• Journal of Korean Society on Water Environment
• /
• v.28 no.4
• /
• pp.531-537
• /
• 2012

The information about the physicochemical environments, the species distribution and community of the epilithic diatom cells in Pyengchang river and inflow streams of Gangwon-do were studied for assessment of biological water quality from June 2008 to October 2010. Total 112 diatom taxa were identified with 2 orders, 9 families, 26 genera, 95 species and 17 varieties. Among the total taxa identified, 13 taxa, 52 taxa and 15 taxa represented the family Achnanthaceae, Naviculaceae and Bacillariaceae, respectively. The pH values of the water was found to be neutral to alkaline due to the limestone grounds of Pyengchang river and inflow streams. The 13 taxa including Epithemia adnata, belonged to alkaline-water diatoms, and three species - Cymbella japonica, Eunotia major and Fragilaria capitellata - are known to be acidic-water species. The species, Hannaea arcus, known as a cryophilic and mountain periphyton was identified at IF2, IF3 and IF4 in low water temperature environments at high altitudes, being a dominating species in P1 and IF1. Four saproxenous species - Achnanthes convergens, Cocconeis placentula var. lineata, Cymbella turgidula and Hannaea arcus - were dominant at some sampling sites. For biological water quality assessment, IF2, IF3 and P3 showed low water quality class. The values of DAIpo and TDI were 10.6 ~ 98.0 and 13.8 ~ 94.2, respectively. Therefore, biological water quality in Pyengchang river and inflow streams was relatively desirable.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.58 no.3
• /
• pp.1-12
• /
• 2016

The objective of this study is to analyze the relationship between stream water quality of TN (total nitrogen), TP (total phosphorus), and BOD (Biochemical Oxygen Demand) and TDI (Trophic Diatom Index) score determined by physico-chemical factors, biomass, and standing crops of epilithic diatoms, and to estimate the required amount of ecological streamflow for good water environment of Trophic Diatom. For the main stream of Chungju dam watershed of South Korea, total 100 field data of 3 years (2008~2010) measured in May and September were used to derive the relationship between water quality and TDI. Trophic Diatom had high correlation (0.55 determination coefficient) with TN. Using the relationship, the required streamflow was evaluated by using the Soil Water Assessment Tool (SWAT) for good Trophic Diatom water environment through T-N water quality maintenance. The SWAT simulated 8 years (2003~2010) stream discharges and T-N water quality along the main stream. From present garde C (score range: 30.0~45.0) to grade A (score above 60.0) of TDI, the May needs additional streamflow of $63.1m^3/sec$ (+36.7 % comparing with the present streamflow of $172.0m^3/sec$) at the watershed outlet.

• Proceedings of the Korea Society of Environmental Biology Conference
• /
• 2004.05a
• /
• pp.31-31
• /
• 2004

• Journal of Environmental Impact Assessment
• /
• v.28 no.2
• /
• pp.169-182
• /
• 2019

This study assessed biological water quality using epilithic diatoms in the Yeong river, Naeseong stream and Wi stream in the upper region of the Nakdong river from May to October 2016. Epilithic diatoms were not mobile, so they could reflect long-term water quality. The sampled epilithic diatoms were identified a total 158 taxa which were composed to 2 orders, 3 suborders, 8 families, 34 genera, 143 species and 15 varieties. Dominant species were Achnanthes convergens and Achnanthes minutissima at Yeong river, Nitzschia inconspicua at Naeseong stream, and Achnanthes minutissima, Cocconeis placentula var. lineata and Navicula minima at Wi stream. As a result of the CCA, Electrical conductivity, total nitrogen and total phosphorus were important factors determining the diatom species composition in the upper region of the Nakdong river. The correlation between diatom indices (DAIpo & TDI) measured to be high in the correlation coefficient (0.87) from the result of correlation analysis. In the result of the assessment of biological water quality using DAIpo and TDI, Yeong river was rated as class A at most sites. Naeseong stream was rated as class C to D at all sites except for N1 which was rated as Class A. Wi stream was rated as class B to C for DAIpo of W1, and TDI was rated as class D. The assessment of biological water quality at this site showed inferior TDI result compared to that of DAIpo. DAIpo and TDI of W2 were rated as class A to D, and the water quality has changed a lot. W3 and W4 were mostly rated as class B and C respectively.

