• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.3 no.2
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• pp.122-128
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• 2022

To present the spatial variation of fish assemblages in the Geum River in Korea, the concept of beta diversity (β-diversity) estimates based on the variance of the community data table was applied. Fish communities and environmental variables were collected from 13 sampling sites along the in mid-low reaches of the River. We calculated the β-diversity and local contribution to beta diversity (LCBD) values at each site depending on the two types of data, 'occurrence' with Jaccard and Sørensen dissimilarity coefficients, and 'abundance' with Hellinger distance. Multivariate and correlation analyses were also performed to determine the relationships between LCBD and other variables, such as community indices and physicochemical and hydrological factors. The β-diversity values of fish communities in the River were estimated as 0.218 and 0.145 for occurrence data table with Jaccard and Sørensen respectively, and 0.268 for abundance data. Similar patterns of LCBD along the sampling sites were detected in two dissimilarity measurements of occurrence table, and LCBD values with abundance data were slightly different. The LCBD values are strongly correlated with community indices, and also suitable for indicating the uniqueness of fish assemblages. However, further research is needed to determine the LCBD value as an indicator of environmental variability.

• Fisheries and Aquatic Sciences
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• v.25 no.11
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• pp.549-558
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• 2022

The Indonesian Archipelago has a very complex geological history, along with equatorial warm sea temperature, resulting in diverse types of coral reefs and high diversity of coral reef fish. Many livelihoods of the coastal community are dependent on coral reef fisheries. The present study aimed to determine which region and location in the Indonesian Archipelago has the most diverse and abundant coral reef fish. The archipelago was divided into four regions: the Indian Ocean, Sunda Shelf, Wallacea, and the Pacific Ocean. Data were obtained from a national coral reef monitoring program of the Indonesian Research Center for Oceanography (RCO)-the National Board for Research and Innovation (BRIN). The reef fish data were collected using the underwater visual census method, from 321 belt transects on 24 locations (districts) across the archipelago. The results show that coral reef fish diversity of the Pacific region was the highest across the archipelago for all three trophic levels, i.e., corallivore, herbivore, and carnivore fish. The Pacific Ocean region also had the highest fish abundance for the three trophic levels. Comparison among locations revealed that the best ten locations in reef fish diversity and abundance were Sabang, Mentawai, Makassar, Selayar, Buton, Luwuk, Ternate, Raja Ampat, Biak, and Wakatobi. Wakatobi reefs showed their supremacy in carnivore fish diversity and abundance, while Biak reefs were the best in herbivore fish. The abundance of corallivore fish was also considerably high in Sabang reefs, but it is still lower than in Raja Ampat, Biak, and Wakatobi reefs. These results provide empirical evidence that the coral reefs of Wakatobi and Biak are the hottest hotspots of coral reef fish diversity and abundance in the Indonesian Archipelago.

• Korean Journal of Ecology and Environment
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• v.52 no.3
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• pp.274-283
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• 2019

Beta diversity is an efficient means of assessing the spatial variation in community composition among sites. To present fish community variation and LCBD (Local Contribution to Beta Diversity) among sites in stream, 6 sampling sites were selected in Cheonggye stream. Fish communities, environmental and habitat variables were collected at sites from April 2014 to October 2015. We used the total variance of the fish community data table (site-by-species community table) based on different forms, presence-absence, abundance, and Hellinger transformation, to estimate and compare beta diversity and LCBD. Fish community data table transformed by Hellinger distance showed the higher values of beta diversity than presence-absence and abundance data table. A similar patterns of LCBD were observed with presence-absence and Hellinger transformed data table. Low value of beta diversity calculated by community data table with abundance was due to the non-normality of fish assemblage data. Additionally, correlation coefficients were calculated to evaluate the relationships among LCBD, community indices and physicochemical variables. LCBD showed negative correlation coefficients with Shannon diversity. Overall, application of beta diversity analysis is an efficient method of addressing spatial variation of fish communities and ecological uniqueness of the sites in stream.

