With the poorer coastal populations of the Asia-Pacific heavily reliant on small-scale fisheries and agriculture to meet their food and livelihood needs, their prospects for a food secure future depends directly on the services provided by coastal ecosystems e.g. fisheries, and their ability to purchase food through income generated by their livelihoods, which also depend directly on coastal ecosystem services. In Southeast Asia these coastal ecosystem services are in decline due to endogenous pressures, such as resource degradation, development, and increasing demand for goods and services, as well as exogenous pressures, such as population growth, rising imports of food and climate change. Using system dynamics, this research aims to understand how interactions among coastal ecosystems, economies and societies influence the food security of coastal communities. The research uses El Nido, Palawan in the Philippines as a case study to develop a dynamic hypothesis for food security that incorporates food sources from marine habitats and from agriculture, and then a system dynamic model to simulate the influence of policies and pressures on food security and the food security resilience. The results will be utilised in an on-ground project to identify opportunities where modifications to existing business activity, or the introduction of new businesses, can improve the food security of coastal communities.