• Korean Journal of Environmental Biology
• /
• v.37 no.2
• /
• pp.204-216
• /
• 2019

To evaluate the biological integrity of aquatic ecosystems, we developed Korean multimetric diatom index (KMDI) using metrics that many researchers have been previously described, and compared to single-metric diatom index such as trophic diatom index (TDI) and diatom assemblage index to organic pollution (DAIpo). For the biological and environmental data, we investigated the epilithic diatoms, water quality and the land-use for 923 sites in Korean streams between 2013-2017, and estuaries between 2010-2017, respectively. Five appropriate metrics were selected according to the following steps; 1) extraction of 300 potential metrics (biological, chemical, physical, and geographical) based on previous references, of these, 2) 46 samples having high separation power were selected, 3) the selected metrics were each tested for variability, redundancy, and sensitivity to the environments, finally 4) construction of multi-metric diatom index comprising single type metrics such as TDI, DAIpo, % motile diatoms, % Achnanthes / (Achnanthes+Navicula), and % number of Gomphonema species. The biological integrity of the 233 sites from the Geum River basin were independently investigated using KMDI. Collectively, the new KMDI showed high sensitivity and explanatory power for environmental factors such as land-use, biochemical oxygen demand, total nitrogen, and electric conductivity. However, it had slightly higher biological integrity for the same sites as compared to single type diatom metrics. Finally, more data accumulation from all over Korea and the development of acceptable diatom metrics were required.

• Korean Journal of Ecology and Environment
• /
• v.46 no.4
• /
• pp.551-560
• /
• 2013

Environmental factors and epilithic diatom communities in the lower streams near the harbor region of South Korean peninsula were examined during no monsoon period in May 2013. The sampling of water and epilithic diatoms was conducted at both streams, 19 regulated streams (RS) that there are one or several dams constructed in the river system, and 19 un-regulated streams (US) that there are no dams within the river. A cluster analysis based on the number of species and abundance of epilithic diatoms through the stations, divided into three groups such as groups I (mainly US), II (mixed with US and RS) and III (mainly RS), respectively. Group I showed that water quality is good and high diversity of diatom, while Group II and III was water quality is relatively poor, but not differed in biomass of diatom from Group I. In addition, Group II that had high conductivity, nitrogen and phosphorus, was the lowest in diatom diversity among them. Dominant species were Nitzschia palea (17%) and Navicula seminuloides (11%) in Group I, Nitzschia inconspicua (19%) and Navicula perminuta (9%) in Group II, and Nitzschia inconspicua (15%) and Nitzschia palea (14%) in Group III, respectively. These taxa were widely distributed in brackish water, and not closely related with specific water quality, like eutrophic water. However, the groups II and III belonged to RS, had not only little biomass, but bad water quality such as high concentrations of nutrient and chlorophyll-a. Therefore, to determine the effect of dam construction on the lower water ecosystem, the planktonic algae, which can occur algal bloom in the estuary, also was considered to be a parallel investigation.

• Korean Journal of Environmental Biology
• /
• v.26 no.3
• /
• pp.233-239
• /
• 2008

In order to access the water quality using epilithic diatom assemblage index to organic water pollution (DAIpo) in the lower part of the Han River, the diatom samples were collected biweekly at 2 stations by means of artificial substrates of ceramic tiles from February, 2004 to February, 2005. A total of 60 taxa, representing 18 genera 51 species, 7 varieties and 2 forms, of diatoms were identified in the present study. Dominant percentages of Aulacoseria granulata and Melosira varians (Indifferent taxa) were 22.76$\sim$30.30% and 17.44$\sim$34.78%, respectively, and Nitzschia palea (Saprophilous taxa) were 15.00$\sim$31.76% at St. 1. In St. 2, the percentages of dominant species, N. palea, were 19.86$\sim$58.20%. Average DAIpo index was 40.6 in St. 1 and 32.1 in St. 2, and the saprobic level was shown $\beta$-mesosaprobic in the lower part of the Han River. It is suggested that epilithic diatoms as bioindicators and a DAIpo index indicate useful for analy-zing assessment of the water quality.

