• Korean Journal of Ecology and Environment
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• v.47 no.4
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• pp.328-336
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• 2014

Nakdan weir, which is located in the second weir among the 8 weirs of Nakdong River, had been constructed from Nov. 2009 to Nov. 2011. To analyze the effect of Nakdan weir construction on benthic macroinvertebrates, we studied 2 sites around Nakdan weir (upstream and downstream) from 2007 to 2014. The average numbers of species and individuals were decreased after the construction (in 2012~2014, 51 species $895inds.\;m^{-2}$) than before construction (in 2007~2009, 25 species $84inds.\;m^{-2}$), especially in upstream site of Nakdan weir. After the construction, especially in 2012, dominance indices (DI) were increased by the decline of some specific taxon population, such as Ephemeroptera and Trichoptera, etc. After construction, individual ratios of GC (Gathering Collectors) and P (Predator) of FFGs (Functional feeding groups) and BU (Burrowers) of HOGs (Habitat orientation groups) were higher than before construction. So the results of this study indicate that the changes by a weir construction, such as the decline of shallow depth area, reduced velocity of water flow and increased ratio of sand bed, etc., can affect the benthic macroinvertebrate communities variously.

• Journal of Korean Society of Forest Science
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• v.101 no.3
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• pp.454-460
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• 2012

This study was conducted for determining the influence of Sediment Control Dam dredging on benthic macroinvertebrate communities in mountain stream of Gyeongsangbuk-do. The sediment control dams were surveyed before and after dredging from mountain streams of Yecheon, Yeongju and Bonghwa in Northern part of Gyeongsangbuk-do. Sampling was taken at upper and down from 3 experimental sites and 2 control sites during May to August 2011. The identified species before dredging were 56 belonged to 31 families, 11 orders, 6 classes and 4 phyla, but after dredging it has decreased to 51 species belonged to 27 families, 10 orders, 5 classes and 4 phyla. The microhabitat damage of benthic macroinvertebrates occurred at experimental sites after dredging of sediment control dams led to reduction of the number of species and individuals. Especially, upper stream of experimental sites showed the reduction of an average of 38% species. In general, species diversity indices and species richness indices decreased after dredging; however, dominance indices increased at experimental sites. In the upper stream of experimental sites, the microhabitat damaged and became pool due to dredging. Also, velocity of flow decreased and the river bed became simply due to the sedimentary matter being finer than sand and silt. As a result, composition of functional feeding groups and functional feeding groups were relatively simpler at upper stream and the degree of community differences was greater between upper and down stream. Also, Chironomidae spp., Ephemeridae spp., and Gomphidae spp. to prefer where slow velocity of flow and lentic increased in a greater rate, and the EPT/C index to indicate the balance of the community decreased.

• Korean Journal of Environment and Ecology
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• v.24 no.1
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• pp.1-13
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• 2010

A biological assessment of water quality was carried out in Unmunsan County Park from November 2007 to September 2008. The benthic macroinvertebrates collected from the surveyed sites were composed of 140 species, 106 genera, 61 families, 13 orders, 5 classes and 4 phyla. The dominant species in all the survey areas was Goerodes KUa of Trichoptera. The dominance index(DI) showed the highest as 0.553 at site 2 and the lowest as 0.354 at site 7. The species diversity index(H') showed the highest as 2.18 at site 7 and the lowest as 1.75 at site 2. Ecological score of benthic macroinvertebrate(ESB) showed the highest as 85 at site 4 and site 7 and the lowest as 51 at site 5. As a result, the areas 4 and 7 needed to be designated as the highest protection area, and the area 5 as the protection area. Besides, the water quality, based on the ecological indicators of benthic macroinvertebrate community, turned out to be oligosaprobic in the whole survey areas.

• The Korean Journal of Ecology
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• v.21 no.6
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• pp.759-770
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• 1998

biotic indices scoring with the benthic macroinvertebrates were assessed as pollution monitoring tools in the north branch of the Han River system, Korea. We investigated the temporal variability of water quality at unpolluted, moderately polluted and heavily polluted sites using several biotic indices and assessed appropriate biological monitoring indices for lotic systems in Korea. The following biotic and chemical indices were employed in order to compare their applicability to the lotic systems : Trent Biotic Index (TBI), Chandler's Biotic Index-Average Score per Taxon (CBI-ASPT), Modified Biological Monitoring Working Party Score System-Average Score per Taxon (BMWP-ASPT), Hilsenhoff's biotic Index (BI) and Family-level Biotic Index (FBI) models for biotic analyses and National Sanitation foundation's Water Quality Index (NSFWQI) and comprehensive Chemical Pollution Index (Pb/n) for chemical analyses of water quality. Index and score values were compared with each other and with 24 water chemistry parameters. All biotic indices were significantly auto-correlated (p<0.001) and BI and FBI/ROK among them were highly correlated (r=0.84). BI and BMWP-ASPT models were also highly correlated with NSFWQI, while TBI values showed high correlation with the Pb/n. The BI and BMWP-ASPT were highly correlated with the most water chemistry parameters. We conclude that the BI model, which includes indicator species and abundance of taxa, is best suited for the bioassessment of lotic systems in Korea. For rapid field-based assessments, FBI/ROK and BMWP-ASPT models are also appropriate.

