Jump to content

Baiji

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Aglondon (talk | contribs) at 11:00, 25 July 2007 (→See also). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

For other uses, see Baiji (disambiguation).

Baiji
File:Lipotes vexillifer.jpg
Drawing of a Baiji
Size comparison against an average human

Critically endangered, possibly extinct  (IUCN 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
Natural range of the Baiji

The Baiji (Chinese: 白鱀豚; pinyin: báijìtún) (Lipotes vexillifer, Lipotes meaning "left behind", vexillifer "flag bearer") was 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, Beiji, Pai-chi (Wade-Giles), 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 Baiji population declined drastically in recent decades as China industrialized and made heavy use of the river for fishing, transportation, and hydroelectricity. The Baiji was last sighted in 2004. 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",[1] which makes it the first aquatic mammal species to become extinct since either the Japanese Sea Lion or Caribbean Monk Seal, both of which became extinct in the 1950s. Even if the Baiji still survives today, it is likely that it will become extinct in the near future.

Anatomy and morphology

Baiji are thought to breed in the first half of the year, the peak calving season being from February to April.[2] A 30% pregnancy rate was observed.[3] Gestation lasts 10-11 months, delivering one calf at a time; the interbirth interval was 2 years. Calves measured around 80-90 centimetres (32-35 in) at birth, and nursed for 8-20 months.[4] Males reach sexual maturity at age four, females at age six.[4] Mature males were about 2.3 metres (7.5 ft) long, females 2.5 metres (8 ft), the longest specimen 2.7 metres.[4] The animal weighed 135-230 kilograms (300-510 lb),[4] with a lifespan estimated at 24 years in the wild.[5]

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

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.[6] Approximately 12% of the world’s human population lives and works within the Yangtze River catchment area, putting pressure onto the river.[7] The construction of the Three Gorges Dam, along with other smaller damming projects, also led to habitat loss.

Evolutionary history

File:Baiji.jpg
A Baiji swimming underwater

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.[8] 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 Rio 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."

Conservation

In the 1950s, the population was estimated at 6,000 animals,[9] but declined rapidly over the subsequent five decades. Now the most endangered cetacean in the world, according to the Guinness Book of World Records,[1] the Baiji was last sighted in September 2004.

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.[10]

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.[11]

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."[10] 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.

Timeline

  • circa 3rd century BC: population estimated at 5,000 animals
  • 1950s: population was estimated at 6,000 animals
  • 1958-1962: The Great Leap Forward denounces the animal's traditional venerated status
  • 1970: The Gezhouba Project begins
  • 1979: The People's Republic of China declares the Chinese River Dolphin endangered
  • 1983: National law declares hunting the Chinese River Dolphin illegal
  • 1984: The plight of the Baiji draws headlines in China[12]
  • 1986: Population estimated to be 300
  • 1989: Gezhouba Dam complete
  • 1990: Population estimated to be 200
  • 1994: Construction of the Three Gorges Dam begins
  • 1996: IUCN lists the species as critically endangered
  • 1997: Population estimated to be less than 50 (23 found in survey); a dead baiji was found with 103 separate open wounds[8]
  • 1998: 7 found in survey
  • 2003: Three Gorges Dam begins filling reservoir
  • 2004: Last known sighting
  • 2006: None found in survey, declared "with all probability extinct"

Surveys

Results of Yangtze River Baiji surveys between 1979 and 1996 ( * Lower reaches only)[7]
Year Survey Area No. of km surveyed No. of Baiji sighted No. of Baiji estimated
1979[13] Wuhan-Chenglingji 230 19 -
1979[14] Nanjing-Taiyangzhou 170 10 -
1979-1981[15] Nanjing-Guichi 250 3-6 groups 400
1978-1985[16] Yichang-Nantong 1600 >20 groups 156
1985-1986[17] Yichang-Jiangyin 1510 42 groups 300
1979-1986[18] Fujiangsha-Hukou 630 78-79 100*
1987-1990[19] Yichang-Shanghai 1669 108 200
1989-1991[20][21] Hukou-Zhenjian 500 29 120
1991-1996[22] Xinchang-Wuhan 413 42 <100

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.[10]

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

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.[7]

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.[7]

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.[23]

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."[24]

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.

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. [7]

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.[25] 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.

Captive specimens

File:QiQi.jpg
Qi Qi, a captive Baiji at the IHB in Wuhan

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[7]
(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

Current status

Main article: Yangtze Freshwater Dolphin Expedition 2006
File:Two expedition boats cruise along the Yangtze ..jpg
Two research vessels cruising the Yangtze in search of the Baiji.

