• 한국환경보건학회지
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• 제30권3호
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• pp.264-271
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• 2004

An aquatic food chain was constructed to provide information of bioaccumulation of DEHP as followed: phytoplankton(Scenedesmus subspicatus) ${\rightarrow}$ zooplankton(Daphnia magna) ${\rightarrow}$ fish(Oryzias latipes). After 10 days of exposure to DEHP, the fish and culture water were analyzed for residual concentration of DEHP and BAF(Bioaccumulation Factor) was determined. In addition, BCF(Bioconcentration Factor) was calculated in exposure tank in which fish were only exposed DEHP by culture water. These experiments provide the relative importance between BAF and BCF. In this study, BCF and BAF did not show any significant difference. Another work in this study was model construction and application to investigate the effect of food chain structure to BAF in higher organism (fish). The model constructed in this study considered the biological characteristics of DEHP such as metabolic parameters, as well as the chemical characteristics such as solubility. This model could be used in prediction of bioaccumulation level in dependent of various food chain structures, when the target organisms or chemicals would be changed.

• 한국양식학회지
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• 제6권4호
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• pp.311-321
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• 1993

Ammonia accumulation is regarded as the limiting factor of the first priority in water qualities of aquatic culture systems. Nitrification efficiency and characteristics in seawater were evaluated using Rotating Biological Contactor (RBC) process as a part of the recycling water treatment facilities for marine fish culture system. Ammonia removal efficiency regarded 99.7 to $83.7\%$ at the ammonia surface loading rates of 48 to $393 mg/m^2$ -day. RBC process was able to withstand to the fluctuation of influent ammonia concentrations and loading and produced the stable effluent. The mathematical model on the fixed-film biological reactor developed by Kornegay seemed to be suitable to RBC process kinetic evaluation for the recycling water treatment of the marine fish culture system. Area capacity constant (P) and half-velocity constant (Ks) in the model were 0.188g/m^2$-day and 1.25mg/l, respectively.

• 한국지리정보학회지
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• 제15권1호
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• pp.99-118
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• 2012

본 연구는 하천구배에 따라 환경요인 및 생물군집이 변화한다는 하천연속성 개념(River Continuum Concept, RCC)을 금강 수계에 적용하여, 수서곤충 섭식기능군의 공간적 분포 특성과 환경요인 사이의 상관관계를 규명하기 위하여 수행되었다. 이를 위해, 수서곤충 생물군집의 서식에 영향을 미치는 물리 화학적 환경요인들과 생물군집의 분포관계를 단계적 다중회귀분석기법으로 분석하였다. 또한, 주요인으로 선정된 환경요인들에 따른 생물군집의 분포특성을 발생확률 예측기법인 빈도비 모델(Frequency Ratio Model, FRM)과 지리정보시스템(GIS)의 공간분석기법에 적용하여 수서곤충 섭식기능군의 분포예측도를 작성하였다. 연구 결과, 고도, 하폭, 유속, conductivity, 수온, 모래의 함량 등 6개 환경요인의 결정계수($R^2$)가 0.5 이상으로 나타나 수서 곤충 섭식기능군의 분포에 영향을 미치는 주요인으로 선정되었다. 그리고 작성된 분포예측자료와 연구지역에 대하여 기 조사된 실측자료를 비교 검증한 결과, 두 자료 사이의 평균제곱근오차(RMSE)가 0.1892~0.4242로 나타나 예측모델의 신뢰성을 확인할 수 있었다. 이 연구의 결과는 수서곤충 섭식기능군을 이용한 하천생태계의 새로운 평가방법 작성에 활용될 수 있을 것이며, 하천 서식지의 보전 및 복원을 위한 기초자료로 활용될 것으로 판단된다.

• 한국어병학회지
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• 제27권2호
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• pp.85-89
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• 2014

Water temperature is a key environmental factor controlling the epizootics of viral diseases in fish. High water temperature is associated with the rapid spread of rock bream iridovirus (RBIV) disease and with high mortality of RBIV infected fish. Although protection of fish against iridoviral disease by active immunization has been reported, little information is available concerning whether fish survived from an epizootic of iridoviral disease can naturally acquire resistance against the viral disease. In the present study, we have demonstrated that juvenile rock bream, which survived from a natural epizootic of RBIV, acquired resistance against recurrence or reinfection of RBIV, and this resistance was established during the subsequent low water temperature period. Furthermore, the possible involvement of the adaptive humoral immune response in the resistance of the juvenile rock bream was suggested by in vivo neutralization experiment.

