Baiji

From Wikipedia, the free encyclopedia

This article is about the dolphin. For other uses, see Baiji (disambiguation).
Baiji
An illustration of the Baiji
An illustration of the Baiji
Size comparison against an average human
Size comparison against an average human
Conservation status

Critically endangered, possibly extinct (IUCN 2.3)[1]
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Subclass: Eutheria
Order: Cetacea
Suborder: Odontoceti
Superfamily: Platanistoidea
Family: Lipotidae
Genus: Lipotes
Species: L. vexillifer
Binomial name
Lipotes vexillifer
Miller, 1918
Natural range of the Baiji
Natural range of the Baiji

The Baiji (help·info) (Chinese: 白鱀豚; pinyin: báijìtún) (Lipotes vexillifer, Lipotes meaning "left behind", vexillifer "flag bearer") is a freshwater dolphin found only in the Yangtze River in China. Nicknamed "Goddess of the Yangtze" (simplified Chinese: 长江女神; traditional Chinese: 長江女神; pinyin: Cháng Jiāng nǚshén) in China, the dolphin was also called Chinese River Dolphin, Yangtze River Dolphin, Whitefin Dolphin and Yangtze Dolphin. It is not to be confused with the Chinese White Dolphin (simplified Chinese: 中华白海豚; traditional Chinese: 中華白海豚; pinyin: Zhōnghuá bái hǎitún). The 2007 IUCN Red List classifies the Baiji as a critically endangered (CR) species, and acknowledges the species is possibly extinct (PE).[1]

The Baiji population declined drastically in recent decades as China industrialized and made heavy use of the river for fishing, transportation, and hydroelectricity. The last confirmed sighting of a Baiji was in 2004, with an (as yet) unconfirmed sighting in August 2007.[2] Efforts were made to conserve the species, but a late 2006 expedition failed to find any Baiji in the river. Organizers declared the Baiji "functionally extinct",[3] which would make it the first aquatic mammal species to become extinct since the demise of the Japanese Sea Lion and the Caribbean Monk Seal in the 1950s. It would also be the first recorded extinction of a well-studied cetacean species (it is unclear if some previously extinct varieties were species or subspecies) to be directly attributable to human influence.

In August 2007, Zeng Yujiang reportedly videotaped a large white animal swimming in the Yangtze.[2]. Although Wang Kexiong of the Institute of Hydrobiology of the Chinese Academy of Sciences has tentatively confirmed [4] that the animal on the video is a baiji, the presence of only one or a few animals, particularly of advanced age, is not enough to save a functionally extinct species from true extinction.

Contents

[edit] Anatomy and morphology

Baiji are thought to breed in the first half of the year, the peak calving season being from February to April.[5] A 30% pregnancy rate was observed.[6] Gestation lasts 10-11 months, delivering one calf at a time; the interbirth interval is 2 years. Calves measure around 80-90 centimetres (32-35 in) at birth, and nursed for 8-20 months.[7] Males reach sexual maturity at age four, females at age six.[7] Mature males were about 2.3 metres (7.5 ft) long, females 2.5 metres (8 ft), the longest specimen 2.7 metres.[7] The animal weighed 135-230 kilograms (300-510 lb),[7] with a lifespan estimated at 24 years in the wild.[8]

When escaping from danger, the Baiji can reach 60 km/h (37 mph), but usually stays within 10 to 15 km/h (6-9 mph). Because of its poor vision and hearing, the Baiji relies mainly on sonar for navigation.

[edit] Distribution

Historically the Baiji occurred along 1,700 kilometres (1,000 miles) of the middle and lower reaches of the Yangtze from Yichang in the west to the mouth of the river, near to Shanghai. This had been reduced by several hundred kilometres both upstream and downstream, and was limited to the main channel of the Yangtze, principally the middle reaches between the two large tributary lakes, Dongting and Poyang.[9] Approximately 12% of the world’s human population lives and works within the Yangtze River catchment area, putting pressure onto the river.[10] The construction of the Three Gorges Dam, along with other smaller damming projects, also led to habitat loss.

[edit] Evolutionary history

Fossil records suggest that the dolphin first appeared 25 million years ago and migrated from the Pacific Ocean to the Yangtze River 20 million years ago.[11] It was one of four species of dolphins known to have made fresh water their exclusive habitat. The other three species, including the Boto and the La Plata Dolphin, have survived in the Río de la Plata and Amazon rivers in South America and the Ganges and Indus rivers on the Indian subcontinent.

