Amazon river dolphins
DAM-BUILDING AND OVERFISHING BOTH IMPACT THE AMAZON’S RIVER DOLPHINS AND MUST BE CURBED, SAYS FERNANDO TRUJILLO.
Why dams are the biggest threat to these cetaceans
River dolphins of the Inia genus arrived in the Amazon two million years ago and are superbly adapted to its rivers and flooded forests. Unlike other dolphins, their vertebrae are not fused, giving greater flexibility for hunting among tangled roots, and they have incredible echolocation capabilities for finding fish.
But it’s very likely that a new assessment being carried out by the IUCN will see all Inia dolphins – there is currently one recognised species, two discovered species and possibly a fourth species in the Orinoco basin – as Critically Endangered because of the decline in their populations and the threats they face. Our assessments suggest there are 30,000–40,000 in total spread over 7 million km2 of the Amazon Basin.
The biggest problem river dolphins face is dams – there are 155 operating within the entire basin, and another 277 are planned. Think about the river system as a heart – dams block its connectivity, creating massive impacts for migratory fish that dolphins feed on.
The other major issue is the sheer number of people living in the Amazon – about 34 million – that has increased pressure on fish stocks, with somewhere between 170–300 species taken to be eaten.
River dolphins are also killed to be used as bait to catch a catfish that is called piracatinga. Although there is currently a five-year moratorium on piracatinga fishing in Brazil, and it’s banned completely in Colombia, dolphins are still targeted. In some areas, locals blame the dolphins for eating fish and shoot or poison them.
We don’t believe we can stop the dams but we can recommend which rivers should be avoided to limit the impacts on dolphins. Sustainable dolphin watching could also help – one part of Colombia has 50,000 visitors a year and they go there mainly to see the river dolphins.
AMAZON RIVER DOLPHINS ARE KILLED TO BE USED AS BAIT TO CATCH PIRACATINGA.”