[3][4] Terre-de-Bas consists of three marine habitats made up of reef flats which house living or dead coral communities, submerged rock slabs, and some seagrass areas.

Census records of 1858 show that 28 people lived on the island and were engaged in farming of crops and vegetables such as cassava, sweet potatoes, yams, corn, peas, pumpkins, and watermelons.

It was only in 1994 that the Conservatoire du Littoral made the two islets central to their activity and later decreed the Biotope Protection Order as a reserve.

Other fish species recorded here are black surgeon (Acantharus bahianus), colas (Ocyurus chrysurus), the fin-tail cardinal (Holocentrus rufus).

Marine Mammal species recorded are bottlenose dolphin (Tursiops truncatus) and Humpback whale (Megaptera novaenglia).

In the forest habitat of Basse-Terre, the IBA-identified species reported are: Least tern (Sterna antillarum), Purple-throated carib (Eulampis jugularis), Green-throated carib (Eulampis holosericeus), Antillean crested hummingbird (Orthorhyncus cristatus), Caribbean elaenia (Elaenia martinica), Scaly-breasted thrasher (Margarops fuscus), and Pearly-eyed thrasher (Margarops fuscatu).