• 한국수산과학회지
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• 제54권4호
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• pp.445-455
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• 2021

We aimed to study the structure of the zooplankton community in the Southern Sea of the Republic of Korea. Zooplankton samples were collected in February (winter), May (spring), August (summer), and November (autumn) of 2020. The zooplankton collected belonged to a total of 166 taxa and 12 phyla, including some unidentified individuals and those from upper taxa. The number of taxa collected were the highest in winter at 117, and the lowest in May at 93. The dominant taxa were Oikopleura spp. in the winter, Gastropoda larvae in the spring, and Paracalanus parvus s.l. in the summer and autumn. The community structure of the zooplankton was clearly distinguishable between the seasons. The mean density of zooplankton was the highest in autumn and the lowest in summer (576,039 and 313,000 individuals/1,000 m³, respectively). Based on the analysis of relationships between the density of the six major taxa and environmental factors, a significant correlation (P<0.05) between the four taxa and environmental factors was found. Therefore, in order to understand changes in the zooplankton community, quantitative and qualitative investigations of biological factors as well as physical factors should be conducted.

• 한국발생생물학회지:발생과생식
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• 제23권1호
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• pp.35-42
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• 2019

Fish shows great difference in growth rate between individuals during larval development and early growth. This difference seriously reduces the production efficiency in fish culture. Growth hormone (GH)/Insulin-like growth factor 1 (IGF1) system is said to play some pivotal roles in fish growth. In this study, we investigated differences of GH, IGF1 and GHR gene expressions in juvenile red spotted grouper (Epinephelus akaara) with different growth performance. Red spotted groupers were reared under the same environmental condition (water temperature $24{\pm}1^{\circ}C$, natural light) for 96 days after hatching. They were divided into 3 groups by size (fast growing, middle growing and slow growing groups: FGG, MGG, and SGG, respectively). RNA was extracted from the brain, liver and muscle tissues from each group, and target gene expression was examined by real-time PCR. In the brain with pituitary gland, expression of GH gene in FGG was significantly higher than the expression in SGG, but the expression of IGF1 and GHR genes in the muscle was highest in SGG. Difference of GHR and IGF1 mRNA in the liver between groups with different growth performance was less clear than that in other tissues, although level of IGF1 mRNA was higher in SGG than in MGG. These results suggest that hormonal governing of growth is not the same in fast growing and slow growing fish, and size grading could cause a shift of hormonal state and growth pattern in this species.

• 근관절건강학회지
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• 제10권1호
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• pp.19-31
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• 2003

Purpose : The purpose of this study was to examine the effect of the self- efficacy, group cohesion and family support on adherence of aquatic exercise in arthritis patients. Method : The Subjects were 30 patients with arthritis who had participated in the 6-week aquatic exercise programs of Korean Rheumatology Health Professionals Society. All subjects were interviewed from November to December, 2001(1st) and Feburary, 2002(2nd) using a structured questionnaire which was composed of 42 items. SPSS Win 10.0 was used for data analysis. Results : Ten out of thirty were adherer who were keeping aquatic exercise for three months since they completed 6-week aquatic exercise program. The major reasons of adherence were affectional reasons and general condition improvement on the first month. The reasons of 3-month adherence were improvement of arthritis symptoms, affectional improvement, expectations, general condition improvement and group activity. The major reasons of drop out were environment factors and physical factors. The environmental reason were time shortage, economic problem and long distance. And the physical factor were cold, pain and other health problem. The scores of self-efficacy were decreased from 528.00 to 476.00 within 3 months after compeleting aquatic exercise program and that was statistically significant(p=.029). But there were no statistically differences in group cohesion and family support. There was a significant positive correlation between exercise adherence and self-efficacy. Factors influencing the exercise adherence was self-efficacy which accounted for 23% of the variance in the exercise adherence. Conclusion : In conclusion, self-efficacy is a significant variable in the exercise adherence and changes within 3 month after completing aquatic exercise program. The results of this study suggested that the strategy for maintaining self-efficacy should be developed.

