Scientists have concluded that the Yangtze River dolphin (aka baiji) is now almost certainly extinct. No trace of the dolphin was found during a recent survey of its habitat
The scientists writing in Biology Letters journal blamed unregulated fishing as the main reason behind their demise. Sam Turvey of the Zoological Society of London, one of the paper's authors, said "The Yangtze river dolphin was a remarkable mammal that separated from all other species over 20 million years ago. This extinction represents the disappearance of a complete branch of the evolutionary tree of life and emphasises that we have yet to take full responsibility in our role as guardians of the planet. While it is conceivable that a couple of surviving individuals were missed by the survey teams, our inability to detect any baiji... indicates that the prospect of finding and translocating them to a reserve has all but vanished."
The scientists added that there were a number of human activities that caused baiji numbers to decline, including construction of dams and boat collisions. However, they concluded that the primary factor was probably unsustainable by-catch in local fisheries. “Unlike most historical-era extinctions of large bodied animals, the baiji was the victim not of active persecution but incidental mortality resulting from massive-scale human environmental impacts - primarily uncontrolled and unselective fishing," the researchers concluded.
The dolphin was the only remaining member of the Lipotidae, an ancient mammal family that from other marine mammals, including over 20 million years ago. The dolphin had a long, narrow beak and low dorsal fin; lived in groups of three or four and fed on fish.
This is not the first man made extinction – other animals have been hunted to extinction (Thylacine, Great Auk, Passenger Pigeon) and it is not going to be the last (Even in Europe one in six species of mammal, including the Iberian lynx and the monk seal, is endangered). I fear we will see many more such extinctions in our lifetimes