• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.4
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• pp.213-228
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• 2009

This study was conducted to investigate spatio-temporal changes in macrobenthic community structure and benthic environmental conditions in Geoje-Hansa Bay, which is the greatest oyster producing site in Korea. Field survey for benthic environment and macrobenthos was seasonally carried out at 15 stations covering oyster farming sites and non-farming sites from February to November, 2008. The grain size of surface sediments was dominated by very fine silt with the mean phi of about $9\;{\Phi}$ and TOC was 1.9% on average. Mean dissolved oxygen content was 8.1 mg/L and lowest in August corresponding to the 2nd degree in seawater quality criteria. Total species number was 351 and mean density was $3,675\;ind./m^2$, both of which were dominated by polychaete worms. Spatio-temporal variation in above two biological variables was great with higher values seasonally in spring and spatially in channels rather than inner bay. Dominant species were Lumbrineris longifolia (21.3%), Aphelochaeta monilaris (17.8%) and Ericthonius pugnax(6.1%), all of which are typical species of organically enriched area. From the multivariate analyses, the whole macrobenthic community was distinguished into two groups of channel and inner bay group. Spatio-temporal changes of macrobenthic community in Geoje-Hansan Bay were related to those of TOC and acid volatile sulfide (AVS). Our results showed that Geoje-Hansan Bay should be intermediately affected by organic pollution, and that such organic enrichment was more remarkable at farming stations in the inner bay.

• Proceedings of KOSOMES biannual meeting
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• 2009.06a
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• pp.159-159
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• 2009

• Journal of the korean society of oceanography
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• v.38 no.1
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• pp.17-23
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• 2003

We report the distribution of $^{210}$ Pb and various metallic elements (Al, Fe, Mg, Ca, Ti, Mn, Sr, Ba, Zn, V, Cr, Zr, Ni, Cu, and Y) in the sediment cores from six shellfish-farming bays in the South Sea of Korea. The $^{210Pb}$ inventories in Deukryang, Gwangyang, and Goseong Bay cores were comparable to those expected from the known fallout input. However, the $^{210}$ Pb inventories were two times higher in Jinju, Gangjin, and Hansan-Koeje Bay cores, suggesting an important role of other sources such as fluvial inputs. Based on the enrichment factor analyses, non-detrital fractions of all the measured elements were found to be insignificant. The Mn was highly enriched only in the surface sediments of the Jinju and Goseong Bay, which implies that the surface-sediment environment of these bays is efficiently oxidizing Mn remobilized from either pore waters or bottom seawaters. These data set provides the sources of heavy metal in sediment around shellfish farms and the current level of metallic elements for the future monitoring.

• The Korean Journal of Malacology
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• v.26 no.2
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• pp.107-114
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• 2010

To evaluate the culture conditions in oyster-farming waters, chemical and biological measurements were made in seawater and oysters from six bays around Tongyeong in November and December 2003. Nutrient levels in the seawater were higher in the western area than in the eastern area, in contrast to particulate organic matter and dissolved oxygen levels. The mean total polycyclic aromatic hydrocarbon ({\sum}PAH) content of the oysters was 194.5-375.9 ng/g dry weight, with four-ring compounds constituting 34.1%-79.6% of PAH. Despite wide temporal variations, a "western > eastern" spatial distribution of PAH was apparent. These low concentrations of PAHs indicate that Tongyeong waters are pristine in terms of PAH contamination. Among the hemocytic biomarkers, only lysosomal activity was significantly reduced in Hansan-Goje Bay, but did not correlate closely with PAH content. This finding indicates that the impact of PAH on cultured oysters is negligible around Tongyeong waters.

• Korean journal of food and cookery science
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• v.15 no.1
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• pp.23-36
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• 1999

The purpose of this study was to investigate the kinds of native and prohibitive foods in Hansan-Do area. The kinds of the prohibitive foods and the reason prohibiting those from pregnant or lactating woman, fisherman and sick people were surveyed by using a guestionnaire from 1994 to 1998. The results showed that Chungmu Gimbab was perceived highly as a native foods and the reason for prohibiting specific foods was not based on scientific evidences.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.4
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• pp.395-407
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• 2002

A 3D hydrodynamic-ecological coupled model was applied to estimate a food supply to oysters in Geoje-Hansan Bay where is one of the oyster culturing sites in Korea, In this study, the primary productivity (PP) was adopted as an index of food supply, and the spatial patterns of average chlorophyll a concentration during a culturing seasons from September to May of the following year were simulated by the model, The numerical result showed that PP was high in the inner part of the bay and the adjacent areas of Hwado island, but low in the outer. This result indicates that PP is essentially influenced by anthropogenic nutrient loadings in the system. The model was calibrated using the field data in May which is non culturing season of oysters and a simulated phytoplankton biomass agreed fairly well with the observed data ($R^{2}=0.70$, $RE=10.3\%$). The computed food supply varied from 0.19 to $1.27\;gC/m^{2}/day$ with a mean value of $0.62 gC/m^{2}/day$ from September to May. The highest value was showed in May ($1.27 gC/m^{2}/day$) and the lowest was in February ($0.19 gC/m^{2}/day$).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.13 no.4
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• pp.207-212
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• 1980

