Factors Affecting Leatherback Turtle Hatchling Production at Jamursba Medi and Wermon Beaches, Bird's Head Papua Barat - Indonesia

Abstract

The Pacific leatherback sea turtle is a “Critically Endangered” species that has experienced a long-term decline over past decades. The largest nesting aggregation of leatherbacks in the Pacific occurs on Bird’s Head peninsula, Papua Barat, Indonesia, and represents the largest producer of hatchlings for the entire Pacific. The adult females as well as hatchlings disperse widely to various areas of the Pacific. The impact of a number of biotic and environmental factors on leatherback nests and hatchling production were quantified at the two primary nesting beaches: Jamursba Medi and Wermon, from 2005 to 2012. The primary threats impacting nests were predation, tidal inundation and erosion, and extreme beach temperatures, all of which significantly affected nest survival, hatching success, and subsequent hatchling production. The minor threats impacting nests were opportunistic poaching, predation by monitor lizards, sand crabs, and root invasions. We estimated an average of 34,364±7,579 hatchlings produced during the boreal summer nesting seasons at Jamursba Medi, and 10,469±6,278 hatchlings produced during the austral summer nesting seasons at Wermon. The results indicated that low levels of nest survival and hatching success represents one of the primary factors causing the decline of western Pacific leatherback at Bird’s Head. As such, the low level of hatchling production will necessitate the development and implementation of effective conservation measures that significantly increase hatchlings production on these beaches. The development of a beach management plan to address these threats is a critical to the recovery of the Pacific leatherbacks