The extinction of the baiji, also called the Yangtze river dolphin, a decade ago was probably the first cetacean extinction in recorded history. It was hunted intensely by humans up til the 1980s, and pollution, net accidents, bycatch and vessel injury may have taken care of the rest. The last confirmed sighting was in 2004. Since then there have been two extensive searches which did not find any baiji. Though it is possible that a small number of isolated baiji exist, the numbers would be so low that the extinction is just a matter of time.
The loss and subsequent criticism appear to have galvanised the Chinese authorities into action with regard to their remaining critically endangered cetacean, the Yangtze finless porpoise. Unlike the baiji, the Yangtze finless porpoise is restricted to the upper reaches of the Yangtze. The reduction in numbers appears to have accelerated over the last 20 years as development and pollution have increased in western China. Estimates of the number remaining in the Yangtze vary from 500 to 1000. The species has been given the status of National First Grade Key Protected Wild Animal: this mandates regular surveying of the population and the condition of its habitat, and ensures strong penalties for those engaging in activities that harm the animal. There are also a small number of Yangtze finless porpoise in captivity, and perhaps 40 in the Tian-ezhou oxbow lake.
The other critically endangered cetacean is the vaquita, aka the Gulf of California porpoise. There are around 100 of these remaining. These exist solely on the Mexican coast in the northern reaches of the Gulf of California. They have not been hunted but have been greatly affected by gillnet traps. There is some concern that the low remaining numbers have led to inbreeding and general genetic decline, which may worsen the chances of recovery.