Spatial characteristics of the Hawksbill (Eretmochelys imbricate Linnaeus, 1766) nesting beach on Kepayang Island, Belitung - Indonesia

Hawksbill sea turtles are scattered in Indonesia, especially on small uninhabited islands and are the only species of turtle most bound to tropical waters. The hawksbill has experienced a drastic decline in population mainly due to bycatch in fishing activities and disturbance of the nesting habitats due to anthropogenic presence. Kepayang Island in Belitung is one of the areas used as hawksbill as a habitat for nesting to laying eggs. To get information about hawksbill on this island, a study was conducted to find out the characteristics of hawksbill nesting beaches on Kepayang Island, Belitung. The survey was carried out in July 2014 and successfully identified 12 nests as an observation sample. Observations show that the coast of Kepayang Island where nesting turtles have a narrow beach width of less than 20 m with a slope of between 10° to 16° and an average intertidal area as wide as 11.5 meters. The texture of sand in the nest is coarse to fine sand which is dominated by fine and medium sand and has a temperature of around 27.7 °C to 30.2 °C measured at the bottom of the nest. The range of sand pH distribution on Kepayang Island is between 6 to 8 with a moisture content of 3.1 to 6.6%. The coastal vegetation formation in Kepayang Island is dominated by Barringtonia and Pescaprae with vegetation in the form of screwpine (Pandanus tectorius), railroad vine (Ipomoea pescaprae) and Barringtonia (Barringtonia asiatica). However, there are predators of turtle eggs and hatchlings, especially water monitor lizards (Varanus salvator), sea birds e.g. brahminy kite (Haliastur indus) and gulls (Chlidonias leucopterus). In general, Kepayang Island has characteristics suitable for hawksbill nesting sites.