• The Korean Journal of Ecology
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• v.18 no.1
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• pp.157-177
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• 1995

Monthly changes in communities of benthic macroinvertebrates collected in the Suyong and Soktae stream of the Suyong river were investigated from September 1993 to August 1994. The total number of species collected during the study period ranged from seven to seventy six species according to pollution levels at the study sites. Monthly changes in species richness appeared differently in different taxonomic assemblages. In chironomids differences in species richness responding to different levels of saprobity were shown consistently as time proceeded. In Ephemeroptera species richness at the relatively clean sites responded sensitively to slight enrichment. In connection with species richness the monthly changes in densities in taxonomic assemblages also appeared to effectively represent environmental impacts. Species diversity generally represented the pollution status also, however the monthly variations at the study sites appeared to be relatively high. The clustering analysis showed that the communities collected at polluted sites were grouped closely, and the communities collected at the relatively clean sites were clustered to the same stream although the degree of community association was low, Through the Principal Component Analysis, the impact of Pollution was reflected in a great degree in overall community variations.

• Korean Journal of Ecology and Environment
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• v.54 no.1
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• pp.24-38
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• 2021

Microhabitat In the upper stream is created by various environment variables such as the bottom substrate and the physicochemical factors, and may influence the distribution of benthic macroinvertebrates. We investigated the bottom substrate and environmental variables influencing the distribution of benthic macroinvertebrate in 26 stream-type waterways established at upper reaches of Geum River. During study period, total 85 families, 160 species, 9305 individuals of benthic macroinvertebrates were recorded. The stream-type waterways, where the bottom substrates consist mainly of pebble (16~64 mm) and cobble (64~256 mm) or with rapid water velocity (more than 0.2 m/s) and high dissolved oxygen (more than 120%), were supported by high species diversity of benthic macroinvertebrate. Hierological cluster analysis and the nonparametric multidimensional scale (NMDS) divided 26 stream-type waterways into a total of three clusters. In Cluster 1, the invertebrate species, such as Branchiura sowerbyi, Cloeon dipterum, Ischnura asiatica, Paracercion calamorum, and Radix auricularia, closely related to aquatic macrophytes, and Chironomidae spp., Limnodrilus gotoi, and Tanypodinae sp. were abundant in waterways, with high coverage of silt and clay as well as high turbidity and total nitrogen. The benthic macroinvertebrate species (Cheumatopsyche brevilineata, Drunella ishiyamana, Dugesia japonica, Ephemera orientalis, Gumaga KUa, Macrostemum radiatum, Potamanthus formosus, Semisulcospira libertine, Stenelmis vulgaris, and Teloganopsis punctisetae) included in Cluster 2 were dominated in sites with high cover rates of pebble and gravel. Cluster 3 was predominantly covered by the Cobbles, was supported by Simulium sp. Such a clear distinction in the study sites means that each stream-type waterways is governed by a clear habitat environment. In the case of some sites with low species diversity, improvement measures are required to restore nature, such as improving the function of inflows and outflows, creating meandering channel, and inducing the settlement of littoral vegetation.

• 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.

• Journal of Ecology and Environment
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• v.34 no.2
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• pp.175-191
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• 2011

Colonization patterns and community changes in benthic macroinvertebrates in the Cheonggye Stream, a functionally restored stream in downtown Seoul, Korea, were studied from November 2005 to November 2007. Benthic macroinvertebrates were quantitatively sampled 15 times from five sites in the stream section. Taxa richness (59 species in total) increased gradually over the first year, whereas the density revealed seasonal differences with significantly lower values in the winter season and after flood events. The benthic macroinvertebrate fauna may have drifted from the upstream reaches during floods and from the Han River, arrived aerially, or hitchhiked on artificially planted aquatic plants. Oligochaeta, Chironommidae, Psychodidae, and Hydropsychidae were identified as major community structure contributors in the stream. Swimmers and clingers colonized relatively earlier in the upper and middle reaches, whereas burrowers dominated particularly in the lower reaches. Collector-gatherers colonized at a relatively early period throughout the stream reaches, and collector-filterers, such as the net-spinning caddisfly (Cheumatopyche brevilineata), predominated in the upper and middle reaches after a 1-year time period. Cluster analyses and multi-response permutation procedures demonstrated that the Cheonggye Stream shares more similarities with the Jungnang Stream than with the Gapyeong Stream. Detrended correspondence analysis and nonmetric multidimensional scaling demonstrated that physical environmental factors (depth, current velocity, dissolved oxygen, and pH) as well as nutrients (total nitrogen and total phosphorous), water temperature, and conductivity could affect the distribution of benthic macroinvertebrates in the study streams.

