The Baiji River dolphin population declined drastically in recent decades as China industrialized and made heavy use of the river for fishing, transportation, and hydroelectricity. As China developed, pressure on the river dolphin grew. Industrial and residential waste flowed into the Yangtze. The riverbed was dredged and reinforced with concrete in many locations. Ship traffic multiplied, boats grew in size, and fishermen employed wider and more lethal nets. By 1981 it was delisted.