The dolphins had become trapped in a shallow area as water receded during the dry season.
Twenty-four pink dolphins stuck in a shallow section of a Bolivian river have been rescued as part of efforts to preserve the iconic but vulnerable species.
The dolphins, of which 14 were female and 10 were male, were rescued on Monday and relocated to the Rio Grande in Bolivia.
Peaceful spots such as the one in which the specimens were found are used by pregnant females to give birth, according to Claudia Venegas, research associate and volunteer at the Noel Kempff Natural History Museum.
But changes in the hydrological basin are causing the dolphins to be unable to follow the natural course of the main riverbed, leaving them trapped as water levels drop, Ms Venegas said.
“In search of calmer areas to raise their babies, they enter different arms of the river, many of which are artificial and which leave the main riverbed,” she said.
“So in the dry season, when the waters recede, many of them can no longer return to the main riverbed.”
Changes to the hydrological basin, including artificial river arms, make it harder for the dolphins to navigate.(Noel Kempff Mercado Natural History Museum via Reuters)
The pink river dolphins, also known as Amazon River dolphins, or bufeos in Bolivia, only live in freshwater.
The species is found throughout much of the Amazon and Orinoco river basins in Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, and Venezuela.
Rescuers carried the dolphins out of the shallow water and loaded them onto a truck to relocate them.(Noel Kempff Mercado Natural History Museum via Reuters)
Little is known about the river dolphins’ populations and habitats, according to WWF.
The dolphins are born grey and turn pink with age. It is not fully understood why they are pink, but one suspected reason is their diet – they mainly eat fish and crustaceans high in carotenoids, an organic pigment that is known to contribute to the pink colour of other species such as flamingos.
Climate change, deforestation, water pollution and agricultural expansion are among the biggest threats faced by the species.