BAIJI WHITE DOLPHIN | FRESHWATER DOLPHIN LIVED IN CHINA
The baiji is a freshwater dolphin species that may be extinct. It is considered to be the first dolphin species to go extinct as a result of human impact. Baiji translates to ‘white fin’ in Chinese, therefore it’s a white-finned dolphin. The Chinese River dolphin, Yangtze River dolphin, Yangtze dolphin, and whitefin dolphin are all names used in China for this species. Local fishermen and boatmen referred to it as the “Goddess of the Yangtze,” and it was revered as a goddess of protection.
As China became more industrialized, the baiji population dropped dramatically as the river was heavily used for fishing, transportation, and hydroelectricity. After observations in the Yangtze River in the 1980s, it has been suggested that baiji may be the first dolphin species in history to be pushed to extinction by humans. The Chinese government authorized a Conservation Action Plan for Cetaceans of the Yangtze River in 2001. Efforts to save the species were attempted, but a late 2006 expedition found no baiji in the river. The baiji was declared functionally extinct by the organizers. Since the loss of the Japanese sea lion (Zalophus Japonicus) and the Caribbean monk seal in the 1950s, the baiji is the first known global extinction of a “megafaunal” vertebrate in over 50 years. It also signaled the extinction of a mammalian family of river dolphins. The baiji’s demise would be the first time a well-studied cetacean species has been explicitly linked to human activity.
Baiji was considered to breed throughout the first part of the year, with the peak calving season occurring between February and April. A 30% pregnancy rate was discovered. The gestation period was 10–11 months, with each calf being delivered one at a time; the interbirth interval was 2 years. Calves were born with a height of 80–90 cm and were breastfed for 8–20 months. Males attained sexual maturity at the age of four, while females attained sexual maturity at the age of six. Males matured to around 2.3 meters in length, females to 2.5 meters, and the longest specimen to 2.7 meters. In the wild, the species weighed 135–230 kilos and had a lifetime of 24 years. The dorsal side of the Yangtze River Dolphin is pale blue to gray, while the ventral side is white. The beak is long and somewhat upturned, with 31–36 conical teeth on each jaw. When the dolphin swims close below the surface of the murky Yangtze River, its dorsal fin is low and triangular in form, like a light-colored flag, thus the name “white-flag” dolphin. When compared to oceanic dolphins, it has smaller eyes. The baiji may reach 60 km/h when fleeing danger, although it normally remains between 30 and 40 km/h. The baiji relies heavily on the sonar for navigating due to its weak vision. The sonar system is also used for socialization, predator avoidance, group coordination, and emotional expression. The form of the skull and melon concentrates and directs sound emission.
The expedition’s findings were published online on August 7, 2007, in the journal Biology Letters, with the authors concluding, “We are obliged to believe that the baiji is now likely to be extinct, mainly due to unsustainable by-catch in local fisheries.” “Witness to Extinction” is a book about those who have witnessed the extinction of species: In fall 2008, Oxford University Press released “How We Failed to Save The Yangtze River Dolphin,” an account of the 2006 baiji survey by Samuel Turvey, the principal author of the Biology Letters publication. This book looked at the baiji’s imminent demise in the context of how and why international conservation attempts to save the species had failed, and whether future vulnerable species conservation recovery programs would encounter similar possibly devastating administrative barriers.