This theme broadly focuses on how existing and emergent markets affect the functioning of marine social-ecological systems at different scales. This refers to fisheries and aquaculture production systems, including both the social and environmental components. It includes studying market structures, actors and commodity chains. Work under this theme also analyses interactions (local-regional-global) that determine effects on systems at different geographical and institutional levels. The fisheries and aquaculture focus is included for two key reasons. First, because trade with marine commodities is significantly less explored than trade with agricultural products, yet fish is an important aspect in future global food security. Second, marine systems can be seen as a test case in which we develop relevant methods to study cross-scale links between production, trade and consumption, which can then be transferred to other social-ecological systems.