Abstract

Wetland areas in Abuloma, Ogbogoro and Eagle Island with evidence of sand mining operations were investigated for impacts of in-stream sand mining on the surface water quality, abundance, composition, and the diversity of phytoplankton. We thus, hypothesized that sand mining will impact phytoplankton abundance. The study lasted six, i.e., October 2020-March 2021. Physico-chemical parameters were assessed using standard procedures while plankton were sampled, identified, and classified employing appropriate techniques and identification keys. The results of water quality assessment shows temperature and pH to be within acceptable limit for tropical waters as recommended by WHO, while Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD), Total Dissolved Solids (TDS), and Electrical Conductivity (EC) (μS/cm) were not within acceptable limit as stipulated by WHO. Phytoplankton results shows that a total of 2,610 individuals from 4 taxa and 43 species were encountered. The family Bacilliarophyceae with 2,466 individuals, dominated while Charophyta with 24 individuals was the least encountered. The result implies that sand mining activities negatively impacted the water quality of the studied areas, which influenced the composition and abundance of phytoplankton populatio

Keywords:Benthic; Macro invertebrate; Sand mining; Phytoplankton; Andoni river; Mangrove forest

Abbreviations: DO: Dissolved Oxygen; BOD: Biochemical Oxygen Demand; TDS: Total Dissolved Solids; EC: Electrical Conductivity; CEMPOS: Centre for Marine Pollution and Seafood Safety; ANOVA: Analysis of Variance