The baiji dolphin consumed a wide range of freshwater fish endemic to the Yangtze River. The baiji dolphin, also called the Yangtze River dolphin for the only body of water the animal was found in, was a species of freshwater dolphin that was declared functionally extinct in 2006.
The baiji dolphin had poor sight and instead relied on its highly developed echolocation ability to locate fish in the low-visibility conditions that continue to plague the Yangtze River. Additionally, the baiji had a pronounced rostrum, or beak, which was used to probe the riverbed in search of fish and crustaceans, such as catfish and shrimp, respectively.
There are 112 species of freshwater fish endemic to the Yangtze River, with an additional 238 species from other freshwater sources. This wide range of freshwater fish from which to select also exposed the baiji to the environmental hazards posed by the fishing industry in China.
Prior to its being declared functionally extinct in 2006, the baiji faced the risk of becoming bycatch in fishing nets and other gear, being injured or killed by collisions with fishing vessels and other life-threatening dangers. Dam construction along the Yangtze river also influenced the baiji's access to their typical prey items.