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[26] (some extinct baleen whale populations might not have been distinct species). Poor water and weather conditions may have prevented sightings,[1] 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.[1]

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 Pacific Northern Right Whale has become the most endangered 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[27]

See also

Template:Cetaceaportal

References

  1. ^ a b c d "The Chinese river dolphin is functionally extinct". baiji.org. 2006-12-13. {{cite news}}: Check date values in: |date= (help); Text "accessdate - 2006-12-13" ignored (help)
  2. ^ Culik, B. (2003). "Lipotes vexillifer, Baiji". Retrieved 2006-12-18.
  3. ^ IWC. 2000. Report of the Standing Sub-Committee on Small Cetaceans. IWC/52/4. 52nd Meeting of the International Whaling Commission, Adelaide, Australia.
  4. ^ a b c d "Animal Info - Baiji". animalinfo.org. Retrieved 2006-12-18.
  5. ^ Nowak, R.M. 1999. Walker's Mammals of the World. 6th Ed. The Johns Hopkins Univ. Press, Baltimore.
  6. ^ 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.
  7. ^ a b c d e f "Report of the Workshop on Conservation of the Baiji and Yangtze Finless Porpoise" (PDF). Retrieved 2006-12-03]]. {{cite web}}: Check date values in: |accessdate= (help)
  8. ^ a b http://www.chinadialogue.net/article/show/single/en/673-Farewell-to-the-baiji
  9. ^ "Rescue Plan Prepared for Yangtze River Dolphins". China Daily. 2002-07-11. Retrieved 2006-12-18. {{cite web}}: Check date values in: |date= (help)
  10. ^ a b c "Red List of Threatened Species". International Union for Conservation of Nature and Natural Resources. Retrieved 2006-12-18.
  11. ^ "Last Chance for China's Dolphin". BBC News. 2006-06-27. Retrieved 2006-06-27. {{cite news}}: Check date values in: |date= (help)
  12. ^ Adams, Douglas. Last Chance to See.
  13. ^ Chen, P. (1980). "Distribution, ecology, behaviour and protection of the dolphins in the middle reaches of the Changjiang River (Wuhan-Yueyang)". Oceanologica Limnologia Sinica. 11: 73–84. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  14. ^ Zhou, K. (1980). "Observations on baiji (Lipotes vexillifer) and finless porpoise (Neophocaena asiaorientalis) in the lower reaches of the Chiang Jiang". Scientia sinica. 23: 785–795. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  15. ^ Zhou, K. (1982). "A brief report on observations of the baiji (Lipotes vexillifer) in the lower reaches of the Yangtze River between Nanjing and Guichi". Acta Theriologica Sinica. 2: 253–254. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  16. ^ Lin, K. (1985). "Population size and conservation of Lipotes vexillifer". Acta Zoologica Sinica. 5: 77–85. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help) [translated by C.H. Perrin, edited by W.F. Perrin, Southwest Fisheries Science Center Administrative Report LJ-86-27}}
  17. ^ 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.
  18. ^ 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.
  19. ^ Chen, P. (1993). "Appraisal of the influence upon baiji, Lipotes vexillifer by the Three-gorge Project and conservation strategy". Acta Hydrobiologica Sinica. 17: 101–111. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  20. ^ Zhou, K. (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. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  21. ^ Zhou, K. (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. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  22. ^ Wang, D. (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. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help); line feed character in |journal= at position 34 (help)
  23. ^ "Conservation of the Yangtze River Dolphin: Emergency Implementation Meeting" (PDF). {{cite web}}: Text "accessdate 2006-12-30" ignored (help)
  24. ^ "INTERVIEW-Chinese river dolphin almost certainly extinct". Reuters AlertNet. 2006-12-13. Retrieved 2006-12-13. {{cite web}}: Check date values in: |date= (help)
  25. ^ "Responsible Ecotourism at Tian-e-Zhou Oxbow Nature Reserve". baiji.org. Retrieved 2006-12-03.
  26. ^ "Rare Yangtze dolphin may be extinct". Retrieved 2006-12-05.
  27. ^ "Chinese River Dolphin (Baiji) Feared Extinct, Hope Remains for Finless Porpoise". WWF. 2006-12-15. Retrieved 2006-12-15. {{cite web}}: Check date values in: |date= (help)
Wikimedia Commons has media related to Lipotes vexillifer.
Wikispecies has information related to Lipotes vexillifer.

News

Retrieved from "https://en.wikipedia.org/w/index.php?title=Baiji&oldid=146968800"