On average, 89% of the dolphins' home "range" (the area they live in) was used for fishing.Dolphins were found to be an average of 252 km from the nearest proposed dam and 125 km from the nearest proposed dredging site. While these are significant distances, the dolphins' ranges spanned over 50 km on average, and dams and dredging can affect large stretches of river habitats. Additionally, many Amazon river dolphins -- already an endangered species -- live closer to the proposed sites than the seven males and one female tagged in this study. The research was carried out by the University of Exeter and Peruvian conservation organisation Pro Delphinus.

 

The construction of dams, mainly in Brazil, is an expanding threat, with 175 dams operating or under construction in the Amazon basin, and at least 428 more planned over the next 30 years. Additionally, the Amazon Waterway has been approved and is under contract for construction. This will involve dredging sites across four main rivers of the Amazon basin, and the expansion of ports to facilitate ship navigation across the Amazon, Ucayali and Marañón rivers. But the researchers say the Peruvian government has an opportunity to protect biodiversity.