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The impact of water quality on the availability of phytoplankton and growth of Litopenaeus vannamei

Musa Muhammad, Thoyibah Auliarifka A., Puspitaningtyas Dyah A., Arsad Sulastri, Mahmudi Mohammad, Lusiana Evellin D., Maftuch Maftuch, Huda Agus S.

Journal of Water and Land Development

2023

no. 56

127--135

This research analysed the availability of phytoplankton and the growth rate of Vannamei shrimp in relation to water quality changes. The research was carried out in February-March 2021 for a half cycle of shrimp cultivation in two ponds of the Brackish Water Fish Culture Probolinggo Laboratory in Probolinggo, East Java, Indonesia. The research used a descriptive method and included a survey. Sampling was made every two weeks for two months. Nine parameters were measured and ten shrimps were taken for a specific growth rate (SGR) measurement once per sampling. Data were analysed using the principal component analysis (PCA) and canonical correspondence analysis (CCA). Secondary data of water quality were added for the PCA. The results show that the phytoplankton found in the first pond consisted of Chlorophyta, Chrysophyta, and Cyanophyta, whereas the phytoplankton in the other pond included Chlorophyta, Chrysophyta, Cyanophyta, and Dinophyta. The abundance of phytoplankton ranged from 12-80∙103 cell∙cm-3, which indicated eutrophic waters. The PCA demonstrated that pH, nitrate, and total organic matter (TOM) significantly influenced phytoplankton abundance in the pond. In addition, water quality parameters, such as temperature, transparency, salinity, nitrite and phosphate levels, were tolerable in both ponds for the growth of shrimps. However, the level of pH was lower than the aquaculture quality standard, whereas those of nitrate, ammonia, and TOM were higher. The growth rate of Vannamei shrimp increased by 0.76–7.34%∙day-1.

Comparative Performance of Physicochemical and Diatom-Based Metrics in Assessing the Water Quality of Mert Stream, Turkey

Maraşlıoğlu Faruk, Bektaş Serdar, Özen Arda

Journal of Ecological Engineering

2020

Vol. 21, nr 8

18--31

In this study, the authors aimed to compare the performance of the physicochemical-based water quality metrics (WQI, SWQMR) and diatom-based diatom metrics (TDI, BDI, GDI) to evaluate the water quality and ecological status of the Mert Stream. A total of 104 epilithic diatom species, belonging to 44 genera, were recorded during the study period. Navicula was the most dominant diatom in the sites near intensive farming areas, while Gomphonema was the most dominant species in the sites in vicinity of urban and industrial settlements. According to the water quality indices based on the physicochemical parameters and diatoms, the water quality in the upper and middle parts of the Mert stream was better than in the lower parts (higher amount of total suspended solids and higher conductivity). The structure of the epilithic diatom community was mostly shaped by total suspended solids, electrical conductivity and nutrients according to Canonical Correspondence Analysis results. The obtained results revealed that diatom metrics, especially GDI, and water quality metrics, especially WQI, can be used for the monitoring of lotic systems and provide useful complementary information on the ecological status of rivers in medium rainfall regions such as Samsun.

Effects of coastal upwelling on picophytoplankton distribution off the coast of Zhanjiang in South China Sea

Wu M-L., Wang Y-S., Wang D.-X., Dong J-D.

Oceanological and Hydrobiological Studies

2014

Vol. 43, No. 3

283--291

Coastal upwelling occurred along the west coast of Guangdong in the northern South China Sea during the summer of 2006. The effects of upwelling on the vertical and horizontal distributions of Prochlorococcus and Synechococcus were investigated. A distinct vertical temperature difference between the surface water and water at a depth of 30 m was observed in the coastal upwelling region. There was a clear spatial variability of temperature, and an increasingly obvious horizontal gradient was created from the coast to offshore waters. Picophytoplankton communities observed from the coast to offshore waters were significantly different. In the coastal upwelling waters, the picophytoplankton community was dominated by Synechococcus within the euphotic zone. Prochlorococcus dominated the picophytoplankton community in the euphotic zone in the non-upwelling region. This difference in the picophytoplankton community structure was due to different hydrodynamics. The results of canonical correspondence analysis demonstrate that temperature, salinity, and phosphate concentration may be important factors affecting the distribution of Prochlorococcus and Synechococcus.