Abstract/Summary

Tropical coastlines are regions of extraordinary productivity and host a diversity of interlinked ecosystems which are vital for humanity, including mangrove forests. These environments provide a clear example of how societies and natural ecosystems interact to form complex ‘social-ecological systems’. Yet, although humans depend on mangrove forests in so many ways, these ecosystems are proving to be highly vulnerable under increased human pressures. This research focuses on the rapid social and ecological change brought about by the expansion of shrimp aquaculture in coastal mangrove areas of Thailand. Like in many other parts of the world, the intensification of shrimp aquaculture along the coast of Thailand over the past few decades has come with high social and ecological costs, including widespread conversion of mangrove forests, negative biophysical changes, and loss of coastal livelihood. The overarching aim of this research was to show how studying shrimp farming in mangrove areas as a social-ecological system can advance understanding of some selected drivers of resilient social-ecological systems, and how they are related. Integrating approaches from the natural and social sciences, the research draws on mixed methods combining biophysical sampling of mangrove ecosystem change, semi-quantitative household surveys, and qualitative participatory approaches. The first research chapter of this thesis (Chapter 4) assesses the influence of mangrove to shrimp pond conversion on ecosystem carbon storage on the southern Andaman sea coast of Thailand. The assessment was based on field inventories of forest structure and soil carbon stocks in mangrove forests and abandoned shrimp pond sites. While the results showed that mangrove conversion for shrimp farming results in a large land-use carbon footprint, the observed pattern of mangrove recovery in abandoned shrimp ponds demonstrates the high resilience capacity of mangrove forests. The second research chapter (Chapter 5) analyses shrimp farming diversity along the Gulf of Thailand coast. The research examines shrimp farmer behaviour in relation to production intensity, and its embeddedness in the wider socio-economic context of shrimp farming households. Shrimp farming intensity was found to be associated with a combination of technical, social, and ecological factors, and a range of different combinations of variables were important in influencing the adoption of farming at a particular intensity, relating to subjective culture and values, risk perceptions, and socio-economic conditions. The final research chapter (Chapter 6) uses participatory methods to explore the different forms of knowledge and perceptions of ecosystem health and ecosystem service delivery among mangrove-dependent communities on Thailand’s Andaman sea coast. The communities were shown to have high dependency on mangroves and hold a wealth of local ecological knowledge. Strong cultural and religious links among user-groups have facilitated greater communication and social cohesion and this could have a positive effect on community resilience by enabling collective synthesis and use of their ecological knowledge. The research also shows how periods of abrupt environmental change can bring coastal communities together, creating opportunity for self-organisation, environmental education, and capacity building, which plays a significant role in the sustainability of natural resources, livelihoods and social resilience. This thesis generates important contributions to the study of social-ecological systems and provides new findings that are relevant to inform sustainability and natural resource management decisions. The findings of this research are also timely to inform implementation of Thailand’s National Economic and Social Development Plan (2017- 2021), which calls for developing environmentally-friendly coastal aquaculture, and encouraging community forest management though creating participatory networks of forest restoration and protection.