Blue Carbon & Ecotourism: Empowering East Kalimantan’s Coastal Communities

East Kalimantan’s extensive mangrove forests represent globally significant blue carbon assets, yet their potential remains largely underutilised for community-based ecotourism. This study examines how integrating mangrove conservation with ecotourism development can advance climate change mitigation and economic empowerment for coastal communities in Berau and Tarakan, East Kalimantan, Indonesia. A convergent mixed-methods design was employed, combining structured surveys of 245 stakeholders, including local community members, tourism operators, government officials, conservation practitioners, and academics, with 32 semi-structured interviews, four focus group discussions, and participatory observation conducted between January 2024 and February 2025. Economic valuation integrated the Travel Cost Method (TCM) to estimate tourism demand and the Contingent Valuation Method (CVM) to assess willingness to preserve mangrove ecosystems, while carbon sequestration potential was quantified through biomass and soil organic carbon (SOC) analysis using validated allometric equations. Results indicate that optimised management of integrated ecotourism and blue carbon mechanisms could generate USD 18,400-22,800 per hectare annually, substantially exceeding returns from extractive land uses such as aquaculture or timber harvesting. However, realising this potential is constrained by significant implementation barriers, including inadequate visitor infrastructure, cited by 67% of stakeholders, and limited institutional capacity, reported by 72%, alongside financial and regulatory obstacles. Since Indonesia opened its domestic carbon exchange to international trading in January 2025, carbon credits have been valued at USD 5.8-8.7 per ton, offering a new and rapidly evolving revenue stream. To address governance fragmentation, this study proposes a quintuple helix framework that coordinates government, academia, the private sector, community organisations, and environmental NGOs. Strategic recommendations include phased infrastructure development, targeted capacity building, transparent benefit-sharing mechanisms, and digital platform adoption. Overall, this integrated approach demonstrates that mangrove ecotourism can simultaneously advance conservation objectives, national climate commitments, and sustainable livelihoods for coastal communities, offering a scalable model for other blue carbon regions in Indonesia and beyond.