The BAIJI (Chinese : 白鱀豚; pinyin : báijìtún (help ·info
), Lipotes vexillifer, Lipotes meaning "left behind", vexillifer "flag
bearer") is a functionally extinct species of freshwater dolphin
formerly found only in the
The baiji population declined drastically in decades as China
industrialized and made heavy use of the river for fishing,
transportation, and hydroelectricity . It has been credibly claimed,
after surveys in the
Swiss economist and CEO of the baiji.org Foundation, August Pfluger funded the expedition, in which an international team, taken in part from the National Oceanic and Atmospheric Administration and the Fisheries Research Agency in Japan, searched for six weeks for signs of the dolphin. The search took place almost a decade after the last exploration in 1997, which turned up only 13 of the cetaceans.
In August 2007, a Chinese man reportedly videotaped a large white animal swimming in the Yangtze. Although it was tentatively confirmed that the animal on the video is probably 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. The last known living baiji was Qiqi (淇淇), who died in 2002. The World Wildlife Fund is calling for the preservation of any possible baiji habitat, in case the species is located and can be revived.
* 1 Anatomy and morphology * 2 Distribution * 3 Evolutionary history * 4 Folklore
* 5 Conservation
* 5.1 Causes of decline * 5.2 Timeline * 5.3 Surveys
* 5.4 Conservation efforts
* 5.4.1 In situ conservation * 5.4.2 Ex-situ conservation * 5.4.3 Captive specimens
* 5.5 Current status
* 6 See also * 7 References
* 8 External links
* 8.1 News
ANATOMY AND MORPHOLOGY
Baiji were thought to breed in the first half of the year, the peak
calving season being from February to April. A 30% pregnancy rate was
observed. Gestation would last 10–11 months, delivering one calf at
a time; the interbirth interval was 2 years. Calves measured around
80–90 centimetres (31–35 in) at birth, and nursed for 8–20
months. Males reached sexual maturity at age four, females at age
six. Mature males were about 2.3 metres (7 ft 7 in) (7.5 ft) long,
females 2.5 metres (8 ft 2 in), the longest specimen 2.7 metres (8 ft
10 in). The animal weighed 135–230 kilograms (298–507 lb), with
a lifespan estimated at 24 years in the wild. The Yangtze River
When escaping from danger, the baiji can reach 60 km/h (37 mph), but usually stays within 30 to 40 km/h (19 to 25 mph). Because of its poor vision, the baiji relies primarily on sonar for navigation. The sonar system also plays an important role in socializing, predator avoidance, group coordination, and expressing emotions. Sound emission is focused and highly directed by the shape of the skull and melon. Peak frequencies of echolocation clicks are between 70 kHz and 100 kHz.
Historically the baiji occurred along 1,700 kilometres (1,100 mi) of
the middle and lower reaches of the Yangtze from
Yichang in the west
to the mouth of the river, near to
Fossil records suggest that the dolphin first appeared 25 million
years ago and migrated from the
Pacific Ocean to the
It is estimated that there were 5,000 baiji when they were described in the ancient dictionary Erya circa 3rd century BC.
It is well known the river dolphins are not a natural group. Their mitochondrial genome reveals a split of two separate lineages, Platanista and Lipotes + (Inia + Pontoporia), having no sister relationship with each other, and the Platanista lineage is always within the odontocete clade instead of having a closer affinity to Mysticeti. The position of the Platanista is more basal, suggesting separate divergence of this lineage well before the other one. The Lipotes has a sister relationship with Inia + pontoporia, and they together formed the sister group to the Delphinoidea. This result strongly supports paraphyly of the classical river dolphins, and the nonplatanistoid river dolphins do represent a monophyletic grouping, with the Lipotidae as the sister taxa to (Iniidae + Pontoporiidae), and is well congruent with the studies based on short interspersed repetitive elements (SINEs).
Low values of haplotype diversity and nucleotide diversity were found for the baiji of the Yangtze River. The analysis of molecular variance (AMOVA) supported a highlevel of overall genetic structure. The males having a higher genetic differentiation than the females suggested a significant female –biased dispersal.
The aquatic adaptations of the baiji and other cetaceans have happened slowly and can be linked to PSGs and/or other functional changes. Comparative genopic analyses have uncovered that the baiji have a slow molecular clock and molecular adaptations to their aquatic environment. This information leads scientists to conclude that a bottleneck must have occurred near the end of the last deglaciation, a time that coincided with rapid temperature decrease and a rise in eustatic sea level. Scientists have also looked into positively selected genes (PSGs) in the baiji genome which are used for DNA repair and response to DNA stimulus. These PSGs have not been found previously in any other mammal species. Pathways being used for DNA repair have been known to have a major impact on brain development and have been implicated in diseases including microcephaly . The slow down of the substitution rate among cetaceans may have been affected by the evolution of DNA damage pathways. Over time, river dolphins, including the baiji, have had a reduction in the size of their eyes and the acuity of their vision. This probably stems from poor visibility in fluvial and estuarine environments. When analyzing the baiji genome, scientists have found that there are four genes that have lost their function due to a frameshift mutation or premature stop codons. The baiji has the lowest single nucleotide polymorphism (SNP) frequency reported thus far among mammals. This low frequency could be related to the relatively low rate of molecular evolution in cetaceans; however, considering that the decrease in the rate of molecular evolution in the baiji was not as great as the decrease in heterozygosity rate, it is likely that much if the low genetic diversity observed was caused by the precipitous decline in the total baiji population in recent decades and the associated breedings.
