• Journal of Environmental Science International
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• v.22 no.6
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• pp.733-744
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• 2013

This study was to investigate characteristics of Seoho watershed in Suwon city. $BOD_5$ and SS were selected due to the one of the important factors of the water qualities. Monitoring was conducted monthly for four years during the non-rainfall time. Also, we have been monitored $BOD_5$, $COD_{Mn}$, SS, TN and TP with two times sampling after the rainfalls. The highest concentrations of $BOD_5$ and SS were observed in downstream compare with upstream and midstream during the non-rainfall time. No change was observed in $BOD_5$ and $COD_{Mn}$ during the non-rainfall time and after the rainfalls. The monitoring result indicated that the concentration of SS was the highest in downstream after the rainfalls. We have collected the samples two times after the rainfalls. The rainfall intensity in first sampling was two times higher than second sampling. TN and TP concentrations were increased with increasing the rainfall intensity at all stream. The ESB (Ecological Score of Benthic macroinverterbrate community) index was used to evaluate the statement of stream. ESB results were identified that the upstream is protected waters and the down and midstream is reformed waters. EBS analysis results indicated that the Seoho watershed was ${\beta}$-mesosaprobic at all stream.

• Journal of the korean society of oceanography
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• v.34 no.4
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• pp.220-230
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• 1999

Four tidal flats, covering two dissipative type beaches and two other tidal mud flats, around Yonaiong-Yongyu Islands, Inchon, Korea were studied in May 1991 to analyze the spatial distribution patterns of benthic communities on macrotidal flats. From the statistical test on spatial patterns of species number, density, and biomass, significant trends were found in species number and biomass. Although quantitative analysis was not performed, the interpretation showed that the variations were ruled out by environmental gradients such as sediment grain size and tidal elevation. The eight communities revealed in this study are as follows: Moerella-Mactra(Group 1), llyoplax-Glycera -Magelona japonica-Magelona sp.-Pe riserrula ( Group 2), Amphiura-Nephtys californiensis-Bullacta-Eohaustorius (Group 3), Leonnates-Heteromastus-Pretankyra-Nephtys polybranchia (Group4), Nephtys chemulpoensis-Macrophthalmus (Group 5), Ceratonereis-Scopimera (Group 6), Haustorioides-Urothoe (Group 7) and Cycladicama-Armandia-Minuspio community (Group 8). Some of these communities were classified into substratum-specific (Group 1 to 3) and tidal elevation-specific communities (Group 4). It was difficult to identify the predominant governing agent in Groups 5,6,7 and 8 because of their presence at extreme types of sediment and at uppermost elevations. Mixed effects seemed to act upon the latter four communities (Group 5 to 8). Based on the number of samples, 60% of the target samples were influenced by substratum properties, 20% by tidal elevation effect and 20% by mixed effect of the two factors. From this, it was concluded that substratum properties serve as the most important factors on soft bottom inhabitants in the area studied.

• Ocean and Polar Research
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• v.34 no.2
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• pp.111-123
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• 2012

To understand the phytoplankton community in the eastern part of the Yellow Sea (EYS), in the summer, field survey was conducted at 25 stations in June 2009, and water samples were analyzed using a epifluorescence microscopy, flow cytometry and HPLC method. The EYS could be divided into four areas by a cluster analysis, using phytoplankton group abundances: coastal mixing area, Anma-do area, transition water, and the central Yellow Sea. In the coastal mixing area, water column was well mixed vertically, and phytoplankton was dominated by diatoms, chrysophytes, dinoflagellates and nanoflagellates, showing high abundance ($>10^5\;cells\;l^{-1}$). In Anma-do coastal waters characterized by high dominance of dinoflagellates, high phytoplankton abundance and biomass separated from other coastal mixing area. The southeastern upwelling area was expanded from Jin-do to Heuksan-do, by a tidal mixing and coastal upwelling in the southern area of Manjae-do, and phytoplankton was dominated by benthic diatoms, nanoflagellates and Synechococcus group in this area. Phytoplankton abundance and biomass dominated by pico- and nanophytoplankton were low values in the transition waters and the central Yellow Sea. In the surface of the central Yellow Sea, high dominance of photosynthetic pigments, 19'-hexanoyloxyfucoxanthin and zeaxanthin implies that haptophytes and cyanobacteria could be the dominant group during the summer. These results indicate that the phytoplankton communities in the EYS were significantly affected by the formation of tidal front, thermal stratification, and coastal upwelling showing the differences of physical and chemical characteristics during the summer.

