Abrolhos is visited every year, from august to november, by the humback whales. This time of the year they are easily spotted in Abrolhos area perfoming a show of jumps and characterists sounds.
The whole archipelago is protected by IBAMA(The instution that take care of natural resources in Brazil), all this to keep this paradise alive.
This is also an excellent place for diving, one of the best in Brazil, with good visibility, shipwrecks and corals.
As you probably have already noticed, Abrolhos is not one of those places that are full of tourists, it´s more like a place for adventurers. Great for people that want to get in touch with nature.
This site www.ilhasdeabrolhos.com.br has a lot of good info about Abrolhos, including more photos, it has an option to see the site in english.
Here´s a video of whales in Abrolhos.
This is it, I really think you should see the site I linked, it has a lot of info about it.
See ya people.