• 한국해양학회지
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• v.30 no.5
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• pp.390-402
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• 1995

Bimonthly sampling was carried out over the period February 1983 to April 1985 at two stations in Kwang-yang Bay, Korea, in order to study the temporal changes of benthic ploychaete communities. In addition, an important focus of the study was the large-scale reclamation and dredging operations that were taking place for industrial purposes during the study period. The muddy station, located on the main channel, showed high mud content (94%), whereas the sandy station, situated on the north channel of Myodo, demonstrated mud content of 42%. At the muddy station, the number of species and individuals were highest in the early sampling stage, but markedly declined in October 1983, and then gradually increased as in the early state. At the sandy station, the number of species highly oscillated during the entire period. The density was affected by the pectinated Lagis bocki showing particulary high density in February 1983 and 1984. However, the high density in the winter time did not occur in February 1985. The analysis of similarities and clusterings between communities were carried out to evaluate temporal changes in community structure. Significant changes occurred during the study period in the community structures at both stations, but each maintained different patterns of species dominance over time. At the muddy station, this transitionary phase was found in October 1983 but in December 1984 at the sandy station. Comparisons with earlier communities suggest that faunal changes in the dominant species composition occurred from Lumbrineris longifolia to Heteromastus filiformis over this time period. The colonization of this opportunistic pioneer, H, filiformis, seems to manifest environmental disturbances in this bay area.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.4
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• pp.315-326
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• 2013

This study investigated the temporal-spatial distribution and variations in water quality parameters (temperature, salinity, pH, DO, COD, SPM, DIN, DIP, silicate, TN, TP, and chlorophyll-a) in the coastal area of Jeju, Korea, adjacent to aquaculture ponds (Aewol-ri, Haengwon-ri, Pyosun-ri, and Ilkwa-ri). Data were collected bimonthly from February 2010 to December 2011. A principal component analysis (PCA) identified three major factors controlling variations in water quality during the sampling period. Aquaculture effluent water led to large changes in nutrient levels. The highest nutrient values were observed during the investigation period. The relatively large increase in organic matter at the sampling stations coupled with sea area runoff events during the summer rainy period. Variation in chlorophyll-a concentration was mainly driven by meteorological factors such as air temperature and rainfall in the coastal areas of Aewol and Haengwon. In the coastal areas of Pyosun and Ilkwa, pollution was caused by anthropogenic factors such as discharge of aquaculture effluent water. High nutrient concentrations at the majority of the coastal stations indicate eutrophication of coastal waters, especially within a distance of 300 m and depth of 10m from drainage channels. Coastal eutrophication driven by aquaculture effluent may be harmful inshore. Events such as eutrophication may potentially influence water pollution in aquaculture ponds when seawater intake is detected because of aquaculture effluent water.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.9 no.3
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• pp.93-105
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• 2004

Spatio-temporal distribution patterns of the major dominant species were assessed from bimonthly monitoring of macrotidal flat in Cheokjeon, Incheon, Korea between September 1990 and July 1992. Overall, macrofauna comprised a total of 111 species, 25,491 inds.136 ㎡. The result of Le Bris index, dominance ranking of the lead-ing species showed that the top 15 species accounting for 74.8% (19,072 inds.) of total density. In Cheokjeon tidal flat, some species were especially habitat-restricted such as genus Nephtys (Annelids; Polychaetes) and Mac-rophthalmus (Crustaceans; Decapods). Based on the density data, the five dominant species were the polychaetes Het-eromastus filiformis, the bivalves Mactra veneriformis and Solen strictus, the brachyurans Macrophthalmus japonicus, the holothuriodeans Protankyra bidentata. The results of one-way ANOVA, mean value of H. filiformis and M. ven-eriformis did not show significant changes with tidal elevation and sediment composition (p>0.05). But, other species (S. strictus, M. japonicus and P. bidentata) showed significant variations (p<0.001). In conclusion, these indicate significant spatial fluctuation with tidal elevation and sediment characteristics in some species.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.2
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• pp.175-187
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• 1997

Benthic community structure was studied in Chinhae Bay during 3 years from June 1987 to May 1990, based on the samples from 12 stations on the seasonal, bimonthly or monthly basis (lim and Hong, 1994a, b). A total of 287 species was sampled with mean density of $1045.5\;ind./m^2$ and biomass of $98.48g/m^2$ during studyperiods. Of these species, there were 91 species of crustaceans $(31.7\%)$, 88 of polychaetes $(30.7\%)$, 56 of molluscs $(19.5\%)$, 22 of echinoderms and 30 of the micellaneous species. Polychaetes were density-dominant faunal group with a density of $824.7\;ind./m^2$, comprising of $18.6\%$ of the total density of the benthic animals. It was followed by molluscs with $14.62\;ind./m^2$ $($14.4\%\;of\;the\;total\;density)$ crustaceans with $50.5\;ind/m^2\;(4.6\%)$ and echinoderms with $13.4\;ind/m^2\;(4.6\%)$. Molluscs were the biomass-dominant faunal group with a mean biomass of $54.62\;g/m^2$. It was followed by polychaetes with $21.74\;g/m^2$ and echinoderms with $6.66\;g/m^2$. Based on community analysis, species richness, diversity and evenness showed decreasing trends toward the inner bay from outer stations, whereas dominance showed increasing. The three most dominant species Lumbrineris longifolia, Paraprionospio pinnata and Theora fragilis had densities over $40\%$ of the total density of benthic organisms in Chinhae Bay. Seasonal changes of benthic communities in the inner bay were high compared to those of the outer bay. It was mainly due to the occurrence of hypoxic condition in the inner area of the bay. Cluster analysis showed that the benthic community could be divided into four stational groups, that is, Group 1, the innermost area, which received the most heavy anthropogenic effects including seawage and waste water, Group II, the central area of the bay, Group III, the transitional area, Group IV, the mouth pan of the bay exposed to the open sea. The areal groups based on the environmental factors coincided with the zonal groups from the species composition. This fact suggests that the overall spatial distribution of macrobenthos in Chinhae Bay was controlled by the sediment organic carbon content of the bay.