• Proceedings of the Korea Society of Environmental Biology Conference
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• 2003.11a
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• pp.12-15
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• 2003

The effects of the non-steroidal ecdysteroid agonist tebufenozide on larvae of C. faviplumus and C. riparius were tested in the laboratory. In the most treatments it reached a statistically significant difference from the control condition. As the concentration of tebufenozide was increased, a relatively larger proportion of the observed mortality was associated with the metamorphosis and molting process. Also, the larval mortality of the first larvae was higher than the fourth-instar larvae in C. riparius. In terms of development, the effects of tebufenozide were delayed growth stage in relatively lower concentration such as 10 $\mu\textrm{g}$/L treatments. Based on the mortality, the susceptibility followed the first-instar C. riparius > the fourth-instar C. flaviplumus > the fourth-instal C. riparius. The morphological effects showed that the first and second segments of body of exposed larvae with tebufenozide expanded slowly and not made a complete cephalothorax of pupae during long times or days. And the head capsule slipped down and forward, revealing a fragile and non-pigmented, unsclerotized new head capsule. There was obvious significant difference in the male/female ratio in contaminated fourth larvae of C. riparius. Also, due to the different emergence periods of male/female in low insecticide concentrations, mating chances or opportunities of insects should be decreased. Accordingly, ecological strategies for keeping of sustainable populations should be disrupted.

• Journal of Environmental Science International
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• v.27 no.11
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• pp.1007-1021
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• 2018

Community dynamics of benthic macroinvertebrates and biological evaluation of water quality were investigated at Gigyecheon of Pohang and Gyeongju, Korea. The survey was carried out at 8 sites from May to October, 2017. As a result, total of 104 species under 54 families, 15 orders, 8 classes in 4 phyla with 5,052 individuals were revealed. The number of species was the most abundantly identified in aquatic insects, 76 species under 34 families, 6 orders. Among them, the order Odonata was the most abundant taxon as 21 species(20.2%). The most abundant individuals were collected in the phylum Mollusca as 1,453 individuals(28.8%). Various species appeared dominantly at each site by season, and the most dominant species was Caridina denticulata denticulata belonging to the class Malacostraca with 0.08 of dominance index. According to the results of community structure analyses, the diversity and richness indices were the highest at site II, the evenness index was the highest at site I, and the dominance index was the highest at site IV. The number of species and individuals of gathering collectors were the highest among functional feeding groups. Those of sprawlers were the highest among habitat orientation groups. The ESB showed a tendency to change according to season and site, and it was the highest in May at most surveyed sites. The KSI was also somewhat fluctuated according to season and site. From these indices, average biological water quality was evaluated as class II.

• Journal of Korean Society on Water Environment
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• v.39 no.4
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• pp.269-287
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• 2023

The genus-level biotic index of benthic macroinvertebrates (Benthic Macroinvertebrates Genus Index, BMGI) was developed and applicated based on the data collected from 13,347 sampling units of 814 sites from 2010 to 2021 in Korea. Tolerant values of 274 indicator taxa were established by analyzing the relationship between the relative frequency and abundance of indicator taxa and the water quality index considering biochemical oxygen demand (BOD₅), total suspended solids (TSS), and total phosphorus (T-P). BMGI showed a slightly higher correlation with water quality than the species-level biotic index (Benthic Macroinvertebrates Index, BMI) that was developed and applied in Korea. Although the BMGI does not contain species-level information, the reason why BMGI shows higher applicability than BMI seems to be due to the increase in the number of indicator taxa and the decrease in the misidentification of immature aquatic insects. The coefficient of determination in multiple regression with BOD₅, TSS, and TP for BMGI was 0.62 in the long-term averaged data of 814 sites, and the standardized coefficient of BOD₅ was -0.46, TSS was -0.17 and T-P was -0.21, respectively. As a result of the evaluation by BMGI, of the 814 sites, 38% were in good, 25% in fair, and 37% in poor condition.

• Korean Journal of Environment and Ecology
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• v.25 no.5
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• pp.691-709
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• 2011

