evidence: A month in the Eparses Islands to reveal the secrets of the reefs and coral - The Eparses Islands, a French overseas territory in the Indian Ocean - A particularly interesting zone for scientific research - The major scientific challenges - Works conducted during the 2011 rotation of the Marion Dufresne - An international and multidisciplinary team [...] These small islands are located in the south-west Indian Ocean around Madagascar. The five entities are Juan de Nova, Europa, Bassas da India, Tromelin and the Glorieuses Islands (composed of Grande Glorieuse and Ile du Lys). [...] The Eparses Islands are all of coral origin as reflected in their morphology in the form of an atoll for Bassas da India, the Glorieuses, Juan-de-Nova and Europa and in the form of a raised atoll for Tromelin. Accumulating a surface area of 44 km², the highest point does not exceed a few metres of altitude. Located at altitudes of between 22° south for Europa and 11° south for the Ile of Lys of the Glorieuses, the Eparses Islands have a tropical climate and are located in the path of hurricanes from the north-east.