the translation of these terms may cause some confusion - in fact, while technically 'lagoas' translate as 'ponds', in rio all lagoas are lagoons and even when the technical definition might be different, all these formations are referred simply as 'lagoas', no matter the size or characteristics.  

on this page, rio institute for the environment - inea, publishes a bulletin with the water quality for the lagoas in the zona west of rio.

the study diagnóstico das restingas no brasil (diagnostic of brazilian sandbanks) by sandro menezes silva, of the botanical and biological sciences of the universidade federal do paraná gives a wealth of information on the types of flora and fauna found in sandbanks (restingas), typical of rio de janeiro's state lagoons.