• Fisheries and Aquatic Sciences
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• v.26 no.9
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• pp.548-557
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• 2023

The purposes of this research were to identify fish species using DNA barcodes or partial sequences of cytochrome b (Cytb) and to assess the diversity of fish in the Mae Tam reservoir, Phayao province, Thailand. Fish samples were collected 3 times, during the winter, summer, and rainy seasons, from 2 sampling sites using gillnets with 3 mesh sizes (30, 50, and 70 mm). A total of 34 representative samples were classified into 12 species, 7 families and 6 orders by morphological- and DNA barcoding-based identifications. However, one cichlid species, Cichlasoma trimaculatum, could only be identified using DNA barcoding. Family Cyprinidae had the greatest diversity, 50.00%. The diversity, richness and evenness indices ranged from 0.43-0.65, 0.64-1.46, and 0.27-0.40, respectively, indicating that fish diversity at both sampling sites was relatively low. A comparison of the catch per unit effort (CPUE) with 3 different mesh sizes found that the 50 mm mesh size was the best (474.80 ± 171.56 g/100 m²/night), followed by the 70 mm (417.41 ± 176.24 g/100 m²/night) and 30 mm mesh sizes (327.88 ± 115.60 g/100 m²/night). These results indicate that DNA barcoding is a powerful tool for species identification. Our data can be used for planning the sustainable management of fisheries resources in the Mae Tam reservoir.

• Korean Journal of Ichthyology
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• v.25 no.3
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• pp.182-184
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• 2013

The 9th Indo-Pacific Fish Conference (IPFC9) was held in Okinawa, Japan from 24th to 28th June 2013. Five hundred and thirty two delegates from 36 countries/regions around the world attended. The Conference took place with a welcome address by Dr. Keiichi Matsuura in the Laguna Garden Hotel next to the Okinawa Convention Center in the evening of 23rd June 2013, one day before the official start of the IPFC9. The winners of the two IPFC9 Bleeker Awards, Jeffrey M. Leis (Ecology) and Gerald R. Allen (Systematics) provided excellent talks on "Change in the early life-history of Indo-Pacific Fishes" and "The center of Indo-Pacific reef fish diversity". A total of 462 papers were presented, including 328 oral and 134 poster presentations. The main themes of IPFC9 included systematics, evolution, zoogeography and phylogeography, biodiversity, ecology, behavior, and conservation. There were 14 symposia, which included topics such as "Top predatory fish in the Indo-Pacific ecosystems", "Fish diversity across environmental extremes", "Ontogeny and systematics of Indo-Pacific fishes", and "Phylogenetics and diversification of the Percomorpha". IPFC10 will be held in Papeete, Tahiti.

• Journal of Ecology and Environment
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• v.48 no.1
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• pp.32-48
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• 2024

Background: Longitudinal connectivity in river systems strongly affects biological components related to ecosystem functioning, thereby playing an important role in shaping local biodiversity and ecosystem health. Environmental DNA (eDNA)-based metabarcoding has an advantage of enabling to sensitively diagnose the presence/absence of species, becoming an efficient/effective approach for studying the community structure of ecosystems. However, little attention has been paid to eDNA-based biomonitoring for river systems, particularly for assessing the river longitudinal connectivity. In this study, by using eDNA we analyzed and compared species diversity and composition among artificial barriers to assess the longitudinal connectivity of the fish community along down-, mid- and upstream in the Hotancheon from the Geum River basin. Moreover, we investigated temporal variation in eDNA fish community structure and species diversity according to season. Results: The results of species detected between eDNA and conventional surveys revealed higher sensitivity for eDNA and 61% of species (23/38) detected in both methods. The results showed that eDNA-based fish community structure differs from down-, mid- and upstream, and species diversity decreased from down to upstream regardless of season. We found that there was generally higher species diversity at the study sites in spring (a total number of species across the sites [n] = 29) than in autumn (n = 27). Nonmetric multidimensional scaling and heatmap analyses further suggest that there was a tendency for community clusters to form in the down-, mid- and upstream, and seasonal variation in the community structure also existed for the sites. Dominant species in the Hotancheon was Rhynchocypris oxycephalus (26.07%) regardless of season, and subdominant species was Nipponocypris koreanus (16.50%) in spring and Odontobutis platycephala (15.73%) in autumn. Artificial barriers appeared to negatively affect the connectivity of some fish species of high mobility. Conclusions: This study attempts to establish a biological monitoring system by highlighting the versatility and power of eDNA metabarcoding in monitoring native fish community and further evaluating the longitudinal connectivity of river ecosystems. The results of this study suggest that eDNA can be applied to identify fish community structure and species diversity in river systems, although some shortcomings remain still need to be resolved.

