|Scientific Name:||Lipotes vexillifer Miller, 1918|
|Taxonomic Notes:||This species was listed in some previous IUCN Red Lists under the family Platanistidae. For approximately the last twenty years it has been accepted that the species in fact belongs to a distinct family: Lipotidae (Rice 1998, Committee on Taxonomy 2016).|
|Red List Category & Criteria:||Critically Endangered (Possibly Extinct) C2a(i,ii); D ver 3.1|
|Assessor(s):||Smith, B.D., Wang, D., Braulik, G.T., Reeves, R., Zhou, K., Barlow, J. & Pitman, R.L.|
|Reviewer(s):||Taylor, B.L. & Lowry, L.|
The Baiji is a relict species and the only representative of the family Lipotidae (Zhou et al. 1978). In the previous assessment (Smith et al. 2008), the Baiji was evaluated as Critically Endangered (CR) (Possibly Extinct), as abundance was believed to be extremely low, and as the numerous serious threats it faced in the wild were still occurring. The last confirmed sighting of a Baiji was in 2002. Although the species is generally believed to be extinct (Turvey et al. 2007) sporadic unconfirmed reports of sightings mean that the species should remain as CR (Possibly Extinct), rather than Extinct (EX), pending the results of a range-wide survey planned for November-December 2017.
The 2008 IUCN Red List assessment classified the Baiji as CR (Possibly Extinct) based on the following criteria:
The following factors justify retaining the classification of the Baiji as CR (Possibly Extinct) in the current assessment:
|Date last seen:||2002|
|Previously published Red List assessments:|
|Range Description:||The Baiji is endemic to the Yangtze River of China. Some individuals were seen in the Qiantang River, immediately south of the Yangtze, after the great flood of 1955 but they disappeared after construction of a hydropower station in 1957 (Zhou 2009). Baijis also occurred in Dongting and Poyang Lakes (Zhou et al. 1977, Chen et al. 1980) but disappeared from both of these appended water bodies of the Yangtze by the 1990s (Yang et al. 2000, Zhang et al. 2003). Their upstream limit in the Yangtze declined from the Three Gorges area approximately 35 km above Gezhouba Dam near Yichang in the 1940s to approximately 170 km below the dam site near Jingzhou (formerly called Shashi) in the 1990s (Zhang et al. 2003, Zhou 2009). These dolphins were once observed as far downstream as the river mouth near Shanghai (Zhou and Li 1989). No dolphins were found downstream of Jiangyin, located 256 km upstream of the mouth, during surveys in 1997-99 (Zhang et al. 2003). During surveys in the late 1990s, Baijis were found mainly in several segments of the Yangtze between Tongling and Dongting Lake, such as the Tongling section, the Poyang Lake mouth area, and the Honghu section (Zhang et al. 2003). Turvey et al. (2010) concluded from community interviews along the length of the Yangtze River that while the Baiji steadily declined in abundance, this decline “was not associated with any major contraction in geographical range across the middle–lower Yangtze drainage, even in the decade immediately before probable global extinction of the species.” Hazy video footage taken in the Tongling area of the Yangtze in 2007 may have been a Baiji but the species identification could not be confirmed. Also, during the last two years there have been unconfirmed reports of sightings made by a team of student volunteers and older fishermen near Tongling (Wang Ding, unpubl. data).|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The first estimate of abundance based on quantitative survey data (1979-81) was made by Zhou (1982), who concluded that the total population comprised only about 400 animals. On the basis of surveys conducted in 1985-86, Chen and Hua (1989) made an educated guess that the total population was around 300. Surveys by Zhou and Li (1989) between 1982 and 1986 suggested that there were 100 Baijis in a 770 km segment of the lower Yangtze from Hukou to the river mouth, compared with 78-79 dolphins counted by Chen and Hua (1989) in the same segment in 1985-86. Repeated surveys of a 500 km segment of the lower Yangtze (Nanjing-Hukou) in 1989-91 produced a maximal count of 12 individuals, leading Zhou et al. (1998) to infer a total abundance of about 30 Baijis in that river segment. Those authors reasoned that if the species still inhabited its historical range of about 1,700 linear kilometers of river, with a density similar to that found in their study area, the total population in the early 1990s would have been only about 100. Attempted comprehensive surveys of the entire species range in 1997-99 resulted in a maximal count (November 1997) of 13 dolphins (including one calf), leading to the generally accepted view that abundance had continued to decline and that the total population was by that time extremely small. The sighting rate in the three years of surveys declined at an annual rate of about 10% (Zhang et al. 2003). Although no credible time series of counts or abundance estimates is available to provide a rigorous evaluation of trends, there is an overwhelming consensus that the Baiji population declined rapidly over several decades before its probable extinction in the early 2000s.|
The last documented sighting (supported by photographic evidence) was in 2002 and the last confirmed stranding was in 2001. In November and December 2006, a comprehensive visual and acoustic survey failed to find a single Baiji in the Yangtze River (Turvey et al. 2007). Two research vessels covered the known habitat of Baijis from Yichang to Shanghai in both the upstream and downstream directions (for double coverage on both sides of the river). In addition, one vessel towed a hydrophone to listen for Baiji whistles and clicks during the downstream survey. Although Dongting and Poyang Lakes were not covered in the 2006 Yangtze mainstem survey, since 2000 no Baijis have been seen by researchers studying Finless Porpoises in those lakes. Another survey conducted for Finless Porpoises in 2012 also failed to detect any Baijis (Mei et al. 2014). One of the assessors (WD) received reports and hazy video footage of a Baiji sighting in the Tongling area of the Yangtze in 2007 but the species identification could not be confirmed. There are more recent unconfirmed reports of Baiji sightings by student volunteers and older fishermen but no photographic, video, or acoustic evidence is available to assess the reliability of these reports. In view of the unconfirmed reports, a precautionary approach has been taken by retaining the classification of the Baiji as CR (Possibly Extinct) rather than changing it to EX, pending the results of a third range-wide survey from Yichang to Shanghai, using the same rigorous methods as were used in surveys conducted in 2006 and 2012, this time with more targeted survey effort in Tongling. If these surveys fail to find a Baiji, the case for changing the species’ status from Critically Endangered (Possibly Extinct) to Extinct will be particularly strong.
