• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.4
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• pp.24-36
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• 2008

The essence of a natural stream restoration project is providing habitats for various creatures in terms of the stream's environmental function. This research suggests the problems of natural stream restoration project by studying streams in terms of habitats for creatures and reviewing the national and international cases on existing natural stream restoration project. As a solution for the above, this research suggests a preservation method for biotope of upper stream areas focusing on the fish biotope area considering the ecological characteristics and preservation value of the respective stream so that the stream can be preserved as habitats for creatures. The research was carried out on Cheonglimli Baekcheon region which is an upper stream area of Buan-Dam located in the public park in Byunsanbando, Buangoon, Jeonlabookdo. We suggest the preservation method based on the habitat environment and keystone species of fish. The habitat environment evaluation was carried out mainly being divided into three groups namely, habitats and surrounding environment, reservoir's features and fish way and the diversity of fish. By improving the problematic elements discovered through such evaluation, it tries to improve the biotope of the stream and continuously preserve the stream. In addition, in order to restore the stream as habitats for various creatures, this research suggests to select keystone species which are suitable for the stream environment and restore the habitats based on the keystone species rather than restoring habitats for all species. Fish not only plays the role of a consumer of Epilithic algae and water beetles but also plays an important ecological role as a food for birds or small mammalia. If such ecologically important biotope for fish is preserved, the ecological environment of the stream will be maintained more stably.

• Ecology and Resilient Infrastructure
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• v.4 no.2
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• pp.105-114
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• 2017

This study performed physical habitat simulation for fish and macroinvertebrate species in the Gongneung River. Target fishes were selected as Rhinogobius brunneus and Zacco platypus. Target macroinvertebrate species were selected as Hydropsyche kozhantschikovi and Chironomidae. Habitat suitability curves were constructed by using monitoring data from the monitoring project which is called "the survey and evaluation of aquatic ecosystem health". For calculation of CSI, weighted mean method was used. For macroinvertebrates species, the weighting factor derived from analytic hierarchy method was considered. River2D, which is capable to simulate flow in two-dimensional space, was selected for flow computation. Composite suitability index was simulated for target fish and macroinvertebrate species for discharge of drought, low, normal, and averaged-wet flow. Simulation results show that Chironomidae and Hydropsyche kozhantschikovi prefer the pool and riffle habitat, respectively. Rhinogobius brunneus and Zacco platypus show high suitability in riffle habitat.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.2
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• pp.102-119
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• 2004

This study investigates the relation between the location of a habitat and the ecological connections according to the habitat type in the riparian zone at the Bokha stream. Stream habitat is classified into nine types for the aquatic insects and fish. For vegetation and birds, habitat is classified into five types of medium-scale streams, including both physical and chemical streams are analyzed accordingly. The major results of this study are as follows: 1) A pool connected to the main stream has a certain water depth (about 80 cm) and is disturbed at least 5 to 6 times a year. Although the pool has a somewhat bad water quality, it provides a habitat for various types of young fish. 2) A meander riffle is about 15 cm deep, the flow velocity in the region is about 75 cm/s. This region does not have large structures to which aquatic insects can attach, so it cannot be used as a spawning ground. 3) A rock type pool is about 60 cm deep, the flow velocity in the meander riffle is about 25 cm/s. In this region, many aquatic insects attached to large structures appear. Due to various riparian vegetation, the rock type pool is used as a habitat for aquatic insects. 4) A pool which is only connected to the main stream during floods has a bad water quality. Despite of its relatively small size, it has a high population density of aquatic insects. faculty.

• Ecology and Resilient Infrastructure
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• v.7 no.1
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• pp.53-62
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• 2020

The present study aimed to investigate the impact of the restoration of the restoration technique on fish habitat using a physical habitat simulation in the Wonju-cheon Stream, Korea. The target species were Pungtungia herzi, Zacco platypus, and Zacco Koreanus, a dominant and sub-dominant species in the Wonju-cheon Stream. The River2D model was used for the computation of the flow and the habitat suitability index model was used to estimate the quality and quantity of habitat using habitat suitability curve. To assess the impact of pool-riffle sequence on change of fish habitat, this present study conducted using the each representative distance, namely, 50 m, 100 m, 200 m, and 300 m. Simulation results indicated that the pool-reffle sequence significantly increased the habitats for the target species than the result without considering pool-riffle sequence. On average, 53% of the Weighted Usable Area (WUA) increased due to pool-riffle sequence in the study area.

