• The Korean Journal of Malacology
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• v.16 no.1_2
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• pp.31-34
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• 2000

A series of rearing experiments have been conducted to determine the growth and survival rate in accordance with body size in closed recirculating sea water system. The abalone, Sulculus aquatilis, spat of 10.24${\pm}$0.85 mm, 0.36${\pm}$0.l g and 24.9${\pm}$1.07 mm 2.07${\pm}$0.57 g in shell length and body weight were used in this study Ranges of water temperature and pH during the rearing period of 90 days were 10.0-24.2$^{\circ}C$ and 7.8-8.2, respectively. Dissolved oxygen during the experiment period was 6.13-7.21 ml/l and inorganic nitrate was 0.68-3.72 $\mu\textrm{m}$ in NH$_4$$\^$+/-N, 0.17-7.79 fm in NO$_2$-N and 0.4-11.52 $\mu\textrm{m}$ in NO $_2$-N, Growth in shell length and body weight of the spat in large group and small group at the end of the experiment were 30.80${\pm}$3.14 mm, 17.98${\pm}$2.61 mm and 3.20${\pm}$0.8 g, 0.36${\pm}$0.1 g, and survival rate of spat in large group and small group at the end of the rearing experiment were 96.0% and 90.0% , respectively.

• Environmental Analysis Health and Toxicology
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• v.22 no.4
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• pp.321-327
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• 2007

4-nonylphenol (4-NP)이 해산어류인 조피볼락, Sebastes schlegeli의 혈장 vitellogenin (VTG), alkaline-labile protein phosphorus (ALPP), calcium(Ca), glutamate pyruvate transaminase (GPT) 및 hepatosomatic index (HSI)에 미치는 영향을 조사하였다. 실험어에 3일간격으로 $estradiol-17{\beta}$ ($E_2$, 5 mg/kg B.W.) 또는 4-NP(0, 10, 50, 100및 200 mg/kg B.W.)을 복강에 2번 주사한 후, 7일째에 채혈과 적출을 통해 혈장과 간장을 수집해 분석이 실시되었다. 대조 실험어에는 용매로 사용된 70% 에탄올만이 투여되었다. $E_2$ 투여 실험어의 혈장 단백질을 전기 영동상으로 분석한 결과 약 170 kDa의 위치에서 짙은 VTG 밴드가 관찰되었으나, 용매만 투여한 대조 실험어의 혈장에서는 동일 밴드가 관찰되지 않았다. 4-NP 투여한 모든 실험어의 혈장 단백질에서는 $E_2$ 투여 실험어와 동일한 VTG 밴드가 관찰되었다. 혈장 ALPP와 Ca 농도도 4-NP 투여 실험어에서 $E_2$ 투여 실험어와 유사하게 증가하였으며, 이들 농도 변화는 VTG 합성과 더불어 증가하는 경향을 나타냈다. 혈장 전위효소인 GPT와 HSI도 $E_2$ 투여 실험어와 유사하게 4-NP가 투여된 모든 실험어에서 급격히 증가하였다. 이상의 결과로부터 연안생태계 내에서 서식하는 어류가 4-NP과 같은 내분비 장애물질(Endocrine Disrupting compounds, EDCs)에 의해 영향을 받는지를 규명하기 위한 생물학적 지표로서 VTG와 더불어 혈장 ALPP와 Ca이 사용가능 할 것으로 판단된다. 또한, 조피볼락과 같은 해산어가 EDCs에 노출되어 VTG가 합성될 때 간장 기능의 손상으로 혈장 전위효소인 GPT가 일시적으로 종가하고 간장도 비대해져 HSI가 높아지는 것으로 판단된다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.3
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• pp.374-384
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• 1999

Benthic marine algal flora and community structure of Yongho-dong area in Pusan, Korea were investigated seasonally in intertidal and subtidal zones by a quadrat method along 5 transect lines from July 1996 to April 1997. In this area, a total of 99 species including 3 blue-green, 13 green, 26 brown and 57 red algae was found. Among them, 33 taxa, together with dominant Ulva pertusa and Corallina pilulifera, occurred throughout the year. Enteromorpha spp. and Ulva spp. vertically distributed in upper and middle zone, while Simphyocladia latiuscula, Chondria crassicaulis, Corallina pilulifera and Sargassum sup. in lower zones. Biomass per unit area exhibited a wide range of variation, from 1,241 g/$m^2$(spring) to 1,648 g/$m^2$(summer) in fresh weight. Maximum and minimum species diversity were recorded in spring and autumn, respectively. Results of the UPGAM cluster analysis suggest that the examined 5 sites can be divided into two groups, sites exposed to open sea (transects 1, 2, 3) and comparatively sheltered sites (transects 4, 5) faced with the Pusan Harbor. The former group is represented by large brown algae, Sargassum and Hizikia, while Ulva pertusa and Lomentaria species are mainly found in the latter group. A calcareous alga, Corallina pilulifera occurred dominantly in both groups throughout the year. In conclusion, number of species in this area was remarkably reduced as compared to the previous data. This result may suggest probably more change of algal vegetation in future, considering the physical and chemical pollutions loaded in the coastal marine environment of this area.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.1
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• pp.68-80
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• 1984