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||Baiji have been generally found in eddy counter-currents below meanders and channel convergences (Hua et al. 1989, Zhou and Li 1989, Zhang et al. 2003). They are known to prey on fish of many sizes and various species, including both surface and bottom feeders (Chen et al. 1997).|
|Continuing decline in area, extent and/or quality of habitat:||Yes|
|Use and Trade:||There is no current trade in or use of this species or its products.|
The decline in Baiji abundance was caused by a combination of factors. The most consequential were probably incidental mortality from interactions with fisheries and loss and/or degradation of habitat by water development and management of navigation channels (Turvey et al. 2013). Other threats contributing to the species’ probable extinction include some level of direct historical exploitation (e.g., during China’s “great leap forward” the Baiji’s traditionally venerated status as Goddess of the River was denounced and Baiji skin was used to produce handbags and gloves; Zhou and Zhang 1991), vessel strikes, harbour construction, sedimentation from poor land use practices, and pollution.
In China, the Baiji is designated in the First Category of National Key Protected Wildlife Species and has full legal protection throughout its range. Protection from deliberate killing or injury appears to have been effective but, as noted under Threats, prohibitions on harmful fishing methods were generally not very effective and Baijis continued to suffer from the mortality, injury, and health impairment caused by the other threats listed.
The Scientific Committee of the IWC reviewed the status of the Baiji in 2000, but members were unable to reach consensus on whether further attempts at live-capture should be made (IWC 2001). The IUCN Cetacean Specialist Group recommended in 2003 that: (1) available resources should be devoted to eliminating the known threats to the species in its natural habitat; (2) immediate action should be taken at national, provincial and local levels to fully enforce the bans on rolling hooks and electric fishing; and (3) if the capture/translocation effort continues, capture operations should be improved to prevent dolphin injury or mortality, water quality in the reserve should be kept at a high standard, and Finless Porpoises should be removed to ensure against deleterious interactions between them and the Baiji(s) (Reeves et al. 2003). In the early 2000s, the Chinese Ministry of Agriculture developed a Baiji conservation plan emphasizing the ex situ approach (Ministry of Agriculture 2001).
The Yangtze region is home to approximately 10% of the world’s human population and the Yangtze River has been undergoing progressive ecological deterioration for many decades. The Baiji is the victim not of active persecution but of incidental mortality resulting from massive-scale human environmental impacts, primarily uncontrolled and unselective fishing (Turvey et al. 2007)
Conservation actions for Baijis may be too late to prevent its extinction. However, such actions can be justified by the fact that almost any substantial conservation measures in the Yangtze will benefit the Critically Endangered Yangtze Finless Porpoise, which is the world’s only freshwater porpoise and was sympatric with the Baiji before the latter’s disappearance. Research should concentrate on confirming the presence or absence of Baijis through rigorous searching effort. This effort should include the range-wide survey planned for November to December 2017 from Yichang to Shanghai in both the upstream and downstream directions (for double coverage on both sides of the river) using visual observers with high-powered binoculars and an acoustic search with a towed hydrophone to listen for Baiji whistles and clicks. Searching effort should also include more intensive surveys using both visual and acoustic techniques in the area around Tongling where recent unconfirmed observations of Baijis were reported. If a Baiji is found during any of these surveys, the conservation recommendations made by the IUCN Cetacean Specialist Group in 2003 (see above) would remain valid.
The Baiji is listed on Appendix I of the Convention on International Trade in Endangered Species (CITES).
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|Citation:||Smith, B.D., Wang, D., Braulik, G.T., Reeves, R., Zhou, K., Barlow, J. & Pitman, R.L. 2017. Lipotes vexillifer. The IUCN Red List of Threatened Species 2017: e.T12119A50362206.Downloaded on 14 December 2017.|