• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.893-900
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• 2009

To estimate the contribution of epiphytic algae attached on reed to organic matter production in constructed wetland, primary productivity by epiphytic algae was investigated in two sub-wetlands (Banweol and Donhwa wetlands) of the Sihwa Constructed Wetland (CW) with different chemistry of inflows. Chlorophyll a concentration of epiphytic algae was higher in the Banweol wetland (range:37~3,581 mgChl.a/$m^2$surface stem, average:655 mgChl.a/$m^2$surface stem) than the Donhwa wetland (range:87~2,093 mgChl.a/$m^2$surface stem, average:527 mgChl.a/$m^2$surface stem). In contrast, assimilation number (AN) representing photosynthetic activity was higher in the Donhwa wetland with low TN/TP ratio than the Banweol wetland. A negative correlation (r=0.46) was observed between TN/TP ratios of inflows and AN in two wetlands, implying that high photosynthetic activity of epiphytic algae may be related with low TN/TP ratio. The areal primary productivity ranged from 307 to 2,473 mgC/$m^2$/day in the Banweol wetland and from 756 to 2,096 mgC/$m^2$/day in the Donghwa wetland, showing high productivity in summer. Average primary production was lower in the Banweol wetland (1,166 mgC/$m^2$/day) than the Donghwa wetland (1,467 mgC/$m^2$/day), although the standing crop (as chlorophyll a concentration) was high in the Banweol wetland. This result may be due to the low photosynthetic activity of epiphytic algae in the Banweol wetland with high TN/TP ratio. The annual primary production (300 tonC/year) of epiphytic algae contributed 33% of the total production in the Sihwa CW. An excessive organic matter production in constructed wetland can negatively affect the efficiency of water treatment. Therefore, the role of epiphytic algae should be considered in management of constructed wetland for water treatment.

• Korean Journal of Ecology and Environment
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• v.39 no.3 s.117
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• pp.402-412
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• 2006

The Shihwa constructed wetland was established to treat the severely polluted water from Banwoul, Donghwa and Samhwa streams. This study was focused on investigating the dynamics of epiphytic algal communities on reed (Phragmites communis) planting area at 5 stations from October 2001 to June 2002. The concentration of total nitrogen and phosphorus of inlet stations from the streams were decreased after flowing through the wetland. However, the TN : TP ratios at all stations were slightly over 16 indicating that the total phosphorus may play some role as a limitation factor. Epiphytic algae on the reed were total 329 taxa which were composed of 295 species, 13 varieties, 3 forma and 18 unidentified species. The species numbers were recorded in the order of Chlorophyceae-Bacillariophyceae-Cyanophyceae-Euglenophyceae-Chrysophyceae. The relative percentage showed a seasonal variation from Cyanophyceae to Bacillariophyceae and to Chlorophyceae. The biomass of epiphytic algae measured by chlorophyll-a concentration ranged from 0.6 to $36.4\;{\mu}g\;cm^{-2}$. Dominant species were 16 taxa which were Lyngbya angusta of Cyanophyceae in the early investigation, and were changed to Stigeoclonium lubricum of Chlorophyceae, and Nitzschia palea of Bacillariophyceae etc. in the late. Species number, standing crops and chlorophyll-a concentrations of epiphytic algae showed higher values at the inlet stations than the stations after flowing through the wetland.

• Korean Journal of Environmental Agriculture
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• v.23 no.1
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• pp.59-67
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• 2004

The Shihwa constructed wetland was established for the treatment of severely polluted water from Banwoul, Donghwa and Samhwa streams. This study was focused on investigating dynamics of phytoplankton communities in open waters and periphytic algae on reed (Phragmites communis) planting area at 5 stations from October 2001 to July 2002. The concentration of T-N and T-P of inlet stations from the streams were decreased by flowed through the wetland. However, the TN/TP ratios at all stations were shown as a little over 16 indicating that the T-P will play some role as a limitation factor. Phytoplankton communities were identified as a total 413 taxa which were composed of 375 species, 21 varieties, 2 forma and 15 unidentified species. Standing crops of phytoplankton communities and chlorophyll-a concentrations ranged from $330{\sim}36,420\;cells/mL$ and $2.5{\sim}170.7\;{\mu}g/L$ respectively, and showed the decreasing tendency after flowing through the wetland at almost all stations. Dominant species were 14 taxa at all stations which were Euglena oblonga and Synura spinosa etc. Periphytic algae on the reed were a total 329 taxa which were composed of 295 species, 13 varieties, 3 forma and 17 unidentified species. The species numbers were recorded in order of Chlorophyceae-Bascillariophyceae-Cyanophyceae-Euglenophyceae-Chrysophyceae. The relative abundance (%) was showed a seasonal variation from Cyanophyceae to Bascillariophyceae and to Chlorophyceae. Chlorophyll-a concentrations, ie. the biomass of periphytic algae were ranged from $5.5{\sim}363.8\;mg/m^2$. Dominant species were 16 taxa which were Lyngbya angusta of Cyanophyceae in the early investigation, and were changed to Stigeoclonium lubricum of Chlorophyceae, and Nitzschia plea of Bacillariophyceae etc. in the late. Species number, standing crops and chlorophyll-a concentrations of phytoplankton and perphytic algae were shown higher values at the inlet stations than the stations after flowing through the wetland.

