The dolphins' fate is in spite of decades of warnings and countless millions of dollars spent by governments, business and environmental groups on trying to help them.
Scientists say the first marine casualty of the new century is likely to be China's baiji dolphin.
There are about 30 left in China's Yangtze River, with a species life expectancy of about 10 years. Next is Pakistan's river dolphin, the bhulan, and third is the irrawaddy dolphin of Southeast Asia. Scientists also fear for India's river dolphin, the susu, which could be another casualty as 2030 approaches. The cause, says Thomas Jefferson, an American scientist at the Ocean Park Conservation Foundation, remains global contamination and the destruction of coastal habitats by urbanisation in an overpopulated planet. The last attempt to place a female baiji into captivity, at China's Shishou marine park, ended in early 1996 when she was found dead and stuck in nets which cordon-off the park.