People traditionally shared the fish and water of the rivers with river dolphins and included river dolphins in myths and stories. These traditional beliefs used to helped river dolphins survive. Today however, people sometimes do not observe taboos against harming river dolphins directly and wound or kill river dolphins in greater numbers than before. River dolphins are threatened critically by widespread habitat degradation and habitat loss caused by pollution, deforestation, dam construction and other destructive river development, and over-fishing. Chemical pollution from urban, industrial and agricultural wastes and runoff weakens the immune systems of river dolphins, leaving river dolphins vulnerable to infectious diseases.
Noise pollution disrupts the direction-finding abilities and reproductive systems of river dolphins.
Deforestation reduces the numbers of fish in rivers, depriving river dolphins of their primary fish prey. Deforestation also changes rainfall runoff patterns, often causing the water level in rivers to drop. The water levels of the rivers sometimes fall further after water is drawn from them for irrigation. The lowered water levels strand river dolphins in drying pools. River dolphins are sometimes hit by logs which logging companies transport down rivers directly.