The Connectivity of Nutrient Ratios on The Abundance of Phytoplankton Population In Jakarta Bay

Abstract

The frequency of algal bloom's event has been increased in Jakarta Bay, recently. Most of the bloom events were tend to be reoccurred after the rainy season. The research was conducted from 2008 until 2015 to study the linkage of nutrients and the ratios on the growth of the phytoplankton population. Collecting samples were conducted using a canonical plankton net of 20 µm mesh size, 125 cm length and 30 cm diameter of the opening mouth. The results of the study showed that the concentration of phosphate in the waters ranged from 0.01-12.5 µg/l (average 4.58 µg/l) and nitrate ranged from 0.01-15.89 µg/l (average 0.72 µg/l). The N/P ratio during the study ranging from 0.2 up to 45.4. High ratios of nutrients were mostly recorded in 2010 where the overall abundance of phytoplankton is very high. There is a strong correlation of N/P ratio with the community structure or composition of the phytoplankton population. The variability of phytoplankton abundance appears to be related to nutrient ratios of nitrate and phosphate.

Phytoplankton Biomass Dynamics in Tropical Coastal Waters of Jakarta Bay, Indonesia in the Period between 2001 and 2019

“…It is predicted that light may have become limiting to phytoplankton in these sites. Reduced underwater light has been reported in this area, possibly due to high levels of organic matter and turbidity as well as high phytoplankton biomass [12,14,30]. At the seaward sites of the bay, the phytoplankton community was more nutrient limited, as nutrient levels decreased due to dilution with the low-nutrient water of the Java Sea, as explained previously [31].…”

“…The accumulation of phytoplankton biomass is facilitated in more enclosed areas of the bay and in calmer waters, leading to higher levels of eutrophication. Koropitan et al [31] described a combination of physical factors associated with this phenomenon, while Sidabutar et al [12] described the influence of stagnant water in the eastern part of the bay.…”

“…Some symptoms of coastal eutrophication were observed in Jakarta Bay, such as hypoxic near-bottom water [11], frequent algal blooms [11][12][13][14], and mass mortality of aquatic biota [46]. Severe impacts occur along the northern coast of Java and nearby islands, including in Lamongan, East Java coastal waters [47], at Lampung Bay [48], at the mouth of the Banyuasin River [44], and in Cirebon coastal waters [49].…”

“…In 2001, it received an annual load of nutrients from 13 small river mouths that amounted to 6700 tons of phosphates, 22,250 tons of dissolved inorganic nitrogen (DIN), and 51,760 tons of silicate per year [10]. As a consequence, the bay shows severe symptoms of eutrophication, including hypoxic near-bottom waters, frequent algal blooms, and mass mortality of aquatic biota [11][12][13][14]. Around 60-80% of domestic wastewater is untreated and flows directly into the sewage system that ends in the bay, resulting in massive accumulation of organic matter in the water [15].…”

The Contribution of Sangga Buana Community as a Learning Media of Civic Engagement Education Based on Ecological and Cultural

“…However, until now Jakarta is still dealing with the dynamics of population problems, as well as the management of ecological use that has not been going well. In addition, referring to the statistical data on the development of the population of DKI Jakarta in 2018 (Putri, et al, 2018;Sidabutar, T., & Srimariana, 2020;Mandasari, et al, 2021), one of the reasons is the increasing development of the population from year to year. As an overview, the data on the development of the population of Jakarta from 2015-2018 is illustrated below.…”