• Fisheries and Aquatic Sciences
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• v.3 no.2
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• pp.97-110
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• 2000

To investigate characteristics of water masses and current structures around Noto Peninsula located in south-east coastal region of the East Sea, observation results of CREAMS (Circulations Research of the East Asian Marginal Seas) cruise and data report of oceanographic observation (Japan Meteorological Agency) in June, 1995 and 1996 were used. Water mass showing characteristics of Tsushima Warm Current (TWC) exists over the continental shelf. The depth is shallower than 200m and its width and thickness are 190km and 200m, respectively. Minimum level of dissolved oxygen occurred at the layers of maximum salinity. In the current structure, a noteworthy phenomenon is that the positions of the high-salinity water (more than 34.6 psu) match well with the distributions of the southwestward flow. In June of 1995 and June of 1996, a southwestward flow were separated into two parts along line C and line G. Current directions derived from the temperature and salinity match well with the distributions of the geostrophic currents in the vertical sections. The isothermal lines and the isohaline, which exist horizontally along the coastal area of the Japan, change abruptly at the frontal area of the Noto Peninsula, then turn toward the center of the East Sea. The dynamic depth anomalies centering around the region far northwest of the Noto Peninsula were relatively high, compared to those of other regions. The isopycnic surface (sigma-t, 25.8) existed near the surface in the central part of the East Sea, but, at the depth of 100m, the isopycnic surface was found in the coastal waters.

• Ocean and Polar Research
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• v.36 no.3
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• pp.277-288
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• 2014

The Korean government is considering the implementation of a project to develop a deep-sea human-operated vehicle (HOV) to improve the level of deep-sea research. Information on the scientific benefits from the project is urgently needed in order to come to a decision about whether to implement the project. This paper measures the conservation value of developing nine attributes associated with HOV by using the choice experiment (CE). A survey of about 356 experts was undertaken and 132 experts completely responded to the survey. To deal with the CE data from the survey, we employed a multinomial logit model. All the coefficient estimates are statistically significant and consistent with prior expectations. Therefore, we can judge that the respondents' works required in the CE survey were within their cognitive abilities and they reported responsible and significant values. Each marginal willingness to pay for each attribute associated with the HOV is statistically significant and provides good information on the scientific values with regard to developing the HOV. The results can be utilized in evaluating and planning several alternatives related to developing the HOV.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.5
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• pp.556-565
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• 2018

The age and growth of butter clams Saxidomus purpuratus were estimated using transmitted light on the shells of 364 samples from January 2017 to December 2017 in Jinhae Bay. Based on monthly variation in the marginal index (MI) of the shell, it is assumed that rings are formed once a year during the period from July to August in this species. The relationship between shell length (SL; mm) and shell height (SH; mm) was expressed by the equation SH=0.8053SL-2.9636 ($R^2=0.94$) and between SL and shell width (SW; mm) by the equation SW=0.5648SL-3.7105 ($R^2=0.90$). The relationship between SL and total weight (TW; g) was expressed by the following equation: $TW=0.00009SL^{3.2141}$ ($R^2=0.96$). von Bertalanffy's growth parameters were estimated using the regression wizard in the SigmaPlot computer program (Systat Software, Inc., v. 10.0). The maximum shell length ($SL_{\infty}$) was 126.16 mm, growth rate was 0.2030/year, theoretical age at shell length 0 ($t_0$) was -0.52 years, and asymptotic total weight ($TW_{\infty}$) was 509.17 g. Growth curves for SL and TW fitted to the von Bertalanffy's equation were expressed as follows: $SL_t=126.16(1-e^{-0.2030(t+0.52)})$, $TW_t=509.17(1-e^{-0.2030(t+0.52)})^{3.2141}$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.5
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• pp.618-623
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• 1999

A relationship between SST (Sea Surface Temperature) fronts and formation of fishing grounds was examined using the data on fishing conditions obtained from 41 Korean purse-seiners during the period of 1991 to 1996. Good fishing grounds observed in the southern sea of Korea and the nothern area of the East China Sea were yearly found around the frontal zone and around the marginal area of Tsushima Current which was the periphery of fronts, Also, there were several fishing grounds, which are not related to the fronts. They can be classified into the following four types : The first type was found in the warm water pocket located in the western area of Cheju Island in winter. The second type was made in a intensive bending of isobathytherm with a higher temperature in the main stream of Tsushima Current between Cheju Island and the Goto Islands in winter. The third type was formed by the topographical vortex motion near the Tsushima Island in winter and spring. The fourth type was found at the area of the reflow Sea Warm Current in southwest sea of Korea between the costal front zone and the Yellow Bottom Cold Waters in summer and autumn.

• Korean Journal of Ichthyology
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• v.18 no.1
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• pp.45-54
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• 2006

Age and growth of the small yellow croaker, Larimichthys polyactis were estimated using right sagittal otoliths of 506 fish specimens from March to December, 2002 and from January to February, 2005 in the South Sea, part of the East China Sea of Korea. Examination of outer margins of the otolith showed that the opaque zone was formed once a year. Marginal increment of the otolith formed annual rings from May and June at the beginning of spawning season. In the relationship between total length and body weight, a multiplicative error structure was assumed because variability in growth increased as a function of the length, and the estimated equation was $BW=0.0044TL^{3.2502}$ ($R^2=0.97$). The relative growth as body weight at total length has significant difference between females and males (P<0.05). For describing growth of the small yellow croaker, Larimichthys polyactis a von Bertalanffy growth model was adopted. The von Bertalanffy growth curve had an additive error structure and the growth parameters estimated from non-linear regression were $L_{\infty}=33.88cm$, K=0.20/year and $t_0=-2.39year$. Growth at age of males and females shows no significant difference (P>0.05). Most examined fish were 1, 2 and 3 years old, although the oldest fish were 7 old for males and 8 for females.

