Freshwater ecosystems and their resident species have declined more rapidly than either terrestrial or marine systems and their species. Freshwater ecosystems face myriad stressors, from habitat loss and pollution to dams and climate change. Today I discuss the state of freshwater conservation science with Ian Harrison. Ian obtained his Ph.D. in systematic ichthyology at the University of Bristol in the UK. He has conducted research on marine and freshwater fishes in Europe, Central and South America, Africa, the Philippines, and the Central Pacific. He has worked for Conservation International and the IUCN’s Global Species Programme since 2008 and he is currently the freshwater specialist for Conservation International’s Moore Center for Science. Ian publishes extensively on the biology and conservation of fishes and the conservation of freshwater ecosystems.