Douglas Adams wrote about the baiji dolphin (Score 5, Informative)

The late Douglas Adams (along with Mark Carwardine) wrote a book titled Last Chance to See about a number of animals on the brink of extinction. The chapter Blind Panic was all about the baiji dolphin's predicament. Practically blind, the baiji dolphin relied sonar to navigate the Yangtze river - the trouble is that the Yangtze is really busy and hence noisy and polluted. The baiji didn't stand a chance, though from the book it seemed that the Chinese did put a lot of effort into trying to save them.

Scott