Our understanding of foraging sea turtle populations in the coastal waters around Taiwan is limited compared to nesting sea turtles. However, in recent years, marine research projects involving citizen scientists have been developing, especially with the growing popularity of water recreation activities. Since 2017, the TurtleSpot Taiwan project has invited citizen scientists to take photos and report sea turtle sightings. Clear photographs of sea turtles’ faces have allowed us to identify individual turtles using unique scale patterns (i.e. photo identification), helping us identify areas where sea turtles are commonly found in the region. Through this data collection, we identified key foraging habitats for sea turtles, including Xiaoliuqiu, Hengchun, and Green Island.

We considered the potential bias of this opportunistic data collection and whether the survey provides a thorough and complete picture of the sea turtle population of the region. Following this thought, we have planned a systematic two-year survey of foraging sea turtles in Hengchun and Green Island, starting in 2023. This survey will be conducted seasonally with trained citizen scientists, including local SCUBA diving instructors and volunteers, to gain further insights into the population ecology and threats to sea turtles in the area and allow us to compare our sighting data via different collection methods. The training provided to the volunteers includes basic knowledge about sea turtles, citizen science and open data, introduction to sea turtle stranding and rescue, survey methods, underwater surveys, data management, and individual identification techniques.

The results of new sea turtle individuals detected via the systematic surveys in Hengchun and Green Island have already surpassed previous records from citizen science sighting reports, addressing the biases of opportunistic reports. Through the systematic survey, we have also noted observations such as the higher proportion of hawksbill turtles on Green Island and the rare documentation of the black sea turtle (Chelonia mydas agassizii) in Hengchun, which is seldom seen in Asia. This project helps us better understand the status of foraging sea turtle populations, encourages long-term local participation in monitoring efforts, and provides data to inform marine conservation policies. In this presentation, we will share our experience in running the project and how we carried out our systematic survey.