In 2006, an expedition to the Yangtze River in China failed to find any Chinese River Dolphins in the river. The species was declared functionally extinct. This means that even if any of the marine mammals still survive they are doomed to extinction. Despite previous conservation efforts to save the rare species of dolphin, Chinese River Dolphins have failed to thrive in captivity and the small population continued to decline. It is very doubtful that any of these mammals survived and if so, scientists believe it would be unlikely for them to find each other to breed. In 2007, a sighting of a Chinese River Dolphin was reported. Whether the animal sighted was acutally a Chinese River Dolphin remains debatable. It is sad that conservation efforts could not help the Chinese River Dolphin to thrive. The loss of this rare marine mammal as well as any other species is truly tragic.