Water mass exchange in triangle seas of the Java-Makassar-Flores (JMF): A modeling study

The ocean dynamics of the marginal seas in the Java-Makassar-Flores (JMF) Triangle seas facilitates the seasonal exchange of water masses between Java, Makassar, and Flores, which influences the occurrence of small pelagic fish. This research investigates seasonal fluctuations in sea currents, seawater temperature, salinity, and phytoplankton primary production (PPN and PPD) based on validated model output datasets from NEMO and PISCES from the INDESO simulation (2008–2015). The model demonstrated seasonal exchanges of the top 50 m of water masses in the area, where the eastward monsoon current transported freshwater (salinity34 PSU) into the Java Sea, pushes fresh Java waters westward. Seasonal salinity changes and PPN/PPD in the shelf region of southern Kalimantan correlated with substantial small pelagic fishing. •Ocean circulation and water mass exchange in the JMF seas were investigated using physical and biogeochemical ocean model.•Exchange of fresh Java and salty ITF waters are driven by monsoon current and ITF Makassar, creating strong salinity front.•The seasonal shifting of salinity front is a proxy for potential fishing grounds of small pelagic fishes in the JMF seas.