• ALGAE
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• v.18 no.1
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• pp.49-58
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• 2003

The short-term dynamics of the summer phytoplankton community structure were investigated in coastal waters around Namhae Island, the Southern Sea of Korea. The study was based on a comprehensive survey constituting 39 collections from 13 stations on July 18-22, August 1-2, 14-16 and 27-30, respectively. The community structure was analysed using cluster analysis and important environmental correlates of the assemblage structure were identified with canonical correspondence analysis (CCA). Water temperature, salinity, NO₂, NO₃, NH₄, PO₄, chlorophyll a and transparency were measured as physico-chemical environmental factors which may be associated with the phytoplankton community structure. Variations of salinity and concentrations of NO₃ and chlorophyll a were not significant. In addition to warmer water temperature, concentrations of NO₂, NO₄and PO₄ decreased at the beginning of August. And transparency was deeper and water column became very unstable after the middle of August. A wide taxonomic diversity was encountered during the survey, including a total of 121 taxa which was composed of 72 diatoms, 48 dinoflagellates and 1 euglenoid species. Cluster analysis showed that the Phytoplankton community could be divided into 4 distinct groups, indicating rapid changes of the community in the short course of this survey. These phytoplankton groups also showed distinctive dispersion patterns in 2-dimensional canonical space, indicating distinct groupings for stations at each survey. Dominant taxa of diatoms (Chaetoceros curvisetus, Chaetoceros spp., Leptocylindrus danicus, Leptocylindrus mediteraneus, Skeletonema costanum, and Pseudo-nitzschia pungen) clustered in region of CCA space corresponding to stations surveyed at the middle of July. Dominant taxa of dinoflagellates were tightly associated with stations surveyed at the middle (Karenia breve) and end (Cochlodinium polykrikoides and Polykrikos schwartzii) of August. The CCA also showed that the phytoplankton community compositions were highly associated with water temperature, transparency, NO₂, NH₄ and PO₄, suggesting that gradients in physical and nutrient conditions affect short-term changes in phytoplankton composition.

• Ocean and Polar Research
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• v.34 no.1
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• pp.53-64
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• 2012

In order to understand the relationship between the formation of hypoxia sediment by eutrophication and changes in benthic foraminiferal assemblage, micropaleontological and geochemical analyses were carried out on one sediment box core (K-1) recovered in the northern Gamak Bay, which is one of the aquacultural areas in the South Sea of Korea. In this analysis, the PON content in the sediment rapidly increased, while the C/N ratio and the C/S ratio decreased since 1977. These results indicate that eutrophication commenced in 1977 in the northern Gamak Bay, and consequently, the hypoxia sediment is 20 cm thick. Ammonia beccarii-Buccella frigida assemblage occurs before the formation of hypoxia sediment. Trochammina hadai-Buccella frigida assemblage appeared in the transitional period toward hypoxia and Trochammina hadai assemblage with a low abundance and diversity is observed in the hypoxia sediment. The agglutinated species T. hadai is regarded as a bio-indicator (opportunistic species) of the organic pollution in northern Gamak Bay.

• ALGAE
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• v.24 no.3
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• pp.139-147
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• 2009

Microalgae using a submersible fluorescence probe in water column (up to 100 m) were measured during the austral summer of 2006 (February) in Prydz Bay, East Antarctica (triangular-shaped embayment in the Indian sector of Southern Ocean). Concurrently, environmental parameters such as temperature, salinity and nitrogen (nitrate, ammonium, urea) uptake rates were measured. The concentration of phytoplankton is relatively high due to availability of high nutrients and low sea surface temperature. Phytoplankton community is dominated by diatoms whereas cryptophytes are in low concentration. The maximum concentration of total chlorophyll is 14.87 ${\mu}g\;L^{-1}$ and is attributed to upwelled subsurface winter water due to local wind forcing, availability of micro-nutrients and increased attenuation of photosynthetically available radiation (PAR). Concentration of blue-green algae is low compared to that of green algae because of low temperature. Comparatively high concentration of yellow substances is due to the influence of Antarctic melt-water whereas cryptophytes are low due to high salinity and mixed water column. Varied concentrations of phytoplankton at different times of Fluoroprobe measurements suggest that the coastal waters of Prydz Bay are influenced by changing sub-surface water temperature and salinity due to subsurface upwelling induced by local winds as also melting/freezing processes in late summer. The productivity is high in coastal water due to the input of macro as well as micro-nutrients.