• Journal of fish pathology
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• v.10 no.2
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• pp.137-142
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• 1997

A monogenean gill parasite, Prosomicrocotyla gotoi, and a digenean intestinal fluke. Opecoelus sphaericus, were found from greenilngs (Hexagrammos otakii) captured at the Korean southern sea. P. gotoi was characterized by having two separated frills of opisthaptor and distinguished from P. chirii in testis and clamp numbers. O. sphaericus had three pairs of finger-like marginal appendages on the ventral sucker and the parasite was distinguished from O. nipponicus in the location pattern of testes. These two helminth species were the first recording species in Korea.

• Animal Systematics, Evolution and Diversity
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• v.28 no.1
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• pp.20-28
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• 2012

Two urostylid ciliates, Anteholosticha pulchra (Kahl, 1932) Berger, 2003 and Metaurostylopsis struederkypkeae Shao et al., 2008, new to Korea, were collected from the Yellow Sea and the East Sea, Korea, respectively. They were identified based on live observation and protargol impregnation. Taxonomical characters of A. pulchra are as follows: $190-300{\times}30-55\;{\mu}m$ size in vivo; contractile vacuole located on the left side of the posterior 1/4 of the cell; spherical-reddish granules at cirral bases and around dorsal bristles, somewhat sparsely distributed throughout the cell surface; four frontal and two frontoterminal cirri; four dorsal kineties; caudal cirri absent. Metaurostylopsis struederkypkeae is characterized as follows: $80-110{\times}40-50\;{\mu}m$ size in vivo; caudal cirri absent; two types of cortical granules: type 1, yellow-green arranged along the ventral cirral rows and dorsal kineties; type 2, small and reddish, with an irregular arrangement; four frontal, four to eight frontoterminal, and two to six transverse cirri; five to seven left and three to five right marginal rows. Sequences of small subunit ribosomal DNA were determined from both species, and pairwise distances with their relatives were analyzed.

• 한국석유지질학회:학술대회논문집
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• spring
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• pp.1-11
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• 1997

Thirty one samples from Late Cretaceous and Tertiary interval sections (468-783m) of the Kachi-I Well in Block II, Yellow Sea Basin, have been analysed for their terrestrially derived palynofloras. The systematic study of the palynomorphs recovered has yielded one hundred and fifty-five taxa; forty-three species of spores belonging to twenty-eight genera, seventy-seven pollen assignable to forty-three genera, and twenty-seven species assignable to fifteen genera and eight fungal remains. The results of both qualitative and quantitative analysis propose a succession of eight terrestrial palynomorph associations. Seven associations are erected in Late Maastrichtian and one in Early to Middle Miocene. Age determinations are on the basis of palynomorph taxa alone for the all associations. The Late Cretaceous/Tertiary unconformity is recognised at between 603 and 613m, based on the palynological data. The sedimentary basin during the Late Cretaceous seem to be lowland shallow marginal lacustrine with stagnant, mesotrophic conditions. On the other hand, the basin during the Early-Middle Miocene is considered to have been characterised by lowland swamp areas. The palaeoclimatic conditions during the Late Cretaceous are considered to be humid tropical to subtropical, while during the Early to Middle Miocene they are considered to be warm temperate with humid conditions. A comparison of palynomorph assemblages between the present study and the previous studies of Late Cretaceous in Circum-Pacific Northern Hemisphere is made, These assemblages reveal that lower sections (612-783m) of the Kachi-I well belong to the Late Cretaceous Aquilapollenites province of Herngreen and Chlonova (1981) and Srivastava (1981, 1994).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.6
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• pp.650-655
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• 2019

The age and growth of Muraenesox cinereus collected in the South Sea of Korea by Danish seine and coastal Long-line fisheries were determined from right sagittal otoliths between May 2018 and April 2019. Otoliths of 353 fish were observed under reflected light, and the edges of the opaque zone were considered to be the otolith ring. Monthly changes in the marginal index indicated that rings (opaque zones) were formed once a year from June to July. The estimated von Bertalanffy growth equation with growth parameters estimated from non-linear regression were L_t=138.37 (1-e^{-0.18(t+0.79)}) for females and L_t=99.00 (1-e^{-0.13(t+3.99)}) for males. The oldest female M. cinereus was 12 years old, and the oldest male was 8 years old.

• Journal of the Korean earth science society
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• v.33 no.6
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• pp.554-566
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• 2012

High-density temperature and salinity profiles from the successful international Argo project made it possible to reproduce the three-dimensional global ocean state in near-real time, which also increased much attention on the data analysis studies of global ocean. This paper reviewed several important issues on the recent data analysis studies such as systematic biases of XBT (eXpendable BathyThermograph) and Argo data, sea level budget discrepancy between steric height and satellite observed data, heat content change, and the current status of the development of objective analysis fields. This study also emphasized that it is required to carry out very cautious ocean data quality control and understand global-scale ocean variability prior to analyzing the regional-scale ocean climate change, particularly, in the East Asian marginal Seas.