Garolim Bay is not only important fishing ground but also expected area for the tidal power plant. The construction and operation of tidal power plant will make change the ecosystem of this bay. Therefore, the actual fisheries stocks should be precisely understood for the effect estimation and overall utilization of the bay after the construction of the tidal power plant. During the study period from January through December in 1981, forty-six adult fishes species, 3 species of fish egg and 25 fishes larvae species have occurred in the bay. Considering the result on monthly distribution of eggs and larvae, the inner area of the bay seems to be important as nursing ground of larvae spawned at the outside bay in winter, e. g., Ammodytes personatus, and Enedrias sp. This inner bay is also major spawning ground for many species spawning in spring and summer, e. g., Gobiidae, Konosirus punctatus, Engraulis japonica, etc. Taking into consideration the annual mean production for three years($1978{\sim}1980$), there are two major fishing seasons. The one is in May-June for Enedrias larvae stock, and the another in October-November for big eyed herring stock. For the mariculture stocks, short necked clam, oyster and laver are important species. After construction of the tidal power plant, the migratory species, i. e., larvae of Enedrias and Ammodytes personatus, Mugil cephalus, Konosirus punctatus, etc. will be directly damaged by the interuption of migration route. On the otter hand, the change of physico-chemical factors of seawater will also affect the ecosystem of the bay. Consequently, for the overall utilization of the bay after construction, the actual ecosystem including the fisheries stocks, must bs precisely revealed, and the mechanical designs, e. g., sluice position and its demension, should be also considered with these biological characters of the bay.

• Korean Journal of Ichthyology
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• v.20 no.3
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• pp.190-197
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• 2008

Spatio-temporal distribution of eggs and larvae of Japanese anchovy Engraulis japonica in the southern sea of Korea was determined using data obtained from icthyoplanktonic surveys and oceanographic observations between Goheung Peninsula and Goeje Island from May to August 2007. Commercial anchovy catch and size composition from four local fishery cooperative associations were also analyzed in relation to the geographic distribution of eggs and larvae. The abundance of anchovy eggs increased from May to July and was lowest in August. Eggs were mainly distributed between Namhae Island and Goeje Island, where water temperatures were $15{\sim}24^{\circ}C$ and salinities were 32~35‰. In 2007 anchovy landings between Namhae Island and Goeje Island were 11,409 tons at Tongyeong association, 4,137 tons at Masan association, and 2,487 tons at Sacheon association. However, landings between Goheung and Yeosu Peninsula were only 4,411 tons (at Yeosu association). The catch by anchovy tow net was high in the area where eggs were abundantly distributed. This indicates that the distribution of egg density was directly correlated with recruitment of E. japonica. All growth stages were abundant in the study area, indicating that this area is a major spawning and growing ground of E. japonica in Korean waters.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.1
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• pp.47-55
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• 2005

Seasonal variations of remineralization and inorganic nitrogen removal capacity were measured from Dec. 2001 to Apr. 2004 in a tidal flat located in south-western pan of Gwanghwa island, Korea by measuring the sediment oxygen demand (SOD) and denitrification. SOD was higher in muddy sediment (Dong-Mak; three year average=$683;m^{-2}d^{-1}$) than sandy sediment(Yeocha; three year average=$457;m^{-2}d^{-1}$). The SOD was high in summer and tended to be lower in winter. During the sediment incubation in Apr. 2002, production of oxygen from sediment was observed implying active benthic photosynthesis. Denitrification was also higher in muddy sediment (Dong-Mak: $5.4;m^{-2}d^{-1}$) than sandy sediment (Yeocha; $3.4;m^{-2}d^{-1}$). The denitrification rate corresponds to the carbon remineralization rate of 9.3 and $5.9\;mg-C\;m^{-2}d^{-1}$ in Dong-Mak and Yeocha, respectively. The denitrification rates were lower compared to rates observed in other coastal area $(0{\sim}200\;{\mu}mole\;m^{-2}h^{-1})$. Although Kwanghwa tidal flat sediments are replete in organic matter, remineralization activity seems to be limited by the availability of labile organic matter. The Kwangwha tidal flat may have potential to effectively remove large load of organic matter. Net remineralization rates were 196 and $132\;mg-C\;m^{-2}d^{-1}$ in Dong-Mak and Yeocha, respectively.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.4
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• pp.159-168
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• 2015

