A Group of Researchers Assessing Physical-Biogeochemical-Bioaccustic Oceanography of Java Sea-Makassar Strait – Flores Sea
Physical and dynamic processes in the triangle of the Java Sea – Makassar Strait – Flores Sea, such as the main crossing of the Arlindo Makassar Strait moorings, the circulation of Monsoon, turbulent energetic region, and coastal upwelling, are thought to affect the distribution of biogeochemistry, as well as the migration of small pelagic fish. While it has been well documented in the previous studies that upwelling events in the southern Makassar Strait (MAK) during the Southeast Monsoon (SEM) period are associated with low sea surface temperature (SST) and high chlorophyll-a (Chl-a) concentrations in the seawater, the dynamic and physical processes that trigger these upwelling events are still less well understood. A multi-disciplinary study of aspects of physical oceanography, biogeochemistry, and biological aspects of fish larvae and Bioacoustics is required through field experiments of MAJAFLOX Cruise 2015.
Agus S. Atmadipoera, Tri Prartono, Indra Jaya and I Wayan Nurjaya of the Faculty of Fisheries and Marine Sciences of Bogor Agricultural University (FPIK IPB); Rina Zuraida from Marine Research and Development Center, Balitbang ESDM, Bandung; together with Asep Priatna and Karsono Wagiyo from the Marine Fishery Research Institute, Balitbang Marine and Fisheries, Jakarta, conducted the research program on integrated Biogeochemical-Biochemical-Bioaccustic Oceanography in the Java Sea – Makassar Strait – Flores Sea.
Some important findings in the study were the strongly mixed layers to the bottom of the Java Sea caused by stirring by the Southeast monsoon. There is also strong physical and biogeochemical evidence from upwelling where, cold temperatures and high salinity from 60 meters rise to the surface are accompanied by decreased nutrients and chl-a spike in the upwelling center.
The Channel has strong internal tidal energy which is released due to narrowing passage of the strait. The internal waves induce such vigorous vertical mixing in the sill region that the vertical diffusivity attains a maximum value of 6 × 10–3 m2s–1 and the salinity maximum and minimum core layers characterizing the ITF thermocline water are considerably weakened. The highest distribution of fish larvae in the Java Sea occurs in the north of East Java, while in the east it occurs in the Makassar Strait near the upwelling area. (Wied)
