scholarly journals Seasonal Distributions of Phytoplankton and Environmental Factors Generate Algal Blooms in the Taehwa River, South Korea

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3329
Author(s):  
Bo-Ram Sim ◽  
Hyung-Chul Kim ◽  
Chung-Sook Kim ◽  
Jin-Ho Kim ◽  
Kyung-Woo Park ◽  
...  

Algal blooms have occurred in the Taehwa River estuary in South Korea despite the improvement of water quality since environmental renewal projects in the 1990s. In this study, we investigated the causes of algal blooms by measuring the water retention time using a floating buoy, water quality parameters, and phytoplankton distribution data from 2012. An algal bloom did not occur in February because of phosphate limitations in the Taehwa River estuary; however, the concentration of nutrients in the water inflow from the basin triggered a significant algal bloom in the upper estuary in the month of May. In this regard, the phytoplankton population was dominated by nano- and pico-sized flagellates. In August, the freshwater inflow into the estuary greatly increased due to heavy rainfall, resulting in a shorter retention time of the water bodies, which seemed to prevent an algal bloom. In November, a bloom of Cryptophyceae occurred at one of the sites (the U2 site) due to sufficient nutrients in the water and the long retention times of the water bodies. Our results indicate that a decrease in the nutrients (N and P) supplied from the basin is required for a reduction in algal blooms in the Taehwa River estuary. Additional studies are needed to further elucidate the effects of the land-based, nutrient-rich pollutants flowing into the Taehwa River estuary on algal bloom generation considering the fact that the streams have different environmental characteristics.

2010 ◽  
Vol 44 (16) ◽  
pp. 4805-4811 ◽  
Author(s):  
Shih-Wei Huang ◽  
Bing-Mu Hsu ◽  
Shu-Fen Wu ◽  
Cheng-Wei Fan ◽  
Feng-Cheng Shih ◽  
...  

2020 ◽  
Author(s):  
Dainis Jakovels ◽  
Agris Brauns ◽  
Jevgenijs Filipovs ◽  
Tuuli Soomets

<p>Lakes and water reservoirs are important ecosystems providing such services as drinking water, recreation, support for biodiversity as well as regulation of carbon cycling and climate. There are about 117 million lakes worldwide and a high need for regular monitoring of their water quality. European Union Water Framework Directive (WFD) stipulates that member states shall establish a programme for monitoring the ecological status of all water bodies larger than 50 ha, in order to ensure future quality and quantity of inland waters. But only a fraction of lakes is included in in-situ monitoring networks due to limited resources. In Latvia, there are 2256 lakes larger than 1 ha covering 1.5% of Latvian territory, and approximately 300 lakes are larger than 50 ha, but only 180 are included in Inland water monitoring program, in addition, most of them are monitored once in three to six years. Besides, local municipalities are responsible for the management of lakes, and they are also interested in the assessment of ecological status and regular monitoring of these valuable assets. </p><p>Satellite data is a feasible way to monitor lakes over a large region with reasonable frequency and support the WFD status assessment process. There are several satellite-based sensors (eg. MERIS, MODIS, OLCI) available specially designed for monitoring of water quality parameters, however, they are limited only to use for large water bodies due to a coarse spatial resolution (250...1000 m/pix). Sentinel-2 MSI is a space-borne instrument providing 10...20 m/pix multispectral data on a regular basis (every 5 days at the equator and 2..3 days in Latvia), thus making it attractive for monitoring of inland water bodies, especially the small ones (<1 km<sup>2</sup>). </p><p>Development of Sentinel-2 satellite data-based service (SentiLake) for monitoring of Latvian lakes is being implemented within the ESA PECS for Latvia program. The pilot territory covers two regions in Latvia and includes more than 100 lakes larger than 50 ha. Automated workflow for selecting and processing of available Sentinel-2 data scenes for extracting of water quality parameters (chlorophyll-a and TSM concentrations) for each target water body has been developed. Latvia is a northern country with a frequently cloudy sky, therefore, optical remote sensing is challenging in or region. However, our results show that 1...4 low cloud cover Sentinel-2 data acquisitions per month could be expected due to high revisit frequency of Sentinel-2 satellites. Combination of C2X and C2RCC processors was chosen for the assessment of chl-a concentration showing the satisfactory performance - R<sup>2</sup> = 0,82 and RMSE = 21,2 µg/l. Chl-a assessment result is further converted and presented as a lake quality class. It is expected that SentiLake will provide supplementary data to limited in situ data for filling gaps and retrospective studies, as well as a visual tool for communication with the target audience.</p>