• Korean Journal of Ecology and Environment
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• v.57 no.1
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• pp.1-16
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• 2024

Most wetlands worldwide have suffered from extensive human exploitation. Unfortunately they have been less explored compared to river and lake ecosystems despite their ecological importance and economic values. This is the same case in Korea. This study was aimed to estimate the assemblage attributes and distribution characteristics of benthic macroinvertebrates for fifty wetlands distributed throughout subtropical Jeju Island in 2021. A total of 133 taxa were identified during survey periods belonging to 53 families, 19 orders, 5 classes and 3 phyla. Taxa richness ranged from 4 to 31 taxa per wetland with an average of 17.5 taxa. Taxa richness and abundance of predatory insect groups such as Odonata, Hemiptera and Coleoptera respectively accounted for 67.7% and 68.2% of the total. Among them Coleoptera were the most diverse and abundant. Taxa richness and abundance did not significantly differ from each wetland type classified in accordance with the National Wetland Classification System. There were three endangered species (Clithon retropictum, Lethocerus deyrolli and Cybister (Cybister) chinensis) and several restrictively distributed species only in Jeju Island. Cluster analysis based on the similarity in the benthic macroinvertebrate composition largely classified 50 wetlands into two major clusters: small wetlands located in lowland areas and medium-sized wetlands in middle mountainous regions. All cluster groups displayed significant differences in wetland area, long axis, percentage of fine particles and macrophyte composition ratio. Indicator Species Analysis selected 19 important indicators with the highest indicator value of Ceriagrion melanurum at 63%, followed by Noterus japonicus (59%) and Polypylis hemisphaerula (58%). Our results are expected to provide fundamental information on the biodiversity and habitat environments for benthic macroinvertebrates in wetland ecosystems, consequently helping to establish conservation and restoration plans for small wetlands relatively vulnerable to human disturbance.

• Journal of Environmental Health Sciences
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• v.45 no.1
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• pp.42-53
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• 2019

Objectives: The Yongpung reservoir in Korea is a crucial facility that supplies water to farms in its surrounding $2km^2$ area. However, its water quality is not suited to the needs of current residents who wish for the availability of environmentally friendly agricultural products and desire to use the waterfront area. The aim of this research was to evaluate the reservoir's fish and benthic macroinvertebrate distributions and determine its water quality and the heavy metal content in its sediment. This basic data can be used to establish environmentally protective plans for the Yongpung reservoir. Methods: Six sites were selected for analysis in this investigation. Three points (YP-1, YP-2, and YP-3) were evaluated for water quality and metal content in sediments; they were located upstream, midstream, and downstream of the reservoir. Samplings of the fish and benthic macroinvertebrate populations were performed at three other sites: St. 1, St. 2, and St. 3. Results: Based on chemical oxygen demand (COD) and total nitrogen (T-N) data, the quality of the Yongpung reservoir water corresponds to Class VI (very poor) according to Korea's lake environmental standards. The lead levels measured in the sediment at the midstream and downstream points of the reservoir were 76.7 and 72.7 mg/kg, respectively, while 8 orders, 15 families, and 16 species of benthic macroinvertebrates were identified in the reservoir. The ecological score of the benthic macroinvertebrate community (ESB) was between 8 and 23, denoting poor to very poor environmental conditions. Further, 4 families and 7 species of fish were identified in the reservoir, with Cyprinidae accounting for 94.3% of all observed freshwater fish. Conclusion: Based on these findings, we conclude that management plans, including the removal of lead from the sediment, are necessary to improve the quality of the agricultural water in this reservoir. The T. japonica, which cover almost 30% of the water area, must also be removed.