• Korean Journal of Environmental Biology
• /
• v.32 no.1
• /
• pp.16-25
• /
• 2014

To identify distribution of epilithic diatom assemblages and the relationship between diatoms and water chemistry, samples were collected twice a year from 2008 to 2012, from at 6 streams in Jeju Island, South Korea. A total of 171 diatom taxa were identified, and Achnanthes lanceolata, Gomphonema pumilum, Melosira varians, Navicula minima and Nitzschia palea were dominantly observed. BOD ranged 0.0~1.6 mg $L^{-1}$, TN 0.230~13.240 mg $L^{-1}$ (average 4.432 mg $L^{-1}$), TP 0.020~0.316 mg $L^{-1}$ (average 0.092 mg $L^{-1}$), and N/P rate ranged 2.5~178.5. Average of epilithic algal chlorophyll-a and AFDM were 1.1 ${\mu}gcm^{-2}$ and 0.6 mg $cm^{-2}$, respectively. According to BOD standard, the water qualities of study area sites were at 'Good' level. However, the healthiness levels assessed from DAIpo and TDI were 'Fair' to 'Poor'.

• Journal of Plant Biology
• /
• v.37 no.4
• /
• pp.417-420
• /
• 1994

Morphology of Achnanthes alteragracillima Lange-Bert. was studied with scanning electron microscopy in epilithic samples from the Kwang River (Kwangchun), Kyungsangbuk-Do, Korea. The species was characterized by the external raphe terminal fissure deflecting up to valve margin, the internal raphe proximal endings slightly deflecting to the opposite direction each other and biased hyaline area at the valve pole. It could be distinguished from A. minutissima K tz., closely related species, in having not straight external raphe terminal fissures, and from A. convergens H.Kob. in having a biased hyaline area at the valve pole and not a convergent striae arrangement at the pole of the raphe valve.

• Korean Journal of Ecology and Environment
• /
• v.48 no.3
• /
• pp.153-167
• /
• 2015

In order to understand the relationship between the distribution of epilithic diatoms and the habitual environments, land-use, water qualities, and epilithic diatoms were studied at 141 sampling sites in the midwestern stream of Korean peninsula (Geum river, Mangyeong river, Dongjin river, and Sapgyo river). The total 183 diatom taxa was appeared in the study, while the dominant species were found to be Nitzschia palea (10.9%) and Achnanthes convergens (8.4%). Based on the abundance of epilithic diatoms, a cluster analysis results indicate that the sampling sites divided the sampling sites into 4 groups (G) at the 25% level. In term of geographic and aquatic environments, G-I and -II accounted for the upper and mid streams of the Geum river, and had large forest areas and good in water quality. G-III accounted for farmland and urban, and high concentration nutrient levels (TN and TP) and electric conductivity. G-IV accounted for mostly farmland, and high levels in turbidity, BOD, nutrient and electric conductivity. CCA results showed that the saproxenous taxa Meridion circulare was the indicator species of G-I, which strongly influenced by altitude and forests. In G-II, the indifferent taxa Navicula cryptocephala was influenced by Chl-a, AFDM, and DO. In G-III and -IV, the indifferent taxa Fragilaria elliptica and saprophilous taxa Aulacoseira ambigua were influenced by electric conductivity, turbidity, and nutrient counts. Meanwhile, random forest results showed that the predicting factor of indicator species appearance in G-I, -II, and -III was found to be electric conductivity whereas in G-IV it was found to be turbidity. Collectively, the distribution of diatoms in the midwestern of Korean peninsula was found to depend more on the land-use and its subsequent water qualities than the inherent characteristics of the aquatic environment.