Distribusi Spasial Keanekaragaman Jenis Plankton di Perairan Estuari Pangkalan Susu, Kabupaten Langkat, Sumatera Utara

Abstract

Estuaries are aquatic ecosystems that play a crucial role in supporting biodiversity, particularly as habitats for various plankton species that form the base of the aquatic food chain. The diversity and abundance of plankton in estuarine waters are significantly influenced by environmental factors such as temperature, salinity, dissolved oxygen, and nutrient content, including nitrate and phosphate. Environmental changes due to anthropogenic activities, such as land conversion, aquaculture, and waste disposal, can affect plankton distribution and disrupt the ecological balance of aquatic ecosystems. This study aims to analyze the spatial distribution of plankton diversity in the estuarine waters of Pangkalan Susu, Langkat Regency, using a purposive sampling method at ten observation stations. Additionally, water physico-chemical parameters were measured, and analyses were conducted using the Shannon-Wiener diversity index (H’), evenness index (E), dominance index (D), and canonical correspondence analysis (CCA). The results showed that the highest plankton abundance was recorded at station 1, while the lowest abundance was observed at station 9 for phytoplankton and at station 8 for zooplankton. Plankton abundance and diversity in the Pangkalan Susu estuary are influenced by environmental factors, where salinity, total dissolved solids (TDS), and water clarity have a positive correlation with plankton, while phosphate and turbidity have negative effects. These findings provide insights into plankton community dynamics and highlight the importance of sustainable estuarine ecosystem management.