• Journal of Korean Society on Water Environment
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• v.33 no.6
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• pp.626-639
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• 2017

Based on an ecological monitoring in a Korean stream (Gapyeong), Habitat Suitability Index (HSI) of nine fish species was developed for three physical habitat factors : current velocity, water depth and substrate. The species were chosen based on their abundance and frequency in the fish community of the Gapyeong stream. The Weibull model was used as the probability density function to analyze the distribution and number of each fish species according to the three identified physical factors, which showed good results. This HSI equation has advantages because it statistically expresses habitat preferences of fish species simply and clearly. From that, we can quantitatively deduce the central tendency and variation of environmental factors for fish distribution. The selected fish species showed different preferences for each habitat factor respectively. Although there are some exceptions, the distribution and abundance of individual species of nektonic fish (Zacco koreanus, Zacco platypus, Microphysogobio longidorsalis and Pungtungia herzi) were positively skewed to deep water and fine substrate while riffle-benthic fish (Koreocobitis rotundicaudata and Coreoleuciscus splendidus) were normally distributed at the shallow and coarse substrate zone. It seems that the species showing the positively skewed distribution to the current, Z. koreanus, Z. platypus, M. longidorsalis and P. herzi have adapted themselves to the fast current and have expanded their niche.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.2
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• pp.146-156
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• 2000

Zonation pattern of macro-invertebrate community structure was examined from Okjukpo sandy beach, Taechongdo, Korea. Macrofauna were collected in June 1998 using a can corer from ten stations along one transect. Mean grain size ranged from 1.97 to 2.23${\phi}$ and sediment organic contents ranged from 0.52 to 1.02%. A total of benthic macro-invertebrates comprised 25 species, providing 10,705 individuals and 89.13 g wet weight in biomass. Peracaridean crustaceans such as amphipods and isopods are the most prominant components in this exposed sandy beach. The dominant species were Eohaustorius setulosus (33%), Excirolana chiltoni (26%), Haustorioides koreanus (12%), Platorchestia crassicornis (8%), and Cycladicama cumingii (6%). The zonation patterns by these animals were very similar to those noted by Dahl(1952) and Jo(1990). They are divided into three faunal zones: 1) subterrestrial fringe dominated by a talitrid amphipod Platorchestia crassicornis, 2) midlittoral zone by a cirolanid isopod Excirolana chiltoni, 3) sublittoral fringe by more diverse amphipods communities.

• Journal of Plant Biology
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• v.38 no.4
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• pp.389-398
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• 1995

The species composition and biomass of intertidal benthic algae at 12 widely dispersed stations representative of mid-western coast of Korea were studied. A total of 151 species of marine algae including 19 Cyanophyta, 20 Chlorophyta, 32 Phaeophyta and 80 Rhodophyta is listed. Three species were found at all 12 stations: Sargassum thunbergii, Stylonema alsidii and Gracilaria verrucosa. Biomass per unit area exhibited a wide range of variation, ranging from a low of 41 g dry $wt{\cdot}m^{-2}$ at both Paeksajang and Taechon to a high of 549 g dry $wt{\cdot}m^{-2}$ at Uihangri, the northernmost station of the study area. The latter value is higher than those reported from any other stations in western coast of Korea. Biomass was composed largely of Phaeophyta at nearly every station. Sargassum thunbergii was dominant over the study area. The distribution of Corallina spp., however, is disjunct, since those occur as dominant species in biomass at the northern stations and to a lesser extent at the southern stations, but are nearly absent from the middle part of the study area.

