• Journal of Korean Society on Water Environment
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• v.29 no.4
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• pp.459-465
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• 2013

A sequencing batch reactor was operated under different pH conditions to see the influence of pH to microbial community in enhanced biological phosphorus removal (EBPR) systems. Long term influences of different steady-state pH conditions on the microbial community composition were evaluated by polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) and fluorescence in situ hybridization (FISH). The shift in populations from polyphosphate-accumulating organisms (PAOs) to Alphaproteobacteria was observed when pH was changed from 7.5 to 7.0. Alphaproteobacteria with the typical morphological traits of tetrad-forming organisms (TFOs) eventually became dominant members. The alphaproteobacterial TFOs were the phenotype expected for glycogen-accumulating organisms (GAOs), which accumulate large amount of glycogen into the cell. The results strongly suggested that low operational pH condition encourages the appearance of the GAOs in EBPR process, significantly reducing the EBPR capacity.

• Korean Journal of Ichthyology
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• v.18 no.3
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• pp.244-250
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• 2006

The ichthyofauna and fish community structure were investigated at five stations in Yeongok stream, Gangneung, during April and December 2005 monthly. During the surveyed period twenty nine species belonging to ten families were collected. Dominant species in number was Zacco platypus (relative abundance : 29.0%) and subdominant was Rhynchocypris steindachneri (12.1%). There were six Korean endemic species including Rhynchocypris kumgangensis. Koreocobitis rotundicaudata and Luciogobius guttatus that were not reported in near streams were collected in Yeongok stream only. Ladislabia taczanowskii was considered as a geographically important species. There were stabilized fish community structure with species diversity index of the community 2.521 in Yeongok stream ichthyofauna.

• Journal of Environmental Science International
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• v.23 no.8
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• pp.1513-1522
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• 2014

Fish passage asssessments were conducted in the fishway at Juksan Weir, which was constructed as a four-major rivers project in the downstream area of Youngsan-River Watershed. For the research, fish-movements/migrations were analyzed for seven times from April ~ October, 2013 using an approach of fish trap-setting. Fish fauna and compositions were analyzed in the fishway, and seasonal- and diel-movement patterns were analyzed in relation to current velocity in the fishway. Also, abundances of exotic fishes such as bluegill sunfish (Lepomis macrochirus), large-mouth bass (Micropterus salmoides), and white curcian carp (Carassius cuvieri) were monitored in the fishway. Current velocity(n = 18) in the fishway showed large variations ($0.82{\pm}0.63m/s$) depending on the location of the fish trap-setting and this physical factor influenced the fish movements. Fish movements, based on the CPUE of individuals, in the fishway was greater in slower velocity (mean: 0.36 m/s, range: 0.10~1.54 m/s) than faster velocity (mean: 1.51 m/s, range: 0.90~1.90 m/s). Seasonal analysis of fish movements showed that most frequent uses (8 speices and 591 individuals, 66.2% of the total) of the fishway occurred in spring period(i.e., June). Diel movement analysis, in the mean time, showed highest in the time period of 00:00 ~ 3:00 am (7 species and 281 individuals, 20.9% of the total). The efficient managements in the fishway at Juksan Weir are required in relation to the hydrological regime.

• 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.

• Korean Journal of Ichthyology
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• v.17 no.4
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• pp.271-278
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• 2005

The ichthyofauna and fish community were studied in Miho Stream from May 2004 to August 2005. During the surveyed period 41 species belonging to 10 families were collected. Twelve of the species (29.3%) are endemic to Korea. Exotic fishes were Carassius cuvieri, Lepomis macrochirus, and Micropterus salmoides. Dominant species was Zacco platypus (54.7%). Comparing the present result with that of Son (1982), the indices of diversity,evenness and richness were lower and the dominance index was higher; Lampetra reissneri, Anguilla japonica, Acheilognathus macropterus, Coreoleuciscus splendidus, Pseudopungtungia nigra, Gobiobotia naktongensis, Lefua costata, Pseudobagrus koreanus, Monopterus albus and Iksookimia choii did not appear; Carassius auratus, Rhodeus uyekii, Rhodeus notatus, Acheilognathus lanceolatus, Pseudogobio esocinus, Hemibarbus longirostris, Microphysogobio yaluensis, Cobitis lutheri, Iksookimia koreensis, Pseudobagrus fulvidraco, and Rhinogobius brunneus, remarkably decreased, and Z. platypus, Pseudorasbora parva, and Squalidus gracilis majimae increased.

