This Epoch Times article discusses the extinction of the Baiji, the Yangtze River Dolphin. It is desperately sad that since Douglas Adams and Mark Carwardine tried to find the Baiji for the original radio series episode "Gone Fishing!", this beautiful creature has been declared extinct.

In 1998 there was an estimated total of only seven dolphins left. When the filling of the Three Gorges reservoir began in 2003, it seemed that the white dolphin was no more. While there were a few rare sightings at this time, the evidence was questionable.

When an expedition in search of living Yangtze dolphins began in November 2007, the results looked very grim. For seven months the Yangtze River was tracked with sophisticated equipment, including cameras and underwater microphones. But the once cheerful sounds of the talking dolphin were never heard. Nothing. The white dolphin had already left the world forever.

As it seemed pointless to return to China to try and find the Baiji, the new TV series instead turned its attention to the Blue Whale and visited the Sea of Cortez in Mexico for this Sunday's final episode.

However, in the first episode "Amazon Manatee", Mark and Stephen were able to spend time with the Amazon Pink River Dolphin or "Boto", and got some marvellous footage and photographs.