• Korean Journal of Ecology and Environment
• /
• v.40 no.1
• /
• pp.163-172
• /
• 2007

In this study, fish fauna and stream characteristics were surveyed during October-November 2003 in 31 small streams, which are small sub-tributaries of Geum River. The small streams were classified into 4 types of steep mountainous (SM), mountainous-flatland (MF), flat land (FL), and agricultural watercourse (AW) streams, and their types were categorized by features of stream width, water depth, bottom substrate, riparian vegetation, and landuse patterns. The fishes collected during this survey were identified 4 families and 8 species. Dominant family was Cyprinidae, and the most dominant species was Rhynchocypris oxycephalus with 73% (419 individuals) of the total. Only one species of R. oxycephalus was observed in the all five steep mountainous streams, which was surrounded by 100% forest area and had no point-and non-point pollution sources. The observed frequency of R. oxycephalus (as a relative proportion of species) showed a significant positive correlation (r=0.754, p<0.001, n=31) with the substrate composition of bedrock and boulder, indicating that the species prefer the bedrock and boulder rather than the sand or small pebble. Evidently, all five steep mountainous streams were judged as excellent condition (1st rank) according to the criteria of biological water quality, the Ministry of Environment, Korea. This result was accord with a general tendency of the species in most upper stream of the Koreas streams. One family and one species were found at the steep mountainous types and 4 families 6 species were at the mountainous-flatland. Four families 8 species were found at the flat land, which showed most diverse habitat, and 2 families 2 species were collected agricultural watercourse. These study results of 1st-order streams suggest that R. oxycephalus was considered as one of 1st rank ecological indicator species, and that the dominant area should be protected from various pollutions and disturbances.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.31 no.2
• /
• pp.226-244
• /
• 1998

The relationship between the transport of eggs and larvae of Anchovy (Engraulis japonica) and the oceanic condition in the southern sea of Korea was examined on August and November 1996. In summer (August), when the Tsushima Warm Current is strong near to the coast, the warm waters such as warm streamers from the Tsushima Warm Current intrude into the coastal area, and cyclonic circulations are formed. The warm water intrusions also generate wakes around Komun Island, Sori Island and Koje Island. In the coastal area where the warm water intrusions occur, the nutrients, dissolved oxygen, suspended solid and chlorophyll are concentrated in probably relation to the upwelling concerned with this warm streamer and/or the wakes. Anchovy eggs and larvae are transported to the coastal area by the cyclonic circulations. The hatching and growth of anchovy larvae are increased because of high primary production in the cyclonic circulations. However, as the amount of Copepods which are a main food for anchovy larvae decrease in the coastal area, anchovy larvae seem to move to the Isushima Warm Water area for seeking a prey. In autumn (November), the Tsushima Warm Current is far away from the coast. In this season the warm water intrusions almost disappear, and the small scaled frontal eddies are formed between the coastal water and the Tsushima Warm Water. As the surface water moves towards offshore, few anchovy eggs and larvae were sampled in the survey area. Chemical and biological substances are concentrated in the leftdown sides of the small scaled frontal eddies because of eddy formation.

• Korean Journal of Environmental Biology
• /
• v.36 no.2
• /
• pp.217-231
• /
• 2018

Planktonic ciliates play an important role in the food web of marine ecosystem as well as a bio-indicator for invasive species from ballast waters or from changing flow of ocean currents due to climate changes. This study was carried out to find some evidences for introduction of such invasive species using ciliate plankton in four major international ports of Korea. We surveyed the seasonal species composition of planktonic ciliate to find out the evidence for the invasive species at Busan, Ulsan, Gwangyang and Incheon ports from February 2007 to November 2008. A total of 45 ciliates species, belonging to 15 genera, were identified during the study period: 33 species occurred at Busan, 31 at Gwangyang, 30 at Ulsan, 18 at Incheon. The abundance of naked ciliates ranged from 566 to $65,151cells\;L^{-1}$ and that of tintinnids 10 to $5,973cells\;L^{-1}$. Based on vector species of ciliates reported from Coos Bay in Oregon, 13 vector species of tinitinnids were identified as follows, Eutintinnus lususundae, E. tubulosus, Favella ehrenbergii, F. taraikaensis, Helicostomella subulata, Stenosemella nivalis, Tintinnopsis ampla, T. beroidea, T. cylindrica, T. directa, T. lohmanni, T. radix, T. rapa. All vector species occurred at Gwangyang port. Most tintinnids were mainly neritic species throughout the survey, while warm water species occurred only in short period at Busan, Ulsan and Gwangyang ports that might be affected seasonally by Tsushima warm current.

