A new $5 billion hydroelectric dam now under construction on a tributary of the Amazon River in Brazil will seriously mess with the area’s unique environment and wildlife and displace thousands of indigenous residents, critics say. Up to 3,000 families will be displaced when the dam’s reservoir floods, and the project will also likely affect over 450 species of fish, many of which are important to the area’s fishing industry. “It’s extremely depressing to think that they’re going to be able to build this dam,” said Glenn Switkes of International Rivers. “This is an area that is one of the world’s hotbeds of biodiversity.” Nevertheless, the Santo Antonio dam is just one of some 70 dam projects planned for Brazil’s Amazon basin region through 2030, including one that would be the world’s third-largest dam. Despite heavy criticism, Brazilian officials say the country’s planned hydroelectric frenzy is fueled in part by concerns about carbon emissions from power plants. “[I]f you don’t do hydroelectric plants, you’ll have to do thermo-electric plants with carbon and oil,” said Environment Minister Carlos Minc.