The relationship between water quality and aquatic organisms in tidal lakes, Medan-Indonesia

Abstract

Abstract Siombak Lake is a tidal lake in Indonesia. The dynamics of the lake’s waters experience two high tides and two low tides within 24 hours (except during neap water). Groups of freshwater, brackish, and marine organisms make up Siombak Lake’s aquatic biota, which varies with the seasons and tidal conditions. The purpose of this study is to clarify how aquatic biodiversity in lakes is impacted by tidal dynamics. This research was conducted at Lake Siombak, Medan City, North Sumatra Province. Data collection was carried out from September 2018 to August 2019. The analysis carried out was a multivariate PCA analysis assisted by Microsoft Excel 2016 and Minitab. The research results show that tidal dynamics cause fluctuations and dynamics in lake water quality and lake biological communities. Plankton are aquatic organisms greatly influenced by water dynamics and water quality. Phytoplankton abundance is influenced by sunlight and nutrient levels, while TSS, salinity and phytoplankton abundance influence zooplankton abundance. The abundance and presence of fish are closely related to their food sources, namely zooplankton, crustaceans, and mollusks. The existence of these tidal dynamics provides sustainability and stability to the environment and ecosystem of Siombak Lake