• Korean Journal of Ichthyology
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• v.17 no.4
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• pp.264-270
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• 2005

The ichthyofauna and fish community structure were investigated at three areas in Lake Chungju from April to October 2004. During the surveyed period,32 two species belonging to 12 families were collected. Dominant species in number was hemibarbus labeo (relative abundance : 23.2%) and subdominant was Erythroculter erythropterus (12.1%). Siniperca scherzeri (9.2%), and Pseudogobio esocinus (8.6%) were also numerous. There were nine Korean endemic species belonging to six families including Acheilognathus yamatsutae. The number of fish species collected was 28 in Danyang, 17 in Jecheon, and 15 in Chungju. Highest dominant index calculated was 0.670 in Chungju, and highest diversity index calculated was 2.442 in the Danyang area. We need closer observation of population fluctuation of some species, including H. labeo, the dominant species by biomass in Lake Chungju.

• Korean Journal of Environmental Biology
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• v.22 no.1
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• pp.111-119
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• 2004

The ichthyofauna and community structure in Lake Paro, Korea, was investigated from December 2002 to september 2003. Buying the surveyed period 45 species belonging 12 families were collected. There were 15 Korean endemic species 33.33％, including Hemibarbus mylodon, Aeheilognathus yamatsutae nnd Ooreoperca hem. Dominant species were Zacco platypus (72.41％) and subdominant species were Hemibarbus labeo (9.75％). Also, Opsariichthys uncirostris amurensis (5.98％), Zacco temmincki (2.42％), Rhinogobius brunneus (2.01％) and Hypomesus olidus (0.88％) were numerous. The biomass of collected fishes were Zacco platypus (82,803.15 g), Hemibarbus labeo (32,942.63 g), Opsariichthys uncirostris amurensis (27,482.39 g), Cyprinus carpio (6,502.87 g), Anguilla japonica (3,022.15 g) and Siniperca scherzeri (2,711.05 g). Of the 10 introduced fishes in Lake Paro Cyprinus carpio (Israeli type), Carassius cuvieri, Micropterus salmoides and Lepomis macrochirus were originated form foreign countries but Anguillta japonica, Hemiculter eigenmanni, Hypomesus olidus, Oncorhynchus masou mason, Chaenogobius urotaenius, Rhinogobius giurinus were introduced from other native river systems.

• Korean Journal of Environmental Biology
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• v.30 no.1
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• pp.15-25
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• 2012

From April to November 2009, we performed field investigation to survey the characteristics of fish fauna and fish community structure inhabited in Yongdam reservoir in the upper Geumgang, which is changed into flat-water zone from flow-water zone by blocking the continuity by the gigantic submerged weir built in the upstream of Geumgang. 15 species belonging to 8 families were collected from natural habitat (St. 1) where its natural characteristics is well preserved, and 11 species were korean endemic fish species. 24 species belonging to 10 families were collected at the down region of Yongdam dam (St. 3), which might be affected by the change of water environment due to the dam, and 11 species were korean endemic fish species. On the other hand, 20 species belonging to 7 families were collected inside Yongdam reservoir (St. 2) which is changed into flat-water zone from flow-water zone by the dam reservoir, and 6 species were korean endemic fish species. In the dam reservoir, due to Yongdam dam built in the upper Geumgang, the original flow-water zone fish such as $Acheilognathus$ $koreensis$, $Pseudopungtungia$ $nigra$, $Coreoleuciscus$ $splendidus$, and $Gobiobotia$ $macrocephala$ were disappeared, and instead, the kinds of fish habitating in the flat-water zone tend to increase rapidly, such as $Carassius$ $auratus$, $Opsarichthys$ $uncirostris$ $amurensis$, $Hemiculter$ $eigenmanni$, $Zacco$ $platypus$, and $Lepomis$ $macrochirus$. Relative abundance of the insective fish was 66.7% at St. 1, 40.0% at St. 2, and 54.2% at St. 3. In order to preserve endemic fish species and aquatic ecosystem, it is desirable to minimize the artificial installation in the upper river, such as a large scale dam which can affect the habitat and if inevitable, it is required to prepare preservation measures when building facilities.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.5
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• pp.535-548
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• 1994

