The endangered Yangtze river dolphin

MURKY water, hazy sky and dull brown riverbanks. Strained eyes peering into the mist. Ears tuned electronically into the depths. And with each hour, each day that passes, a nagging question that grows louder: is this how a species ends after 20 million years on earth?

When they write the environmental history of early 21st-century China, the freshwater dolphin expedition now plying the Yangtze river may be seen as man's farewell to an animal it once worshipped.

A team of the world's leading marine biologists is making a last-gasp search for the baiji, a dolphin that was revered as the goddess of Asia's mightiest river but is now probably the planet's most endangered mammal.

Environmentalists warn that more and more species are being threatened in China, where forests can be home to more varieties of life than all of the United States and Canada combined.

The baiji expedition started out as a typically modern-day mission: a cascade of beer from the brewery sponsoring the launch, technical support from international research institutes and a shipfull of good intentions and high hopes. But more than halfway through the six-week expedition, the mood is grimmer as the participants contemplate the possibility that man may have killed off its first species of dolphin.

Spotters on the two boats have yet to glimpse a pale dorsal fin or hear the telltale trace of a sonar whistle, but the organisers refuse to give up. "The likelihood of the baiji being extinct in five to 10 years is 90 per cent or more, but we must have hope and do everything possible," says August Pfluger, head of baiji.org, a Swiss-based group devoted to saving whales and dolphins.

Few people outside China have heard of the baiji, a light grey, long-snouted river dolphin that relies on sonar rather than its eyes to navigate through the murky Yangtze water. But even more than the panda, the demise of this mammal illustrates the sacrifices that the world's most populous country has made in its race to grow richer.

In the 1950s, there were thousands of baiji in the Yangtze. By 1994, the number fell below 100. This year, there has only been one, unconfirmed, sighting.

On board the Kekao-1 survey boat, it is not hard to see reasons for the decline. As commerce booms, the Yangtze has grown thick with container ships, coal barges and speed boats, whose hulls and propellers can run down or tear up the dolphins. Others have been blown up by bombs, electrocuted or snarled on 1000 metre-long lines of hooks set by local fisherman who use unorthodox and illegal methods to boost catches.

Pollution is fouling their habitat. Near Huaneng, the acrid smoke billowing out of a paper factory and coal-fired power plant is so pungent that the crew grimace more than a kilometre away. The factory discharges a torrent of filthy water directly into the river.

The completion of the Three Gorges dam has not helped. Although it is far upriver, the giant barrier has worsened a decline of the smaller fish on which the baiji feed and the shrinkage of the sand bars around which they played.

Scientists hope to save the species by capturing and moving specimens to a nature reserve — the 20-kilometre-long oxbow lake at Tian'ezhou — where they will be protected from river traffic and fishing.

Even with just a couple of dozen baiji, the team believe the population could recover. They point to Tian'ezhou's herd of several hundred Père David's deer. The last 18 deer, which is indigenous to China, were taken to Woburn Abbey in the late 19th century and successfully bred and reintroduced to China.

But so far, not one baiji has been found. With hope fading, the missing dolphin hunt threatens to turn into a murder investigation, a whodunnit for an entire species.

Scanning the water with binoculars, Samuel Turvey, of the Zoological Society of London, said the baiji is a mammal family that diverged 20 million years ago from other ancient groups. "Its loss would be a major blow to biological diversity. This isn't a twig — it is a branch on the tree of life. To lose it would be so depressing. Yet nothing has been done for 30 years. Why does nobody pay attention to a species until there are almost none left?"

China's leading baiji expert, Wang Ding, has monitored the river for more than 20 years and acknowledges that action should have come earlier. "When we started we could be certain of seeing baiji on every trip. It would have been better if we had tried to conserve them then but at the time China was very poor and the government was focused only on economic development. People did not care about the environment at all."

The strain of supporting 400 million people — one in 20 of the world's population — is taking its toll on a river that had been one the most biologically diverse regions in the world. Wang estimates that fish stocks have halved in 10 years.

