John Koehn has and a career of over 40 years in the research of native freshwater fish, particularly in the Murray-Darling Basin. He has over 300 scientific publications and applied his research knowledge to improve management. His work has had a broad range but movements, habitats, recruitment, modelling and population dynamics, threatened species recovery and alien species management have all had a focus. He had led many recovery teams, authored recovery plans and was senior author of the Murray-Darling Native fish strategy. He is a past President of ASFB and been inducted into the ASFB Hall of Fame.