Forty-four surface sediments from Doam Bay were analyzed for total organic carbon (TOC), total nitrogen (TN), total metal (Al, Fe, Mn, Cr, Cu, Ni, Pb, Zn) and further chemical partitioning of metals were carried out in some samples. The TOC (0.32~3.10%) and TN (0.03~0.26%) values of the samples were similar to those of other coastal area. The C/N ratios ranged from 7.9 to 11.9 with an average 9.3 which revealed that contribution of terrestrial organic matters was relatively rare. Contents of analysed metals showed a level lower than threshold effects level (TEL) in sediment quality guidelines. Based on the chemical speciation of metals, the lattice fractions were found in the order Cr > Cu > Ni > Zn > Pb > Mn, while Mn and Pb are the ratio of the non-lattice fractions accounted for more than 50%. The average baseline values were obtained relative cumulative frequency curves and linear regression analysis. The respective baseline concentrations for Cu, Ni, Pb, Zn, Cr and Mn were 11.8, 23.1, 26.8, 76.6, 56.7, 585 mg/kg, respectively. Based on geoaccumulation index ($I_{geo}$) with a baseline values of Mn showed that face the contamination phase from estuarine stations. However, in case of Zn and Pb, although there is no sign of contamination, it could be release from sediment when there is a change in the environment, which is caused from the high ratio of non-lattice fractions.

• Korean Journal of Ecology and Environment
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• v.33 no.4 s.92
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• pp.342-349
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• 2000

This paper demonstrates the influence of intensity of the monsoon on morpho-hydrological fluctuations in Taechung Reservoir during 1993${\sim}$1994. During the study, hydrological variables including rainfall, inflow, and discharge volume showed distinct contrast between 1993 and 1994. Interannaul differences in rainfall occurred during the monsoon in July${\sim}$August monsoon and influenced inflow, discharge, and water residence time (WRT). Total inflow in 1993 was four times greater than that of 1994, and summer inflow in 1993 was 8 times greater than summer 1994. Annual Mean WRT was 93.2 d in 1993 vs. 158.6 d in 1994 and the largest differences occurred between monsoons of 1993 and 1994. Morphometric variables reflected the interannual contrasts of hydrology, so that in 1993 surface area, total volume, shoreline development, and mean depth increased consistently from premonsoon to postmonsoon and over this same period in 1994 they decreased. This outcome indicates that the area of shallow littoral zones in 1993 was greater than in 1994. Also, the drainage area to surface area (D/L) at 80 m MSL was 60.7 which was much greater than values in Soyang and Andong reservoirs and natural lakes world-wide. The morpho-hydrodynamic conditions seemed to influence in-reservoir nutrient concentration which is one of the most important factors regulating the eutrophication processes. I believe, under the maximum hydrodynamic fluctuations in Korean waterbodies during the monsoon, applications of mass balance models to man-made lakes for assessments of external loading should be considered because the models can be used under the seasonally stable inflow and water residence time.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.20 no.2
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• pp.83-90
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• 1984

The secular fluctuations of catches and fishing grounds of mackerals and the oceanographic conditions for the fishing grounds are examined by using the data of catches of mackerals by middle and large class purse-seiner during 1951 to 1981 and those of oceanographic observation carried out by Japan Meteorological Agency. The results are as follows; The fishing grounds of mackerals are respectively distributed at northeastern and southwestern areas from the central part of the East China Sea through every season of the studied years: 1968, 1974 and 1980. The narrow belt type of fishing grounds were formed inside of the Kuroshio in spring and winter of the three years. In summer mackeral species move northward and the fishing grounds are formed in the southern sea of Korea. In winter, however, mackeral species move southward and the fishing grounds are appeared in the Tsushima Current region. The dispersion of fishing grounds is generally larger in summer and smaller in spring, and especially it is the largest in summer in 1980. It seems that the concentration and dispersion of fishing grounds are related to the depth of thermocline and the position of horizontal temperature gradient in this area.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.5
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• pp.614-619
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• 1996

Seasonal of gen consumption of surfclam, Mactra veneriformis in Kunsan coastal area had been measured under seasonal ambient temperature condition from January to December 1994. Samples were collected monthly and divided into two groups by shell length of 2 cm (1 year class) and 3 cm (2 year class). The effects of temperature $(15,\;20\;and\;25^{\circ}C)$ and salinity $(10,\;20\;and\;30\%_{\circ})$ showed that oxygen consumption decreased with the lower temperature and salinity. Seasonal changes of oxygen consumption in surfclam varied with ambient temperature; it was showed below $0.5mg{\cdot}g^{-1}{\cdot}h^{-1}$ winter season and $1.93\~2.44\;mg{\cdot}g^{-1}{\cdot}h^{-1}$ in summer season. The difference of oxygen consumption in two groups was appeared markdly in summer season. The relationship between oxygen consumption and the seasonal ambient temperature were obtained exponential equation as $Y=e^{-1.6312+0.0879X}$ for 2 cm group and $Y=e^{-2.2366+0.0994X}$ for 3 cm group. The slop of regression line between two groups was not significant, and so there was no difference in patterns of the oxygen consumption between two groups.