Serial installation of massive weirs impacts the nutrients, solids, chlorophyll, and water chemistry along the river gradient

Kakore, Blandina Genes; Atique, Usman; An, Kwang-Guk

doi:10.1007/s13762-022-04563-4

Cited by 3 publications

(1 citation statement)

References 49 publications

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“…Phytoplankton groups, as the foundation of aquatic food chains, are microscopic organisms that live under presence of carbon dioxide, sunlight, and nutrients in both fresh and saline water ecosystems with photosynthetic capacity (Lindsey & Scott, 2010 ). Chlorophyll‐ a (Chl‐ a ) is the most important photosynthetic pigment in phytoplankton organisms, which has been considered as a good indicator of the nutrients' enrichment (Agwanda & Iqbal, 2019 ; Kakore et al., 2022 ). Therefore, Chl‐ a can be used as a biomass indicator of the trophic status in lakes (Atique & An, 2020 ; Koponen et al., 2001 ).…”

Section: Introductionmentioning

confidence: 99%

Satellite‐Based Monitoring of Eutrophication in the Earth's Largest Transboundary Lake

et al. 2023

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The world's large lakes and their life‐supporting services are rapidly threatened by eutrophication in the warming climate during the Anthropocene. Here, MODIS‐Aqua level 3 chlorophyll‐ a data (2018–2021) were used to monitor trophic state in our planet's largest lake, that is, the Caspian Sea that accounts for approximately 40% of the total lacustrine waters on Earth. We also used the in situ measurements of chlorophyll‐ a data (2009–2019) to further verify the accuracy of the data derived from the MODIS‐Aqua and to explore the deep chlorophyll‐ a maxima (DCMs) in the south Caspian Sea. Our findings show an acceptable agreement between the chlorophyll‐ a data derived from the MODIS‐Aqua and those measured in situ in the coast of Iran (coefficient of determination = 0.71). The oligotrophic, mesotrophic, and eutrophic states cover 66%, 20%, and 13% of the sea surface area, respectively. The DCMs are dominantly regulated by water transparency and they generally observe at depths of less than 20 and 30 m during the cold (autumn and winter) and warm (spring and summer) seasons, respectively. Our results suggest an ever‐increasing chlorophyll‐ a in the shallow zones (i.e., coasts) and even in deep regions of the sea, mainly due to nutrient inputs from the Volga river delta. Alarming increase of chlorophyll‐ a in this transboundary lake can amplify eutrophication under the lens of global warming and further threaten the lake ecosystem's health, where almost all legal agreements have not yet been implemented to protect the lake environment and its rich resources.

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Section: Introductionmentioning

confidence: 99%

Satellite‐Based Monitoring of Eutrophication in the Earth's Largest Transboundary Lake

et al. 2023

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Assessment of the impacts of constructing artificial structures on the water quality and hydrological environment of a meandering river

Kwon,

Kim,

Choi

et al. 2024

Water Environment Research

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When an artificial structure is built in a river, the river changes significantly in water quality and hydraulic properties. In this study, the effects of the weirs constructed in the middle section of a river as a four major rivers restoration project in Korea on water quality and hydrological characteristics were analyzed. For multi‐dimensional data analysis, a self‐organizing map was applied, and statistical techniques including analysis of variation were used. As a result of analysis, the cross‐sectional area of the river increased significantly after the construction of the weir compared to before the construction of the weir, and the flow velocity decreased at a statistically significant level. In the case of water quality, nitrogen, phosphorus, and suspended solids tended to improve after weir construction, and chlorophyll‐a and bacteria tended to deteriorate. Some water quality parameters such as chlorophyll‐a were also affected by seasonal influences. In order to improve the water quality deteriorated by the construction of the weir, it is necessary to consider how to improve the flow velocity of the river through partial opening or operation of the weir. In addition, in order to determine the effect of sedimentation of particulate matter due to the decrease in flow rate, it is necessary to conduct investigations on sediments around weirs in the future.Practitioner Points Compared to before the construction of the weir, there was no significant change in the flow rate of the river after the construction of the weir. In the case of chlorophyll‐a and bacteria, the water quality was deteriorated after weir construction. To improve the deteriorated water quality, it is required to consider the fundamental management of each pollutant source and the flexible operation of both weirs. For some improved water quality parameters, further research is needed to determine whether these improvements are directly attributable to the construction of a weir.

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Correlations Between Spatiotemporal Variations in Phytoplankton Community Structure and Physicochemical Parameters in the Seungchon and Juksan Weirs

Chung,

Son,

Kim

et al. 2024

Water

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The Yeongsan River is one of the four major rivers in South Korea. Since the construction of two weirs as part of the Four Major Rivers Project to secure water resources in 2011, issues with algal blooms have frequently arisen, prompting the Ministry of Environment of Korea to conduct continuous monitoring of water quality and algal outbreaks. This study, conducted between 2019 and 2023, examined the relationship between the phytoplankton community structure and physicochemical factors at the Seungchon and Juksan weirs. Phytoplankton were categorized into four groups (Bacillariophyceae, Chlorophyceae, Cyanophyceae, and other phytoplankton), and 20 dominant genera were selected for analysis. As microalgal species vary depending on environmental conditions, understanding the specific relationships among the microalgae observed in the study area can help explain their occurrence mechanisms and contribute to the development of effective management strategies. Therefore, we used principal component analysis (PCA) to analyze the seasonal variation patterns of the four microalgal groups and visualize key data features through dimensionality reduction. Additionally, PCA was employed to identify and visualize environmental factors related to seasonal variations in phytoplankton communities. PCA helped elucidate how different environmental factors influence phytoplankton fluctuations across seasons. We used canonical correspondence analysis (CCA) to investigate the relationships among the 20 dominant genera in each group and environmental factors. Additionally, CCA was used to analyze the relationship between the distribution of the top five dominant phytoplankton taxa in each group and various environmental factors. CCA allowed for a detailed examination of how these dominant taxa interact with environmental conditions. PCA revealed significant correlations between other phytoplankton and Chl-a in spring and Cyanophyceae and water temperature in summer. Bacillariophyceae was positively correlated with nitrogen-based nutrients but negatively with phosphate phosphorus (PO4-P). CCA revealed significant correlations between dominant genera and environmental factors. Stephanodiscus sp. was associated with nitrogen-based nutrients, whereas Microcystis sp. and Dolichospermum sp. were associated with water temperature and PO4-P. Stephanodiscus sp. affected water treatment through filtration and sedimentation issues, whereas Microcystis sp. and Dolichospermum sp. produced the toxin microcystin. These findings offer valuable insights for water quality management.

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Serial installation of massive weirs impacts the nutrients, solids, chlorophyll, and water chemistry along the river gradient

Cited by 3 publications

References 49 publications

Satellite‐Based Monitoring of Eutrophication in the Earth's Largest Transboundary Lake

Satellite‐Based Monitoring of Eutrophication in the Earth's Largest Transboundary Lake

Assessment of the impacts of constructing artificial structures on the water quality and hydrological environment of a meandering river

Correlations Between Spatiotemporal Variations in Phytoplankton Community Structure and Physicochemical Parameters in the Seungchon and Juksan Weirs

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