Many of its endemic species are near extinction, including the Chinese alligator, arguably the world's most endangered reptile; the giant salamander, one of the world's largest amphibians; and two sturgeon species. The list is growing.

Wang says China will add the finless porpoise — another Yangtze cetacean — to the endangered list this year. In less than a decade, the porpoise population has shrunk by two-thirds to about 1000. Spotters on the expedition saw only 30, down from about 100 six months before. Wang is increasingly despondent over their fate.

Scientists warn that the river is losing its capacity to support life, which will ultimately affect humans. "The baiji is like a canary in a coalmine," says Zhang Xiangfeng, of the Institute of Hydrobiology. "Since the 1990s, the water in the lakes near the Yangtze has become so polluted that we can't drink from them. Since I entered the institute 23 years ago, there are more and more ships and less and less animals. The river looks like a highway."

Jim Harkness, the former representative of the WWF in Beijing, assumes the baiji are already extinct. "The ecosystems that have suffered the worst damage in China are freshwater."

Humanity, he warned, is driving animals to extinction many times faster than ever before. And China threatens to accelerate the trend because it has so much to lose. Harkness says the forests of Sichuan province contain more species than in all of North America.

"The problem in China is that it is one of the globe's most important centres of biodiversity, yet it has a huge population. Economic growth and environmental degradation are both proceeding at an unprecedented rate. And because of the political situation, it's not like people can stand up for a species of moss being destroyed by mining."

However, public and state awareness about the need for conservation is growing. China has more than 2000 nature reserves. "China has made an effort to do more but certainly economic development — which leads to changing eating habits, more dams and more roads — is a threat to many species," says Xie Yan, of the Wildlife Conservation Society, which will soon assess how species numbers have changed in recent years.

But economics takes priority. As a member of the Yangtze management commission, Wang wants a fishing ban, but so far there is only a temporary halt during spawning.

Whether this is too little, too late for the baiji will not be conclusively determined by the expedition. But if the most advanced survey of the river yet comes up blank, the baiji's prospects are grim. "If we cannot find any baiji, the message to society will be that there is no hope for them," says Wang.

Pollution is fouling their habitat. Near Huaneng, the acrid smoke billowing out of a paper factory and coal-fired power plant is so pungent that the crew grimace more than a kilometre away. The factory discharges a torrent of filthy water directly into the river.

The completion of the Three Gorges dam has not helped. Although it is far upriver, the giant barrier has worsened a decline of the smaller fish on which the baiji feed and the shrinkage of the sand bars around which they played.

Scientists hope to save the species by capturing and moving specimens to a nature reserve — the 20-kilometre-long oxbow lake at Tian'ezhou — where they will be protected from river traffic and fishing.

Even with just a couple of dozen baiji, the team believe the population could recover. They point to Tian'ezhou's herd of several hundred Père David's deer. The last 18 deer, which is indigenous to China, were taken to Woburn Abbey in the late 19th century and successfully bred and reintroduced to China.

But so far, not one baiji has been found. With hope fading, the missing dolphin hunt threatens to turn into a murder investigation, a whodunnit for an entire species.

Scanning the water with binoculars, Samuel Turvey, of the Zoological Society of London, said the baiji is a mammal family that diverged 20 million years ago from other ancient groups. "Its loss would be a major blow to biological diversity. This isn't a twig — it is a branch on the tree of life. To lose it would be so depressing. Yet nothing has been done for 30 years. Why does nobody pay attention to a species until there are almost none left?"

China's leading baiji expert, Wang Ding, has monitored the river for more than 20 years and acknowledges that action should have come earlier. "When we started we could be certain of seeing baiji on every trip. It would have been better if we had tried to conserve them then but at the time China was very poor and the government was focused only on economic development. People did not care about the environment at all."

The strain of supporting 400 million people — one in 20 of the world's population — is taking its toll on a river that had been one the most biologically diverse regions in the world. Wang estimates that fish stocks have halved in 10 years.

