• Ecology and Resilient Infrastructure
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• v.2 no.1
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• pp.33-41
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• 2015

In this study, an optimal improvement method of stream channel structure is presented for the enhancement of fish habitat suitability by genetic algorithm. The correlation between fish habitat suitability and physical disturbance in stream is analyzed according to the changes of hydraulic characteristics by channel structure rehabilitation. Zacco koreanus which is an indicator fish of the soundness of aquatic ecosystem was selected as a restoration target species by investigating the community characteristics of fish fauna and river environments in Wonju stream. The habitat suitability is investigated by PHABSIM with the habitat suitability index of Zacco koreanus. Hydraulic analysis by HEC-RAS and physical disturbance evaluation in stream are carried out. The optimal channel width modified for the enhancement of fish habitat suitability is provided. The correlation analysis between habitat suitability and physical disturbance with the change of hydraulic characteristics by channel modification showed that the proper channel modification enhanced fish habitat suitability and mitigated physical disturbance in the stream. The improvement of physical disturbance score by the channel structure rehabilitation for the enhancement of fish habitat suitability was confirmed in this study.

• Journal of Ecology and Environment
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• v.46 no.1
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• pp.41-53
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• 2022

Background: Due to the rapidly changing climatic conditions, South Korea faces the grand challenge of exotic species. With the increasing human movement, the influx of alien species to novel regions is prevalent across the globe. The latest research suggests that it is easy to prevent the introduction and establishment of alien species rather than controlling their spread and eradication. Like other countries, the Korean Ministry of Environment released a list (in 2018) of 45 potential risky exotic fish species considered likely to be invasive candidate fish species if they ever succeed in entering the Korean aquatic ecosystems. Results: The investigation into the invasion suitability traits showed that potential risky fish species could utilize those features in becoming invasive once they arrive in the Korean aquatic ecosystems. If the novel species establish viable populations, they are likely to incur higher economic costs, damage the native aquatic fauna and flora, and jeopardize the already perilled species. Furthermore, they can damage the installed infrastructure, decline overall abundance and biodiversity, and disturb the ecosystem services. Here we reviewed the list of fish species concerning their family, native origin, preferred aquatic biomes, main food items, current status in Korea, and potential threats to humans and the ecosystems. Data shows that most species are either already designated as invasive in the neighboring counties, including Japan, Vietnam, Thailand, and China, or originate from these countries. Such species have a higher climate match with the Korean territories. Conclusions: Therefore, it is exceptionally essential to study their most critical features and take regulatory measures to restrict their entry. The incoming fish species must be screened before letting them in the country in the future. The regulatory authorities must highlight the threatening traits of such species and strictly monitor their entrance. Detailed research is required to explore the other species, especially targeting the neighboring countries fish biodiversity, having demonstrated invasive features and matching the Korean climate.

• Korean Journal of Ichthyology
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• v.12 no.3
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• pp.215-222
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• 2000

Fish fauna of the coastal waters off Taean, Chungchyungnam-do, Korea, was investigated from May 1996 to July 1999. The specimems collected from the three localities were identified into 73 species belonging to 63 genera and 40 families. Of them the largest group was order Perciformes, comprising 35 species and 16 families, and showed 47.9% in total number of species. Chasmichthys gulosus and C. dolichognathus were commonly found from the st. 1, Sebastes schlegeli and Hexagrammos otakii, from the st. 2 and Cynoglossus joyneri, Acanthopagrus schlegeli, Pagrus majar, Chirolophis wui and Pholis fangi from the st. 3 of sampling localities. Porocottus sp. is described on the basis of 2 specimens collected from the st. 1 of sampling localities. The species was distinguished from all the other members of the genus by the following combination of characters: united dorsal fin, scales on trunk above lateral line, cirri on anterior part of lateral line.

