Jakarta Bay, an industrialized and densely inhabited coastal area, presents considerable environmental issues as a result of excessive organic pollution and nutrient inflow. Understanding the spatiotemporal variability of the carbonate system in such an affected bay is critical for assessing marine ecosystem health. The spatiotemporal variability of the carbonate system, pH, partial pressure of carbon dioxide (pCO2), total alkalinity (TAlk), and dissolved inorganic carbon (DIC) was investigated in Jakarta Bay during the rainy and dry seasons of 2023. pH datasets from 2011 to 2023 were also collected from the Environmental Agency of DKI Jakarta (DLH DKI Jakarta) for trend analysis. The temporal analysis shows that during the SE monsoon, the lowest pH (mean: 8.06 ± 0.43); lowest TAlk (mean: 2099 ± 340 µmol kg-1); highest pCO2 (mean: 879 ± 1177 µatm); and highest DIC (mean: 2068 ± 806 µmol kg-1) were observed. The pH distribution gradually increased from the river outlet to the outer bay; inversely, pCO2, TAlk, and DIC gradually decreased. Furthermore, from 2011 to 2023, pH in Jakarta Bay showed a slight upward tendency that was statistically insignificant, reflecting high variability and the influence of local biogeochemical processes. The carbonate system variability reflects changes in biogeochemical (Chl-a, DO and nutrients) and physical (SST and Sal) parameters. In addition, the semi-enclosed hydrodynamic properties, together with the influence of human activities, including a continuous supply of nutrients and organic materials from the mainland through the incoming rivers, further affected the balance of the carbonate system in the bay.
Tito C. K., Bengen D. G., Prartono T., Damar A., Martin P. & Zhang M., 2026. Long-term pH trends and spatiotemporal variability of the carbonate system in Jakarta Bay. Thalassas: An International Journal of Marine Sciences 42: 45. doi: 10.1007/s41208-026-01072-w. Article.
