Human activities have caused extensive fragmentation of riverine corridors. Dams, culverts, and other barriers prevent migratory and riverine fishes from accessing key habitats. This is particularly problematic for diadromous fishes like Atlantic salmon and American shad that must transition between fresh- and saltwater habitats in order to complete their life cycles. My research interests focus on identifying conditions that are most conducive to improving passage at barriers. I use an integrative approach, incorporating biomechanics, physiology, ecology, behavior, and engineering. Swimming performance and behavioral responses to hydraulic conditions (turbulence, velocity, etc.) are major interests, as is development of quantitative methods for identifying and characterizing barriers. This work has broad relevance, not only to stewardship and management of aquatic resources, but also to understanding fundamental aspects of the ecology and evolution of fishes.