• Korean Journal of Environment and Ecology
• /
• v.34 no.6
• /
• pp.515-529
• /
• 2020

Constructed wetlands undergo biological and physical changes such as an increase in the proportion of arid plants due to the natural succession process after formation. It can adversely affect not only the purification function but also the habitat of species. As such, this study aims to identify environmental factors affecting biodiversity and propose management plans based on the monitoring results of physical environmental changes and the emergence of species in seven constructed wetlands selected based on the water depth and surrounding conditions among the lands purchased by the Nakdong River basin. We examined the environmental conditions and emergence of the Odonata, which is a wetland-dependent species, to predict the trend of changes in biodiversity and abundance. The results showed that the open water area decreased as the emergent plants spread to the deep water in 2015 compared to 2012 when they were initially restored to a depth of 0.2 to 1 m. While a total of 54 dragonfly species were observed, the habitat diversity, such as vegetation, water surface, and grassland, remained similar to the initial formation of the wetlands despite the expansion of the emergent plants. On the other hand, the number of Agrionidae species, which prefer areas with fewer aquatic plants, decreased between 2012 and 2015 due to the diminished water surface. The p-values of the differences in the number of species and population between wetlands by year were 2.568e-09 and 1.162e-08, respectively, indicating the statistically significant differences. The decrease in open water surface was found to have the greatest effect on the biodiversity and habitat density of dragonflies. The time-series survey of constructed wetlands confirmed that the spread of Phragmites communis, P. japonica, Typha orientalis, etc., caused a decrease in species diversity. It suggests that environmental management to maintain the open water surface area is necessary.

• Ecology and Resilient Infrastructure
• /
• v.9 no.3
• /
• pp.163-173
• /
• 2022

Climate change is a key factor that greatly influences changes in the biological seasons and geographical distribution of species. In the ecological field, the BioClimatic predictor (BioClim), which is most related to the physiological characteristics of organisms, is used for vulnerability assessment. However, BioClim values are not provided other than the future period climate average values for each GCM for the Shared Socio-economic Pathways (SSPs) scenario. In this study, BioClim data suitable for domestic conditions was produced using 1 km resolution SSPs scenario detailed data produced by Rural Development Administration, and based on the data, a species distribution model was applied to mainly grow in southern, Gyeongsangbuk-do, Gangwon-do and humid regions. Appropriate habitat distributions were predicted every 30 years for the base years (1981 - 2010) and future years (2011 - 2100) of the Acer pictum subsp. mono. Acer pictum subsp. mono appearance data were collected from a total of 819 points through the national natural environment survey data. In order to improve the performance of the MaxEnt model, the parameters of the model (LQH-1.5) were optimized, and 7 detailed biolicm indices and 5 topographical indices were applied to the MaxEnt model. Drainage, Annual Precipitation (Bio12), and Slope significantly contributed to the distribution of Acer pictum subsp. mono in Korea. As a result of reflecting the growth characteristics that favor moist and fertile soil, the influence of climatic factors was not significant. Accordingly, in the base year, the suitable habitat for a high level of Acer pictum subsp. mono is 3.41% of the area of Korea, and in the near future (2011 - 2040) and far future (2071 - 2100), SSP1-2.6 accounts for 0.01% and 0.02%, gradually decreasing. However, in SSP5-8.5, it was 0.01% and 0.72%, respectively, showing a tendency to decrease in the near future compared to the base year, but to gradually increase toward the far future. This study confirms the future distribution of vegetation that is more easily adapted to climate change, and has significance as a basic study that can be used for future forest restoration of climate change-adapted species.

• Journal of the Korean Society of School Health
• /
• v.11 no.2
• /
• pp.171-187
• /
• 1998

