Some modules of the ecological models, developed in the frame of the program, are important contributions to the world science. The most important contribution is the development of two-dimensional (2D) and three-dimensional (3D) models for the simulation of mercury transport and fate, for which a great interest is shown by many foreign researchers. The research group has been collaborating with Japanese researchers on measurements and modelling of mercury processes in the Minamata Bay (Japan) and in the Gulf of Trieste for four years. An integrated approach of solving mercury pollution problems in a watershed (Idrijca and Soča rivers) together with the adjacent coastal sea (Gulf of Trieste) was applied in the frame of the EU project EUROCAT. In the frame of another EU project MERCYMS the research group has done simulations of mercury cycling in the whole Mediterranean Sea. The coupling of the developed model with atmospheric model of mercury transport (elaborated by Italian and Greek partners) is a novelty in the world science. Further progress was done in the application of methods of artificial intelligence with the development of ecological models on the basis of data analysis. Together with the Joseph Stefan Institute the researchers are included in the COST/ESPRIT programme and collaborate at the development of new tools of artificial intelligence. Integrated approach of water quality protection in complete watersheds reaches over the borders of Slovenia into the Danube catchment and the Adriatic Sea, which is interesting for the EU.