The potential role of eutrophication, tidal and climatic on the rise of algal bloom phenomenon in Jakarta Bay

Abstract

Over the past several years, a number of algal bloom incidents has been increasingly observed in Jakarta Bay. The increasing frequency of algal bloom incidents, and subsequent environmental impacts are a rising threat to the coastal resources, economy and public health. Eutrophication, tidal and climatic are the three processes that suspected to have a potential role with algal bloom incidences in this bay. To understand the role of these three processes, a monitoring program had been conducted from 2008 until 2015. The study reveals that algal bloom occurrences have a strong relationship with major nutrients ratio. Besides that, the bloom incident occurred particularly after the rainy season to dry season. The tides have a potential role in the spread of bloom formation and stratification. During the study the concentration of phosphate in these waters ranging from 0.01-2.5 μg/L and nitrate 0.01-15.89 μg/L. The ratio of major nutrient (N/P ratio) in this waters ranging from 0.2-45.4. The N/P ratio tends to be higher in 2010, where the abundance of phytoplankton raising conspicuously. The N/P ratio may controlling the occurrences of algal bloom, while tidal responsible in bloom distribution, and climatic particularly precipitation, effecting nutrients availability.