Lipotes vexillifer is probably the most endangered of all cetaceans. It is listed as critically endangered on the IUCN's Red List of Threatened Species, it is listed as endangered by the U.S. Fish and Wildlife Service, and it is on CITES appendix I. The total population is estimated at less than 100 animals; surveys in the late 1990s put the minimum population estimate at 13. A 2006 survey of the entire range of L. vexillifer failed to find any individuals at all, and it is probable that the species is now extinct.
There are three major factors that threaten baiji survival: dams and floodgates that block fish migration in the river's tributaries and lakes, fisheries accidentally killing dolphins, and boat propellers. Population numbers also declined through hunting and development of irrigation facilities. The heavy pollution and underwater noise characteristic of the Yangtze also affects the Baiji. These stresses, as well as lack of food, can inhibit reproduction.
China began providing legal protection in 1975. Programs are being established to breed Lipotes vexillifer in captivity, though no one has yet succeeded at housing wild baiji for long. In 1992 an oxbow jutting off from the main Yangtze river was set aside as a reserve where baiji could be relocated and allowed to live under semi-natural conditions. In the face of ongoing degradation of the Yangtze river, this "ex-situ" conservation strategy may be the species' only hope for survival. In 2006, a survey of the entire range of baiji will be carried out by the baiji.org foundation in collaboration with Chinese administrators and the Institute for Hydrobiology. Scientists are hopeful this survey will give them a better idea of exactly how many baiji remain and where they are located, so that they can eventually be relocated to reserves.
US Federal List: endangered
CITES: appendix i
IUCN Red List of Threatened Species: critically endangered