• Environmental Analysis Health and Toxicology
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• 제31권
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• pp.21.1-21.7
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• 2016

Objectives The present study analyzes metal contamination in sediment of the East Kolkata Wetlands, a Ramsar site, which is receiving a huge amount of domestic and industrial wastewater from surrounding areas. The subsequent uptake and accumulation of metals in different macrophytes are also examined in regard to their phytoremediation potential. Methods Metals like cadmium (Cd), copper (Cu), manganese (Mn), and lead (Pb) were estimated in sediment, water and different parts of the macrophytes Colocasia esculenta and Scirpus articulatus. Results The concentration of metals in sediment were, from highest to lowest, Mn ($205.0{\pm}65.5mg/kg$)>Cu ($29.9{\pm}10.2mg/kg$)>Pb ($22.7{\pm}10.3mg/kg$)>Cd ($3.7{\pm}2.2mg/kg$). The phytoaccumulation tendency of these metals showed similar trends in both native aquatic macrophyte species. The rate of accumulation of metals in roots was higher than in shoots. There were strong positive correlations (p <0.001) between soil organic carbon (OC) percentage and Mn (r =0.771), and sediment OC percentage and Pb (r=0.832). Cation exchange capacity (CEC) also showed a positive correlation (p <0.001) with Cu (r=0.721), Mn (r=0.713), and Pb (r=0.788), while correlations between sediment OC percentage and Cu (r=0.628), sediment OC percentage and Cd (r=0.559), and CEC and Cd (r=0.625) were significant at the p <0.05 level. Conclusions Bioaccumulation factor and translocation factors of these two plants revealed that S. articulatus was comparatively more efficient for phytoremediation, whereas phytostabilization potential was higher in C. esculenta.

• 한국수산과학회지
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• 제44권6호
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• pp.759-771
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• 2011

We evaluated the pollution levels of organic matter and metallic element (Fe, Cu, Pb, Zn, Cd, Ni, Cr, Mn, As, and Hg) in the intertidal surface sediments of Aphae Island using several sediment quality guidelines (SQGs) and assessment techniques for sediment pollution. Based on the textural composition of sediment, the surface sediments were classified into two main sedimentary facies: slightly gravelly mud and silt. The concentrations of chemical oxygen demand (COD) and acid volatile sulfide (AVS) in the sediments ranged from 4.6-9.9 (mean $7.4{\pm}1.1$) $mgO_2/g{\cdot}dry$ and from ND-0.53 (mean $0.04{\pm}0.10$) mgS/$g{\cdot}dry$, respectively. These values were considerably lower than those reported from a farming area in a semi-enclosed bay of Korea and for SQGs in Japan. The metallic element concentrations in the sediments varied widely with the mean grain size and organic matter content, implying that the concentrations of metallic elements are influenced mainly by secondary factors, such as bioturbation, the resuspension of sediment, and anthropogenic input. The overall results for the comparison with SQGs, enrichment factor (EF), and geoaccumulation index ($I_{geo}$) indicate that the surface sediments are slightly polluted by Cr and Ni, and moderately polluted by As. Our results suggest that the intertidal surface sediments of Aphae Island are not polluted by organic matter or metallic elements and the benthic conditions are suitable for healthy organisms.

• 한국수산과학회지
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• 제50권2호
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• pp.175-182
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• 2017

We examined the effects of environmental factors on zoospore release and germling growth of the green tide alga Cladophora albida under various conditions of temperature${\times}$irradiance (zoospore release), temperature${\times}$irradiance${\times}$ nutrient (germling growth), and a single factor test of salinity. Zoospore release was maximized at $30^{\circ}C$ and $100{\mu}mol\;photons\;m^{-2}s^{-1}$ in the temperature irradiance experiment and at 34 psu in the salinity experiment. Maximum germling growth was observed at $25^{\circ}C$ with $100{\mu}mol\;photons\;m^{-2}s^{-1}$ and PES (Provasoli's Enriched Seawater) in the temperature irradiance nutrient experiment, and at 34 psu in the salinity experiment. Germlings grew faster at higher irradiances for a given temperature level, and also grew faster as salinity increased over the range of 5-34 psu. Overall, optimal environmental conditions for zoospore release were $30^{\circ}C$, $100{\mu}mol\;photons\;m^{-2}s^{-1}$ and 34 psu. Maximal germling growth occurred at $25^{\circ}C$, $100{\mu}mol\;photons\;m^{-2}s^{-1}$, PES, and 34 psu. C. albida blooms are most likely to occur under these optimal environmental conditions, as plentiful zoospore release and rapid germling growth lead to population growth.