Resource users as land-sea links in coastal and marine socioecological systems

Coastal zones, which connect terrestrial and aquatic ecosystems, are among the most resource-rich regions globally and home to nearly 40% of the global human population. Because human land-based activities can alter natural processes in ways that affect adjacent aquatic ecosystems, land-sea interactions are increasingly recognized as critical to coastal conservation planning and governance. However, the complex socioeconomic dynamics inherent in coastal and marine socio-ecological systems (SES) have received little consideration. Drawing on knowledge generalized from long-term studies in Caribbean Nicaragua, we propose a conceptual framework that clarifies the multiple ways that socioeconomically driven behavior can link the land and sea. In addition to other ecosystem effects, we illustrate how feedbacks resulting from changes to aquatic resources can influence terrestrial resource management decisions and land uses. An assessment of this framework using empirical studies from a variety of coastal SES suggests its broad applicability, but also highlights the paucity of research that explicitly investigates the effects of human behavior on coastal SES dynamics. Therefore, we encourage both researchers and policymakers to consider direct, indirect, and bidirectional cross-ecosystem links that move beyond traditionally recognized land to sea processes.