Initiation of Harmful Algal Blooms as a Bioindicator of Water Environmental Quality at Coral reefs ecosytem in the Tidung Island Kepulauan Seribu Ratna Komala, Mieke Miarsyah, Eka Putri Azra, Moh Isnin Noer
Department of Biology , Faculty of Mathematics and Natural Science, Universitas Negeri Jakarta , Indonesia
Abstract
The study was conducted to analyze the harmful microalgae population that has the potential to cause Red Tide in coral reef ecosystems, and analyze environmental parameters that affect its population on the Tidung Island of the Thousand Islands. Observations were made in May to October 2019 with descriptive research methods with direct observation techniques. The results showed that 34 genera of microalgae were identified as belonging to 4 main classes, namely Bacillariophphyceae, Dinophyceae and Desmidiaceae. Population fluctuations are the highest in August and the lowest in June. The highest abundance of microalgae is represented by the genus Skeletonema. Several genus of Harmfull algae are identified but have no potential to cause Red Tide because their abundance is still in a safe condition which is under 1 million individuals / m3, and the diversity is classified as moderate so that the environment is still in good enough quality. Environmental parameters that affect the temporal microalgae population are turbidity, Biologycal Oxygen demand (BOD), Total Dispended Solid (TDS) and Nitrite (NO2)
