Gotta ask Henrique about more precise information on the Belo Monte dam...
About the ban/ dam/ amazon destruction relations... IBAMA is a so-called "third-scale" agency of the brazilian government, that is subordinate to a Ministery and the President (in this order), and a small part of the government really cares about the protection of wildlife. A much bigger part works for the "development" of Brazil, through energy production and the expansion of agricutural areas, so you can imagine who "tries to stop the development", right? Yes, IBAMA is the "guilty" here. The president doesn't think a nice little fishie of the Xingu River (or even a big one which is very important to the amazon region fishermen as the dourada,
Brachyplatystoma flavicans, in the Madeira River) is something really important, since its protection only slow down the so-called development.
The ban is needed to protect the species, but there is another part of the government that doesn't care about the endangered species protected by the ban. Controversial, but true.
Best regards.
Daniel.