About the River Dolphins

After the extinction of the Baiji, there are only four living species of river dolphins that inhabit freshwater rivers and estuaries. These dolphins live in some of the most densly populated areas of the world. 

Map showing the distribution of four species of river dolphins
http://vaquita.tv/education/extinction-yangtze-river-dolphin/

Amazon River Dolphin
http://www.pawnation.com

The Amazon River Dolphin (Boto) is found only in the freshwater Amazon, Orinoco, and Araguaia Rivers of South America. It is the largest of all the river dolphins. Although there are tens of thousands remaining, they are vulnerable according to the IUCN red list because of the decline their population is facing (12).

Ganges River Dolphin
www.edgeofexistence.org

                                                                             
The Ganges River Dolphin (Susu) is one of the two river dolphin species that is essentially blind. They are listed as being endangered by the IUCN, and live in some of the most densely populated areas of the world. This includes the Ganga and Brahmaputra river systems of Bangladesh, India and Nepal. Their distribution range has been greatly reduced due to dams, and their population has been estimated to be as low as 1,200 individuals (9,12).

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 Indus River Dolphin
http://wwf.panda.org

The Indus River Dolphin is one of the world's rarest animals and after the extinction of the Baiji, it is now the rarest river dolphin. It is an endangered species that is endemic to Pakistan's Indus River. The Indus River Dolphin is also essentially blind, as it has no developed lense. There are as little as 1,100 individuals of this species left and their numbers continue to decline (12).

Rescuing an Indus River Dolphin

http://worldwildlife.org/species/indus-river-dolphin

                                                                          The Franciscana (La Plata Dolphin) is scientifically classified as a river dolphin, but actually lives in marine habitats. They inhabit estuaries and shallow coastal waters of the east coast of South America. There are several gaps in their habitat, and their population estimates are unknown (11). 

Why Should We Care?

River dolphins are iconic and charismatic flagship species for the habitats in which they live in. They are apex predators, and are therefore critical in maintaining the balance in their ecosystems (2). The removal of an apex predator disrupts the food web and tropic levels.  River dolphins are also ecological indicators of the health of an ecosystem, and the decline or loss of an apex predator is an indication that drastic deterioration and degredation has taken place (13). Therefore, the loss of these apex predators can serve as a warning sign of an  imminent ecosystem collapse (14). 

As a flagship species, river dolphins can help provide awareness and action for saving rivers and the countless species within them. The major river systems in which these dolphins live in are also used by billions of people for water, food, and other resources (11). By saving the river dolphins, we will also protect the human communities who depend upon the rivers for freshwater and survival. 

Furthermore, species such as the Ganges and Indus river dolphins are the only living representatives of its family, like the Baiji was. The loss of these species will result in the loss of an ancient lineage and the many evolutions within them (11).