• Atmosphere
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• v.18 no.4
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• pp.387-395
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• 2008

The impact of horizontal resolution on a regional climate model was investigated by simulating precipitation over the Korean Peninsula. As a regional climate model, the SNURCM(Seoul National University Regional Climate Model) has 21 sigma layers and includes the NCAR CLM(National Center for Atmospheric Research Community Land Model) for land-surface model, the Grell scheme for cumulus convection, the Simple Ice scheme for explicit moisture, and the MRF(Medium-Range Forecast) scheme for PBL(Planetary Boundary Layer) processing. The SNURCM was performed with 20 km resolution for Korea and 60 km resolution for East Asia during a 20-year period (1980-1999). Although the SNURCM systematically underestimated precipitation over the Korean Peninsula, the increase of model resolution simulated more precipitation in the southern region of the Korean Peninsula, and a more accurate distribution of precipitation by reflecting the effect of topography. The increase of precipitation was produced by more detailed terrain data which has a 10 minute terrain in the 20 km resolution model compared to the 30 minute terrain in the 60 km resolution model. The increase in model resolution and more detailed terrain data played an important role in generating more precipitation over the Korean Peninsula. While the high resolution model with the same terrain data resulted in increasing of precipitation over the Korean Peninsula including the adjoining sea, the difference of the terrain data resolution only influenced the precipitation distribution of the mountainous area by increasing the amount of non-convective rain. In conclusion, the regional climate model (SNURCM) with higher resolution simulated more precipitation over the Korean Peninsula by reducing the systematic underestimation of precipitation over the Korean Peninsula.

• Ocean and Polar Research
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• v.24 no.3
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• pp.267-278
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• 2002

This study investigated the spatial characteristics of warming trends and the dipole-like pattern of temperature field in the Antarctic Peninsula using surface air temperature (SAT) of 10 stations in the vicinity of the Antarctic Peninsula. SAT data for the 1962-2001 period at 6 stations (Rothera, Faraday/Vernadsky, Bellingshausen, Orcadas, Esperanza, Halley) revealed in general the larger warming trends in autumn and winter except for Halley. The largest warming was shown for August in the west side of the Peninsula (more than $0.9^{\circ}C/decade$). On the other hand, the recent 14-year SAT data showed the strong warming trends at 9 stations except for Halley in the earlier period (April-June) than August for the 1962-2001 period. The largest warming appeared in May at Esperanza and Butler Island. SAT of the two sides showed significant positive correlations over most of the period except for the mid- and the late 1970s, in which significant negative correlations were found. In the correlation analysis between SAT and sea surface temperature (SST) anomalies in the NINO 3.4 region, strong negative correlation was found in the west side of the Peninsula. Details of the correlation analysis exhibited that the negative correlation was significantly strong from the early 1980s to the mid-1990s. However, it was difficult to find significant correlations of ENSO with SAT in the east side of the Peninsula. So, in this study it failed to find out clearly the out-of-phase relationship of SAT across the Antarctic Peninsula.

• Journal of Conservation Science
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• v.4 no.1 s.4
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• pp.3-10
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• 1995

This study focused on the reconstructional point of Shinan ship-wreck that was excavated between $1976\~1984$. The wreck, which might be sunk in the beginning of the 14th century, is regarded as a vessel of Yuan dynasty, China. This paper tried to find out some structural characteristics and principal dimensions for restoration. The Shinan shipwreck's structural characteristics are summarized as follow, 1) The Shinan shipwreck is formed V-shaped cross section with bar keel, 2) The vessel is divided 8 holds by 7 bulkheads. 3) The ship has flat type stem and transome stern. 4) A rabbeted clinker -built is basically adopted on planking joint. 5) A wooden sheathing, which means a sort of protecting board against marine insects, is covered outside of the main hull, 6) For making an watertight structure, oakum and lime mixtured t'ung-oil are used along the seam of planking and bulkhead. 7) A V-shaped deep water-way exists at both deck side. 8) The shipwreck is believed to have 2 masts at least. 9) The shiptimbers are classified as Chinese Red Pine(Pinus Massonina) which is mainly grown in the southern part of China. Considering as mentioned above the structural characteristics, Shinan ship-wreck could be classified as Chinese Fu-chuan type(복선형) of sea-going ship. The Shinan ship's principal dimensions which are calculated on the basis of Chinese traditional shipbuilding custom, are as follow, Length overall(L.O.A). : 34.80m Length water line(L.W.L) : 24.90m Breadth(B.max.) : 11m Breadth(B) : 10m Depth at keel line(H) : 3.75m Draft(D). : 3.15m Freeboard(F) : 0.65m Ratio, length/breadth(L/B). : 2.26 Ration, breadth/depth(B/D) : 3.5 Height of stem : 7m Height of stern : 10m Displacement : ab.340ton.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.5
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• pp.454-459
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• 2012