It is estimated that there were 5,000 Baiji when they were described in the ancient dictionary Erya circa 3rd century BC. A traditional Chinese story describes the Baiji as the reincarnation of a princess who had been drowned by her family after refusing to marry a man she did not love. Regarded as a symbol of peace and prosperity, the dolphin was nicknamed the "Goddess of the Yangtze."

[edit] Conservation

In the 1950s, the population was estimated at 6,000 animals,[12] but declined rapidly over the subsequent five decades. Only a few hundred were left by 1970. Then the number dropped down to 400 by the 1980s and then to 13 in 1997 when a full-fledged search was conducted. Now the most endangered cetacean in the world, according to the Guinness Book of World Records,[3] the Baiji was last sighted in August 2007.[2]

[edit] Causes of decline

The World Conservation Union (IUCN) has noted the following as threats to the species: a period of hunting by humans during the Great Leap Forward, entanglement in fishing gear, the illegal practice of electric fishing, collisions with boats and ships, habitat loss, and pollution.

During the Great Leap Forward, when traditional veneration of the Baiji was denounced, it was hunted for its flesh and skin, and quickly became scarce.[1]

As China developed economically, pressure on the river dolphin grew significantly. Industrial and residential waste flowed into the Yangtze. The riverbed was dredged and reinforced with concrete in many locations. Ship traffic multiplied, boats grew in size, and fishermen employed wider and more lethal nets. Noise pollution caused the nearly blind animal to collide with propellers. Stocks of the dolphin's prey declined drastically in recent decades as well, with some fish populations declining to one thousandth of their pre-industrial levels.[13]

In the 1970s and 1980s, an estimated half of Baiji deaths were attributed to entanglement in fishing gear. By the early 2000s, electric fishing was considered "the most important and immediate direct threat to the Baiji's survival."[1] Though outlawed, the destructive fishing technique is widely practised throughout China. The building of the Three Gorges Dam further reduced the dolphin's habitat and facilitated an increase in ship traffic.

[edit] Timeline

[edit] Surveys

Results of Yangtze River Baiji surveys between 1979 and 1996 ( * Lower reaches only)[10]
Year Survey Area No. of km surveyed No. of Baiji sighted No. of Baiji estimated
1979[16] Wuhan-Chenglingji 230 19 -
1979[17] Nanjing-Taiyangzhou 170 10 -
1979-1981[18] Nanjing-Guichi 250 3-6 groups 400
1978-1985[19] Yichang-Nantong 1600 >20 groups 156
1985-1986[20] Yichang-Jiangyin 1510 42 groups 300
1979-1986[21] Fujiangsha-Hukou 630 78-79 100*
1987-1990[22] Yichang-Shanghai 1669 108 200
1989-1991[23][24] Hukou-Zhenjian 500 29 120
1991-1996[25] Xinchang-Wuhan 413 42 <100

[edit] Conservation efforts

Soon after it decided to modernize, China recognized the precarious state of the river dolphin. The government outlawed deliberate killing, restricted fishing, and established nature reserves.

In 1978, the Chinese Academy of Sciences established the Freshwater Dolphin Research Centre (淡水海豚研究中心) as a branch of the Wuhan Institute of Hydrobiology. In the 1980s and 1990s, several attempts were made to capture dolphins and relocate them to a reserve. A breeding program would then allow the species to recover and be reintroduced to the Yangtze after conditions improve. However, capturing the rare, quick dolphins proved to be difficult, and few captives survived more than a few months.[1]

The first Chinese aquatic species protection organisation, the Baiji Dolphin Conservation Foundation of Wuhan (武汉白鱀豚保护基金), was founded in December 1996. It has raised 1,383,924.35 CNY (about 100,000 USD) and used the funds for in vitro cell preservation and to maintain the Baiji facilities, including the Shishou Sanctuary that was flooded in 1998.

Conservation efforts of the Baiji along the Yangtze River
Conservation efforts of the Baiji along the Yangtze River

Since 1992 five protected areas of the Yangtze have been designated as Baiji reserves. Four were built in the main Yangtze channel where Baiji are actively protected and fishing is banned: two national reserves (Shishou City and Xin-Luo) and two provincial (Tongling and Zhenjiang). A fifth protected area is an isolated oxbow lake located off of the north bank of the river near to Shishou City: the Tian-e-Zhou Oxbow Semi-natural Reserve. Combined, these five reserves cover just over 350 kilometres (220 miles), about 1/3 of the Baijis range, leaving two-thirds of the species' habitat unprotected.[10]

As well as these five protected areas there are also five "Protection Stations" in Jianli, Chenglingji, Hukou, Wuhu and Zhengjiang. These stations consist of two observers and a motorised fishing boat with the aim of conducting daily patrols, making observations and investigating reports of illegal fishing.[10]

