what is well known, however, is that not only are these islands rich in corals and important to many migratory seabirds, but they are often visited by dolphins and other cetaceans - as dolphins use these water to feed, rest, and even procreate.

in fact, protecting and better understanding these islands is important in order to fully understand rio's unique ecosystem, promoting scientific and educational activities in the area, as well as a sustainable use of the region, and the orderly development of all related activities. one project aimed at promoting a better understanding of the cagarras is the projeto ilhas do rio - more information can be found on these important islands and the local flora and fauna.

officially the archipelago is formed by the comprida, redonda das palmas - and islets called  ilhota grande, ilhota piquenha, ilhota redonda, laje da cagarra, laje da redonda, and ilhotas da cagarra. however, many residents also include the nearby island lage da cagarra, and ilha rasa home to the lighthouse.