"So long and thanks for all the fish," said a dolphin in a memorable scene in Hitchhiker's Guide to the Galaxy. This was the final farewell of dolphins as they left the planet, because man failed to listen to their warning of impending doom.

This may not be the appropriate epitaph for the Yangtze River Dolphin, but it states clearly how mankind fails to listen as yet another great species is wiped off the face of the Earth.

After scouring the Yangtze river for six weeks in search of the dolphin, called the Baiji, marine biologists found not even a single one. The expedition's goal was to find and place the dolphins within a sanctuary and breeding program but was unfortunately too late.

A year after failing to find a single specimen, the Baiji was officially declared extinct, and its demise was laid on the hands of the great number of container ships and fisherman in the river, whose nets and hooks were the cause of more than half of the dead Baiji in the river.  Pollution and the creation of the dam blocked off most of their food supply. All of these factors could have been avoided with the proper precautions but instead man is again responsible for the extinction of another species.

The Yangtze river dolphin's extinction marks the first of the cetacean family (the same family of whales and dolphins) to be wiped off because of human activity. The dolphin was special in its own way and had its own family branch. Sam Turvey of the Zoological Society of London, who led the expedition to find the dolphin, said:

The loss of such a unique and charismatic species is a shocking tragedy. This extinction represents the disappearance of a complete branch of the evolutionary tree of life and emphasises we have yet to take full responsibility in our role as guardians of the planet. [...] There is a lot of interest now in the baiji - but it has come too late. Why does no one pay attention to a species until there are none left? We really have to use the baiji as a wake-up call to act immediately to prevent it happening again.

The Baiji's death marks the fourth mammal family to become extinct because of humans. There would come a time when there are too many extinctions to mourn and too little left to protect, and all of it weighs on the shoulders of mankind. If not for other species, perhaps man should reconsider its priorities before it starts threatening itself.

It's another sad day for the earth. Scientists have declared the (formerly) rare Chinese river dolphin baiji extinct. The six-week search on the Yangtze River failed to find even a shadow of the blind white dolphin. Swiss naturalist August Pfluger concluded that even if the search team missed one or two dolphins, it's safe to conclude that the baiji is "functionally extinct". This means that even if there are baijis in the river, their chance of survival is nil.

Now, who should be blamed for the demise of the "goddess of the Yangtze"? All signs point to the ship traffic on the Yangtze. This is in addition to the evil effects of overfishing, dam-building, and environmental degradation.

Back in the 1980s, there were about 400 baijis left on the Yangtze. It should've been a clear indication that the dolphins were in grave danger. But as commerce started flourishing, the dolphin population plummeted to 100 in the mid-1990s. In 2004, only one baiji was found. Since then, the fate of the dolphin has been sealed.

It's sad enough to have lost a species that dates back 20 million years, but what's even worse is that the death of the baijis could signal the start of a "wave of extinction" involving other species. If the trend continues, we'd be shedding more tears for other dolphin species in the next 20 years.