The Xiamen Symposium on Marine Environmental Sciences (XMAS 2025)

The seagrass beds along the Okinawan coast of Japan are crucial not only for the marine ecosystem but also for the local fishing industry, which supports the livelihoods of coastal communities. In recent years, an environmental issue has emerged, as seagrass beds have been deteriorating and becoming depleted due to increased grazing pressure from the growing population of green sea turtles. Since 2024, we have initiated a project to study the current statuses of green turtle foraging aggregation and seagrass beds in three coastal waters around Okinawa (Iriomote, Irabu, and Kume Islands). The project will collect information on the habitat use, population demographics, and life stage information of green turtles, assess the loss of seagrass beds, and calculate the carrying capacity of each seagrass area for green turtles. In addition, we will use a population dynamics model based on field data and experiments to simulate the factors behind the rapid increase in green turtle populations and develop future ecosystem management plans. We are also conducting sociological research to explore ecosystem management plans that are socially and ecologically acceptable. The research for this project will be carried out by experts from five universities and national research institutes, but the project as a whole will be driven by collaboration and communication with a range of local and external experts. Our goal is to explore how these turtles can coexist with seagrass beds and use this knowledge to promote sustainable ecosystem management. 

green turtle, seagrass, marine life management