Integrating Social–Ecological Systems and SEM-PLS Analysis in Formulating Sustainable Marine Ecotourism Development Strategies: Evidence from Lihaga Island, North Sulawesi, Indonesia

Marine ecotourism has emerged as a tourism development approach that seeks to balance marine ecosystem conservation, local community well-being, and long-term economic sustainability. The Social–Ecological Systems (SES) framework developed by Ostrom and McGinnis provides an analytical approach for understanding the complex interactions between ecological and social components within natural resource management systems. This study aims to formulate sustainable marine ecotourism development strategies on Lihaga Island by applying a Social–Ecological Systems (SES) framework in combination with Structural Equation Modeling–Partial Least Squares (SEM-PLS) analysis. The SES framework is employed to examine the interlinkages among resource systems, resource units, governance structures, and actors, while SEM-PLS is used to test the structural relationships among latent variables influencing the sustainability of marine ecotourism. The results indicate that although Lihaga Island possesses high ecological potential and strong tourism appeal, the sustainability of its development is constrained by weak governance, limited infrastructure, and insufficient integration of local communities into the marine ecotourism value chain. The recommended strategies include strengthening collaborative governance, protecting and rehabilitating coastal ecosystems, and promoting community-based economic empowerment through ecotourism initiatives. These findings are expected to provide a scientific basis for the formulation of marine ecotourism management policies in small island regions of Indonesia.