whereas ilha redondo (adjacent to the cagarra islands) has been preserved in its natural state, ilha redondo (guanabara bay) is home to a gas treatment terminal - constructed by brazilian oil company petrobras in 2010 to meet growing demand for oil, gas and other petrochemicals.

nevertheless, local mariners know the difference, and boating tours, diving expeditions and the like will surely arrive at the correct redonda.

since april 2010, the ilhas cagarras have been declared a 'natural monument' named monumento natural das ilhas cagarras, or 'mona cagarras'.