In 2001 the Chinese government approved a Conservation Action Plan for Cetaceans of the Yangtze River. This plan re-emphasised the three measures identified at the 1986 workshop and was adopted as the national policy for the conservation of the Baiji. Despite all of these workshops and conventions little money was available in China to aid the conservation efforts. It has been estimated that US$1 million was needed to begin the project and maintain it for a further 3 years.[26]

Efforts to save the mammals proved to be too little and too late. August Pfluger, chief executive of the Baiji.org Foundation, said, "The strategy of the Chinese government was a good one, but we didn't have time to put it into action."[27]

[edit] In-situ conservation

Most scientists agreed that the best course of action was an ex-situ effort working in parallel with an in-situ effort. The deterioration of the Yangtze River had to be reversed to preserve the habitat. The ex-situ projects aimed to raise a large enough population over time so that some, if not all, of the dolphins could be returned to the Yangtze, so the habitat within the river had to be maintained anyway.

[edit] Ex-situ conservation

The Shishou Tian-e-Zhou is a 21 kilometre (13 mile) long, 2 kilometre (1.2 mile) wide oxbow lake located near Shishou City in Hubei Province. Shishou has been described as being "like a miniature Yangtze … possessing all of the requirements for a semi-natural reserve". From the designation as a national reserve in 1992 it has been intended to be used for not only the Baiji but also the Yangtze Finless Porpoise. In 1990 the first Finless Porpoises were relocated to the reserve and since then have been surviving and reproducing well. As of April 2005 26 Finless Porpoises were known to live in the reserve. A Baiji was introduced in December 1995, but died during the summer flood of 1996. To deal with these annual floods a dyke was constructed between the Yangtze and Shishou. Now water is controlled from a sluice gate located at the downstream mouth of the oxbow lake. It has been reported that since the installation of this sluice gate, water quality has declined since no annual transfer of nutrients can occur. Roughly 6,700 people live on the ‘island’ within the oxbow lake and so some limited fishing is permitted. [10]

Success of Shishou with the porpoises and with migratory birds and other wetland fauna has encouraged the local Wetlands Management Team to put forward an application to award the site Ramsar status.[28] It has also been noted that the site has incredible potential for ecotourism, which could be used to generate much needed revenue to improve the quality of the reserve. The necessary infrastructure does not currently exist to realize these opportunities.

[edit] Captive specimens

A Baiji conservation dolphinarium was established at the Institute of Hydrobiology (IHB) in Wuhan in 1992. This was planned as a backup to any other conservation efforts by producing an area completely protected from any threats, and where the Baiji could be easily observed. The site includes an indoor and outdoor holding pool, a water filtration system, food storage and preparation facilities, research labs and a small museum. The aim is to also generate income from tourism which can be put towards the Baiji plight. The pools are not very large (25 m arc [kidney shaped] x 7 m wide x 3.5 m deep, 10 m diameter, 2 m deep and 12 m diameter, 3.5 m deep) and so are not capable of holding many Baijis at one time.

Douglas Adams and Mark Carwardine documented their encounters with the endangered animals on their conservation travels for the BBC programme Last Chance to See. The book by the same name, published in 1990, included pictures of a captive specimen, a male named Qi Qi (淇淇) that lived in the Wuhan Institute of Hydrobiology dolphinarium from 1980 to July 14, 2002. Discovered by a fisherman in Dongting Lake, it became the sole resident of the Baiji Dolphinarium (白鱀豚水族馆) beside East Lake. A sexually mature female was captured in late 1995, but died after half a year in 1996 when the Shishou Tian-e-Zhou Baiji Semi-natural Reserve (石首半自然白鱀豚保护区), which had contained only Finless Porpoises since 1990, was flooded.

Details of captive baijis[10]
(IHB = Institute of Hydrobiology, NNU = Nanjing Normal University, NFRI = Nanjing Fisheries Research Institute)
Name Date range Location Sex Conditions of rearing Survival time
Qi Qi 1980-01-12 - 2002-07-14 IHB M Outdoor & indoor, non-filtered 22.5 years
Rong Rong 1981-04-22 - 1982-02-03 IHB M Outdoor non-filtered 228 days
Lian Lian 1986-03-31 - 1986-06-14 IHB M Outdoor non-filtered 76 days
Zhen Zhen 1986-03-31 - 1988-09-27 IHB F Outdoor non-filtered 2.5 years
Su Su 1981-03-03 - 1981-03-20 NNU F Indoor 17 days
Jiang Jiang 1981-12-07 - 1982-04-16 NFRI M Outdoor non-filtered 129 days

