Ulsan is one of Korea’s leading industrial cit- ies. After the establishment of heavy industrial and petrochemical complexes during the 1970s, residential areas began to develop as more people gathered to the region. In the 1990s, population peaked at over 1,000,000 and urbanized areas surged as well. However, such rapid develop- ment triggered serious environmental problems
Beginning in the 2000s, significant efforts have been made to restore and preserve the natural environment, followed by positive results. For ex- ample, water pollution in Taehwagang was once so severe that mass sh deaths occurred multiple times; in recent years, the water quality has im- proved enough for salmon to retur
