Development of Digital Teaching Materials on Coastal Ecology Based on Education for Sustainable Development to Enhance Geographic Literacy Among Senior High School Students in Coastal Areas

<ns5:p>Background Coastal ecosystems are among the most productive and socioeconomically important environments globally. However, students in coastal communities often exhibit limited geographic literacy regarding the ecological processes that sustain these ecosystems. This challenge is compounded by the limited availability of contextualized and sustainability-oriented digital learning resources. Objective This study aimed to develop, validate, and evaluate the effectiveness of Education for Sustainable Development (ESD)-integrated digital teaching materials (DTMs) on coastal ecology in improving geographic literacy among senior high school students in coastal areas. Method The study employed a Research and Development (R&amp;D) approach using the ADDIE model, consisting of Analysis, Design, Development, Implementation, and Evaluation stages. Participants included 148 Grade XI students from four coastal-area schools selected through purposive sampling. The developed DTMs were validated by four subject-matter experts and three instructional technology specialists. Geographic literacy was assessed using a validated 40-item instrument covering spatial thinking, environmental knowledge, geospatial skills, and sustainability orientation. Effectiveness was examined through a quasi-experimental pre-test–post-test control group design. Results The DTMs demonstrated high validity, with mean scores of 3.82/4.00 for content and 3.76/4.00 for media quality. Students in the experimental group showed a significant improvement in geographic literacy following the intervention (d = 0.84, p &lt; .001), while the control group exhibited no significant change (p = .21). Among the assessed dimensions, sustainability orientation recorded the strongest effect (d = 0.91). Conclusion ESD-integrated DTMs on coastal ecology effectively enhance geographic literacy among coastal secondary school students. The findings provide an empirically validated framework for integrating sustainability principles into maritime and geography education, particularly within developing archipelagic contexts.</ns5:p>