Three Gorges Probe

Dam could imperil endangered-crane habitat, author warns

Kelly Haggart

February 20, 2002

Downstream impacts of the Three Gorges dam could ‘fatally degrade’ an important wintering ground for the world’s most endangered crane species, writer-naturalist Peter Matthiessen warns in a new book.

 

A cluster of small lakes on the northwest edge of Poyang Lake – 1,000 km from the dam site, in Jiangxi province – were discovered in recent years to be the winter destination of "the last significant flock of the Siberian crane: in effect, 99 per cent of all Grus leucogeranus left on earth," Matthiessen writes in The Birds of Heaven: Travels with Cranes. But now, he warns, "the precious Poyang ecosystem may be destroyed by the construction of a gigantic hydropower dam upriver on the Yangtze."

Poyang, China’s largest freshwater lake, acts as a natural floodwater retention area, fluctuating in size from 4,000 square km in the flood season to less than 1,000 square km in the dry season. When it expands during the summer months, it merges with nine smaller lakes nearby. But after the floodwater recedes, nutrient-rich marshes and mud flats around these small lakes provide a crucial winter habitat for four crane species, including the endangered Siberian crane.

"Manipulation of the water flow by the Three Gorges dam will permanently alter the hydrology of the Poyang lakes – a system already severely damaged by watershed and wetland degradation," Matthiessen writes.

"Saving the Poyang habitat might possibly depend on diking the northwest lakes and marshes and pumping water in during the spring and summer to simulate the waxing and waning of the Yangtze; otherwise the dam may fatally degrade the winter habitat of 99 per cent of the earth’s last Siberian cranes."

In 1981, Zhou Fuchang and Ding Wenning of the Beijing Institute of Zoology discovered the spot where the "great white crane" (as the Siberian crane is known in China) spends the winter before migrating to summer breeding grounds in Siberia. Ornithologists have counted 2,626 Siberian cranes wintering at Poyang, along with smaller numbers of white-naped, hooded and Eurasian cranes.

The Siberian differs from the 14 other crane species in its almost complete dependence on wetlands, Matthiessen writes. "Because it has never adapted to man’s farmlands, it has suffered considerable harm from wetland pollution and destruction by ever-increasing human activity in its northern breeding grounds as well as in its winter sanctuary."

The Siberian is one of three crane species that are predominantly white, and these white cranes are considered the most threatened. The Siberian is hunted all along its arduous migration routes, Matthiessen reports, and "despite its higher numbers, it is presently regarded as the most endangered of the three."

The cranes have also faced perils in their winter home. After villagers looking for a livelihood killed 600 of the cranes and other rare birds to make white-feather fans in the winter of 1983-84, Jiangxi authorities set up the 22,400-hectare Poyang Lake Migratory Bird Nature Reserve in the lake’s northwest corner.

But now the birds face a new threat, Matthiessen writes, in the shape of "a grand folly of enormous cost" that threatens to leave "social and environmental ruin in its wake." In addition to its impact on the Poyang wetlands, Matthiessen says the Three Gorges dam could also slow the formation of new delta land through sedimentation in the Yangcheng Nature Reserve further downstream in Jiangsu province. In winter, this area now provides "good habitat for five to seven hundred red-crowned cranes, the largest population of Grus japonensis anywhere on earth," he writes.

Matthiessen spent much of the past decade travelling across five continents to visit the breeding and wintering grounds of all of the 15 crane species. (His book is exquisitely illustrated with life-like drawings and paintings of cranes by acclaimed Canadian wildlife artist Robert Bateman.) Matthiessen sees the giant birds – some stand more than five feet tall – as a metaphor for environmental loss: "Perhaps more than any other living creatures they evoke the retreating wilderness, the vanishing horizons of clean water, earth and air which their species – and ours, too, though we learn it very late – must ultimately depend for survival."

"Since most crane species are cosmopolitan in range, they offer an opportunity to protest the stunted industrial (hence political) vision behind the broad range of unrestrained, often senseless activities, from war to the ill-advised building of great dams, that degrade or destroy what is left of precious habitats around the world – precious not only to cranes and other wildlife but to our inheritors and their children."

George Archibald and James Harris of the International Crane Foundation note in a foreword to Matthiessen’s book that 11 of the 15 species "may fairly be considered threatened or endangered. If we act quickly and concertedly, there is still a chance to save the rare cranes and a wide array of their beautiful wetland territories, but the opportunity may close in this decade or the next."

 

The Birds of Heaven: Travel with Cranes, by Peter Matthiessen, illustrated by Robert Bateman, North Point Press (2001).

Categories: Three Gorges Probe

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