English abstract
The purpose of this study was to describe and classify beaches and to evaluate the most important physical and human-related factors affecting beach selection by the green turtles, Chelonia mydas, during the peak nesting season. Three surveys, between July and October 2005, covered around 100 km of coastal area along the Ash-Sharqiyah region of the Sultanate of Oman. The surveyed beaches varied remarkably in terms of physical and anthropogenic characteristics as well as in term of nesting density. Green turtles nested on beaches with different beach aspects, vegetation and ghost crab densities. Green turtles appeared to prefer beaches of shorter length, steeper beach face slope and backed by hills or cliffs. Sand grain size had no significant relationship with nest site selection. However, nesting beaches were characterized by significantly lower sand compaction and well to moderately sorted sand suggesting that better drainage and aeration could be essential factors that made these beaches suitable for nesting activities. Furthermore, some human related factors were also shown to be significantly correlated to the nest site selection: sea turtles selected beaches with few ORV tracks, little artificial lighting, little human litter and limited human accessibility, in other words beaches with little human disturbance. Multiple regression analysis suggested that nesting density was most influenced by beach length, proximity to paved roads and sand compaction. For effective conservation of green turtles, the
control of human access to beaches with ideal physical characteristics is thus
critical to reduce human impacts on these beaches.