Author(s):  
Shefaliben Sureshbhai Patel ◽  
Susmita Sahoo

The seasonal investigation about the water quality from Damanganga river estuary on two habitats downstream and upstream was carried out from January to December 2019 containing three major seasons: winter, summer and monsoon. For this monitoring activity total 29 parameters (24 physico-chemical parameters and 5 heavy metals) were analyzed. Multivariate analyses suggested inter dependency among these studied parameters. Water Quality Index is computed based on the major fluctuated and affected parameters. The calculated values of WQI for all three seasons ranged from 122.84 to 173.82 which suggested poor water quality of the water body. WQI values of the investigation area proposed that the estuarine water quality is deteriorated due to high value of presented heavy metals (Aluminum, Iron, Manganese, Boron and Zinc), Chloride, Ammonium and Sulfate in water sample. In this case, the downstream station is having accessional pollutant contaminations while the upstream station is having diminutive pollutant contaminants. Temporally, the dominant frailty found during the winter followed by summer and monsoon. This study field exhibited poor quality of water; the reason behind this might be the impressive surrounding industrial zone as well as other anthropogenic activities. There is quite normal probability distribution expressed by the represented water quality data at the both habitats. The Bray-Curtis cluster analysis shows different percentage similarity level between the water quality parameters.  


Estuaries ◽  
1986 ◽  
Vol 9 (3) ◽  
pp. 169 ◽  
Author(s):  
J. W. Pierce ◽  
D. L. Correll ◽  
B. Goldberg ◽  
M. A. Faust ◽  
W. H. Klein

Author(s):  
Shefaliben Sureshbhai Patel ◽  
Susmita Sahoo

The seasonal investigation about the water quality from Damanganga river estuary on two habitats downstream and upstream was carried out from January to December 2019 containing three major seasons: winter, summer and monsoon. For this monitoring activity total 29 parameters (24 physico-chemical parameters and 5 heavy metals) were analyzed. Multivariate analyses suggested inter dependency among these studied parameters. Water Quality Index is computed based on the major fluctuated and affected parameters. The calculated values of WQI for all three seasons ranged from 122.84 to 173.82 which suggested poor water quality of the water body. WQI values of the investigation area proposed that the estuarine water quality is deteriorated due to high value of presented heavy metals (Aluminum, Iron, Manganese, Boron and Zinc), Chloride, Ammonium and Sulfate in water sample. In this case, the downstream station is having accessional pollutant contaminations while the upstream station is having diminutive pollutant contaminants. Temporally, the dominant frailty found during the winter followed by summer and monsoon. This study field exhibited poor quality of water; the reason behind this might be the impressive surrounding industrial zone as well as other anthropogenic activities. There is quite normal probability distribution expressed by the represented water quality data at the both habitats. The Bray-Curtis cluster analysis shows different percentage similarity level between the water quality parameters.  


Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 375
Author(s):  
Cheng He ◽  
Youru Yao ◽  
Xiaoman Lu ◽  
Mingnan Chen ◽  
Weichun Ma ◽  
...  

In estuary areas, meteorological conditions have become unstable under the continuous effects of climate change, and the ecological backgrounds of such areas have strongly been influenced by anthropic activities. Consequently, the water quality of these areas is obviously affected. In this research, we identified periods of fluctuation of the general meteorological conditions in the Yangtze River Estuary using a wavelet analysis. Additionally, we performed a spatiotemporal evaluation of the water quality in the fluctuating period by using remote sensing modeling. Then, we explored how the fluctuating meteorological factors affect the distribution of total suspended solids (TSS) and chlorophyll-a (Chla) concentration. (1) The results show that from 2000 to 2015, temperature did not present significant fluctuations, while wind speed (WS) and precipitation (PR) presented the same fluctuation period from January 2012 to December 2012. (2) Based on the measured water sample data associated with Moderate Resolution Imaging Spectroradiometer (MODIS) imagery, we developed a water quality algorithm and depicted the TSS and Chla concentrations within the WS and PR fluctuating period. (3) We found that the TSS concentration decreased with distance from the shore, while the Chla concentration showed an initially decreasing trend followed by an increasing trend; moreover, these two water quality parameters presented different inter-annual variations. Then, we discussed the correlation between the changes in the TSS and Chla concentrations and the WS and PR variables. The contribution of this research is reflected in two aspects: 1. variations in water quality parameters over a wide range of water bodies can be evaluated based on MODIS data; 2. data from different time periods showed that the fluctuations of meteorological elements had different impacts on water bodies based on the distance from the shore. The results provide new insights for the management of estuary water environments.


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