The reconstructed demographic history over the last 100,000 years featured a continual population contraction through the last glacial maximum, a serious bottleneck during the last deglaciation, and sustained population growth after the eustatic sea level approached the current levels. The close correlation between population trends, regional temperatures, and eustatic sea levels suggest a dominant role for global and local climate changes in shaping the baiji's ancient population demography.
Per Chinese folklore, a beautiful young girl is said to have lived with her stepfather on the banks of the river Yangtze. He was evil, and a greedy man out for his own self-interest. One day, he took the girl on a boat, intending to sell her on the market. Out on the river, though, he became infatuated with her beauty and tried to take advantage of her. But she freed herself by plunging into the river whereupon a big storm came and sank the boat. After the storm had thus settled, people saw a beautiful dolphin swimming – the incarnation of the girl – which became known as the ‘Goddess of the Yangtze.’ The baiji, in the region of Yangtze, is regarded as a symbol of peace and prosperity.
In the 1950s, the population was estimated at 6,000 animals, 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 , the baiji was last sighted in August 2004, though there was a possible sighting in 2007. It is listed as an endangered species by the U.S. government under the Endangered Species Act . It is now thought to be extinct.
CAUSES OF DECLINE
World Conservation Union
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.
A range of anthropogenic led causes (e.g. boat collisions, dam construction) which also threaten freshwater cetaceans in other river systems, have been implicated in the decline of the baiji population. However, the primary factor was probably unsustainable by-catch in local fisheries, which use rolling hooks, nets (gill nets and fyke nets) and electrofishing ; similarly by-catch constitutes the principal cause of mortality in many populations of small cetaceans worldwide. Although there are relatively few data available on baiji mortality, at least half of all known baiji deaths in the 1970s and 1980s were caused by rolling hooks and other fishing gear, and electrofishing accounted for 40% of baiji deaths recorded during the 1990s. Unlike most historical-era extinctions of large-bodied animals, the baiji was the victim not of active persecution but of incidental mortality resulting from massive-scale human environmental impacts, primarily uncontrolled fishing.
Its extinction merely reflects the latest stage in the progressive
ecological deterioration of the Yangtze region. In the 1970s and
1980s, an estimated half of baiji deaths were attributed to
entanglement in fishing gear and nets. By the early 2000s, electric
fishing was considered "the most important and immediate direct threat
to the baiji's survival." Though outlawed, this fishing technique is
widely and illegally practiced throughout China. The building of the
Three Gorges Dam
There are some scientists who have found that pollution has resulted in emerging diseases caused by paracitic infection in the Baiji population. The Baiji's reliance on aquatic environments could have resulted in interaction with both terrestrial and marine pathogen risks. Since the Baiji has a limited distribution endemic to the Yangtze River, the freshwater environment may have a higher pathogen level than marine waters (although systematic environmental studies have yet to be conducted). The pathogens in these waters could lead to viral infections that can result in epizootics , which has caused the deaths of thousands of marine mammals over the last twenty years. There have also been captured/killed individuals that have had helminth infestations in the stomach which leads scientists to believe that parasitic infections could be another cause of decline amongst the Baiji.
It has been noted, however, that the declining geographical range that baiji have been spotted in is not connected to the population loss of baiji. A model provided by Yangtze fishing communities show that the baiji population was not connected by geographical range or fragmentation of location, as the baiji make long-term and periodic movements throughout several years. The movements of the baiji left the species unaffected by dwindling geographical range.
* 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 Dam project begins
* 1979: The People\'s Republic of
1979 Wuhan-Chenglingji 230 19 –
1979 Nanjing-Taiyangzhou 170 10 –
1979–1981 Nanjing-Guichi 250 3–6 groups 400
1978–1985 Yichang-Nantong 1600 >20 groups 156
1985–1986 Yichang-Jiangyin 1510 42 groups 300
1979–1986 Fujiangsha-Hukou 630 78–79 100*
1987–1990 Yichang-Shanghai 1669 108 200
1989–1991 Hukou-Zhenjian 500 29 120
1991–1996 Xinchang-Wuhan 413 42 < 10
During the 1970s,
In 1978, the
Chinese Academy of Sciences established the Freshwater
The first Chinese aquatic species protection organisation, the Baiji
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
The fifth protected area is an isolated oxbow lake located off of the
north bank of the river near to
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 motorized fishing boat with the aim of conducting daily patrols, making observations and investigating reports of illegal fishing.