• Journal of Plant Biology
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• v.26 no.4
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• pp.181-190
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• 1983

Seasonal occurrence of benthic algae and changes of subtidal vegetation were studied for their species composition, diversity and biomass during 1982 and 1983 at several selected sites at Juckdo Island (38$^{\circ}$12'N, 128$^{\circ}$32'E), eastern coast of Korea. Three large brown algae which played a role in change of algal vegetation through their great biomass were investigated with regard to their seasonal growth. Large brown algae such as Undaria pinnatifida, Costaria costata, Laminaria japonica, Agarum cribrosum, Sargassum confusum and S. hornerii constitute the major portion of vegetation in this area throughout the year. Algal vegetation in spring time is characterized by dominance of species U. pinnatifida and C. costata, whereas the summer vegetation by S. confusum and S. hornerii. In autumn large brown algae are shedded and only small algae, such as Chondrus ocellatus and Grateloupia filicina, remain. The vegetation in winter is dominated by the growth of U. pinnatifida and C. costata. Monthly changes in mean length and weight of randomly collected U. pinnatifida, C. costata and S. confusum are as follows; U. pinnatifida occurs from December to June and shows their maximum growth during March (120 cm in length, 201 g/individual in wet weight), its maximum growth rate is 1.4 cm/day, 3.3 g/day in this month. The growth season of C. costata is very similar to U.pinnatifida, but their average maximum length(110 cm) and weight (106 g/ind.) are lower than U. pinnatifida. The greatest growth rate is during March (1.8 cm/day, 2.0g/day). S. confusum is present throughout the year and reaches the maximum growth (102 cm, 63g/ind.) in July. Maximum growth rate (1.5 cm/day, 1.2 g/day) occurs also during this month. U. pinnatifida and C. costata show different months of maximum growth evidently during the two year. This seems to be caused by a considerable damage to the local vegetation followed by heavy storm in February 1983.

• Journal of Ecology and Environment
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• v.48 no.1
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• pp.110-119
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• 2024

Background: The Mae Kha Canal is one of Chiang Mai's most important waterways. It supports local agriculture, irrigation, and transportation as well as provides stormwater drainage to prevent floods. Due to the unregulated rapid urbanization of the city and lack of efficient waste and wastewater management systems over the past few decades, the canal has become heavily polluted. This study aimed to evaluate the water quality of Mae Kha canal through assessment of the physico-chemical water quality and coliform bacteria. Moreover, benthic macroinvertebrates were samples and assessed using the Biological Monitoring Working Party (BMWP^Thai) and Average Score Per Taxon (ASPT^Thai) as biological indices. Results: The physico-chemical showed low dissolved oxygen levels, high levels of ammonia and phosphates, and elevated levels of biochemical oxygen demand, indicating that the water quality had significantly deteriorated. The canal was found to be heavily polluted, with most sites falling into the polluted to very heavily polluted. Coliform bacteria analysis revealed alarmingly high levels of total coliform bacteria and fecal coliform bacteria in the canal. The BMWP^Thai and ASPT^Thai scores indicated poor to very poor water quality. Conclusions: The physico-chemical and coliform bacteria indicated that the water quality of the Mae Kha canal had significantly deteriorated. The biological indices also indicated the poor to very poor water quality. This study underscores the urgent need for comprehensive remediation efforts, emphasizing strategic planning, investment, and community engagement to revive the canal's ecological health and water quality.

