Water development projects, including dams, embankments, and ship locks, have had extensive deleterious effects on two species of river cetacean in China: the baiji (Lipotes vexillifer) and the Yangtze population of finless porpoises (Neophocaena phocaenoides asiaeorientalis). The Gezhouba and Three Gorges dams are located in the mainstem of the Yangtze. The latter, once completed, is expected to further degrade countercurrent habitat in the upper and middle reaches of the river. Numerous smaller dams in tributaries of the Yangtze and its appended lakes have dramatically reduced the availability of migratory fish. Baiji once occurred in the Xinan River but apparently were extirpated after the construction of a high dam.