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
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." Furthermore, the conservation attempts have been criticized, as even with the international attention about the need for conservation for the baiji, the Chinese government did not " any serious investment" to protect the baiji.
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
The success of
A baiji conservation dolphinarium was established at the Institute of
Hydrobiology (IHB) in
Douglas Adams and
Mark Carwardine documented their encounters with
the endangered animals on their conservation travels for the BBC
Last Chance to See . Through firsthand experience, they went
to China, drinking
Baiji beer and
Baiji cola, staying in the Baiji
Hotel and using Lipotes vexillifer toilet paper. They came across
Baiji weighing scales and
Baiji fertilizer. They met Qi Qi, the
beautiful bluish-grey dolphin with a long, narrow, slightly upturned
beak, a low triangular dorsal fin, broad flippers with tiny eyes.
Qi-Qi was just a year old then, injured by fishing hooks in 1980 and
taken into captivity to be nursed back to health. Out of the seven
times Mark and Douglas had visited China, never did they encounter a
wild and free Yangtze river dolphin. It is even more impossible now
with the likelihood that Lipotes vexillfer may be the first cetacean
to have been driven to extinction by human activity. 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
Details of captive baijis
(IHB = Institute of Hydrobiology, NNU =
Nanjing Normal University
Qi Qi 1980-01-12 – 2002-07-14 IHB M Outdoor traditional Chinese : 長江淡水豚類考察; pinyin : Chāng Jiāng dànshuǐ túnlèi kǎochá) raised suspicions of the first unequivocal extinction of a cetacean species due to human action (some extinct baleen whale populations might not have been distinct species). Poor water and weather conditions may have prevented sightings, but expedition leaders declared it "functionally extinct " on December 13, 2006, as fewer are likely to be alive than are needed to propagate the species. However, footage believed to be a baiji from August 2007 was released to the public.
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 vaquita 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. ”
A report of the expedition was published online in the journal Biology Letters on August 7, 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".
"Witness to Extinction: How We Failed To Save The Yangtze River Dolphin", an account of the 2006 baiji survey by Samuel Turvey, the lead author of the Biology Letters paper, was published by Oxford University Press in autumn 2008. This book investigated the baiji's probable extinction within the wider-scale context of how and why international efforts to conserve the species had failed, and whether conservation recovery programmes for other threatened species were likely to face similar potentially disastrous administrative hurdles.
Some reports suggest that information about the baiji and its demise
is being suppressed in China. Other reports cite government media
English language reports in
In August 2007, Zeng Yujiang reportedly videotaped a large white
animal swimming in the Yangtze in
On October 3, 2011 the sighting of almost 20 porpoises was reported in Chinese media. The sighting was done from a bridge in Nanjing city. It should be noted however, that the sighting has not been confirmed by independent media sources.
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. 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. The report detailing this was officially released in September 2007. Senior Chinese government officials and scholars said the dam could cause a “huge disaster ... if steps are not taken promptly.” The same scholars and officials previously had defended the Three Gorges Dam project. 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 down 1,500 polluting industrial and mining enterprises and building 70 sewage and waste treatment plants, all of which are "progressing well."
In October 2016 several news sources announced a recent sighting of what has been speculated to be a baiji.
* Cetaceans portal
* ^ Mead, J.G.; Brownell, R. L. Jr. (2005). "Order Cetacea". In
Wilson, D.E.; Reeder, D.M.
* ^ A B Zhou, Xuming; Sun, Fengming; Xu, Shixia; Fan, Guangyi; Zhu,
Kangli; Liu, Xin; Chen, Yuan; Shi, Chengcheng; Yang, Yunxia
Baiji genomes reveal low genetic variability and new
insights into secondary aquatic adaptations". Nature Communications.
4: 2708. PMC 3826649 . PMID 24169659 . doi :10.1038/ncomms3708 .
* ^ Marderspacher, F (2007). "Bye Baiji?". Current Biology. 17:
R783–R784. doi :10.1016/j.cub.2007.08.055 .
* ^ "Rescue Plan Prepared for
* ^ Chen, P.; Liu, P.; Liu, R.; Lin, K.; Pilleri, G. (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.
* ^ Zhou, K.; Pilleri, G.; Li, Y. (1980). "Observations on baiji
(Lipotes vexillifer) and finless porpoise (Neophocaena asiaorientalis)
in the lower reaches of the Chiang Jiang". Scientia Sinica. 23:
* ^ Zhou, K.; Li, Y.; Nishiwaki, M.; Kataoka, T. (1982). "A brief
report on observations of the baiji (Lipotes vexillifer) in the lower
reaches of the
Wikimedia Commons has media related to LIPOTES VEXILLIFER .
Wikispecies has information related to: LIPOTES VEXILLIFER
* US National Marine Fisheries Service baiji web page * ARKive – images and movies of the baiji (Lipotes vexillifer) * Lipotes vexillifer – EDGE of