• Journal of Korea Water Resources Association
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• v.54 no.11
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• pp.985-998
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• 2021

In general, the upstream dam changes downstream flow regime dramatically, i.e., from natural flow regime to hydropeaking flows. This study investigates the impact of the natural flow pattern on downstream fish habitat in a regulated river in Korea using the physical habitat simulation. The study area is a 13.4 km long reach of the Geum-gang River, located downstream from the Yongdam Dam, Korea. A field monitoring revealed that three fish species are dominant, namely Zacco platypus, Coreoleuciscus splendidus, and Opsariichthys bidens, and they account for 70% of the total fish community. Specially, Opsariichthys bidens is an indigenous species in the Geum-gang River. The three fish species are selected as target fish species for the physical habitat simulation. The Nays2D model, a 2D shallow water equation solver, and the HSI (Habitat Suitability Index) model are used for hydraulic and habitat simulations, respectively. To assess the impact of the natural flow pattern, this study uses the annual natural flow regime and hydropeaking flows from the dam. It is found that the natural flow regime increases significantly the Composite Suitability Index (CSI) in the study reach. Then, using the Building Block Approach (BBA), the scenarios for the modifying dam operations are presented in the study reach. Both Scenario 1 and scenario 2 are proposed by using the hydrological method considering both magnitude and duration of the inflow and averaging the inflow over each month, respectively. It is revealed that the natural flow regime embodied in scenario 1 and scenario 2 increases the Weighted Usable Area (WUA) significantly, compared to the hydropeaking flows. In conclusion, the modifying the dam operations by restoring to the natural flow pattern is advantageous to fish community.

• Korean Journal of Environment and Ecology
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• v.35 no.5
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• pp.490-502
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• 2021

This study was conducted to analyze the current status of fish fauna and characteristics of the fish community according to the habitat of Woraksan National Park, Korea. The spatially balanced sampling selected 20 stations from major streams of Woraksan National Park, and three surveys were conducted in each season. The physical environments of the habitat were mostly mountain streams (Aa), with large stones and gravels scattered over the stream. The average altitude of the habitat was 304.4 m, and the average depth of water was 40.3 cm, being less than 1 m in most cases, and the river water level was distributed from 3rd to 5th streams. The principal component analysis of the physical environmental factors by habitat showed that the substrate properties differed according to the altitude. The survey identified a total of 2,183 individuals in 16 species belonging to 7 families. The dominant species was Zacco koreanus(86.2%), and the subdominant species was Rhynchocypris oxycephalus(3.8%). Pseudopungtungia tenuicorpa, classified as the endangered wildlife II, was the first endangered legally protected species found in this survey. Analysis of the rank abundance curve model in the fish community showed the Zipf model at 9 out of 20 points, the Lognormal model in 3 points, and the Preemption model in 4 points. The remaining 4 habitats showed only one species and were not analyzed. The canonical correspondence analysis of 20 stations and fish species was performed to understand the characteristics of the fish community according to environmental factors. The fish communities were divided according to differences in habitat environment by the altitude.

• Spatial Information Research
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• v.6 no.1
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• pp.91-102
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• 1998

The objectives of this research were to develop fish-habitat relationship models which can be used to estimate fish species riclmess of small and medium rivers in Korea, and test the accuracy of the models. The models are based on the Aquatic GAP Analysis model in the New York Cooperative Fish & Wildlife Research Unit (19%), and they employ three habitat factors; river size, physical habitat, and water quality of each river segment. Model 1 and model II are based on the water quality standard for life support of EP A and the water quality class of Korea, respectively. Test sites for this study include one urban stream and three less spoiled tributaries of the Han River. The results of this research can be summarized as follows. First, the number of habitat types identified by model I and model II are nine and 14, respectively. Second, the average accuracy of the three distribution maps of rare or endangered fish species are 80.6% (model 1) and 81.2% (model II). Third, the accuracy of fish species richness are 94% (model 1) and 95% (model II), and the water quality is the most important factor affecting fish species richness. Fourth, the accuracy of fish species list are 50.5% (model 1) and 68.7% (model II), but the accuracy of less spoiled stream segments and that of polluted stream segments are 67.1% and 86.5%, respectively. Finally, it can be concluded that the overall performance of model II is better than that of model I at our test sites.

