WUHAN, March 27 -- A project began Friday to relocate the Yangtze River's finless porpoises, as the critically endangered species' natural habitat is threatened by pollution, overfishing and river traffic.

There are only around 1,000 finless porpoises, a dolphin-like freshwater mammal with iconic "grins" on the face, in the Yangtze River and two lakes that are linked to the busy waterway.

On Friday, eight porpoises from Poyang Lake in Jiangxi Province were placed in metal containers filled with water and took bus tours to two reserves in Hubei Province.

The relocation project was launched by the Ministry of Agriculture, Ministry of Environmental Protection, the Chinese Academy of Sciences and three provincial governments.

Yu Kangzhen, vice agriculture minister, said the country was determined to step up efforts to protect the endangered species, since its population had shrunk by an average of 13.7 percent every year despite many preservation measures.

"Our plan is to move them into waters free of human activities, so they can flourish," said Zhao Yimin, an official with the ministry.

The two reserves -- Hewangmiao and Tian'ezhou -- are located in old and traffic-free sections of the Yangtze River.

There are plans for more reserves to be established in the river's middle and lower reaches, said Yu Kangzhen.

The Yangtze River, China's longest waterway, is rich in aquatic bio diversity. A decade ago, it was the only river in the world that had two kinds of aquatic mammal living in it at the same time -- the finless porpoise and the white-flag dolphin.

However, a 2006 survey found no white-flag dolphins in the river, suggesting they were "functionally extinct," which means the population is too small for the species to reproduce.

Scientists predict that without efficient protection the finless porpoise will also disappear in five to ten years.

Porpoise expert Wang Ding, with the Chinese Academy of Sciences, said an overemphasis on the Yangtze's economic value and the ignorance of its natural attributes has resulted in the deterioration of habitat for the river's endangered species.

Many porpoises have been found in recent years to be wounded or killed as a result of starvation, pollution-induced disease or clashes with ship propellers.

Cao Wenxuan with the Chinese Academy of Sciences said the biggest threat faced by the animal was a lack of food. The porpoises eat fish but the fish population is also rapidly decreasing.

Human activities, such as shipping, dredging and fishing are also threatening the species, he said.

Experts worry that conservation efforts focusing on the Yangtze River will be too little too late, as the river faces increasing environmental and transportation pressure from the rapid economic development in the region.

"The Yangtze is full of dangers for the porpoises, and human activity is set to increase. The only way to prevent the species from dying out is to place them in new reserves," said Cao.

Last September, China released a guideline to enhance the traffic capacity of the Yangzte, as part of its effort to build an economic belt along the river. It emphasized that the development should prioritize protection measures.

Zhao Yimin said the Yangtze River economic belt development strategy was adding to the pressure of porpoise protection.

"There is still no clear answer to how to pursue economic development without it taking its toll on the environment," he said.