By 1997, 44 percent of the original natural habitats of Indonesia were converted to other uses, and even larger portions of its lowland tropical rain forests were lost. Several key coral reefs were decimated by dynamite and cyanide fishing. Indonesia had more types of animal threatened with extinction (600) than any country in the world. All the rivers in Jakarta were dead, choked by acids, alcohol and oils, and a thick smog cloud enveloped the city. Environmental degradation, due to mining in outer Java islands and quarrying for building materials in Java, was constantly increasing, exposing Indonesians to erosions, forest fires the size of Belgium and landslides.