This study was performed to classify habitat types depending on environmental factors and to find out distribution characteristics of functional feeding groups of aquatic insects which were collected at that habitat types. Field survey was conducted twice in a year for every spring and fall from 2007 to 2008 for 38 sites in the Geum River. During the field survey 15 environmental factors were measured at each 38 sites and analyzed by similarity analysis method to classify habitat types. The result of similarity analysis showed that the 38 sites could be grouped into 7 classes like as C1 and C3 class belong to Head water(HD), C2 and C4 and C5 class belong to Middle stream(MS), C6 and C7 class belong to Large River(LR) based on euclidean distances 4. And also, we could extract the main environmental factors affecting the classification of habitat types such as Stream Width and Elevation of physical environmental factors, Water Temperature, Conductivity and DO of chemical environmental factors, percentages of Sand, Silt and Gravel of substrate factors. Total 142 species of aquatic insects in 46 families, 9 orders were collected during the field surveys and the occurrence number of species and individuals showed high correlation with the Velocity factor and the percentage of Sand factor of each habitat types. In addition, correlation analysis between functional feeding groups and environmental factors represented that (1) Filtering-collectors(FC) affected by Velocity, Stream Width and Silt, (2) Gathering-collector(GC) affected by Velocity, (3) Predator(P) affected by Elevation, Velocity, Boulder, Conductivity and Sand, (4) Plant-piecer(PP) affected by Water Width and Silt, (5) Scraper(SC) affected by Elevation and Conductivity, (6) Shredder(SH) affected by Elevation, Boulder, DO, pH, Conductivity and Water Temperature respectively. As a result of this study, Elevation, Stream Width, Velocity, Conductivity, Water Temperature and percentage of Sand factors which were deduced by stepwise multiple regression analysis had correlations($r{\geqq}0.600$, p<0.01) with biota community inhabitation. Therefore these six environmental factors were regarded as major environmental factors that might affect highly the distribution of functional feeding groups in stream ecosystem of the Geum River.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.3 no.1
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• pp.27-37
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• 2000

This study aims at restoring urban forest destructed and eliminated by industrialization, urbanization, and city development and presenting a direction to manage remaining urban forest ecologically. To this end, an experiment zone where Populus tomentiglandulosa T. Lee were selective cutted and a control zone where Populus tomentiglandulosa T. Lee were kept intact were created in Chongdam Park located in Kangnam-ku, Seoul. Then, the structural changes of herbaceous plant species, the growth of targeted woody plants, and the increase of the number of insect and bird species were examined. The conclusions reached in this study are as follows. First, for the sake of ecological restoration and management of urban forest, it is good to selective cutting. Although timing, frequency, and methods may vary depending on the features and types of urban forest, the study revealed that selective cutting contributes to the restoration speed of origin vegetation and the enhancement of biodiversity including plants and insects. Second, as for the correlations of selective cutting and the appearance of plant species, the growth of origin vegetation, and insect distribution, the study showed that the impact of meteorological environment such as brightness is much greater than that of soil environment. Third, in order to manage urban forest, tramping pressure needs to be controlled efficiently. The efficient control of tramping pressure would contribute in the appearance of herbaceous plants. It would also be beneficial in promoting biodiversity of birds by removing the impact of people using routes. Fourth, in order to enhance the overall biodiversity of urban forest, diverse environment needs to be provided. In particular, it is necessary to supply water that is insufficient in urban forest. Providing habitats such as forest wetland performs an important function to amphibians and birds that require water as well as the appearance of aquatic plants and insects. Therefore, ways to introduce water efficiently should be initiated.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.44-44
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• 2003

Gene expression in five tissues of the abalone (Haliotis discus hannai) was investigated using an expressed sequence tag (EST) analysis. Randomly selected clones were obtained from cDNA libraries constructed with gill (GI), digestive diverticula(DD), hepatopancreas (HP), foot/mucus (FM) and rectangular muscle (RM). Of 1,235 clonesanalyzed (288 clones for GI, DD, HP each,166 for FM, and 205 for RM), 741 (60.0%) clones in total turned out to share significant similarity with the sequences from NCBI GenBank (less than 10/sup -3/ of e-values), 423 sequences showed poor similarity (> 10/sup -3/), and 71 sequences didn't match with any sequences in GenBank. The percent unique sequence (singleton) was ranged from 56.1% (RM) to 74.7% (FM) among libraries. On the other hand, overall percent singleton was 55.3% when all the ESTs from five libraries were assembled into contigs. Analysis of the organisms represented by the best hit for each EST (e-values < 10/sup -3/) showed that 23.8% matched with mammalian entries, 24.0% with mollusks, 14.4% with insects, 11.6% with fish and 26.2% with others. The expressed patterns differed among the tissues when judged by the categorization of the sequences from each library into 10 broad functional classes. In all the libraries, the class I (no hit o. poor similarity) was the largest category with an average of 40.1%. This largest class was followed by class V (general metabolisms) in DD (21.9%), GI (14.6%) and HP (16.7%), while the 'cell structure and motility'(class VI) was the second largest class in remaining two libraries (31.2% for RM and 9.6% for FM). The class IX (cell division and proliferation) was the smallest class in all the libraries (less than 3%). This report provides the first tissue-specific lists of expressed abalone genes, which could be a fundamental basis for genomics program of abalone species.

