Abstract
Abstract As a biological parameter of the aquatic ecosystem, plankton has various species and forms a specific community for each water. Plankton can characterize the water’s condition through its species richness. Both phytoplankton and zooplankton were observed in this research to determine the biodiversity. Plankton samples were collected using a plankton net from the surface water of Sawaibu Bay, Manokwari City, West Papua Province, Indonesia. Morphological identification is applied to approximate the plankton genera and count the diversity indices. Classes of Cyanophyceae, Bacillariophyceae, Dinophyceae, Chrysophyceae, Protozoa, and Crustaceae were found in Sawaibu Bay. Phytoplankton from the Bacillariophyceae group (30-90 x 10 2 cell/m 3 ) and zooplankton from the Crustacean group (1.51-38.6 x 10 2 ind/m 3 ) were high in abundance. Both phytoplankton and zooplankton’s evenness, dominance, and diversity index varied between stations. The biodiversity approach could be a snapshot of the aquatic ecosystem state.