Apparently humans have (effectively) killed off another species:
The white dolphin known as baiji, shy and nearly blind, dates back some 20 million years. Its disappearance is believed to be the first time in a half-century, since hunting killed off the Caribbean monk seal, that a large aquatic mammal has been driven to extinction.
A few baiji may still exist in their native Yangtze habitat in eastern China but not in sufficient numbers to breed and ward off extinction, said August Pfluger, the Swiss co-leader of the joint Chinese-foreign expedition.
"We have to accept the fact that the Baiji is functionally extinct. We lost the race," Pfluger said in a statement released by the expedition. "It is a tragedy, a loss not only for China,
but for the entire world. We are all incredibly sad."