern offshore in summer and in the southern part in winter. The under-yearlings of the mottled skate were mainly caught in the offshore in spring and autumn. The mottled skates were found at the temperature ranges of $3.8{\sim}14.5^{\circ}C$, and the salinity of 31.2~34.2. The catch data of the fish suggested that water temperature be a critical factor for the distribution with the optimal ranges of $5{\sim}14^{\circ}C$. Salinity and water depth were not critical as much as the water temperature for the distribution of the mottled skates in the Yellow Sea. Also, the annual fluctuations of the fish catch were reviewed using the catch data from korea fisheries cooperative and national statistics from 1991 to 2009.

• Ocean Science Journal
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• v.41 no.4
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• pp.255-260
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• 2006

Long-term variability in the intermediate layer of the eastern Japan Basin has been investigated to understand the variability of water mass formation in the East Sea. The simultaneous decrease of temperature at shallower depths and oxygen increasing at deeper depths in the intermediate layer took place in the late 1960's sand the mid-1980's. Records of winter sea surface temperatures and air temperatures showed that there were cold winters that persisted for several years during those periods. Therefore, it was assumed that a large amount of newly-formed water was supplied to the intermediate layer during those cold winters. Close analysis suggests that the formation of the Upper Portion of Proper Water occurred in the late 1960's and the Central Water in the mid-1980's.

• Journal of the Korean Institute of Navigation
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• v.14 no.2
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• pp.33-59
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• 1990

In cold season, the developed extratropical cyclones and associated cold fronts, and NW winter monsoon are encountered very frequently in the North Pacific, especially in the northwest part of it. The two sea areas, namely, the northwest part of North Pacific, especially the eastern area far off Japan east coast, and Burmuda Triangle in the North Atlantic are generally known as two of the most dangerous areas in the world because of high incidence of sea casualties. Even large ocean going vessels were sunk frequently due to strong winds and very high seas caused by NW monsoon or developed cyclones during the winter months. The purpose of this paper is to analyse the real state of heavy weather and high sea phenomena on the vesscls at sea, thus helping mariners operate in such conditions.

• Animal Systematics, Evolution and Diversity
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• v.33 no.4
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• pp.274-277
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• 2017

A sea star was collected from the Korea Strait in the waters adjacent to eastern Jeju Island, Korea ($33^{\circ}39^{\prime}86^{{\prime}{\prime}}N$, $127^{\circ}33^{\prime}12^{{\prime}{\prime}}E$) at a depth of 92 m on November 5, 2016. This specimen was identified as Marginaster paucispinus Fisher, 1913, from the family Poraniidae of the order Valvatida, based on morphological characteristics. The genus Marginaster Perrier, 1881 and M. paucispinus, which were first reported in the South China Sea, are new to the Korean fauna. Partial sequences of mitochondrial COI and 16S ribosomal RNA of M. paucispinus were have been determined for the first time and were deposited in GenBank. They are the first molecular records for the genus Marginaster.

• Ocean and Polar Research
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• v.25 no.2
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• pp.155-182
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• 2003

An annotated listing of bivalve mollusks collected at 31 sampling sites in Yeongil Bay (eastern coast of Korea) at a depth of 0-52m is presented here. A total of 98 species belonging to 75 genera and 36 families are enumerated; all species are provided with habitat data (bathymetric distribution and bottom sediments character), given separately far living and dead (empty shells) specimens, and some with taxonomic and zoogeographic comments. Fifty-six species are illustrated with photographs. Astarte hakodatensis Yokoyama, 1920 (Astartidae), Nitidotellina pallidula (Lischke 1871) (Tellinidae) and Lyonsia nuculanoformis Scarlato in Volova et Scarlato, 1980 (Lyonsiidae) are found to be new to the Korean fauna, and the genus Salaputium Iredale, 1924 (Crassatellidae) with one species Salapurium Iredale, 1924(Crassatellidae) with one species Salaputium cf. unicum Hayami and Kase, 1993, previously described as being found only from submarine caves in the Ryukyu Islands, is recorded as being found in the East Sea(Sea of Japan) for the first time.

