Baiji (Lipotes vexillifer), the Chinese river dolphin, was a freshwater cetacean species that lived in the Yangtze River. According to fossil records, this species first appeared in the Pacific Ocean then migrated to the Yangtze River around 20 million years ago. In the 1950s, its population was estimated at 6000 individuals, however, only 13 individuals were visually sighted in 1997, and in 2006 the Baiji was declared functionally extinct.
According to Chinese legend, baiji was the reincarnation of a drowned princess, and it was considered to be a national treasure. But its habitat, the Yangtze River, the cradle of Chinese civilization, quickly became one of the world’s busiest waterways. While large-scale economic developments, intensive fishing, agricultural run-offs and industrial pollution led to the drastic degradation of the river system, the biggest threat came from unselective and uncontrolled fishing activities. Therefore, for years conservationists campaigned for the protection of the Baiji. Recommendations included the establishment of an ex situ breeding population away from the main Yangtze channel. But in 2006, an intensive visual and acoustic survey covering 1700 km failed to find any surviving individual.
During the search for baiji, the population of Yangtze finless porpoise (Neophocaena phocaenoides asiaorientalis) or river pig was also surveyed. Although, this species was once a common inhabitant of the river system, fewer than 400 individuals were recorded. Consequently, its conservation status was adjusted to critically endangered. As a conservation measure, five finless harbour porpoises were transferred to the Tian-e-Zhou Oxbow Nature Reserve where currently more than 30 individuals live, and two to five calves are born every year. In addition, within the framework of a breeding program, the first Yangtze finless porpoise was born in captivity in 2005. Nevertheless, the quality of the Yangtze River is expected to worsen, which will probably impact the remaining wild population.
The loss of baiji represents the first extinction of cetacean species that was driven by human activity, and unless in situ conservation efforts are implemented, finless porpoises could be lost as well.
By Wanda Bodnar