To investigate heavy metals (Hg, Pb and Cd) and their potential health risks in commercial dried laver (Porphyra sp.), we collected 45 samples from the major production areas on the western and southern coasts of Korea (Hwaseong, Seocheon, Gunsan, Muan, Shinan, Jindo, Haenam, Wando, Jangheung, Goheung and Busan). The Hg, Pb and Cd concentrations were measured using inductively coupled plasma spectrometry (ICP-MS) or a mercury analyzer. The average Hg, Pb and Cd concentrations in the dried laver were $0.006{\pm}0.0017$, $0.196{\pm}0.0614$ and $0.894{\pm}0.4882$ mg/kg, respectively. Based on the 2007 Korean Public Nutrition Report, these levels are 0.02, 0.11 and 2.47% of the provisional tolerable weekly intake (PTWI) for Hg, Pb and Cd, respectively, established by the FAO/WHO. The hazard quotient (HQ) determined from the ratio of exposure and safe levels were less than 1.0. Therefore, the levels of overall exposure to Hg, Pb and Cd for dried laver were below the recommended JECFA (Joint FAO/WHO Expert Committee on Food Additives) levels, which indicate safe levels for public health.

• The Korean Journal of Malacology
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• v.20 no.2
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• pp.131-134
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• 2004

Growth and spawning of Crassostrea rivularis inhabited in estuary of Gahwacheon, Sacheon, Gyeongsangnam-do, Korea were investigated from June 1995 to August 1996. The shell height of two-year oyster ranged from 56.7 ${\pm}$ 4.8 mm in October to 87.7 ${\pm}$ 24.6 mm in June, and that of three-year oyster was from 123.0 ${\pm}$ 24.7 mm to 133.2 ${\pm}$ 10.5 mm. Condition factor was in a range from 0.0409 ${\pm}$ 0.0138 (October) to 0.0732 ${\pm}$ 0.0267 (July), and it began to increase in December. It reached the maximum in July, then decreased rapidly thereafter. The spawning period was determined to be July and August on the basis of monthly changes in condition factor and relative growth of meat weight to shell weight.

• The Korean Journal of Malacology
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• v.20 no.2
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• pp.171-181
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• 2004

Partial sequences of the mitochondrial cytochrome oxidase subunit Ⅰ(mtCOI) gene of veneroid clams were obtained to eluciadate molecular phylogeny. A total of nine veneroids and one corbiculid were collected from southern and western sea of Korea. The mtCOI sequences of the clams obtained from the present study and three veneroids sequences from GenBank were analyzed by maximum parsimony and neighbor-joining methods. The subfamilies Samarangiinae, Dorsiniinae, Cyclinae, Meretricinae and Chioninae were monophyletic, but Pitarinae was paraphyletic. One transitions and two transversions among two samples of Ruditapes philippinarum and a R. variegata were observed.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.1
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• pp.10-15
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• 2000

Goals, research direction, and operational structure of the Global Ocean Ecosystem Dynamics (GLOBEC), which is co-sponsored by the Scientific Committee on Oceanic Research (SCOR) and the Intergovemmental Oceanographic Commission (IOC), are described. Following the Joint Global Ocean Flux Study (JGOFS) activities on the lower trophic level in ecosystem during 1980s-90s, scientists have considered the responses of the mid and higher trophic levels to the environmental or climate change. The scientific steering committee of the GLOBEC published the implementation plan in 1999, and the IGBP will support the GLOBEC as one of its core projects for 10 years. The GLOBEC programme has four major components: the research foci, framework activities, regional programmes, and integrating activity. The core of GLOBEC research is the four research foci: retrospective analyses, process studies, predictive and modelling capabilities, and feedbacks. Currently, four regional programmes have been undergoing in the world ocean: Southern Ocean GLOBEC (SO-GLOBEC), Small Pelagic Fishes and Climate Changes (SPACC), Cod and Climate Change (CCC), and Climate Change and Carrying Capacity (CCCC). Also, national GLOBEC programmes were already established in 9 nations.