Status Trofik Danau Toba Provinsi Sumatera Utara

Abstract

Lake Toba, one of the largest lakes in Indonesia, plays a pivotal role in the region's ecology, economy and society. Increased anthropogenic activities around the lake, such as fish farming with floating net cages (KJA) and domestic waste, has a detrimental effect on water quality, leading to eutrophication.This study aims to analyse the trophic status of Lake Toba based on the spatial and temporal distribution of chlorophyll-a, nutrient concentrations (nitrogen and phosphate), and other water quality parameters. The data were collected in situ at 21 stations during the dry and rainy seasons.The parameters measured included brightness, dissolved oxygen, chlorophyll-a, and nutrient concentrations, trophic status analysis using the Trophic State Index (TSI), TRIX, Trophic Level Index (TLI), and TLIlamp methods. The results demonstrated that there were variations in the spatial and temporal distribution of trophic status in Lake Toba, with some areas showing a tendency towards eutrophic conditions due to high concentrations of nutrients and chlorophyll-a. This research is expected to provide a foundation for the sustainable management of Lake Toba to maintain water quality and ecosystem sustainability.