Bye bye River Dolphin?

I don't mean to be the harbinger of bad news - but it happens this week we've had another piece of important but incredibly depressing news from the aquatic world.

It looks like we might have to wave goodbye to the Yangtze river dolphin in China. Researchers from Zoology Society of London (ZSL) reported that during a two month expedition along the Yangtze river they found absolutely no trace of these dolphin.

The researchers have pointed the finger of blame at unregulated fisheries that accidentally caught the river dolphins, as well as the construction of dams and collisions with the huge amount of boat traffic that now ply the waters of the Yangtze river. They proclaimed this as could be the first cetacean to be driven extinct at the hand of mankind and the first extinction of a large vertebrate for over fifty years - so it's the first time a large, charismatic creature has disappeared from the planet that most of us will remember.

Facts about the Yangtze river dolphin:

• It was the only remaining member of an entire branch of the evolutionary tree, called the Lipotidae, a group of mammals that separated from other marine mammals around 40-20 million years ago.
• If any Yangtze river dolphins had been found during ZSL's expedition, they would have been taken to an oxbow lake to begin a captive rearing programme.
• The Yangtze river dolphin had a long narrow beak which it used to feed on fish.
• The Yangtze river dolphin was top of the list on ZSL's EDGE programme, which stands for "Evolutionarily Distinct and Globally Endangered species" - the world's mammals were ranked in terms of how distantly related each one is to it's nearest neighbour and how engendered they are.
• The extinction of the Yangtze river dolphin highlights the threats faced by other rare and endangered species in the river ecosystem which includes endangered freshwater porpoises, giant salamanders and Siberian cranes.