The Zooplankton composition and surface water quality in some watershed around the aquaculture areas at the Ben Tre province

Abstract

The research was conducted in 3 districts: Binh Dai, Ba Tri and Thanh Phu in Ben Tre province in September 2017 (wet season) and April 2018 (dry season). The study recorded 63 taxa of zooplankton belong to 40 genera, 7 classes, and six groups: Protozoans, Rotifers, Cladocerans, Copepods, Ostracods and larvae (of shrimp and crab). Rotifers dominated the local zooplankton quantitatively, with 55,56% of the total organisms. Total zooplankton densities oscillated from 120 – 23 304 ind.m-3 during the wet and dry season. The total zooplankton in the wet season is higher in the dry season. The result of the research showed that zooplanktons were affected by season and salinity. The water quality indices (pH, temperature, salinity, TDS, DO, NO3-, NH4+, PO43-) were under limitation to use for aquaculture activities, aquatic organism conservation, and daily living. The Shannon – Wiener index (H’) fluctuated from 0,51 to 2,02, the Simpson index fluctuated from 0,15 to 0,8, the Pielou index fluctuated from 0,23 to 0,94. The bioindex showed that the water bodies are polluted (from α, β – mesosaprobic level to polysaprobic level). Our results indicated that there was a difference between water environmental parameters and zooplankton communities among seasons and stations. Therefore, it is necessary to combine these two indicators for better accurate results in water quality assessment.

Surface Water Quality in Urban Areas in Southern Most Province of Vietnam

“…From that, it can be seen that the DO content in surface water in the study area is no longer suitable for organisms to grow. Compared with the previous study [33], the DO concentration at monitoring points in Ben Tre Province is relatively higher, ranging from 5.33-6.97 mg/L. Similarly, in the water bodies observed in the study by [17], DO concentration ranged from 9.1-14.1 mg/L which is higher than the current study area.…”

“…The results of the present study tend to be lower than some monitoring locations adjacent to the East Sea and West Sea, the salinity fluctuated in the range of 23.5-28.8‰ [32]. However, this result compares well with the study in Ben Tre province, salinity ranged from 0.6-27.3‰ [33].…”

Correlation Between Surface Water Quality Plankton Composition in Water Bodies in Hau Giang Province, Vietnam

“…The density of Nauplius larvae of the Copepoda was found to be strongly correlated with BOD (r = 0.304), NH 4 + -N (r = 0.627) and pH (r = 0.435), while the negative correlation occurred between larval density with TSS (r = -0.472) and DO (r = -0.788). This can be demonstrated that, when the environment is rich in organic matters and nutrients, Nauplius larvae would grow and develop well, with a high density in the water body (Van & My, 2020). For the Copepoda, the density was negatively correlated with DO (r = -0.792), positively correlated with BOD (0.325), NH 4 + -N (0.420) and coliform (0.513).…”

“…The composition of zooplankton in the study area is relatively higher than in some other study areas in the Mekong Delta. For example, the composition of zooplankton in water bodies in Ben Tre province only recorded 63 species belonging to 5 groups with 1 species of protozoa, 35 species of Rotatoria, 6 species of Cladocera, 16 species of Copepod and 2 species of Ostracoda ( Van & My, 2020). In water bodies in Can Tho city, 79 species of zooplankton were identified, of which 21 species of Protozoa, 42 species of Rotatoria, 10 species of Cladocera and 7 species of Copepoda (Dung & Oanh, 2011).…”

Seasonal Variations in Groundwater Quality under Different Impacts Using Statistical Approaches

“…Local water resources include rainfall, surface water, and groundwater. An interlaced river system in the province has facilitated sufficient water supply for domestic, agricultural, industrial, and aquaculture activities [27]. However, the surface water quality of the province is gradually polluted [28].…”