368 / 2024-09-15 12:38:28

Nest productivity for green turtles (Chelonia mydas) at Qilianyu of Xuande Islands, South China Sea

Chelonia mydas,Nesting productivity,Nesting habitat characteristics

Session 72 - Sea turtle and marine mammal conservation: management, academic and outreach perspectives

Green turtles (Chelonia mydas) have been documented nesting in southern China, including Guangdong Province, Hong Kong, Taiwan, and the South China Sea. In 2016~2018, more than 100 nests were recorded each year among 7 islands of the Qilianyu (Xuande Islands, South China Sea), revealing that the Qilianyu represents the largest extant nesting ground for green turtles in China. In August and September 2017, a total of 95 green turtle (Chelonia mydas) nests were geolocated on 5 islands of the Qilianyu; North Island had the highest number of nests (n = 58) and nest density (18.5 nests/ km). The number of eggs in each nest ranged from 58 to 131 (89 ± 20 [mean ± SD], n = 15), and the nest productivity was 14.8%~96.8% (70.7% ± 26.3%, n = 15). These data represent the first report for green turtle nesting productivity in the Xuande Islands. Long-term monitoring should continue. Nesting habitat characteristics, including vegetation, sand particles, humidity, and oceanography at different islands, should be examined to understand the nest site selection mechanism of local green turtles. We also recommend nesting beach monitoring and research at the Yongle Islands and elsewhere in the South China Sea.