Impact of anthropogenic activities on water quality and plankton communities in the Day River (Red River Delta, Vietnam)

Abstract

Planktons are a major component of food web structure in aquatic ecosystems. Their distribution and community structure are driven by the combination and interactions between physical, chemical, and biological factors within the environment. In the present study, water quality and the community structure of phytoplankton and zooplankton were monthly investigated from January to December 2015 at 11 sampling sites along the gradient course of the Day River (Red River Delta, northern Vietnam). The study demonstrated that the Day River was eutrophic with the average values of total phosphorus concentration 0.17 mg/L, total nitrogen concentration 1.98 mg/L, and Chl a 54 μg/L. Microscopic plankton analysis showed that phytoplankton comprised 87 species belonging to seven groups in which Chlorophyceae, Bacillariophyceae, and Cyanobacteria accounted for the most important constituents of the river's phytoplankton assemblage. A total 53 zooplankton species belonging to three main groups including Copepoda, Cladocera, and Rotatoria were identified. Plankton biomass values were greatest in rainy season (3002.10-3 cell/L for phytoplankton and 12.573 individuals/m for zooplankton). Using principal correspondence and Pearson correlation analyses, it was found that the Day River was divided into three main site groups based on water quality and characteristics of plankton community. Temperature and nutrients (total phosphorus and total nitrogen) are key factors regulating plankton abundance and distribution in the Day River.

Surface Water Quality Assessment Using Phytoplankton and Zoobenthos: A Case Study at Bung Binh Thien, An Giang Province, Vietnam

“…The percentage of Cyanophyta, Baccillariophyta, Chlorophyta, Dinophyta, and Euglenophyta were 44.0%, 34.1%, 16.7%, 3.6%, and 1.6%, respectively (Figure 3b). The phytoplankton of Cyanophyta, Baccillariophyta, and Chlorophyta were also found dominated in constructed wetland (Cao et al, 2007) and rivers (Hoang et al, 2018;Duong et al, 2019). The proportions of Chlorophyta, Dinophyta and Euglenophyta were relatively stable from site S1 to S9 whereas the proportions of Cyanophyta and Bacillariophyta were highly oscillated.…”

“…In addition to physicochemical parameters, phytoplankton is also selected as indicator for quality of water since its diversity and abundance that are closely related to characteristics of water environmental such as light, temperature, nutrients, carbon dioxide, bicarbonate, presence of phytoplankton consumers (i.e. zooplankton, fish) (Cao et al, 2007;Oanh and Lien, 2015;Hoang et al, 2018;Duong et al, 2019). Some phytoplankton phyla such as Bacillariophyta, Cyanophyta, Chlorophyta can be used to indicate nutrient-rich and high organic water environment (Bac, 1998;Lan, 2000;Oanh et al, 2014;Hoang et al, 2018).…”

“…zooplankton, fish) (Cao et al, 2007;Oanh and Lien, 2015;Hoang et al, 2018;Duong et al, 2019). Some phytoplankton phyla such as Bacillariophyta, Cyanophyta, Chlorophyta can be used to indicate nutrient-rich and high organic water environment (Bac, 1998;Lan, 2000;Oanh et al, 2014;Hoang et al, 2018). Cyanophyta is an indicator for static water and organic-rich water environment.…”

“…Several studies have been implemented on water indication of zoobenthos. Water quality affected by domestic wastewater, urban wastewater, aquaculture wastewater, and landfill operation has been investigated using zoobenthos (Dung et al, 2011;Oanh et al, 2014;Hoang et al, 2018;Giao, 2019).…”

The Urgent Need for River Health Biomonitoring Tools for Large Tropical Rivers in Developing Countries: Preliminary Development of a River Health Monitoring Tool for Myanmar Rivers

“…Anthropogenic activities in developing countries such as river regulation and pollution have a potentially negative cumulative impact on rivers and wetlands water quantity and quality, hence negatively impacting on river-dependent people, often the poorest people in a region [1,2].…”