PHYTOPLANKTON BIODIVERSITY IN RIVERS WITH MINIMAL ANTHROPOGENIC DISTURBANCE AND PROSPECTS AS A FUTURE FOOD SOURCE

Abstract

Natural rivers with minimal disturbance from human activities hold great potential as a source of aquatic biodiversity, including phytoplankton, which play a crucial role as primary producers in aquatic ecosystems and as the foundation of the food chain in freshwater bodies. The presence of phytoplankton not only reflects the ecological condition of a water body but also holds great potential as a source of microalgal biomass that can be utilized for various human needs, including as a source of food and natural feed in the future. This study aims to examine phytoplankton biodiversity in the Uram Jaya River in Lebong Regency, Bengkulu Province, and to assess its prospects as a future food source based on aquatic biological resources. The research method involved collecting phytoplankton samples using a plankton net at four observation stations selected based on river flow characteristics and aquatic environmental conditions. The collected samples were then analyzed in the laboratory using a microscope to identify the taxonomic composition of the phytoplankton down to the genus or species level. Analysis of the phytoplankton community structure was performed by calculating species diversity using the Shannon–Wiener Diversity Index. The results of the study indicate that the phytoplankton community in the Uram Jaya River exhibits a high level of diversity, with a diverse species composition comprising various groups of microalgae. The highest diversity index value was found at Station III with an H’ value of 3.380, followed in order by Station II with an H’ value of 2.917, Station IV with an H’ value of 2.855, and Station I with an H’ value of 2.785. Based on taxonomic identification results, the most dominant phytoplankton classes found at the study sites with natural water conditions were Chlorophyceae and Xanthophyceae. Several genera and species of phytoplankton that were commonly found and have potential as natural feed include Scenedesmus, Protococcus viridis, Grammatophora sp., Tetraedron sp., Actinastrum lagerheimii, Ulothrix sp., and Trachelomonas volvocina, which are known to contain nutrients such as protein, vitamins, and bioactive compounds that have the potential to be utilized as a natural food source for aquatic organisms or as an alternative nutrient source in the future.