(CHENG MIN)

A Yangtze finless porpoise plays with its caretaker at the White Fin Dolphin Zoo in Wuhan, central China's Hubei Province, on April 18. Seven Yangtze finless porpoises are raised in the zoo.

Since March 3, 10 corpses of Yangtze finless porpoise have been found near the Dongting Lake in central China's Hunan Province.

The Yangtze finless porpoise and white fin dolphin are the only two cetacean mammals in the Yangtze River and nearby fresh waters. Only a few thousand Yangtze finless porpoises still live in the Yangtze River, but are estimated to decrease by 5 to 10 percent every year.

Experts say that shipping, illegal fishing, sand excavation, climate change, river pollution, and competition from human beings for food, have all contributed to Yangtze finless porpoises' decline.