Growth rates of oysters at four oyster farms in Hansan-Geoje Bay, near Chungmu, southern Korea, and density-dependent relative shell growth were investigated from November 1979 to May 1980 with the following results: The oysters at Sorang farm showed the best growth, the shell height in May 1980 attaining 10.10 cm, at Hwado 8.69cm and Songdo 8.57cm, all of which started growing in June 1979. At Chubong the oysters which started growing in July attained 8.6cm. The best grown oysters at Sorang shelved relatively slow growth in meat weight until February 1980, and then showed rapid growth upto May. At Hwado and Songdo they grew fast from December 1979 to February 1950, and from April to May 1980. Those at Chubong gradually increased growth rate from December 1979, and in April and May they showed rapid growth but still being smaller than the others. The ratio of meat weight to shell weight increased at Whado, Songdo and Chuhong after December 1979, but at Sorang it increased rapidly after February 1980. The ratio of shell length to shell height was 0.60 and up when the individual number of oysters attached to each cultch-disc(oyster shell) was less than 13, 0.56 to 0.60 when 14 to 25, and 0.51 or less when over 28, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.5
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• pp.471-476
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• 1985

In order to set up a predictive model for effective spat collection of Pacific oyster, Crassostrea gigas, the survival rate and time required at each developmental stage of drifting larvae were surveyed during the period from June 13 to October 16 in 1984 at the main oyster farming area, Hansan Bay, the southern part of Korea. The advent of D-shape larvae ca. $72{\times}61{\mu}m$ long had two peaks in that area : July 16 and September 20. Umbo-shape larvae ca. $189{\times}217{\mu}m$ and full grown larvae co. $303{\times}308{\mu}m$ long also showed two peaks: July 21 and September 25 for the former, and July 28 and September 30 for the latter. About five days were required for D-shape larvae to develop to umbo-shape larvae. The instantaneous death rate was 0.24 and the daily survival rate 0.78 with a mean survival rate of $29.38\%$, at this intermorphological stage. The turnover time of umbo to full grown larvae varied from five to seven days with a instantaneous death rate of 0.15, daily survival rate of 0.86 and mean survival rate of $38.54\%$. Ten to twelve days were required for each group of the D-shape larvae to reach a full grown stage, and their mean survival rate was $11.32\%$ during this developmental period.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.3
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• pp.129-136
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• 2014

This study deals with red tide detection by using the remote sensing imagery from the Geostationary Ocean Color Imager (GOCI), the world's first geostationary orbit satellite, around the southern coast of Korea where the most severe red tide occurred recently. The red tide zone was determined by the available data selection from the GOCI imagery during the period of red tide occurrence and also the severe red tide zone was detected through the spatial analysis by temporal change out of the red tide zone. This study results showed that the coast in the vicinity of the Hansan and Yokji in Tongyeong-si was classified into the severe red tide zone, and that the red tide was likely to spread from the coast of Hansan and Yokji to the one of Sanyang-eub. In addition, the comparative analysis between the area of red tide occurrence, the prevention activities of Gyeongsangnam-do provincial government and the amount of the damage cost over time showed close correlation among them. It is still early to conclude that the study is showing the severe red tide zone and the spread path exactly due to various factors for red tide occurrence and activities. In order to improve the reliability of the results, the more data analysis is required.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.1
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• pp.11-20
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• 2010

Oyster production is playing an important role in domestic aquaculture, but facing some problems such as exports decrease, a slowdown in domestic demand and marine environmental deterioration. In order to obtain the suitable and sustainable oyster production, suitable sites selection is an important step in oyster aquaculture. This study was conducted to identify the suitable sites for lunging culture of oyster using Geographic Information System(GIS)-based multi-criteria evaluation methods. Most of the parameters were extracted by Inverse Distance Weighted(IDW) methods in GIS and eight parameters were grouped into two basic sub-models for oyster aquaculture, namely oyster growth sub-model(Sea Temperature, Salinity, Hydrodynamics, Chlorophyll-a) and environment sub-model(Bottom DO, TOC, Sediment AVS, Benthic Diversity). Suitability scores were ranked on a scale from 1(leased suitable) and 8(most suitable), and about 80.1% of the total potential area had the highest scores 5 and 6. These areas were shown to have the optimum condition for oyster culture in GeojeHansan Bay. This method to identify suitable sites for oyster culture may be used to develop bivalve culture management system for supporting a decision making.