Many of its endemic species are near extinction, including the Chinese alligator, arguably the world's most endangered reptile; the giant salamander, one of the world's largest amphibians; and two sturgeon species. The list is growing.

Wang says China will add the finless porpoise — another Yangtze cetacean — to the endangered list this year. In less than a decade, the porpoise population has shrunk by two-thirds to about 1000. Spotters on the expedition saw only 30, down from about 100 six months before. Wang is increasingly despondent over their fate.

Scientists warn that the river is losing its capacity to support life, which will ultimately affect humans. "The baiji is like a canary in a coalmine," says Zhang Xiangfeng, of the Institute of Hydrobiology. "Since the 1990s, the water in the lakes near the Yangtze has become so polluted that we can't drink from them. Since I entered the institute 23 years ago, there are more and more ships and less and less animals. The river looks like a highway."

Jim Harkness, the former representative of the WWF in Beijing, assumes the baiji are already extinct. "The ecosystems that have suffered the worst damage in China are freshwater."

Humanity, he warned, is driving animals to extinction many times faster than ever before. And China threatens to accelerate the trend because it has so much to lose. Harkness says the forests of Sichuan province contain more species than in all of North America.

"The problem in China is that it is one of the globe's most important centres of biodiversity, yet it has a huge population. Economic growth and environmental degradation are both proceeding at an unprecedented rate. And because of the political situation, it's not like people can stand up for a species of moss being destroyed by mining."

However, public and state awareness about the need for conservation is growing. China has more than 2000 nature reserves. "China has made an effort to do more but certainly economic development — which leads to changing eating habits, more dams and more roads — is a threat to many species," says Xie Yan, of the Wildlife Conservation Society, which will soon assess how species numbers have changed in recent years.

But economics takes priority. As a member of the Yangtze management commission, Wang wants a fishing ban, but so far there is only a temporary halt during spawning.

Whether this is too little, too late for the baiji will not be conclusively determined by the expedition. But if the most advanced survey of the river yet comes up blank, the baiji's prospects are grim. "If we cannot find any baiji, the message to society will be that there is no hope for them," says Wang.

Wang says China will add the finless porpoise — another Yangtze cetacean — to the endangered list this year. In less than a decade, the porpoise population has shrunk by two-thirds to about 1000. Spotters on the expedition saw only 30, down from about 100 six months before. Wang is increasingly despondent over their fate.

Scientists warn that the river is losing its capacity to support life, which will ultimately affect humans. "The baiji is like a canary in a coalmine," says Zhang Xiangfeng, of the Institute of Hydrobiology. "Since the 1990s, the water in the lakes near the Yangtze has become so polluted that we can't drink from them. Since I entered the institute 23 years ago, there are more and more ships and less and less animals. The river looks like a highway."

Jim Harkness, the former representative of the WWF in Beijing, assumes the baiji are already extinct. "The ecosystems that have suffered the worst damage in China are freshwater."

Humanity, he warned, is driving animals to extinction many times faster than ever before. And China threatens to accelerate the trend because it has so much to lose. Harkness says the forests of Sichuan province contain more species than in all of North America.

"The problem in China is that it is one of the globe's most important centres of biodiversity, yet it has a huge population. Economic growth and environmental degradation are both proceeding at an unprecedented rate. And because of the political situation, it's not like people can stand up for a species of moss being destroyed by mining."

However, public and state awareness about the need for conservation is growing. China has more than 2000 nature reserves. "China has made an effort to do more but certainly economic development — which leads to changing eating habits, more dams and more roads — is a threat to many species," says Xie Yan, of the Wildlife Conservation Society, which will soon assess how species numbers have changed in recent years.

But economics takes priority. As a member of the Yangtze management commission, Wang wants a fishing ban, but so far there is only a temporary halt during spawning.

Whether this is too little, too late for the baiji will not be conclusively determined by the expedition. But if the most advanced survey of the river yet comes up blank, the baiji's prospects are grim. "If we cannot find any baiji, the message to society will be that there is no hope for them," says Wang.