This news article tells us something that marine mammalogists have been expecting for a while: it sure looks like the baiji, or Yangtze river dolphin, is now extinct.
This is pretty much a straightforward tale of habitat loss, as human uses of the Yangtze River in China — and human pollution — reduced viable habitat for the baiji. Habitat loss is, of course, one of the most common modern reasons why species now become threatened, endangered, or extinct. Habitat loss is also the one thing that humans cannot somehow cast as a positive thing on the ledger if they reverse it: reverting habitat does not have a primary, direct economic benefit for the humans who do it. There are a number of indirect benefits that may accrue from preserving species diversity by preventing habitat loss, but somebody in the short-term here-and-now beloved of stockholders has to say, “We won’t develop this land that we own because conservation is important.” It is not an easy sell.
The Chinese marine biologist mentioned in the linked article, Wang Ding, was another student trained by my advisor, William E. Evans. He has spent the last several years working on conservation of the baiji. I hope that the survey turns out to be wrong, much like the early 1900s report of only eight Northern Elephant Seals remaining alive. The Northern Elephant Seals have made a comeback, despite an East Coast museum sending out a crack team of collectors to get those final eight seals before some other museum did. The seals, though, were simply overhunted, and obviously there were some refugia where a remnant population was able to begin the recovery. Habitat loss is a different situation, and it is harder to see how the baiji could fail to turn up in the present survey, but reappear later.