Trindade Island (20º 30' S; 29º 20' W) is located 1160 km (620 nautical miles) off the coast of the state of Espírito Santo, south-eastern Brazil. The island is volcanic, c. 3–3·5 million years old, and constitutes, with the Martin Vaz Archipelago, the eastern end of the Vitória-Trindade submarine ridge. Although the island has an emergent landmass area of only 9·28 km2, it is surrounded by 32 km2 of shallow (0–50 m depth) platform. The main feature of the Trindade Island seascape is a large, flat fringing reef of encrusting coralline algae distributed along almost the entire island shore. The reef crest is in the surf zone (3–6 m deep), extends tens of metres from the island volcanic rocky shores and sandy beaches and has relatively high structural complexity. As depth increases seaward, there is a wide reef slope beyond the reef crest. The slope comprises habitats varying in structural complexity and ends at the interface, i.e. the zone between reef and non-consolidated substrata.