• Korean Journal of Ecology and Environment
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• v.37 no.4 s.109
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• pp.378-384
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• 2004

We investigated the variations of epilithic diatom community and assessed water quality of the water system of Ulleung Island by DAIpo in April, May, July, August, October, and November of 2003, and January and February of 2004. Samples were collected from four sampling stations. Total 95 taxa were identified from this study and dominant species were Nitzschia inconspicua, Achnanthes minutissima, Gomphonema angustum and Cocconeis placentuja var. lineata. The variation of DAIpo values was ranged from 51.14 to 77.77 and the water quality by DAIpo was estimated between ${\alpha}-oligosaprobic$ and ${\beta}- oligosaprobic$ states.

• Journal of Environmental Impact Assessment
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• v.28 no.2
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• pp.169-182
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• 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 Ecology and Environment
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• v.48 no.2
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• pp.115-121
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• 2015

In order to assess the water quality of Kumho river using Diatom Assemblage Index to organic water pollution (DAIpo) and to campare from the previous water quality, 5 sites in Kumho river were selected and assessed total of 6 times, every April and September from April 2010 to September 2012. As a result, 116 taxa were found in 2 Order, 3 Suborder, 7 Families, 26 Genera, 103 species and 13 varieties. Saprophilous species of 10 dominant species including Achnanthes minutissima, were increased as going to downstream sites. Correlation coefficients (r) between epilithic diatom communities and physicochemical factors were from - 0.62 to 0.71. Correlation coefficients (r) between TN and diatom indices (DAIpo, TDI) were 0.57 and 0.65, respectively. Therefore, epilithic diatom communities were greatly influenced by TN. The Correlation between DAIpo and TDI measured to be high in correlation coefficient (r=0.62) from the result of correlation analysis. Mean of DAIpo values ranged between 37.24~74.98 and decreased as going to downstream sites. Saprobic level was estimated as ${\beta}$-oligosaprobic at st. 1, ${\alpha}$-oligosaprobic at st. 2 and ${\beta}$-mesosaprobic at st. 3. But st. 4 and 5 which were ${\alpha}$-mesosaprobic and polysaprobic in the previous results, were improved as ${\beta}$-mesosaprobic. The RPId, general assessment of the water quality using DAIpo, was 52.27, which means the water quality of Kumho river was middle level.

• Journal of Korean Society on Water Environment
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• v.25 no.4
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• pp.606-614
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• 2009

To evaluate the biological water quality, diatom-based biological indices (DAIpo and TDI) were examined in the Sum-River and the Dal-stream. Having BOD concentrations below $2mg{\cdot}L^{-1}$ in most sites, water quality of both rivers was good. The DAIpo and TDI values ranged from 29.8 to 91.4 and from 38.7 to 93.0 respectively. From the biological water quality assessment, DAIpo and TDI for both rivers displayed fair to fairly poor water quality levels. However, the two indices showed more polluted conditions than expected from the BOD vlaues. In addition, DAIpo, having wider range of differences, appears to be more sensitive to the change in water quality when compared to TDI values. Statistical analysis using principal component analysis showed that Nitzschia palea and Diatoma vulgare might not be the appropriate indicators due to their low correlations with other indicators.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2004.05a
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• pp.245-248
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• 2004

다대포 갯벌의 YP는 0.06~0.13 mg/L이었고 진우도의 TP는 0.06~0.11 mg/L로 조사시기별로는 두 조사지역간 차이는 없었고 TN은 다대포의 경우 1.44~2.87 mg/L, 진우도는 0.15~1.09 mg/L로 조사되어 매 조사시기마다 진우도보다는 다대포에서 월등히 높았으며 두 지역 모두 해역의 어염등급에 비추어볼 때 상당히 오염이 진행된 상태였다. 조사된 미세조류는 Navicula, Nitzschia, Cyclotella, Cymbella, Synedra 등 13속 26종류로 호청수성 조은 Achnanthes convergence 등 1속 2종류, 호오염성 종은 Nitzschia palea 등 5속 8종류, 광적응성 종은 Cymbella minuta 등 3속 5종류였으며 매 시기마다 우점을 보인 종은 Nitzschia, Navicula 였다. DAIpo 지수는 다대포의 경우, 평균 31.1 진우도는 평균 48.4로 조사되어 비교적 낮은 DAIpo 값을 보였지만 계절별로는 다대포와 진우도의 경우 모두 봄인 5월에 가장 높은 DAIpo 값으로 비슷한 경향을 보였으나 다대포의 경우에서는 매 계절마다 진우도보다 더 DAIpo값이 낮게 조사되었다. DAIpo 값으로부터 갯벌의 오염도를 판정하면 다대포는 $\alpha$-중부수성, 진우도는 $\beta$-중부수성에 해당하여 다대포의 경우가 진우도보다 더 오염이 심한 것으로 조사되었다.

