Thesis (DTech. degree in Nature Conservation.)--Tshwane University of Technology, 2010. / Hawksbill sea turtles (Eretmochelys imbricata) have been reduced by more than 80% worldwide in the last century and are considered critically endangered. Although nesting populations have been subject to numerous studies, there is a considerable lack of knowledge pertaining to the in-water behaviour and ecological functions of wild foraging hawksbill populations. This is especially true for the Western Indian Ocean as important topics such as habitat use and dietary items have scarcely been explored. Between 2006 and present, more than 178 hours of in-water observations of foraging hawksbill activity was recorded on a small insular reef at D'Arros Island, Seychelles. Most of the 827 sightings were of known, resident turtles (> 90%), facilitating analyses on both a population and individual level. Habitat types were identified and described, turtle densities estimated, population dynamics established, home ranges calculated, food items identified, food intake quantified, feeding behavior described, food resources quantified, diet selectivity indices calculated, intra/interspecific competition quantified and activity and dive patterns were described.