• Journal of Korean Society on Water Environment
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• v.36 no.1
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• pp.36-47
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• 2020

Three large scale weirs were constructed 2010 - 2011 in the Namhan river, Korea. The purpose of this study was to investigate the spatial distribution of benthic macroinvertebrates and the influence of environmental factors at the weirs 2014 - 2015. The number of species was higher in the riparian zone than in the transition or the limnetic zone. This seems to be because of the diversification of microhabitats and food sources according to the development of littoral zones. From the riparian zone to the limnetic zone, the individual abundance proportion of gathering collectors among functional feeding groups decreased, and that of filtering collectors increased. In the limnetic zone, sprawlers and climbers among habitat orientation groups decreased, and burrowers increased. This means that coarse particulate organic matter originated from land or riparian zone was transformed to fine particulate organic matter in the limnetic zone. Asian clam (Corbicula fluminea) and chironomids were dominant species based on individual abundance. Asian clam, a major taxon considering biomass, was abundant toward the limnetic zone. This is becasue of the shallow depth, suitable water current, slightly coarse substrate, and good water quality. There was no significant relationship between the water quality and the characteristics of the benthic macroinvertebrate community because the water quality was spatially not heterogenous. The more influential factors for benthic community were physical factors, especially water depth. Water depth showed a markedly significant correlation with Shannon-Weaver's species diversity (r=-0.90), Margalef's species richness (r=-0.82), and McNaughton's dominance (r=0.86). Water depth showed a positive correlation (r=0.68) with the Kong and Kim BMSI (Bentic Macroinverebrates Streambed Index), and this may be related to the coarse substrate of the limnetic zone.

• Korean Journal of Ecology and Environment
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• v.55 no.1
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• pp.10-18
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• 2022

This study analyzed the relationship between the community structure of benthic macroinvertebrates and habitat changes in open estuaries among the sites included in the national estuary monitoring program. The estuary survey was conducted under the "Guidelines for Investigation and Evaluation of Biometric Networks" and classified by sea area, 80 places in the East Sea, 102 places in the South Sea, and 19 places in the West Sea were investigated. In a total of 201 open estuaries, benthic macroinvertebrates were identified with 4 phyla, 9 classes, 41 orders, 139 families, 269 species and 196 species in the East Sea, 182 species in the South Sea, and 90 species in the West Sea. The highest population densities were Insecta in the East Sea, the Malacostraca in the South Sea, and the Annelida in the West Sea. Through SIMPER analysis, species contributing to the similarity of benthic macroinvertebrates communities in each sea area were identified. Some species greatly influenced the similarity of clusters. The benthic community in the East Sea was affected by the salinity, so the contribution rate of freshwater species was high. On the other hand, the benthic communities of the South and West Seas showed species compositions are influenced by the substrate composition. As results, the benthic macroinvertebrate community in Korean estuaries was impacted by salinity and substrate simultaneously, and the close relationship with geographical distance was not observed. The result of this study is expected to be used to respond to environmental changes by identifying and predicting changes in the diversity and distribution of benthic macroinvertebrates in Korea estuaries.

• Korean Journal of Ecology and Environment
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• v.43 no.2
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• pp.190-198
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• 2010

This study was conducted to examine the effects of dams on benthic macroinvertebrate communities in Korean streams and rivers. Four low-head dams and three large dams were studied throughout South Korea. Sampling was taken at immediately upper (impoundment), lower (riffle area), and control (riffle area) sites from the dams during 2004-2007. The upper sites, of which substrate heterogeneity and velocity were relatively low, showed a lower degree of species richness, density, and diversity indices, which is very different from the lower and control sites. Heavily polluted streams showed a lesser degree of community differences between the upper and lower sites. In the large dams, the upper and lower sites showed very low values of species diversity indices and very high values of dominance indices compared to the control sites. In the low-head dams, however, the difference of degree of the values was relatively smaller. Compositions of the functional feeding groups and the habitat orientation groups were relatively simpler at the upper sites than at the lower sites and the degree of difference was greater in the large dams. Species richness and community indices of benthic macroinvertebrates were more significantly affected by habitat characteristics than water quality at the upper sites; however, those were more significantly related with water quality at the lower sites. In conclusion, large and low-head dams could simplify stream habitats particularly at the upper sites (impoundment), and they negatively affected on the benthic macroinvertebrate communities inhabited the habitats. The impact was larger in the large dams than in the low-head dams.

• Journal of Korean Society on Water Environment
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• v.34 no.1
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• pp.84-95
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• 2018

The community structure of benthic macroinvertebrates in the fine sediments of freshwater was analyzed according to various sampling tools and methods. The sediment core with the inner diameter of 7.5 cm was more effective in cost and labor in comparison to that of ${\Phi}5cm$ or ${\Phi}10cm$. The number of species increased with the increase in sample size (replicates). When it was collected five times with the ${\Phi}7.5cm$ sediment core, Shannon-Weaver's diversity and McNaughton's dominance of the sample reached about the 80 % level of the community estimates. Most species appeared in the sediment layer of 0-4 cm, and there were no newly recruited species below the depth of 4 cm. Individual abundance of benthic macroinvertebrates decreased exponentially along with the increase in sediment depth. Compared with the individual abundance of the 0-15 cm sediment layer, the abundance was 60 % in the 0-2 cm layer, 25 % in the 2-4 cm layer, 10 % in the 4-6 cm layer and 95 % in the 0-6 cm layer. Compared with organisms collected with the sieve of 0.2 mm pore, the number of species and the individual abundance sifted through the sieve with pore of 1 mm were 36 % and 88 %, and those with pore of 0.5 mm were 5 % and 55 %, respectively.