Community Structure of Plankton in the River Estuary of Former Tin Mining Area in Belitung Island, Indonesia.

River estuaries face significant management challenges due to human activities, making it crucial to protect their biodiversity, ecological functions, and the ecosystem services they offer. This study investigates the community structure of plankton in a river estuary of a former tin mining area in Belitung Island, Indonesia. Multiple sites along the Manggar River were sampled for water during the dry season. The results show that the average value of dissolved oxygen in the river is 5.28 ppm, indicating good water quality for the aquatic environment. There are a total of 73 species, 12 classes, and seven phyla of phytoplankton – including Rhodophyta (one species), Euglenozoa (five species), Myzozoa (six species), Charophyta (16 species), Chlorophyta (10 species), Cyanobacteria (five species), and Ochrophyta (eight species) identified in the river. Meanwhile, for zooplankton, there are Foraminifera (one species), Ciliophora (four species), Rotifera (nine species), Arthropoda (three species), Nematoda (one species), Cercozoa (two species), and Amoebozoa (four species). The study identified several indicator species (i.e. Centropyxis sp., Notholca sp., and Arcella sp.) that could serve as bioindicators for monitoring the ecological health of the Manggar River. The findings underscore the importance of maintaining water quality in the river, particularly after mining activities. The diverse plankton communities help infer their probable trophic pathways and related ecological functions, which are vital to the river’s food web. [ABSTRACT FROM AUTHOR]