393 / 2024-09-16 09:51:56

Hotspots of green turtles identified in Southeast Asia call for international collaboration and cross-boundary management effort

sea turtles, migratory pattern, hotspots, satellite tracking, Southeast Asia

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

Green turtle (Chelonia mydas) is the most abundant sea turtle species in Chinese waters. The uncertainty regarding locations and ranges of their foraging grounds, combined with the complexity of their migratory behavior, increases the difficulty of conservation actions. Based on a satellite tracking study on 27 green turtles from 2016 to 2024, we revealed that the areas with dense active areas closely coincided with the documented seagrass beds, indicating a strong relationship between the turtles' hotspots and their foraging grounds. These hotspots scattered in Southeast Asia, including the waters near Nghĩa Hà, Hòn Cau Island, Cù Lao Thu Island, the Bai Long Wei Island and Cô Tô Archipelago in Vietnam; the eastern and western coasts of the Leizhou Peninsula and the Qiongzhou Strait; the eastern waters of Hainan; the waters around Xisha Islands, Nansha Islands and Dongsha Island, the South China Sea; the coastal area of Huizhou in Guangdong; the waters near Putian in Fujian; the waters near the Penghu Archipelago and the northern coast of Taiwan; the waters near Cabalete Island in the Philippines; and the waters of the northern part of Pulau Banggi Island in Malaysia. Further investigations of important foraging seagrass beds will be crucial for determining the movement ranges of green turtles in different countries. The 27 green turtles tracked moved actively in coastal waters from Guangxi to Guangdong and northward to Fujian Province, passing through the Qiongzhou Strait and Taiwan Strait, and forming a key migratory corridor. Nearshore migratory pattern makes green turtles vulnerable to human impacts. For marine species with long distance migratory behavior and nearshore habit such as green turtles, the success of their protection will highly depend on the effective international and regional collaboration.