• Korean Journal of Ecology and Environment
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• v.34 no.3 s.95
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• pp.223-238
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• 2001

Longitudinal distribution of the fish fauna of the 20 main channel and tributary sites in the Nakdong River was investigated from July 1999 to December 2000. A total of 4,791 individuals of fisHes were collected from three to seven sampling programs of all study sites and 48 species of 17 families were collected. Dominant family was Cyprinidae (25 species, relative abundance (RA): 91.8%). Zacco platypus (RA: 18.0%) was found to be the most abundant inhabitant. Subdominant species were Opsariichthys bidens (17,1%), Squalidus chankaensis tsuchigae (13.2%), Hemibarbus labeo (9.9%), and Z. temmincki (8.2%). Among the total species, 12 species were identified as endemic species (4 families, 24.5% of 1,172 individuals). Four exotic fishes were collected (Carassius cuvieri, 25 indv.; Micropterus salmoides, 214 indv.; Lipomis macrochirus, 14 indv.; Oreochromis niloticus, 6 indv.). M. salmoides was distributed in mid to lower part of the Nakdong River. As the result of cluster analysis, sampling sites were divided into three groups (upper, middle and lowerpart). Site below Gumi (St. 10) were considered as the lower part of the Nakdong River. Combined with previous surveys, about 80 species are present in the main channel and tributaries of the Nakdong River. Since the middle of 1990s, population density of the M. salmoides rapidly increased in the stagnant lower part of the river(RA 8.8% in lower 5 sites). The feeding strategy of M. salmoides was "generalized" on Daphnia sp. (<100 mm), and "specialization" about Cladocera (<150 mm) and Insecta(<200 mm).

• Korean Journal of Ecology and Environment
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• v.35 no.3 s.99
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• pp.220-231
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• 2002

The fish fauna and Community were surveyed from April 2000 to September 2001 at 23 stations in the nam river, the first tributary located to the lower reach of the Nakdong River system. During the study period, 39 species belonging to 29 genera and 11 families were collected. Of which 14 species are endemic species or subspecies in Korea. Introduced species from other river system, O. bidens had not been collected at all after the report of Yang (1973) but many individuals were captured at main stream and tributary in this survey. Introduced species from abroad M. salmoides increased at most of stations. Dominant species in main stream were Z. platypus, O. bidens and H. labeo. On the contrary, Z. temmincki, Z. platypus and S. gracilis majimae dominated the tributaries. Diversity indices of main stream and tributaries were 0,979 and 0.966 respectively. St. 3 of main stream and St.1 and 16 of tributaries had high diversity indices (1.05, 0.962, 0.956) and lower dominant indices (0.102, 0.369, 0.200). As a whole, dominant index was 0.160, diversity index 1.044 and evenness index 0.656. It indicated that the community structure of this river was stable and diverse relatively.

• Journal of Environmental Impact Assessment
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• v.14 no.4
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• pp.237-245
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• 2005

We investigated the water environmental assessment by the species biotic index (SBI) of freshwater fish at the Namdaecheon in Gangneung city, Gangweon-do during June and July in 2004 and June in 2005. In fish fauna, 29 species and 10 families were collected. Dominant species was Zacco platypus (relative abundance 15.33%) and subdominant species was Rhynchocypris steindachneri (13.13%). Species biotic index (SBI) in station 1, 2, 3, 4 was 1.70, 2.85, 1.00 and 3.39 respectively and water environmental grade by SBI was all very good. Station 5 was 4.13 in SBI and good grade. Station 6 was 4.47 and fairly good. Station 7 was 7.25 and poor. And station 8 was 8.10 and very poor grade. Results of water environmental grade by SBI and water quality grade were very similar in this stream.

• Animal Systematics, Evolution and Diversity
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• v.21 no.2
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• pp.207-217
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• 2005

The fish described in this paper were sampled from four watersheds in the Eastern, Chao Phraya, Peninsular, and Maeklons regions of central Thailand, between the years 2000-2004. A total of 124 species were captured from 160 stream and river sites, using an electrofishing method. 33 of these species were captured in the Eastern region and 42 in the Peninsular region. In the Chao Phraya and Maeklong areas, the fish species were both more abundant and more varied, and 52 and 91 species, respectively, were collected in these regions. Seven species (Brachydanio albolineatus, Rasbora paviei, System us binotatus, Homaloptera smithi, Monopterus albus, Macrognathus circumcintus, Channa gaucha) were commonly found in all of the watersheds.

