Increasing governance complexity is manifested in the growing number of governance processes and actors involved as well as increasing interconnectedness between governance system elements. This makes institutional overlaps and resulting interactions an important part of the governance landscape and one of several considerable factors influencing policy results. The research looks at regional environmental governance (REG) through the prism of pluri-regionality, a governance situation where REG processes overlap and interact. In order to grasp this complexity at the systemic level, the research introduces the notion of REG complexes as a research unit considering two case studies of the Barents and the Black Sea REG complexes.

The research has confirmed the main hypothesis that pluri-regional environmental governance situations bring up new features, processes, motivations and consequences only appearing at the level of REG complexes.