Duration: 2012 - 2015

Due to a rapid population growth nutrient loads from domestic wastewater and industrial activities from the JMA have increased substantially over the past 2 decades. The elevated nutrient levels lead to recurrent microalgae blooms, often associated with fish kill events.

Model simulations will provide a basis for the definition of critical areas and for recommendations aiming to improve the effectiveness of potential mitigation measures. In order to evaluate potential coherence patterns of different environmental stressors, measured and modelled nutrient gradients are related to data on phytoplankton biomass and to the occurrence of microalgae bloom events.

Intensive field measurements are carried out in order to provide data required for the development of the hydrodynamic and water quality models. The bilateral research activities foster and strengthen the long-standing international cooperation and networking with the Indonesian partners. Associated capacity building and training activities provide an efficient transfer of scientific knowledge and environmental awareness and thus support the development of research capacities and technical infrastructure in Indonesia. The project is an integral part of the joint BMBF research project MABICO (Impacts of Marine Pollution on Biodiversity and Coastal Livelihoods) of the SPICE III program.

The field studies reveal strongly enhanced nitrogen and phosphorus levels in the numerous waterways crossing the Metropolitan Area. Accordingly, elevated nutrient and chlorophyll-a concentrations were found in the coastal water in front of the main sites of freshwater runoff. However, concentrations rapidly decrease down to oligotrophic conditions towards the open sea.

Ammoniumverteilung [µM] in der Bucht von Jakarta im Oktober 2012 (NN = Messwert unterhalb der Nachweisgrenze von 0,05 µM)
Distribution of ammonium [µM] in Jakarta Bay in October 2012 (NN = data below detection limit of 0.05 µM)

For the purpose of numerical modelling a computational grid was created to cover greater part of the Java Sea. The current grid size lies around 1 km and is refined to about 100 m for the Jakarta Bay.

Bathymetrie und Gitternetz des Strömungsmodells für das Untersuchungsgebiet in der Javasee
The computational grid and bathymetry for the Java Sea

Research Divison:


  • Dr. Karl-J. Hesse


  • M.Sc. Simon van der Wulp
  • TA Daniela Koch
  • Dr. Norbert Ladwig

Indonesian Partners:

  • Research Center for Marine and Fisheries Product Processing and Biotechnology (BBRP2B)
  • Agricultural University Bogor (IPB)

German partners:

  • Leibniz Center for Tropical Marine Ecology Bremen (ZMT)
  • Institute of Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University
  • Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute Jena (HKI)
  • Faculty of Agricultural and Environmental Sciences, University of Rostock

Funded by:

  • German Federal Ministry of Education and Research (BMBF)