Community structures and fish densit were investigated on three different types of artificial reefs, dice, turtle artificial reef and tubes, constructed in the Korean waters. Variations of fish fauna according to type of artificial reef and the proper artificial reef in each area for optimizing harvest were discussed. Fish were captured by trammel gill net during May, June, September and November, 1988 and both identified and counted. Fourty-five fish species were found in the artificial reefs. Of these, Sebastes spp., Hexagrammos otakii, Pleuronectidae, Navodon modestus and Stephanolepis cirrhifer showed high occurrence-frequency. The dominant species groups were coastal settlement, demersal or rock fishes such as Pleuronectidae, Rajiformes, Stephanolepis cirrhifer, Navodon modestus, Hexagrammos otakii and Sebastes spp. in all of the Artificial reefs except the oceanic area of southern waters. Scomber japonicus was predominant in the oceanic area of southern waters. Composition of demersal, rock and pelagic fishes were different depending on the types of artificial reef. Dice artificial reefs were occupied by rock fish, on the other hand turtle artificial reefs were dominated by dermersal fish. Fish density was high at the dice artificial reef in all survey areas except the middle area of Eastern waters, with high fish density evident in the Tube artificial reef. Fish community structures were remarkably different between Dice and Turtle artificial reefs. The Tube artificial reef showed intermediate characteristics between the above two types of artificial reefs. The coastal areas of Southern waters and the middle and southern areas of Western waters revealed similar fish fauna. Results from the oceanic areas of Southern waters were well associated with the middle and southern areas of Eastern waters.

• Korean Journal of Ecology and Environment
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• v.35 no.3 s.99
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• pp.237-246
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• 2002

Tamjin Dam is built in the upper reaches of the Tamjin River which flows through the Janghung-gun and Gangjin-gun of the Jeollanamdo, Korea. In order to map out a preservation strategy of the fish community from dam construction, We studied the distribution of fish distribution and changes of the habitat environment. we found 49 fish species inhabiting in the downstream and upstream of the Tamjin Dam. Among them, migratory fish were two species sweet smelt, Plecoglossus altivelis and freshwater eel, Anguilla japonica. The Coreoperca kawamebari which designated as a species to be protected by The Ministry of Environment of Korea was also observed. After the dam construction, reservoir would be filled with water and running water system will change to standing water system. Then the habitat and spawning space for mountain torrent fish will be reduced and the migration of migratory fish to upstream will be blocked. Through our study, we proposed several ways to protect fish community. In order to preserve the reduced habitat and spawning area of mountain torrent fish, a fishway has been diagnosed to be built in the shallow reservoir in the entrance of the upriver. The establishment of artificial spawning ground on the riverside has been recommended. In addition, We propose a creation of a shelter for fresh water eel, Anguilla japonica in areas where the depth of the water is about l0m by laying rocks. Since it is difficult for a spawning ground to be formed naturally in the reservoir due to the year-round changes in water level, We suggested a floating spawning facility using an artificial fixture. In the downstream of the dam, a waterway-style habitat and spawning ground in the river and increasing the diversity and abundance of fish fauna in the Tamjin River. A low-cost and highly efficient operational fishway has been recommended so that migratory fish such as Plecoglossus altivelis (sweetfish) can migrate from the lower reaches to the upper reaches of the river.