Coral Reefs In Fatu Huku Island, Marquesas Archipelago, French Polynesia

Fatu Huku is an uninhabited coral reef island in the southeastern Marquesas Islands (9 degrees 26'10 '' S, 138 degrees 55'26 '' W), French Polynesia. The island is 1.3 km(2), with a lagoon of 23.7 km(2). The deepest part of the lagoon is measured at 36.6 m, while outer reefs recorded a deepest point of 114.7 m. Distinct geomorphic features identified from satellite imagery include passes, channels, single and triple barrier reefs, fringing reefs, ledge, and bulge. In 2016 a digital depth model constructed using water depths and video (R-2 = 50.66 and r=0.81) was used to calibrate and validate four habitats: deep water, reef flat, coral reefs, and sand. The classification of habitats was implemented with a satisfactory overall accuracy of 0.75. The relationships between benthic habitats and morphometry (bathymetry, slope, hotspots, and ecotones) are discussed.