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.505-515
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• 2015

The objectives of this study were to determine the effects of stream nutrient regime, N:P ratios and suspended solids on fish tolerance/trophic compositions and stream ecosystem health, based on multi-metric model, during 2008-2013. Also, stream ecosystem health was evaluated in relation to chlorophyll-a (CHL) as a measure of algal productivity or indicators of trophic state to water chemical parameters. Total number of sampled fish species were 50 and showed a decreasing trend from 2008 to 2013. The minnow of Zacco platypus, based on the catch per unit effort (CPUE), was the most dominant species (25.9%) among the all species. Spatial heterogeneity was evident in the fish tolerance guilds that showed the dominance of sensitive species (89%) in the headwaters (S1) and the dominance of tolerant species (57%) in the urban. These conditions were directly influenced by concentrations of nutrients and organic matter (COD). The N:P ratios, as a barometer of water pollution, had a negative linear function (R² = 0.40, P < 0.01) with CHL, and the ratios had an important role in changes of COD concentration (R² = 0.40, P < 0.01). Under the circumstances, the N:P ratio directly influenced the relative proportions of fish trophic/tolerance compositions. According to the regression analysis of omnivore (O_m) and insectivore sp. (I_n) on total nitrogen and total phosphorus, nitrogen had no significant influences (P > 0.05) to the two compositions, but phosphorus influenced directly the two guilds [slope (a) = -32.3, R² = 0.25, P < 0.01 in the I_n; a = 40.7, R² = 0.19, P < 0.01 in the O_m]. Such water chemistry and fish trophic guilds determined the stream ecosystem health, based on the multi-metric fish model.

• Journal of Korean Society on Water Environment
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• v.28 no.4
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• pp.512-522
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• 2012

This study is focused on fish fauna and distributional features along with physical gradients and stream orders in the Tamjin River basin, Korea. Fish sampling and investigation were conducted for 2 years from 2009 to 2010. Total number of fish species collected were 47 species of 16 family. The group of cyprinidae was mostly abundant. Both fish abundance and biotic index were declined with increasing altitude and longitudinal distance from the river mouth. Two species of Zacco temminckii and Pungtungia herzi were prevalent in most of sampling sites and showed no altitudinal and longitudinal differences. Most other species, however, were spatially restricted to specific regional altitudes. Several species including Zacco platypus, Squalidus gracilis majimae and P. herzi were broadly distributed from river mouth to 50 km. Eight species including Z. temminckii and Rhynchocypris oxycephalus only appeared in over 10 km from the river mouth. Both Odontobutis platycephala and Pseudobagrus koreanus were classified as "upstream dewelling species" observed only in over 30 km from the river mouth. High proportion of tolerant and omnivorous species were more dominated in the downstream zone of the dam, whereas intolerant and insectivorous species were abundant in the upstream zone of the dam. The variable of stream order showed positive relationship between number of fish species and total individuals collected. Sensitive species including insectivore had a declining tendency with increasing stream order, while tolerant specie including omnivore species had relatively increased with stream order. Overall, our study suggested that fish distribution considerably depends on altitudinal gradient and longitudinal distance from the river mouth as well as physical habitat.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.4
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• pp.507-528
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• 2015

The Fish Collection Project collected 356 fish species from the Southern Sea of Korea during 2010-2012, 55 more than previously collected. The fishes belonged to 3 classes, 29 orders and 128 families. The 5 dominant orders, Perciformes, Scorpaeniformes, Pleuronectiformes, Tetraodontiformes, and Clupeiformes, accounted for ~80% of the identified species. Additionally, 126 species were collected from the Southern Sea for the first time, while 85 species that had been found in previous collections were not seen. The species variety of fish in the Southern Sea may be influenced by its unique oceanographic conditions such as increased water temperatures in coastal areas, so regular surveys would assist our understanding of the fish community. We suggest that various collection methods, including diving, be used to collect fish species inhabiting rocky shore or deep-sea areas, where commercial fishing gear is difficult to deploy.