Study area in the bay of Toliara (36.5 km coastal stretch), South-West Madagascar (A). Geomorphological reef units are represented as distinct colors. The commonly-known local names of internal reefs are indicated. Numbers correspond to the villages with Ambohitsabo (1), Besakoa (2), Mahavatsy 2 (3), Ankiembe-bas (4), Mahavatsy 1 (5), Ankiembe-haut (6), Ankilibe (7), Namakia (8), Antsifotse (9), Antanandreviky (10), Sarodrano (11), and Ambanilia (12). White dots refer to the villages surveyed. Fishers pulling a beach seine (B). A Vezo traditional sailing pirogue set up for fishing (C).