• Korean Journal of Ichthyology
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• v.21 no.1
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• pp.38-46
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• 2009

The ichthyofauna in certain reservoirs in Gyeongju-si, Gyeongsangbuk-do were studied from August 17 to September 22, 2005. During the study period, 22,747 individuals belonging to 25 species, 20 genera, 9 families and 4 orders were collected. Of these, 14 species were cyprinid fishes, and the dominant species was Pseudorasbora parva (relative abundance 52.28%). There were six Korean endemic species (8.51%), including Sarcocheilichthys variegatus wakiyae, Squalidus chankaensis tsuchigae, Squalidus mulimaculatus, Hemiculter eigenmanni, Pseudobagrus brevicorpus and Odontobutis platycephala the dominant species was Squalidus chankaensis tsuchigae (7.59%). There were six introduced species (25.00%), of which Hemiculter eigenmanni, Pseudobagrus fulvidraco and Hypomesus nipponensis were introduced from other native stream systems (20.99%), and Cyprinus carpio (Israeli), Carassius cuvieri and Lepomis macrochirus were exotic species (4.01%).

• Korean Journal of Environmental Biology
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• v.31 no.3
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• pp.180-188
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• 2013

The objectives of the study were to analyze chemical water quality and fish community structures in the downstreams of Geum River during 2004~2005. Water quality parameters showed that ionic dilution was evident during July~August due to a rainfall and river runoff by Asian monsoon. Mean concentrations of BOD showed a seasonal variation and were greater in the downstream than in the midstream. The total number of fish species observed was 34 (11 families) and 30.3% of them was Korean endemic species. The dominant species with > 20% of the total were Zacco platypus (25.9%) and Microphysogobio jeoni (21.5%) in the river. Exotic species observed was only one species, Carassius cuvieri with relative abundance of 1.8%. According to the structure analysis of fish community, species richness index was highest (3.714) in S6 and lowest in S4 (1.961), while species diversity index was highest in S2 (1.01) and lowest in S5 (0.507). Tolerant species dominated the fish community (49%), and the sensitive species were rare (4.4%), indicating a biological degradation of ecosystem. In the mean time, omnivore species was composed of 49% in the fish community and insectivore species was nearly same with the proportion of the omnivores.

• Korean Journal of Ichthyology
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• v.20 no.1
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• pp.36-44
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• 2008

Feeding habits of Micropterus salmoides were investigated from the stomach contents of specimens ranging from 13 to 511 mm in standard length (n = 419), which are collected in the Lake Okjeong, Korea, 2006 to 2007. M. salmoides is a very strong carnivorous fish eating living organisms such as lots of fishes, small amount of aquatic insects and shrimps. As they grow, the feeding habits changed : they fed mainly on Branchioda in 10 to 20 mm in SL., aquatic insects and small fishes in 30 to 50 mm in SL., fishes including Zacco platypus, Hemiculter eigenmanni and Rhinogobius brunneus over 50 mm. However, among the prey organisms, M. salmoides most preferred living fishes. Analysing ichthyofauna of the Lake Okjeong from 1981 to the present investigation, after and before introduction of M. salmoides, it was showed that there was a certain reduction in fish diversity. Consequently, it is likely to let the strongly fish-eating habit to reduce a diversity of native fishes in the lake.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.478-485
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• 2013

Fish field survey, especially fish distribution and their ecological characteristics, was performed in the downstream region of Gyeongan stream during the period of before (June) and after (October) the summer monsoon in 2010. Depending on the characteristics of each site, fyke net or casting net was used for fish sampling. Feeding classification was determined by the analysis of stomach contents. Total number of family and species sampled were 5 and 17, respectively. The dominant family was Cyprinidae (12 species), and relative abundance (RA) of the most dominant species, Lepomis macrochirus and Zacco platypus, was 38% and 24%, respectively. Exotic species and Korean endemic species observed were 3 (423 individuals, RA 44%) and 4 (98 individuals, RA 10%), respectively. Tolerance guild analysis as characteristics of ecological indicators revealed an undoubtedly high percentage (97%), compared to others as reflected by the identification of just one sensitive species. Analysis of trophic guilds showed that L. macrochirus dominated among insectivores (44% RA). The food of L. macrochirus composed of, aquatic insects, benthic invertebrates, zooplankton, Chironomidae, and waterweed. Thus, we determined that L. macrochirus could be classified as insectivores (partially carnivores) in this study. Conversely, Z. platypus consumed Cladocera exclusively, greater than 90% of their feed. We presume that stable isotope analysis would identify the exact position of these species in the food web.

