A Brazilian judge, Julier Sebastio da Silva, has halted work on a major river transportation system, as it poses an environmental risk. Silva suspended environmental licenses for projects being undertaken along a waterway that joins the Parana and Paraguay rivers and runs through parts of central-western Brazil, Paraguay, Bolivia, Argentina and Uruguay. The waterway is used by Brazil to export grain and minerals to Argentina, Paraguay, Bolivia and Uruguay. But the Paraguay river cuts through large parts of the Pantanal, a vast wildlife sanctuary. Environmentalists warn that the project could destroy thousands of plant and animal species of Pantanal. Studies indicate that the waterway could upset the region's ecosystem and affect migration patterns.