[edit] Current status

See also: Yangtze Freshwater Dolphin Expedition 2006

The Xinhua News Agency announced on 4 December 2006 that no Chinese River Dolphins were detected in a six-week survey of the Yangtze River conducted by 30 researchers. The failure of the Yangtze Freshwater Dolphin Expedition (simplified Chinese: 长江淡水豚类考察; traditional Chinese: 長江淡水豚類考察; pinyin: Chāng Jiāng dànshuǐ tún lèikǎochá) raised suspicions of the first unequivocal extinction of a cetacean species due to human action[29] (some extinct baleen whale populations might not have been distinct species). Poor water and weather conditions may have prevented sightings,[3] but expedition leaders declared it "functionally extinct" on 13 December 2006 as fewer are likely to be alive than are needed to propagate the species.[3] Although on a hopeful note, footage believed to be a baiji from August 2007 was released to the public.[30]

The Japanese Sea Lion and Caribbean Monk Seal disappeared in the 1950s, the last aquatic mammals to become extinct. Several land-based mammal species and subspecies have disappeared since then. If the Baiji is now extinct, the North Pacific Right Whale has become the most endangered marine mammal species.

Some scientists retain hope for the species:

“ The fact that the expedition didn't see any Baiji dolphins during this expedition does not necessarily mean that the species is extinct or even 'effectively extinct', because it covered a considerable distance in a relatively short period of time... However, we are extremely concerned. The Yangtze is highly degraded, and we spotted dramatically fewer Finless Porpoises than we have in the past. ”
 
— Wang Limin, director of the World Wide Fund for Nature, Wuhan office[31]

A report of the expedition was published online in the journal Biology Letters on August 7th, 2007, in which the authors conclude "We are forced to conclude that the baiji is now likely to be extinct, probably due to unsustainable by-catch in local fisheries"[32]

A possible sighting of one of the dolphins in Anhui Province was reported on August 29, 2007.[33][34]

Some reports suggest that information about the baiji and its demise is being suppressed in China.[35] But in fact it is widely reported and discussed, including government media China Central Television and Xinhua News Agency.[36]

The IUCN will likely accept a proposal to change the conversation status from "critically endangered" to "critically endangered (possibly extinct)" in time for the updated Red List, due out on 12 September, 2007[37].

In August 2007, Zeng Yujiang reportedly videotaped a large white animal swimming in the Yangtze.[2] Wang Kexiong of the Institute of Hydrobiology of the Chinese Academy of Sciences has tentatively confirmed that the animal on the video is a baiji.

The lives of Finless porpoise are also in risk. On October 11, 2007, Chinese state media announced that under a development plan an additional 4,000,000 people will be relocated from their homes near the dam by the year 2020 due to ecological concerns, while a forum of officials and experts warned of a possible “environmental catastrophe” if preventive measures are not taken.[38][39][40] Currently, the quality of water in the Yangtze is falling rapidly, due to the dam's preventing dispersal of pollutants; algae blooms have risen progressively since the dam’s construction; and soil erosion has increased, causing riverbank collapses and landslides.[41] The report detailing this was officially released in September 2007.[42] Senior Chinese government officials and scholars said the dam could cause a “huge disaster ... if steps are not taken promptly.”[41] The same scholars and officials previously had defended the Three Gorges Dam project.[43] Xinhua also reported that tens of billions of yuan had been spent to prevent pollution and geological disasters by tree planting, measures to maintain species diversification, shutting 1500 polluting industrial and mining enterprises and building 70 sewage and waste treatment plants, all of which are "progressing well." [43]