• Korean Journal of Environmental Biology
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• v.31 no.1
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• pp.37-44
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• 2013

This study was to investigate water quality and biotic community characteristics in Juam Lake. In water quality, water temperatures was $3.8{\sim}21.2^{\circ}C$, 6.7~8.6 in pH, $64{\sim}76{\mu}s\;cm^{-1}$ in Conductivity, $5.3{\sim}13.2mg\;L^{-1}$ in DO, $2.5{\sim}3.3mg\;L^{-1}$ in COD, $1.0{\sim}5.1mg\;L^{-1}$ in SS, $0.622{\sim}0.841mg\;L^{-1}$ in T-N, $0.007{\sim}0.019mg\;L^{-1}$ in T-P and $2.8{\sim}8.8mg\;m^{-3}$ in Chl-a. Revised Carlson's Index (TSIm) assessment using total phosphorus (TP) and chlorophyll-a domonstrated that the trophic states of Juam Lake were rated as mesotrophic. A total of 53 species of phytoplankton were identified. They were 28 Bacillariophyceae, 13 Chlorophyceae, 3 Cyanophyceae, and 9 Other algal taxa. The standing crops of phytoplankton was ranged from $113cells\;mL^{-1}$ to $2,909cells\;mL^{-1}$. A total of 16 species of zooplankton were identified (10 rotifers, 4 cladocerans and 2 copepods). Total zooplankton abundance was $309ind.\;L^{-1}$ to $435ind.\;L^{-1}$. The collected benthic macroinvertebrates from the surveyed sites in Juam Lake were 1,038 individuals, 33 species, 21 families and 12 orders. A dominant species was Uracanthella rufa and a subdominant species was Ecdyonurus kibunensis. Hydrophytes recorded from Juam Lake were identified 9 taxa. Emerged plants, floating plants among the hydrophytes was classified 8, 1 taxa, respectively. Ecosystem disturbance wildplant by Environment Ministry found were Paspalum distichum var. distichum and Ambrosia artemisiaefolia. A total of 30 species (6 families) were collected fishs from Juam Lake. There were 10 Korean endemic species (33.3% of collected species number) and 3 exotic species (10.0%).

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.23 no.2
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• pp.91-108
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• 2018

An ecological study on subtidal macrobenthic fauna was conducted from 25 stations in the estuarine area of Wando-Doam Bay, southern coast of Korea during August 2013. A total of 186 species was collected with a mean density of $1,229ind./m^2$ and a mean biomass of $265.7g/m^2$. Polychaetes showed the richest benthic fauna comprising 43% of total fauna, whereas mollusks appeared as density- and biomass-dominant fauna accounted for 45% and 48% of the mean density and biomass, respectively. The number of species and mean faunal density were relatively higher at the stations surrounded by Sinjido, Joyakdo and Gogeumdo showing a gradual decrease toward inner bay stations. Species number and density were negatively correlated with bottom water temperature, but they were positively correlated with both the bottom salinity and DO. The most dominant species in terms of density was a semelid bivalve, Theora fragilis which showed a positive correlation with TOC content of surface sediment and its high density occurred around Gogeum-Sinji-Joyakdo area where dense aquaculture facilities exist. In the bay mouth area, an amphipod species, Eriopisella sechellensis showed its higher density at the stations with low organic content but fine grains. The combination of water temperature, salinity, pH of bottom water, water and sulfur content of the surface sediment could explain 71% of the spatial distribution of macrobenthic fauna from the Bio-Env analysis. From the cluster analysis, the study area consisted of 6 distinct station groups lineated from offshore area toward inner area. Ampharete arctica, Goniada maculata, Eriopisella sechellensis, Theora fragilis, Caprella sp. were identified as the main contributing faunas in classification by the SIMPER analysis. From the value of BPI, the benthic communities at the inner and central Wando-Doam Bay were assessed to be in a normal condition whereas those at the outer Wando harbor and Gogeum-Sinji-Joyakdo area were assessed in a poor or very poor condition due to the high concentration of particulate organic matter might be originated from the nearby dense aquaculture facilities. This study indicated that pristine inner bay has been influenced by the organic material supplied from the outer bay. Thus it is necessary to establish an ecological management plan to reduce organic enrichment of sediment from dense aquaculture facilities in the outer bay.