Scientists in China are preparing a drastic rescue plan for one of the planet's rarest animals, a dolphin with the misfortune of living in one of China's busiest and most polluted rivers.

The plan calls for professional fishermen to round up all the fewer than 100 Yangtze River dolphins, one of only four freshwater dolphin species in the world. The captured dolphins would then be released in a protected reserve.

Government scientists say the dolphins' only hope is to be moved from their sole natural habitat, the lower Yangtze River in central China. Their numbers have dwindled rapidly with the increase in fishing, boat traffic and industry along China's longest river.

Other experts agree that unless something is done, the blue-gray dolphins _ the same size as their more playful ocean cousins but with longer, thinner snouts _ will be extinct in 20 years.

But they say simply relocating the dolphins won't solve the river's worsening condition, or help other species. They also say there may be difficulty catching the smart, fast-moving creatures, and getting them to accept their new home.

``Tracking down the dolphins will be like looking for a needle on the bottom of the ocean,'' said Zhou Kaiya, an expert on dolphins at Nanjing University.

The extreme nature of the plan to transplant an entire species underscores the mounting environmental costs of China's rapid economic growth.

The government has begun or is considering expensive programs to save other rare animals as well, including leopards, tigers and China's most distinctive wild animal, the panda.

The dolphins have lived in the Yangtze for 25 million years. Called the ``Goddesses of the Yangtze,'' they were a traditional symbol of peace and prosperity to Chinese living along the river's banks.

But in recent decades, the dolphins have been decimated, most by being accidentally entangled in fishermen's nets and hooks. There were about 6,000 in the 1950s.

``The dolphins have no chance of survival if they stay in the river,'' said Wang Ding, deputy director of the Institute of Hydrobiology in the central city of Wuhan.

The institute will oversee the relocation effort, which Wang said has been approved by the Ministry of Forestry and could begin next year.

The 50 million yuan (dlrs 6 million) plan would hire 50 professional fishermen in boats to search a 1,700-kilometer (1,100-mile) stretch of the Yangtze and capture the dolphins using nets.

The animals would then be released in the newly created Tian'erzhou nature reserve in Hubei province. The reserve is built around a 21-kilometer (13-mile) segment of the Yangtze that was left behind when the main river changed course.

The reserve is already home to 20 finless porpoises, another threatened aquatic mammal found in the Yangtze and elsewhere in Asia. Wang said the porpoises, which were put there on a trial basis by the biology institute in Wuhan, have thrived.

Critics say the Yangtze River dolphins aren't as hardy as the porpoises.

They note that only one has survived in captivity, at the institute in Wuhan. Attempts to breed the 24-year-old male, named Qi Qi, have failed. Three prospective mates died soon after capture, as have all other caught dolphins.

Some experts also doubt whether the captive population would offer a big enough gene pool. They say inbreeding could become a problem.

The plan's backers say mammal populations in captivity have been successfully increased in the past.

They point to the reintroduction into the wild in the late 1980s of Pere David's deer, another species found only in China. The deer was hunted to extinction in the wild 1,000 years ago, but a few dozen survived until modern times in the pleasure parks of China's emperors, and later in European zoos.

``It's not a perfect solution, but it's the best option we have,'' Wang said. ``And there's no time to lose.''

(China Daily July 11, 2002)