• Korean Journal of Environment and Ecology
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• v.29 no.4
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• pp.552-563
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• 2015

The characteristics of ichthyofauna and fish community in Lake Goesan were examined from April 2010 to October 2012. During the survey period thirty six species belonging to 11 families were collected. Dominant species by number were Hemibarbus labeo (29.9%) and Zacco platypus (20.0%). In biomass, the dominant species were H. labeo (37.2%) and Carassius auratus (17.9%). Also, fourteen Korean endemic fish species (38.9%) and one endangered species (Acheilognathus signifer) were collected. Further, one catadromous species was observed for stock enhancement (Anguilla japonica), in addition to two land-locked anadromous species (Hypomesus nipponensis, Plecoglossus altivelis) and three exotic species (Cyprinus carpio (Israeli type), C. cuvieri, Micropterus salmoides). According to the length-weight relation of C. auratus and M. salmoides, the b values were 3.13~2.99, 3.11~2.99, showing a declining tendency annually. However, for H. labeo and Z. platypus, the b values were 2.98~3.07, 3.06~3.23 respectively, showing an increasing trend. The slope values for C. auratus and M. salmoides population conditions were controlled by K factor showing a tendency to decrease, but H. labeo and Z. platypus were showing a tendency to gradually increase.

• Korean Journal of Ichthyology
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• v.9 no.1
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• pp.141-152
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• 1997

The dynamics of fish community was investigated in the Lake Paldang from September 1995 to August 1996. The collected fishes were classified into forty two species involving in eleven families. Dominant species was Erythroculter erythropterus (relative abundance : 27.96%) and subdominant species was Lepomis macrochirus (20.69%). Also, Squalidus japonicus coreanus (19.25%), Opsariichthys bidens (4.07%), Hemibarbus labeo (3.42%), Acheilognathus yamatsutae (2.68%) and Micropterus salmoides (2.68%) were numerous. Dominant species was L. macrochirus in spring and autumn and S. japonacus coreanus in summer. E. erythropterus was subdominated in all seasons. The still-water fishes increased after construction of Paldang Dam. Ten were endemic species in Korea. Four species were exotic, and they occupied 24.75% in relative abundance. Dominance index was high at St. 2, diversity and evenness at St. 5, and richness at St. 4. In these stations, collection was made with casting net and scoop net. In the stations where collection was made with fixed shore net, dominance index was high at St. 8, diversity and evenness at St. 14, and richness at St. 7. E. erythropterus showed a stable age structure, while L. macrochirus was composed of mainly 3~4 year classes.

• Korean Journal of Ecology and Environment
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• v.47 no.spc
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• pp.31-38
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• 2014

The fish community and upstream of glass eels (Anguilla japonica) in the Imjin River estuary Gyeonggi-do, Korea was investigated from 2008 to 2012. During the surveyed period 43 species belonging to 18 families were collected. Korean endemic species was Microphysogobio jeoni which showed a ration of 0.04% in collected species. Exotic fishes were Carassius cuvieri and Ctenophayngodon idellus, and comprised 0.06% of the total individual number. Among the fish species observed, 17 species of the freshwater fish (40.5%), 6 species of migration fish (14.2%), 8 species of the brackish water fish (19.1%) and 11 species of sea water fish (26.1%). In terms of composition ration, Anguilla japonica (glass eels, 49.8%), Coilia ectens (23.3%), Saurogobio dabryi (8.1%), Repomucenus olidus (3.3%), Lateolabrax maculata (2.9%) and Chelon haematocheilus (2.8%) were found to display high individual number. On the other hand, C. ectens (33.6%), C. haematocheilus (14.2%), Cyprinus carpio (10.5%), Mugil cephalus (9.1%) and S. dabryi (7.6%) were dominated of biomass. The dominant species of individual was A. japonica (glass eels), and subdomint species included C. ectens. The fish biomass catched of fisherman in the Imjin River (Paju-si) were 83.6~240.3 t by each year. The year 2011 and 2012 were decreased rapidly. Among these, M. cephalus (48.0~80.0%), C. carpio (6.7%), Carassius auratus (4.9%), Silurus asotus (3.9%), Takifugu obscurus (2.5%), Anguilla japonica (adult, 2.2%) and Pseudobagrus fulvidraco (2.1%) dominated of biomass. Body weight of glass eels at each year were 0.03~ 1.13 t, average 212.0 kg and 1,325,000 individual by 0.16 g each one individual.