In recent years, adolescent issues including smoking, drinking, drug abuse, juvenile delinquency, deviant sexual behavior, mental health problems, high suicide rate, juvenile delinquency and absence without due notice, etc are emerging as serious social problems and the debate on these controversial issues is heating up. The previous studies on adolescent health behavior and social juvenile delinquency such as run-away from home and absence without due notice have been conducted mostly by cause analysis utilizing social demographic factors or biological factors. In other words, the main factors analyzed were demographic and economic factors or parent's educational level, etc, which were the fixed environmental ones that were unable to cause the change in the health behavior. Accordingly, the purpose of this study is to analyze factors which are changeable and fixable among the factors influencing the adolescent's health behavior and misconducts and, eventually influencing factors which can be used as the basis to establish health policies and health promotion program to reduce the health risk behavior and misconducts of adolescents. The study subjects were selected by dividing senior high school student in Seoul by region and through random sampling. The 890 subjects were selected from 10 schools including the preparatory school, vocational schools and institutional schools. The duration of the study was for July 1-5, 1997 for the first survey and the second one, for August 25-September 10. Regarding the analysis method, the SAS program was used. The adoptablity of theoretical model was tested through covariance structural analysis utilizing PC-LISREL 8.12 Program. The major findings of the study are as follows: As a result of establishing the model of factors influencing health behavior and juvenile delinquency, in case of male students as the health behavior self-efficacy, education level of fathers, economic level, self-control and the health interest of parent were higher, students were more likely to practice the health promoting behavior. Juvenile delinquency and health risk behavior were prevalent among those with the less shyness, the lower health behavior self-efficacy, lower self-control, lower self-assertiveness, lower economic level. The self-control was the most powerful factor. In case of female students, those with higher health behavior self-efficacy were more likely to practice the health promoting behavior whereas those with lower health behavior self-efficacy, lower self-control, lower self- assertiveness, less shyness were more likely to practice health risk behavior and juvenile delinquency. In case of prep schools, those with higher health behavior self-efficacy and better perceived health status were more likely to practice the health promoting behavior while those with less shyness, lower health behavior self-efficacy and lower academic achievement were more likely to engage in health risk behavior and juvenile delinquency. In case of vocational schools, as health behavior self-efficacy and economic level were higher, the practice rate of health promoting behavior was higher. As the self-control, shyness, self-assertiveness, health behavior self-efficacy were lower, the rate of health risk behavior and juvenile delinquency were higher. In case of social institutional schools, as, the health behavior self-efficacy, social support and economic level, health interest of parents were higher, the rate of health promoting behavior were higher. As the self-control, shyness, self-assertiveness, health behavior self-efficacy and social support were lower, the rate of health risk behavior and juvenile delinquency were higher. So the health promoting behavior was positively related to the health behavior self-efficacy, health interest of parents, social support, education level of fathers, level of perceived health status, economic level. The health risk behavior and juvenile delinquency were higher with the lower health behavior self-efficacy, self-control and self-assertiveness, lower health locus control, less shyness and loneliness, lower economic level and academic achievement. In conclusion, the health risk behavior and juvenile delinquency can be reduced by enhancing self-control, self-assertiveness, health behavior self-efficacy and social support. According to the final model drawn by connecting health behavior and juvenile delinquency, the reduction of health risk behavior can greatly contribute to decreasing social juvenile delinquency as the process of juvenile delinquency was extended from common behaviors to problem behaviors and further into juvenile delinquency.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.24 no.6
• /
• pp.750-763
• /
• 2018

This study conducted 10 sampling sites survey 4 times to determine the trophic structure and energy flow of marine ecosystems for Uljin marine ranching area, Korean East Sea from March to October 2013. Based on the ecological characteristics of biological species, one used the non-Metric Multidimensional Scaling method based on the similarity of species. A total of 19 classified species groups formed categories including, top predators, seabirds, large pelagic fishes, small pelagic fishes, rockfishes, pleuronectiformes, benthic fishes, semi-benthic fishes, cephalopods, benthic feeders, epifauna, bivalves, abalone, Cnidaria, zooplankton, benthic algae, microalgae, phytoplankton and detritus. The biomass, production/biomass, consumption/biomass, diet composition data of each species groups to input data used in Ecopath mode estimated the trophic structure and energy flow of marine ecosystems in the Uljin marine ranching area. One estimated each species groups on the trophic level from 1 to 5.687. The sum of all consumption was estimated at $229.7t/km^2/yr$ and the sum of all exports was as estimated $3,432.4t/km^2/yr$. Total system throughput was at $6,796.2t/km^2/yr$, and the sum of all production was estimated at $3,613.1t/km^2/yr$. Net system production according to these results was estimated at $3,490.3t/km^2/yr$ and total biomass (excluding detritus) was estimated at $167.3t/km^2/yr$ in the Uljin marine ranching area.

• Journal of Preventive Medicine and Public Health
• /
• v.42 no.2
• /
• pp.89-95
• /
• 2009

Objectives : To assess the protective effects of wearing protective devices among the residents and volunteers who participated in the cleanup of the Hebei Spirit oil spill. Methods : A total of 288 residents and 724 volunteers were surveyed about symptoms, whether they were wearing protective devices and potential confounding variables. The questionnaires were administered from the second to the sixth week following the accident. Spot urine samples were collected and analyzed for metabolites of 4 volatile organic compounds(VOCs), 2 polycyclic aromatic hydrocarbons(PAHs), and 6 heavy metals. The association between the wearing of protective devices and various symptoms was assessed using a multiple logistic regression adjusted for confounding variables. A multiple generalized linear regression model adjusted for the covariates was used to test for a difference in least-square mean concentration of urinary biomarkers between residents who wore protective devices and those who did not. Results : Thirty nine to 98% of the residents and 62-98% of volunteers wore protective devices. Levels of fatigue and fever were higher among residents not wearing masks than among those who did wear masks(odds ratio 4.5; 95% confidence interval 1.23-19.86). Urinary mercury levels were found to be significantly higher among residents not wearing work clothes or boots(p<0.05). Conclusions : Because the survey was not performed during the initial high-exposure period, no significant difference was found in metabolite levels between people who wore protective devices and those who did not, except for mercury, whose biological half-life is more than 6 weeks.