• Journal of Environmental Health Sciences
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• v.36 no.2
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• pp.148-154
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• 2010

In this study, a method for river water quality evaluation by algal examination was investigated. For development of this method, algae living in small rural streams in Gwangcheon-Cheon were collected and observed by microscope. Samples were collected at six stations from May 2008 to May 2009. To elucidate the relationship between pollution and the algal species, diatom grasps were collected from the streams and used to determine the water quality grade. The numerical EC value was compared with the value of DAIpo (Diatom Assemblage Index of Organic Water Pollution), and the results showed a tendency to a mutually inverse relationship. Further, the numerical BOD and COD values were compared to the DAIpo value. The results showed that, various diatoms reside in Gwangcheon-Cheon, and water quality was found to be second-grade at all the examined points. These results indicate pollution of streams by livestock wastewater; however continuous monitoring will be necessary to more definitely determine the reason for the Gwangcheon-Cheon pollution.

• Korean Journal of Ecology and Environment
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• v.50 no.4
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• pp.470-477
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• 2017

The aims of this study were to analyze the physico-chemical factors and the characteristics of epilithic diatom community from 15 sites of the Naeseongcheon and tributaries located in the upper region of the Nakdong river from May to October 2016. The biological water quality was assessed using DAIpo and TDI. A total of 163 diatom taxa were identified with 2 orders, 3 suborders, 9 families, 35 genera, 145 species, 16 varieties and 2 forms. Cocconeis placentula var. lineata appeared at every examined sites. Achnanthes lanceolata, Nitzschia fonticola, Nitzschia inconspicua and Reimeria sinuata were common taxa of the Naeseongcheon. Nitzschia inconspicua and Achnanthes minutissima were major dominant species. As a result of the CCA, Electrical conductivity and total nitrogen concentration were important factors determining the diatom species composition. In the result of the biological assessment using DAIpo, the Naeseongcheon was rated at class B with an average of 62.38. In the result of assessment using TDI, the Naeseongcheon was rated at class C with an average of 66.12.

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

• Journal of environmental and Sanitary engineering
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• v.19 no.2
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• pp.45-50
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• 2004

To investigate the epilithic diatom community and water quality of the Osan stream, water samples were collected from the eight stations from April to September 2003. Sampling was two times before and after heavy rain. Total 52 diatom were identified and divided into 12 saproxenosus taxa, 6 saprophilous taxa and 34 indifferent taxa, respectively. The DAIpo values higher after heavy rain than before that. According to tolerance degree to the organic water pollution, all sampling stations ranged from $\alpha$-oligosaprobic to $\alpha$-mesosaprobic. Thus, the result indicates that the water quality of Osan stream is gradually improved by heavy rain.

• Korean Journal of Ecology and Environment
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• v.45 no.3
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• pp.289-301
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• 2012

A biological assessment of water quality was made at 9 sites of the Joyang-river and inflow streams located in Jeongseon-gun Gangwon-do, from June 2008 to September 2010. The investigation consisted of physico-chemical factors, biomass, and standing crops of epilithic diatoms. In addition, the community structure of epilithic diatoms was analyzed, and the water quality was assessed using DAIpo and TDI. The pH varied from 7.4~10.2 which is attributed to the Joyang-river area consisting of limestone. A total of 117 taxonomic groups of epilithic diatoms, including: 2 orders, 6 families, 23 genera, 95 species, 15 varieties, 2 forms, and 5 unidentified species, were found in the Joyang-river. 11 taxa, including Achnanthes laterostrata and Cymbella delicatula which live in neutral to alkali pH, were found. An indicator species of alkali waters, Cymbella delicatula, was routinely observed to have a relative frequency of over 10% in I3 and I4. In the result of the biological assessment using DAIpo, the Joyang-river was rated class A, with an average of 77.03 and inflow streams were rated class B with an average of 65.84. As for the results of TDI analysis, the Joyangriver was rated class A~B, and inflow streams were rated class A~D. Accordingly, the water quality of the Joyang-river was determined to be superior to that of inflow streams. Although the main stream showed low water quality at sites J2 and J3, correlating with a reduction in the quality of inflow stream, I1 in September 2009.