Have you heard of the Yangtze River Dolphin? For the longest time, it used to be found along 1,700 kilometres of the middle and lower reaches of the mighty Chinese river. The Baiji, as it is known, was white finned, a little over two metres long, had poor eyesight and relied mainly on sonar for navigation. A few decades ago, as populations along the river grew, as shipping traffic rose, as more and more dams fragmenting the Baiji's habitat came up, as fishing by increasingly impoverished Chinese intensified, Baiji numbers began to crash.