• Korean Journal of Environment and Ecology
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• v.35 no.3
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• pp.265-276
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• 2021

This study investigated the characteristics of fish communities and river health in the Sincheon stream of Imgin River between April and October 2019. The survey collected 3,677 objects in 30 species belonging to 12 families from 23 survey stations. The dominant and subdominant species were Zacco platypus (28.4%) and Oryzias sinensis (13.6%), respectively, followed by Z. koreanus (11.8%), Rhynchocypris oxycephalus (11.7%), Carassius auratus (9.6%), and Pseudorasbora parva (7.9%) in that order. Among the fish species collected, 10 (33.3%) were endemic species in Korea. The exotic species were 5 (16.7%), including Micropterus salmoides, Lepomis macrochirus, Cyprinus carpio (Israeli type), Poecilia reticulata, and Xiphophorus maculatus. The land-locked species included Cottus koreanus and Rhinogobius brunneus, while C. koreanus was a climate change-sensitive species. The dominance of the fish community was low, and the diversity was high in the Sincheon mainstream, Sudongcheon and Cheongdamcheon, whereas Dongducheon and Sangpaecheon showed higher dominance and low diversity. The river health was very good and good in the uppermost and Sudongcheon areas, whereas the upper stream was normal, and the middle and lower streams were poor and very poor, respectively. The water quality was also mostly poor or very poor from the midstream to the downstream, and only Sudongcheon was very good. Therefore, the water quality had a great impact on fish habitat and eventually affected river health significantly. Although the water quality of Shincheon has improved each year, the introduction of several foreign species had a very negative effect. Improvement of river health in Shincheon requires water quality improvement and management of exotic fish species.

• Korean Journal of Ecology and Environment
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• v.34 no.3 s.95
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• pp.239-250
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• 2001

Fish fauna of 13 sites in a main channel and its tributaries of the Taehwa River and 9 Sites of other headwater streams in the Ulsan area (Mt. Gaji) were investigated from February 1999 to October 2000. All sites were the 1st to 5th order streams in the Ulsan area, and 10 sites (45.5%) were intermittent streams. A total of 2,695 flsh specimens were collected and classified into 14 families and 44 species. Cyprinidae accounted for 40.9% (18 species) of the total fish species collected and 68.4% (1,845 ind.) of the total abundance. Subdominant families were Cobitidae (6 species; 78 ind.), Gobiidae (5 species; 240 ind.), and Gasterosteidae (2 species: 128 ind.). Zacco temmincki (RA 23.0%, 14 sites) was the dominant species; subdominant species were Moroco oxycephalus (20.2%, 11 sites), Zacco platypus (8.0%, 10 sites), Mugil cephalus (5.2%, 3 sites). Among the total species, 8 species were endemic species to Korea. The dominant Korean endemic species was Squalidus chankaensis tsuchigae (53.6% of Korean endemic species) and subdominant species were Iksookimia longicorpa (20.5%), and S. japonicus coreanus (6.6%) . Due to the intermittent nature of streams in the Ulsan area, a conservation program of nsh fauna is strongly needed.

• Journal of Environmental Impact Assessment
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• v.6 no.1
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• pp.77-92
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• 1997

To know of the biological basic method that can improve the environment of the organisms that inhabit at Deokjin Park. We studied the flora and the fauna in Deokjin Park on June, 1996. The study was surveyed and researched according to the items floras, phytoplanktons, insects and vertebrates. The floras are composed of eleven varieties, one forma, eighty-three species, eighty-four genera and forty-nine families. In the lake of Deokjin Park, the dominant species were Nelembo nucifera and Spirodela polyrhiza. The authors thought that those species be artificially excluded in winter for the improvement of the quality of water. The phytoplanktons were composed of forty genera, eighteen families, ten orders and six classes. Among those, Anacystis(=Microcystis) and Anabaena that make eutrophication, were distributed in the lake of Deokjin Park. The fauna of insects were composed of forty-one species, thirty families and eleven orders. The authors observed seven species of fish, two species of amphibian, three species of reptile, seven species of the bird and one species of mammal. Among those, Bull-frog and Blue-turtle as exotic species must be excluded by artificial methods for the other native organisms of the lake of Deokjin Park.