The theme of the 140th meeting of AFS, “Merging our Deeper Currents”, reminds us that fundamental connections exist between the physical and biotic processes characterizing aquatic systems or populations. Organisms are often studied and managed without an understanding of the spatial and temporal scales over which connections exist.  Natural physical and biotic processes affect the degree of connectivity among populations and can impose barriers to dispersal or reproduction.  Human-imposed alterations of aquatic systems have effects on natural patterns and the permeability of seemingly contiguous aquatic habitats.  In addition, systems are often segmented to simplify inherent complexities in order to understand and manage systems.  Imposed segmentation is reflected in broad divisions such as separating freshwater and marine environments, or in finer divisions like defining populations or management units.  However, as divisions become established, the understanding of connectivity among the separate parts can be obscured or lost.  Individuals can move between environments and populations, blurring predefined boundaries.  Molecular genetic techniques have been used as a tool by fisheries researchers and managers for investigating causal relationships between natural processes, human actions, and the spatial structuring of aquatic organisms, often across geographic, political, or species boundaries.  Management issues addressed by papers in this symposium include: a) management to maintain population structure and long-term viability, b) developing strategies for restoring lost or impacted populations, c) assessing the effect of sport and commercial fisheries, d) measuring the extent and effects of human-induced versus natural processes on individual or species distributions, e) maintaining population adaptive potential for future conditions, and f) incorporating uncertainty when management decisions must be made with limited data.  This symposium will provide a valuable review of the current uses of genetic, demographic, and hydrogeomorphological data to connect sources of knowledge to increase the ability of managers to provide science-based stewardship of fish resources.