Assessing sustainability of coastal marine systems to inform policy and management
Marine ecosystems provide many benefits to people, including food, protection from coastal storms, and places for recreation and spiritual renewal. These benefits are threatened by human impacts at multiple scales, including fisheries over-exploitation and global climatic change. More solutions-oriented knowledge of the connections between people and nature is urgently needed. I will discuss the approach my collaborators and I have developed to investigate the connections between people and marine ecosystems in the context of the small-scale fisheries of Mexico’s Gulf of California. How does environmental and institutional variation shape the ecological and economic outcomes associated with small-scale fisheries? In particular, how does variation in the life histories of targeted species and regional oceanography correspond to differences in local fisheries institutions, and what are the implications of this geographic variation for sustainability of coastal marine systems? To answer these questions, we use ecological methods such as field experiments and surveys and remotely sensed oceanographic data, and employ equally well-tested social science approaches, including interviews, quantitative surveys, and statistical and analytical models.
To illustrate the value of this coupled systems approach, I will present findings from two geographic scales. First, using a coupled bio-economic model based on the situation in La Paz, in the Mexican state of Baja California Sur (BCS), I will show how fishers’ decisions are influenced by both environmental and institutional variation, and the consequences of these interactions for ecosystem health and human well-being. Second, I will place these local-scale results in a broader context. Drawing on both natural and social science theory and data, we developed integrative indicators of coastal sustainability in four dimensions, based on the social-ecological systems framework developed by Elinor Ostrom and colleagues (Ostrom 2009, Science). Key environmental and institutional factors related to sustainability vary substantially throughout BCS. Fishing communities that exhibit greater potential for social-ecological sustainability in one dimension do not necessarily exhibit it in others. These results highlight the importance of integrative, coupled system analyses when implementing spatial planning and other ecosystem-based strategies and yield an understanding of the sustainability of coupled social-ecological systems that is quite distinct from that provided by either biophysical or social sciences alone.