• Korean Journal of Environment and Ecology
• /
• v.33 no.3
• /
• pp.266-279
• /
• 2019

We investigated the characteristics of fish communities and habitat status of endangered species Rhodeus pseudosericeus in Heuk Stream, a tributary of the Han River, from April to October 2018. During this period, we collected 47 species of 14 families from 10 survey stations using kick nets, cast nets, and long bag set nets. The dominant and subdominant species were Zacco platypus (37.6%) and Z. koreanus (13.8%), respectively. The next most abundant species were Squalidus gracilis majimae (11.1%), Pungtungia herzi (7.7%), Rhodeus pseudosericeus (5.0%), Microphysogobio yaluensis (4.3%), and Hemibarbus longirostris (3.0%). Among the fish collected, 19 species (40.4%) were Korean endemic species. Endangered species were R. pseudosericeus and Acheilognathus signifer while exotic species were Micropterus salmoides and Oncorhynchus mykiss, and land-locked species were Plecoglossus altivelis and Rhinogobius brunneus. The community analysis showed that the dominance and evenness indexes were mostly low and that the diversity and richness indexes were high. Moreover, the river health (index of biological integrity) was mostly excllent (1 site is good, 9 sites are very good). R. pseudosericeus inhabited widely from St. 3 to St. 9 in Heuk Stream, and its population size was large. Age groups for R. pseudosericeus estimated by the frequency distribution of total length in spawning season (April) indicated the 32~45 mm group as 1-year old, the 46~59 mm group as 2-years old, 60~69 mm group as 3-years old, and the 70~89 mm group as 4-years or older. Total length range of male and female was similar, and the sex ratio of female (426) to male (394) was 1 : 0.95. A. signifer, which had been released in Heuk Stream, inhabited from St. 4 to St. 5, but its population size was small. Lastly, this paper discusses a conservation plan for fish in Heuk Stream.

• Korean Journal of Environment and Ecology
• /
• v.34 no.6
• /
• pp.530-542
• /
• 2020

This study surveyed the central mountain area of Demilitarized Zone (DMZ) from March to October 2018 to reveal the appearance patterns of freshwater fish. We collected 7,744 individuals of 43 species in 12 families with skimming nets and cast nets in 12 stations during the survey. The dominant species was Zacco koreanus (30.3%), and the subdominant species was Z. platypus (18.5%), followed by Rhynchocypris oxycephalus (10.0%), R. steindachneri (6.7%), Microphysogobio yaluensis (5.9%), Acheilognathus signifer (4.5%), Pungtungia herzi (4.2%), and Orthrias nudus (2.6%). Among the collected species, four were legally protected. They included Hemibarbus mylodon, which was a natural monument, and Lethenteron reissneri, A. signifer, and Pseudopungtungia tenuicorpa, which were class II endangered wildlife designated by the Ministry of Environment. Twenty Korean endemic species (46.5%) and one exotic species, Micropterus salmoides, were also collected. Additionally, three climate-change sensitive species, R. kumgangensis, Ladislavia taczanowskii, and Cottus koreanus, and three landlocked species, L. reissneri, C. koreanus, and Rhinogobius brunneus appeared. The dominant species in each station were Z. koreanus (15 stations), Z. platypus (four stations), R. oxycephalus (four stations), and C. koreanus (one station). The species dominance index decreased from upstream to downstream (mainstream of Gimhwanamdae Stream), while the species diversity index and the species richness index increased. The community structure of the rivers was divided into the uppermost stream, upper stream, Han River, and Imjin River. Compared to antecedent surveys, this study collected the highest number of species. Two new species (Sarcocheilichthys variegatus wakiyae and Micropterus salmoides) were caught, while six species (Siniperca scherzeri, Leiocassis ussuriensis, Brachymystax lenok tsinlingensis, Rhodeus ocellatus, Abbottina springeri, Aphyocypris chinensis) did not appear. Gimhwanamdaecheon Stream has high biological value with the inhabitation of many species, including species under legal protection and high diversity and richness index scores. This paper also discussed a protection plan for this area.