• Ecology and Resilient Infrastructure
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• v.2 no.4
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• pp.317-323
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• 2015

This study investigated the impact of the morphological change on a physical fish habitat in the downstream reach of a dam using long-term mobile bed simulation. The quasi-steady model was used for hydraulic simulation and the habitat suitability index model was applied for physical habitat simulation. For simulating long-term morphological change of the stream bed, The Exner equation was used. Sorting of bed material was also considered. The results of simulation showed that erosion and armoring process occurred in a reach downstream of the dam and change of physical habitat for Zacco platypus followed. These results indicate that channel morphology and substrate conditions effected the physical habitat for considering long-term investigation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.2 no.1
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• pp.47-62
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• 1969

A goby, Synechogobius hasta (Temminck et Schlegel) was studied to investigate the food consumed and the biological change of the food organisms, and the fish were sampled from the closed tributary and the lower Part of the Naktong River, near Pusan, during the period from November of 1967 to December of 1968. The fish were sampled from four stations (Fig. 1), the total number of fish being 1,295 and they were grouped and analysed monthly. The content of the alimentary canal was analysed in three categories according to modified Nilsson's method (Dahl 1962) with a slight alteration: 1) The number of each item of stomach contents was counted and the percentage of each item in proportion to the total number of food organisms is indicated by the letter 'N' representing numerical percentage in Table 2. 2) The percentage of fish which contained any items of food organisms in proportion to the total number of fish caught in a given season is indicated by the letter 'O' representing frequency of occurrence. 3) Dominant groups of food items were selected and the percentage of the number of each dominant item in proportion to the number of the food organisms belonging to the dominant groups is indicated by the letter 'D' representing dominance. All food organisms were classified in 50 food item categories and then they were grouped in 13 main groups (Fig. 2-1), and they were further divided into 1) obligatory bottom animals, 2) organic drifts and 3) actively swimming forms; according to the conditions of the animal communities within the habitat. Since the majority of its food was composed of the obligatory bottom animals ($94.6\%$), the fish appeard to be a typical bottom feeder. And the dominant food organisms of the fish is generally determined by the local composition of the benthic fauna within the fish habitat. And their seasonal rhythm occurs among the food organisms in the stomach by the biological interaction. Locality variation in the population of the same food organism occurs due to the difference of food organisms in the habitat of the fish at Seonam and Garak, and at Seongsan and Hadan the condition of the niche for the fish in the both regions seems to be the same since the composition and the seasonal variation of the organisms were the same. The results may be summarized as follows: 1) The goby mainly feed on the animals of bottom fauna, and the food organisms are deter-mined by the food compositions within the habitat. 2) Seasonal variation of the stomach content shows the seasonal rhythm due to the biological variation of the population and their interaction. 3) The goby shows no preference on specific food, and the food is composed of a variety of animals. 4) Major food items of the goby are Polychaeta, Palaemon modestus, Isopoda, Gammaridea, Insecta (nymphs and larvae), Ilyoplax deschampsi, and Paratye compressa. 5) Logitudinal succession oil the population of the food organisms is apparently recognized within the community of Seongsan, Garak and Seonam. 6) The goby begins to descend toward the estuary and sea around April when the water temperature reaches $20^{\circ}C$, and they begin to return to river waters in September.

• Journal of Ecology and Environment
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• v.40 no.2
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• pp.107-119
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• 2016

Background: Previous studies on the biological integrity on habitat and landuse patterns demonstrated ecological stream health in the view of regional or macrohabitat scale, thus ignored the mesoscale habitat patterns of pool, riffle, and runs in the stream health analysis. The objective of this study was to analyze influences on the mesohabitat structures of pool, riffle, and run reaches on the fish guilds and biological integrity in Geum-River Watershed. Results: The mesohabitat structures of pool, riffle, and run reaches influenced the ecological stream health along with some close relations on the fish trophic and tolerance guilds. The mesoscale components altered chemical water quality such as nutrients (TN, TP) and BOD and these, then, determined the primary productions, based on the sestonic chlorophyll-a. The riffle-reach had good chemical conditions, but the pool-reach had nutrient enrichments. The riffle-reach had a predominance of insectivores, while the pool-reach has a predominance of omnivores. Also, the riffle-reach had high proportions of sensitive fish and insectivore fish, and the pool-reach had high proportions of tolerant species in the community composition. The intermediate fish species in tolerance and omnivorous fish species in the food linkage dominated the community in the watershed, and the sensitive and insectivorous fishes decreased rapidly with a degradation of the water quality. All the habitat patterns were largely determined by the land-use patterns in the watershed. Conclusions: Trophic guilds and tolerance guilds of fish were determined by land-use pattern and these determined the stream health, based on the Index of Biological Integrity. This study remarks the necessity to include additional variables to consider information provided by mesohabitats and land-use distributions within the selected stream stretch. Overall, our data suggest that land-use pattern and mesohabitat distribution are important factors to be considered for the trophic and tolerance fish compositions and chemical gradients as well as ecological stream health in the watershed.