A painstaking six-week hunt on the Yangtze for any remaining signs of the baiji ended yesterday with the news scientists had been dreading: there don’t appear to be any remaining.

“The baiji is functionally extinct. We might have missed one or two animals but it won’t survive in the wild,” said August Pfluger, a Swiss naturalist involved in the expedition. “We are all incredibly sad.”

… The dolphin, which dates back 20 million years, has been pushed to extinction by the severe degradation of its habitat. Increasingly noisy shipping traffic on the Yangtze affected the dolphins’ sonar, while severe pollution and over-fishing diminished food supplies. The completion of the massive Three Gorges dam project upriver also did not help, worsening the decline of the smaller fish on which the baiji fed and shrinking the sand bars around which they once played. … Read the full story.