• Korean Journal of Ichthyology
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• v.21 no.4
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• pp.253-261
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• 2009

Habitat environment and feeding habitat of Iksookimia koreensis and Cobitis lutheri were investigated in the Mangyeong River, Jeollabuk-do, Korea from 2005 to 2006. They together inhabit the upper and middle stream, but they showed differences in their microhabitat. I. koreensis inhabited the stony zones of relatively rapid waters with a water depth of 30~60 cm, whereas C. lutheri lived in the sandy zones of relatively slow waters with a depth of 30~100 cm. The two species were active during daylight hours from March to October but hibernated in the winter season. During hibernation I. koreensis still lived in the gravel and stone and C. lutheri burrowed in the sand. I. koreensis ingested mainly chironomid and other aquatic insects, whereas C. lutheri fed mainly on Chironomidae, Copepoda and Branchiopoda. The feeding rate of both species was highest in April and September, but they did not feed in the winter.

• Journal of Ecology and Environment
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• v.44 no.1
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• pp.1-7
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• 2020

Background: Fish body size is a major determinant of freshwater trophic interactions, yet only a few studies have explored the relationship between the fish body size and trophic interactions in river upstream. In this study, we investigated the relationship between the body size and trophic position (TP) of Coreoperca kawamebari (Temminck & Schlegel, 1843) in an upstream of the Geum River. Results: A stable isotope analysis (based on δ¹⁵N) was used to determine the TP based on the body size of C. kawamebari. The regression analysis (n = 33, f = 63.840, r² = 0.68) clearly showed the relationship between the body length and TP of C. kawamebari. The TP of C. kawamebari was clearly divided by body size into the following classes: individuals of size < 10 cm that feed on insects and individuals of size > 10 cm feed on juvenile fish. This selective feeding is an evolutionarily selective tendency to maximize energy intake per unit time. Furthermore, the diet shift of C. kawamebari was led by different spatial distributions. The littoral zone was occupied by individuals of size < 10 cm, and those of size > 10 cm were mainly in the central zone. The littoral zone can be assumed to be enriched with food items such as ephemeropterans and dipterans. Conclusion: The TP of C. kawamebari, as a carnivorous predator, will have a strong influence on biotic interactions in the upstream area of the Geum River, which can lead to food web implication.

• Journal of environmental and Sanitary engineering
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• v.14 no.4
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• pp.50-68
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• 1999

The present study was performed to examine on the fauna and standing crops of benthic macroinvertebrates in Pongwha and Youngwol region of upper parts of south han river and Naktons river. The Actual site suvry was caried out on the two times during the April·June to October·November, 1988. Main five areas are Mt. Awrawe(1,067m), Mt. Sontal (1,236m), Mt. Munsu(1,206m), Peak Okyopong(357m) and Mt. Pungnak(760m) area. Total taxa of benthic macroinvertebrates of the study area were 118 species, 45families12 orders, 5 classes in 4 phyla. Occurrence species according to the major taxa of aquatic insects were 35 species (29.66%) in ephemeroptera, 25 species(21.19%) in trichoptera, 25 species(21.19%) hemiptera, 1 species(0.85%) in megaloptera. Non-aqautic insect were 5 species in mollusca, 3 ratio was 8.5 percent. Occurrence species(plecoptera) at clean waters were appeared 12 species at Mt. Awrawe and Sontal area. Occurrence species at each survey area was 67 species at Mt. Awrawe area, 60 species at Mt. Sontal area, 43 species at Mt. Munsu area, 37 species at Mt. P'ungnak area and 34 species at Peak Okyo area, respectively. Species diversity indices were 2.96~3.80 at Mt. Awrawe area, 2.79~3.62 at Mt. sontal area, but 2.64~3.12, 1.59~2.46 and 1.98~2.59 at, Mt. Munsu, P'ungnak and Peak Okyo area, respectively. In this region, occurrence species and individual density were smaller than that of Dong river with good habitat, but those were more abundant than that of Poseong river with similar environment conditions. Therefore, occurrence species and individual density of the present survey region were appeared as somewhat abundant.

• Korean Journal of Ichthyology
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• v.22 no.4
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• pp.249-255
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• 2010

Ecological characteristics of landlocked and anadromous populations of Hypomesus nipponensis were investigated from December 2008 to April 2009 in the Soyangho (landlocked population) and Hyangho (anadromous population). Morphological differences between the landlocked and anadromous populations were not found. The spawning season was March in the Soyangho and late February in the Hyangho. Individuals of both populations were sexually mature at sizes over 60 mm total length. Gonadosomatic index of the landlocked population (female: 20.5%, male: 3.7%) was higher than in the anadromous population (female: 17.4%, male: 3.3%). Number of eggs in the ovaries was greater in the anadromous Hyangho (7,325) population and fewer in the Soyangho (4,902) population; this corresponded to the greater total length in the former. Condition factor was 0.6 (0.49~0.74) in the Soyangho population and 0.7 (0.47~0.76) in the Hyangho population. Stomach contents of H. nipponensis consisted mainly of zooplankton and aquatic insects, and the size of prey was larger in the Hyangho population than in the Soyangho population.