“The Xingu is a highly unique river,” Lúcia Rapp Py-Daniel, a biologist and researcher at the National Institute for Amazonian Research, told Mongabay by phone. “Several species of fauna and flora have adapted to the rapids flowing over an almost continuous bed of rock that exists only there. We are seeing a loss of biodiversity, particularly with the disappearance of fish species that in many cases have not yet been studied.”