Scientists have declared the Yangtze River dolphin functionally extinct. This conclusion follows an extensive survey conducted in late 2006 in which a team of scientists and conservationists spent a month and a half traveling along China's Yangtze River from Yichang to Shanghai searching for the critically endangered mammal. Sadly, they found no sign of the dolphin.

The Zoological Society of London has recently confirmed the extinction, pointing out that although there may be some individuals that still survive in the Yangtze, there are too few dolphins to sustain a viable population.

The Yangtze River dolphin (Lipotes vexillifer) is the first marine mammal to become extinct since the Caribbean monk seal disappeared in the 1950s. The Yangtze River dolphin is the only representative of the Family Lipotidae. It diverged from its closest relatives (the Amazon and Indian river dolphins) about twenty million years ago.

The extinction of the Yangtze River dolphin can be directly attributed to human activity. The Yangtze River is among the world's busiest and most degraded river ecosystems. Over 400 million people live within its watershed and its banks run past large cities such as Shanghai, Nanjing, and Wuhan. Heavy industrial traffic, fishing activity, and pollution are all significant factors that have contributed to the dolphin's decline.

The extinction of the Yangtze River dolphin is also the result of conservation inaction. For two decades, conservationists have recommended that a population of the endangered dolphin be established outside the Yangtze River, but funding was sparse and in the end little was done to protect the dolphin, both nationally and internationally.

Find out more:

• Yangtze River Dolphin Declared Extinct (Zoological Society of London)
• Too Late for the Baiji? (EDGE Blog)
• Yangtze River dolphin (Lipotes vexillifer) (EDGE)
• Requiem for a Freshwater Dolphin (Scientific American)