• Journal of Environmental Impact Assessment
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• v.20 no.6
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• pp.845-856
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• 2011

In order to establish fundamental data for stream restoration and environmental flow, we investigated inhabitation and species diversity of fish to substrate size in the typical streams of Geum River Basin. Field monitoring including fish sampling was conducted from October 2007 to October 2009. Substrate size was determined according to six different : silt (Si), sand (Sa), fine gravel (Fg), coarse gravel (Cg), cobbles (Co) and boulders (Bo). A total number of fish caught in the 18 sites was 7,649 representing 10 families 50 species, and Si, Sa, Fg, Cg, Co and Bo stations occupied 30, 29, 38, 30, 27 and 17 species, respectively. The most frequently found species in number was pale chum (Zacco platypus, 29.7%, n=2,275) followed by Z. koreanus (22.5%, n=1,720) in total stations. Biological diversity with increase of substrate size from the dominance of part species showed higher values as dominance index, lower and diversity, richness and evenness index. Index of biological integrity (IBI) and qualitative habitat evaluation index (QHEI) scores decreased with increase of substrate size. Therefore, it is necessary to make an effort on stream rehabilitation with evaluation of physical habitat condition by indicator species in order to maintain biodiversity and perform ecological restoration.

• Journal of Environmental Science International
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• v.21 no.11
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• pp.1361-1369
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• 2012

A biological assessments of fish community structure were carried out in the lower reach of Seomjin River from May 2009 to November 2010. The collected fish from the six surveyed sites were 63 species belonging to 24 families, and 10 orders. Although species was different depending on sites, the numbers of individuals were not shown significance on sites. Locational dominant species were different. For example, the dominant species on May were Zacco platypus at W-1, Zacco temminckii at W-2, Acanthogobius flavimanus at W-3 and W-4, and Leiognathus nuchalis at W-5 and W-6. There is no seasonal differences in species. Species diversity was the best up to 2.64 on May at W-1 from 1.33 on November at W-6. As a result of an analysis about environmental factors for the numbers of fish species and individuals in each surveyed sites, the most effective groups were DO, BOD, and COD. The proportional difference was high on May than November between transient and asymptotic projections for population size and population growth rate for simulations starting at the current or theoretical stage distribution.

• Animal Systematics, Evolution and Diversity
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• v.26 no.2
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• pp.105-114
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• 2010

A study of Han River fish assemblage dynamics for 4 years was conducted. From April 2005 to August, 2008, fishes inhabiting two sites of Han River were sampled for identification. For further analysis, 40 individuals of the dominant species were sampled monthly from March 2006 to November 2008. The fish assemblage at site 1 was dominated by Zacco platypus (32.69%), while the subdominant species were Acheilognathus yamatsutae (14.4%), Acanthorhodeus gracilis (9.43%), Squalidus japonicus coreanus (6.84%), and Tridentiger brevispinis (5.18%). The most abundant species at site 2 was Korean Chub (Zacco koreanus) with relative abundance of 62.45% and followed by Pungtungia herzi (10.29%), Coreoperca herzi (8.67%), and Coreoleuciscus splendidus (6.82%) as the subdominant species. At both sites, the endemics populations show an increasing pattern during the whole survey period, while the natives were declining in the last two years.

• Fisheries and Aquatic Sciences
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• v.26 no.4
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• pp.268-281
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• 2023

Coral reef fisheries are prominent for the archipelagic countries' food sufficiency and security. Studies showed that fish abundance and biomass are affected by biophysical variables. The present study determines which biophysical variables are important predictors of fish diversity, abundance, and biomass. The study used available monitoring data from the Indonesian Research Center for Oceanography, the National Board for Research and Innovation. Data were collected from 245 transects in 19 locations distributed across the Indonesian Archipelago, including the eastern Indian Ocean, Sunda Shelf (Karimata Sea), Wallacea (Flores and Banda Seas), and the western Pacific Ocean. Principal component analysis and multiple regression model were administered to 13 biophysical metrics against 11 variables of coral reef fishes, i.e., diversity, abundance, and biomass of coral reef fishes at three trophic levels. The results showed for the first time that the covers of other fauna, coral rubbles, and soft corals were the three most important predictor variables for nearly all coral reef fish variables. Other fauna cover was the important predictor for all 11 coral reef fish variables. Coral rubble cover was the predictor for ten variables, but carnivore fish abundance. Soft coral cover was a good predictor for corallivore, carnivore, and targeted fishes. Despite important predictors for corallivore and carnivore fish variables, hard coral cover was not the critical predictor for herbivore fish variables. The other important predictor variables with a consistent pattern were dead coral covered with algae and rocks. Dead coral covered with algae was an important predictor for herbivore fishes, while the rock was good for only carnivore fishes.