evidence: The islands of Europa and Bassas da India lie in the Mozambique Channel near the southern end of Madagascar. Both are coralline islands, or atolls, and Europa is about 100 km southeast of Bassas da India. Europa, with 30 km2 of land area, is 6–7 km in diameter with a maximum altitude of 6 m. Its shallow lagoon (generally 1 m deep) is open to the sea at one side, and covers about 9 km2, including some 700 km2 of mangrove swamp that is particularly extensive to the south. The mangrove stands are important nursery grounds for sea turtles and sharks. Bassas da India atoll is an almost perfectly circular atoll with less than 1 km2 of permanently dry land area. The reef is 12–13 km in diameter, although it is almost entirely submerged at high tide, and therefore, does not support any vegetation. Bassas da India's coral structure is still forming. These islands are subject to the Agulhas Current and experience occasional cyclones. Water temperatures are usually above 30°C, and southeast trade winds dominate during the austral winter. Annual rainfall averages 600 mm. [...] Europa Island functions as an important nesting ground for sea turtles and seabirds, and also claims an endemic subspecies of land bird as well as two endemic subspecies of lizard. While Bassas da India is of scientific and biogeographical interest due to its relatively undisturbed reef system, the limited area of permanently dry land is not sufficient to support significant terrestrial life. The hawksbill turtle is fairly common on the island.