Distribusi Spasial dan Temporal Plankton di Danau Toba Provinsi Sumatera Utara

Abstract

Lakes are aquatic ecosystems that have an important role in supporting biodiversity, especially as a habitat for various types of plankton that are the basis of the aquatic food chain. Changes in environmental conditions due to utilization around the lake waters, such as land conversion, fisheries cultivation, and waste disposal, can affect the distribution of plankton and the balance of the aquatic ecosystem. This study aims to analyze the Spatial and Temporal Distribution of Plankton in Lake Toba, North Sumatra Province using the purposive sampling method at twenty-one observation stations during the rainy season and dry season in August-December 2024. Measurements of water physicochemical parameters were carried out and analysis using the Shannon-Wiener diversity index (H'), uniformity index (E), dominance index (D), and Principal Component Analysis (PCA). The results of plankton identification conducted in the dry season in Lake Toba showed the presence of 10 classes of plankton with a total of 96 species. Phytoplankton consists of 76 species. Meanwhile, zooplankton consists of 20 species. In the rainy season, the results of plankton identification in Lake Toba showed the presence of 10 classes of plankton with a total of 99 species. Phytoplankton consists of 82 species, that the abundance of plankton is higher during the rainy season compared to the dry season. These findings provide insight into the dynamics of plankton communities and the importance of sustainable management of estuary ecosystems.