• Ocean Science Journal
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• v.42 no.2
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• pp.81-88
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• 2007

The paper reviews data available on euglenophycean algae of the genus Eutreptiella from the Russian waters of East/Japan Sea. Five species (such as E. braarudii, E. eupharyngea, E. gymnastica, E. cf. marina, and E. pascheri) were identified in our study. E. cf. marina and E. pascheri were found for the first time in the fare astern seas of Russia (including East/Japan Sea, Bering and Okhotsk seas). Morphological descriptions of species are based on light and electron microscopical studies and supplied with information on ecology and distribution. Original micrographs of these species obtained by light and electron microscopy are presented. It was established that E. eupharyngea, E. gymnastica, and E. pascheri cause water "blooms" in spring and summer in eutrophic coastal areas of Peter the Great Bay (East/Japan Sea), where their cell concentrations at these periods exceed $1\times10^6\;cells\;l^{-1}$.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.21 no.2
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• pp.99-104
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• 1985

In order to provide the basic data required for setting up the proper strategies to minimize the future marine pollution in the vicinity sea area of the Geoje Island, the general water quality parameters and dye diffusion experiment were carried out from January to March, 1983. Although TSS and COD level in the investigated sea area showed still slightly lower than the area of Seaside Industrial Complex Zones, seriously increasing due to the construction of heavy industrial plants. Dissolved oxygen showed more than 8 ppm, and inferred still enough for the reservation of the investigated sea area. The dye patches moved south-eastward with forming an elliptical shape and then turned slowly to the area of Kujora during flood tide, and it moved northwestward and then blocked the entrance of Jangseungpo during ebb tide, The diffusibility in the area may be assessed to be quite better than other coastal areas.

• Journal of Environmental Science International
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• v.27 no.12
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• pp.1291-1298
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• 2018

Marine ecosystems are frequently exposed to a variety of chronic and acute pollutants derived from anthropogenic production and consumption activities. Mussels are sessile (can provide location-specific information), medium-sized (have enough tissue matrix for chemical analysis) filter-feeders (show accumulation of pollutant chemicals from seawater). These biological and ecological characteristics make mussels virtually ideal for pollution monitoring. In this study, Korean mussels (Mytilus coruscus) were collected from nine different sites situated along the coasts of the western sea to the eastern sea of Korea in 2017. Total mercury concentration was highest (mean ${\pm}$ standard error, $92.7{\pm}3.5ng/g\;dry$) on Baengnyeongdo Island in the western sea, and the sites in the southern sea showed the lowest mean concentrations (42.3 - 44.5 ng/g dry). These results were discussed in terms of possible pollution sources.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.5
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• pp.644-650
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• 2023

We examined the effects of serotonin on the spawning response, sperm motility, and D-shaped larva production in Eastern Gooeyduck clam Panopea sp. based on the sperm densities at fertilization and washing after mixing the eggs and sperm. The highest spawning induction was found showed in females and males injected with 1 mL of 2 mM serotonin. The spawning responses in females and males were higher at concentrations greater than 1 mM and 0.75 mM, respectively. Regarding the activities of sperm in sea water after serotonin injection, the sperm showed activity at >90.0% until 120 mins. We also examined the effects of sperm concentration at the fertilization and washing times after mixing the eggs and sperm. We confirmed that washing within 1 minute at a concentration of 1,500 sperms/mL or less can prevent egg destruction by polyspermy and secure a large number of D-phase larvae. These results should be useful for developing the aquaculture process for Eastern Gooeyduck clam, Panopea sp.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.3
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• pp.190-199
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• 2008

To investigate hydrographic structure and characteristics of the tropical ocean in the eastern and the western Pacific, CTD(Conductivity-Temperature-Depth) data along $131^{\circ}W$ and $137^{\circ}-142^{\circ}E$ in July-August 2005 were analyzed. Sea surface temperature along $131.5^{\circ}W$ in summer is highest in the Equatorial Counter Current(ECC) because of the high-temperature water greater than $28^{\circ}C$ moving through the ECC from the western Pacific to the eastern Pacific in spring and summer. Based on the evidence of the presence of low salinity and high dissolved oxygen water in the North Equatorial Current(NEC), we suggested that the low salinity water moved from the Gulf of Panama to the east of Philippine along the North Equatorial Current(NEC). The South Equatorial Current(SEC) had the most saline water from surface to deep layer because the saline water from the Subtropical South Pacific Ocean moved to the north. The salinity minimum layer was observed at 500-1500 m depth along $131.5^{\circ}W$. The water mass with the salinity minimum layer in the north of $5^{\circ}N$ came from the North Pacific Intermediate Water(NPIW) and that in the south of $5^{\circ}N$ came from the Antarctic Intermediate Water(AAIW), which was more saline than the NPIW. Cyclonic cold eddy with a diameter of about 200km was found in $4-6^{\circ}N$. Sea surface temperature along $131.5^{\circ}W$ in the eastern Pacific was lower than along $137^{\circ}-142^{\circ}E$ in the western Pacific; on the other hand, sea surface salinity in the eastern Pacific was higher than in the western Pacific. Subsurface saline water from the Subtropical South Pacific Ocean was less saline in the eastern Pacific than in the western Pacific. Salinity and density(${\sigma}_{\theta}$) of the salinity minimum layer south of $14^{\circ}N$ was higher in the eastern Pacific than in the western Pacific.