[edit] See also

Cetaceans Portal

[edit] References

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  2. ^ a b c d "Rare Dolphin Seen in China, Experts Say", New York Times, 2007-08-30. Retrieved on 2007-08-30. 
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  5. ^ Culik, B. (2003). Lipotes vexillifer, Baiji. Retrieved on 2006-12-18.
  6. ^ IWC. 2000. Report of the Standing Sub-Committee on Small Cetaceans. IWC/52/4. 52nd Meeting of the International Whaling Commission, Adelaide, Australia.
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  8. ^ Nowak, R.M. 1999. Walker's Mammals of the World. 6th Ed. The Johns Hopkins Univ. Press, Baltimore.
  9. ^ Reeves, R.R., Smith, B.D., Crespo,E.A. & Notarbartolo di Sciara, G. (eds.) (2003) Dolphins, Whales and Porpoises: 2002-2010 Conservation Action Plan for the World’s Cetaceans. IUCN/SSC Cetacean Specialist Group. IUCN, Glad, Switzerland and Cambridge, U.K.
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  14. ^ Adams, Douglas. Last Chance to See. 
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  20. ^ Chen, P. & Hua, Y. (1989) Distribution, population size and protection of Lipotes vexillifer. pp. 78–81 In W.F. Perrin, R. L. Brownell, Jr., K. Zhou and J. Liu (eds.), Biology and conservation of the river dolphins. Occasional Papers of the IUCN Species Survival Commission, No. 3.
  21. ^ Zhou, K. and Li, Y. 1989. Status and aspects of the ecology and behaviour of the baiji (Lipotes vexillifer) in the lower Yangtze River. pp. 86–91 In W. F. Perrin, R. L. Brownell Jr., K. Zhou and J. Liu (eds.), Biology and conservation of the river dolphins. IUCN Species Survival Commission Occasional Paper 3.
  22. ^ Chen, P.; Zhang, X., Wei, Z., Zhao, Q., Wang, X., Zhang, G. and Yang, J. (1993). "Appraisal of the influence upon baiji, Lipotes vexillifer by the Three-gorge Project and conservation strategy.". Acta Hydrobiologica Sinica 17: 101-111. 
  23. ^ Zhou, K.; Sun, J. and Gao, A. (1993). "Photo-identification and population monitoring of the baiji (Lipotes vexillifer) on the lower Yangtze.". Working paper presented to Baiji Population and Habitat Viability Workshop, Nanjing, China. June 1–4 1993.. 
  24. ^ Zhou, K.; Sun, J. and Gao, A. (1993). "The population status of the baiji in the lower reaches of the Yangtze.". Working paper presented to Baiji Population and Habitat Viability Workshop, Nanjing, China. June 1–4 1993. 
  25. ^ Wang, D.; Zhang, X., Liu, R. (1998). "Conservation status and the future of baiji and finless porpoise in the Yangtze River of China.". Report on the eight international symposium on river and lake environments. ISRLE’96, Wuhan, China.. 
  26. ^ Conservation of the Yangtze River Dolphin: Emergency Implementation Meeting.
  27. ^ INTERVIEW-Chinese river dolphin almost certainly extinct. Reuters AlertNet (2006-12-13). Retrieved on 2006-12-13.
  28. ^ Responsible Ecotourism at Tian-e-Zhou Oxbow Nature Reserve. baiji.org. Retrieved on 2006-12-03.
  29. ^ Rare Yangtze dolphin may be extinct. Retrieved on 2006-12-05.
  30. ^ White Dolphin Appears From the Brink. Retrieved on 2007-08-29.
  31. ^ Chinese River Dolphin (Baiji) Feared Extinct, Hope Remains for Finless Porpoise. WWF (2006-12-15). Retrieved on 2006-12-15.
  32. ^ Turvey, Samuel T.; Pitman, Robert L.; Taylor, Barbara L.; Barlow, Jay; Akamatsu, Tomonari; Barrett, Leigh A.; Zhao, Xuijiang; Reeves, Randall R.; Stewert, Brent S.; Wang, Kexiong; Wei, Zhuo; Zhang, Xianfeng; Pusser, L.T.; Richlen, Michael; Brandon, John R. & Wang, Ding (2007-08-07). "First human-caused extinction of a cetacean species?". Biology Letters. Royal Society Publishing. 10.1098/rsbl.2007.0292. 
  33. ^ "Extinct" white-flag dolphin spotted in Yangtze River
  34. ^ Rare Dolphin Seen in China, Experts Say, NY Times.
  35. ^ R.I.P. Yangtse River Dolphin - Null Hypothesis. Retrieved on 2006-12-21.
  36. ^ Endemic dolphin "extinction" mirrors Yangtze health decline.
  37. ^ Yangtze river dolphin is almost certainly extinct. New Scientist (2007-08-08). Retrieved on 2007-08-08.
  38. ^ BBC News, "Millions forced out by China dam", 10-13-07, retrieved 10-13-07.
  39. ^ Xinhua, "Millions more face relocation from Three Gorges Reservoir Area", 10-11-07, retrieved 10-14-07.
  40. ^ Xinhua, "China warns of environmental "catastrophe" from Three Gorges Dam", 09-26-07, retrieved 10-14-07.
  41. ^ a b "China's Three Gorges Dam Under Fire", Time, October 12, 2007. 
  42. ^ mwcnews.net/content/view/17341&Itemid=1.
  43. ^ a b Mary Ann Toy, The Age AU, "Three Gorges Dam 'could be huge disaster'", 10-13-07, retrieved 10-13-07.

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