• Journal of Korean Society on Water Environment
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• v.37 no.3
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• pp.190-203
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• 2021

Water quality, benthic macroinvertebrate communities, and other factors were investigated to explore the effects of the effluent discharge from a sewage treatment plant into Jwagwang stream in Busan in 2019. During the study period, the flow rate of this stream was in the range of 10,400 m³/day to 52,200 m³/day except for the discharge of about 24,000 m³/day of the effluent. After discharge, the flow velocity increased by about 65% and the water depth increased by about 40%. At sites downstream of the discharge point, BOD, COD, TOC, T-N, T-P, and other water quality values were worse than those of the upstream sites. The periphytic algal chlorophyll-a concentrations in the natural substrata were higher than those of the upstream sites, especially in May and August. However, at sites downstream of the discharge point, the individual numbers of Annelida were decreased and individual numbers of the insecta of arthropoda were increased. Also, species numbers and the diversity and dominance indexes were improved in the sites downstream of the discharge point. The functional feeding groups (FFGs) of collector-filterers were increased and the habitat orientation groups (HOGs) of sprawlers, burrowers, and clingers were especially increased at the sites with additional reclaimed wastewater effluent flow. Regardless of the effluent discharge, BMI, an indicator of ecological stream health using benthic macroinvertebrate species, did not show large gaps between the study points. Although the water quality of the sites downstream of the discharge point was much worse than those upstream, their ecosystem soundness was better than those of the upstream sites from an ecological perspective.

• Korean Journal of Ecology and Environment
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• v.33 no.3 s.91
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• pp.230-243
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• 2000

A large-scale community data were patterned by utilizing an unsupervised learning algorithm in artificial neural networks. Data for benthic macroinvertebrates in streams of South Korea reported in publications for 12 years from 1984 to 1995 were provided as inputs for training with the Kohonen network. Taxa included for the training were 5 phylum, 10 class, 26 order, 108 family and 571 species in 27 streams. Abundant groups were Diptera, Ephemeroptera, Trichoptera, Plecoptera, Coleoptera, Odonata, Oligochaeta, and Physidae. A wide spectrum of community compositions was observed: a few tolerant taxa were collected at polluted sites while a high species richness was observed at relatively clean sites. The trained mapping by the Kohonen network effectively showed patterns of communities from different river systems, followed by patterns of communities from different environmental disturbances. The training by the proposed artificial neural network could be an alternative for organizing community data in a large-scale ecological survey.

• Korean Journal of Ecology and Environment
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• v.36 no.1 s.102
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• pp.29-37
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• 2003

Benthic macro-invertebrates were seasonally collected in the Onchen Stream in Pusan, from July 2001 to March 2002. Generally 4 phylum 5 class 10 order 19 family 23 species were observed in the study sites. Ephemeroptera, Plecoptera and various species appeared in headwater stream while Oligochaeta and Chironomidae were dominated in downstream sites. Community abundance patterns, especially the dominant taxa, Oligochaeta and Chironomidae, appeared to be different depending upon the sampling months. Oligochaeta was usually observed in July, December and March while Chironomidae was appeared in September. The biological indices, TBI(Trent Biotic Index), BS (Biotic Score), BMWP (Biological Monitoring Working Party)were calculated with the appeared communities of the sampling sites through the survey months. TBI showed 1 to 8, BMWP was 1 to 93 and CBI appeared 9 to 387 in the different sites. The biological indices decreased from headstream to downstream sites, We implemented the unsupervised Kohonen network for patterning of community abundance of the sampling sites. The patterning map by the Kohonen network was well represented community abundance of the sampling sites. Also, we conducted RTRN (Real Time Recurrent Neural Network) for predicting of the biological indices in the different sites. The results appeared that the predicting values by RTRN were well matched field data (correlation coefficient of TBI, BMWP and CBI were 0.957, 0.979 and 0.967, respectively).

• Korean Journal of Ichthyology
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• v.26 no.2
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• pp.118-124
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• 2014

As part of researching the feeding habit of Liobagrus somjinensis, the study of its stomach contents and benthic aquatic macroinvertebrates fauna at the waters the fish was collected were carried out monthly from January to December 2010 in Yo stream, Somjin River Sikjeong-dong, Namwon-si, Jeollabuk-do, Korea. In the survey of the stomach contents, the prey organisms are all aquatic insects consisting of 5 orders, 14 classes and 16 species. They fed mainly on Trichoptera and Ephemeroptera including dominant insects such as Hydropsyche kozhantschikovi (79.1%), Chironomidae spp. (48.7%), Baetiella tuberculata (34.2%) at the occurrence rate. Based the result, L. somjinensis appeared to be an aquatic insect feeder that consumes only benthic aquatic insects. The feeding rate of L. somjinensis was the highest in November, whereas it was the lowest in December to next February when they did not feed in the winter season. A survey of the benthic aquatic macroinvertebrates fauna was accompanied for prey preference at the waters. They have 7 orders, 20 classes and 27 species, and among them, two species, Hydropsyche kozhantschikovi (39.0%) and Epeorus pellucidus (18.1%), were aquatic dominant insects. Among 7 orders interestingly, Odonata and Megaloptera, known as having a larger size than other aquatic insects, were not found at the stomach contents. As a result, Liobagrus somjinensis most prefer Hydropsyche kozhantscikovi which is the most dominant species with relatively a smaller size at the waters the study was performed.