River dolphins — found in South America and South Asia — are among the most threatened cetaceans, with individual welfare harms driven by fishing gear, pollution, and dam construction.
River dolphins entangled in gillnets drown within minutes — a rapid but distressing death. Those that survive net entanglement with injuries may experience prolonged suffering from lacerations and infection. Mercury poisoning from artisanal gold mining causes progressive neurological deterioration — disorientation, loss of coordination, and ultimately death. Boto (Amazon pink dolphins) are sometimes deliberately killed for use as fish bait in catfish traps, involving active cruelty. Dam construction causes chronic welfare harms by reducing prey availability and fragmenting populations. The loss of the baiji — the first cetacean driven to extinction in modern times — demonstrates the stakes of inadequate river dolphin protection.