• Korean Journal of Ecology and Environment
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• v.43 no.1
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• pp.91-102
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• 2010

Water quality and epiphytic diatom on the submerged stems of reed (Phragmites communis), which occupy 90% of the Donghwa wetland macrophytes were monthly monitored at three points such as inflow stream, high- and low-level wetlands, and outflow stream between March and October, 2005. 1) A diverse and high density of diatom species observed in the cold-season, especially Nitzschia palea and Nitzschia amphibia dominated the diatom community without wetlands. 2) High DAIpo and TDI indices were measured over the sampling periods and stations, regardless of nitrogen increase and phosphorus increase through the wetlands. 3) Higher density of diatom species in high wetland than low wetlands was attributed in the enough nutrients and light penetration by low growth of reed. Therefore, epiphytic diatom of reed stem in Donghwa wetland, where high nutrients released from the sediment and reed debris after the death of macrophytes, flourished with low canopy of low reed vegetation.

• Korean Journal of Ecology and Environment
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• v.42 no.1
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• pp.1-8
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• 2009

This study used a mesocosm which presumes movement of the nutrient (especially $PO_{4^-}P$) in the wetland. After setting up the mesocosm inside the wetland and adding the $PO_{4^-}P$, observed the movement of the $PO_{4^-}P$ every hour. We analyzed the variables which had the possibility of affecting $PO_{4^-}P$ concentration in the wetland-flora, absorbing rate of algae, settling rate, release rate. Immediately after adding $PO_{4^-}P$, the concentration of the TP in water column at each mesocosm was 0.48, 12.4, 20.4, $23.6\;mg\;L^{-1}$, after 21 days they were 0.6, 1.92, 6.97 and $6.94\;mg\;L^{-1}$ respectively. The concentration of the TP in water column at the mesocosm decreased on average 73.7%. The concentration of the $PO_{4^-}P$ inside reed, algae and sediment in the mesocosm was increased from $0.73mg\;gDW^{-1}$, $3.81mg\;gDW^{-1}$, $466.1mg\;kg^{-1}$ to $0.83mg\;gDW^{-1}$, $4.57mg\;gDW^{-1}$ and $813.3mg\;kg^{-1}$ respectively. Algae is more sensitive than reeds in absorption of the nutrient. TP removal by settling was highest. Budgeting of TP indicated that P moved from particulates in the water column to sediment and algae. Immediately after adding $PO_{4^-}P$, water column (24.2%) and sediment (49.0%) dominated TP storage, with algae (10.3%) and reed (16.4%) holding smaller proportions of TP. After 21 days, Sediment (59.0%) and algae (17.9%) dominated TP storage, with water column (7.1%) and reed (15.8%) holding smaller proportions of TP. Estimation of phosphate movement using mesocosms is an appropriate method because wetlands have many controlling factors. Analysed data can be compared to background data for wetland construction and management.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.1
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• pp.56-62
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• 2009

Stable carbon isotope analysis was used to investigate the autotrophic carbon sources supporting fisheries in three coastal bay systems of the southern coast of Korea. Carbon isotope ratios (${\delta}^{13}C$) of 31 fish species were analysed and compared with those of a range of potential primary food sources [e.g., seagrass (Zostera marina), seagrass epiphytes, benthic microalgae, macroalgae, marine particulate organic matter (marine POM), marsh plant (Phragmites australis) and terrestrial POM]. ${\delta}^{13}C$ values (range, -16.2${\sim}$-8.3‰) of fishes from the coastal embayment systems were overlapped with those of seagrass (-8.3${\pm}$1.9‰), seagrass epiphytes (-12.4${\pm}$0.6‰), benthic microalgae (-15.4${\pm}$1.6‰) and macroalgae (-16.0${\pm}$1.8‰). In addition, fishes (-12.9${\pm}$1.5‰) from the study area had distinctly higher ${\delta}^{13}C$ values compared to those collected in offshore sites (-17.3${\pm}$0.8‰) of the southern sea of Korea and Nakdong River (-23.2${\pm}$1.6‰). This result indicates that carbon supporting fish communities of these coastal bay systems is mainly derived from the local benthic producers.

• Korean Journal of Ecology and Environment
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• v.38 no.3 s.113
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• pp.403-411
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• 2005

The Shihwa constructed wetland was established for the treatment of severely polluted water from Banwoul, Donghwa and Samhwa streams, This study was focused on investigating dynamics of phytoplankton community at 5 stations of open waters in the Shihwa constructed wetland from October 2001 to July 2002. The concentration of T-N and T-P of inlet stations from the streams were decreased by flowed through the wetland. However, the TN/TP ratios at all stations were shown as a little over 16 indicating that the T-P plays an important role as a limitation factor. Phytoplankton communities were identified as a total of 413 taxa which were composed of 375 species, 21 varieties, 2 forma and 15 unidentified species. The standing crops of phytoplankton communities and chlorophyll-a concentrations ranged 330 ${\sim}$ 36, 420 cells $mL^{-1}$ and $2.5\;{\sim}\;170.7\;{\mu}g\;L^{-1}$ respectively, and showed a decreasing tendency after flowing through the wetland at almost stations. Dominant species were 14 taxa at all stations which were Euglena oblonga, Synura spinosa, and etc. The species composition, standing crops and chlorophyll concentrations of phytoplankton communities appeared a distinct differences between open waters of inlet from stream and open waters flowed through the wetland. Theses results were affected from decreasing effects of TN, TP and SS by flowed through the wetland from inlet waters of streams.